[500561] Fix an issue with the labelFontSize and fontSize

Bug: 500561
Change-Id: I3d7ecdbb87230fbcdfe5f1e70baca06d5a9a4d8f
Signed-off-by: Stéphane Bégaudeau <stephane.begaudeau@obeo.fr>

38 files changed, 836 insertions, 655 deletions

diff --git a/plugins/org.eclipse.sirius.doc/doc/Release_Notes.html b/plugins/org.eclipse.sirius.doc/doc/Release_Notes.html
index 0efd8a76b0..db6c8b386d 100644
--- a/plugins/org.eclipse.sirius.doc/doc/Release_Notes.html
+++ b/plugins/org.eclipse.sirius.doc/doc/Release_Notes.html
@@ -159,6 +159,12 @@
 				<code>org.eclipse.sirius.diagram.ui.layoutDataManager</code> is deprecated. It is replaced by the new extension point 
 				<code>org.eclipse.sirius.diagram.ui.formatDataManager</code>. The deprecated extension point will be removed in the next 5.0 Sirius major release. Several classes associated with this deprecated extension point are also deprecated (see Developer-Visible Changes for details).
 			</li>
+			<li><span class="label label-info">Modified</span> The properties 
+				<code>fontSize</code> and 
+				<code>labelFontSize</code> have been renamed into 
+				<code>fontSizeExpression</code> and 
+				<code>labelFontSizeExpression</code> since both of them were already treated as expression.
+			</li>
 		</ul>
 		<h3 id="DeveloperVisibleChanges">Developer-Visible Changes</h3>
 		<ul>
@@ -537,6 +543,12 @@
 				<code>domainClassExpression</code> has been renamed into 
 				<code>iterableExpression</code>.
 			</li>
+			<li><span class="label label-info">Modified</span> The properties 
+				<code>fontSize</code> and 
+				<code>labelFontSize</code> have been renamed into 
+				<code>fontSizeExpression</code> and 
+				<code>labelFontSizeExpression</code> since both of them were already treated as expression.
+			</li>
 		</ul>
 		<h4 id="Changesinorg.eclipse.sirius.ecore.extender">Changes in 
 			<code>org.eclipse.sirius.ecore.extender</code>
diff --git a/plugins/org.eclipse.sirius.doc/doc/Release_Notes.textile b/plugins/org.eclipse.sirius.doc/doc/Release_Notes.textile
index c9282293fb..1f05ef01ea 100644
--- a/plugins/org.eclipse.sirius.doc/doc/Release_Notes.textile
+++ b/plugins/org.eclipse.sirius.doc/doc/Release_Notes.textile
@@ -24,6 +24,7 @@ h3. Specifier-Visible Changes
 * <span class="label label-success">Added</span> In the definition of the Properties view, hyperlink and label widgets can now have widget actions
 * <span class="label label-success">Added</span> Hyperlink and label widgets now have a @displayExpression@, if blank the result of the value expression will be used after a call to the method @java.lang.Object#toString()@.
 * <span class="label label-info">Modified</span> The rules concerning the layout of compartments have been changed/completed. You can have a look at the "dedicated chapter":specifier/diagrams/Diagrams.html#compartments_layout in the specifier documentation for more details.
+* <span class="label label-info">Modified</span> The properties @fontSize@ and @labelFontSize@ have been renamed into @fontSizeExpression@ and @labelFontSizeExpression@ since both of them were already treated as expression.
 * <span class="label label-info">Modified</span> The property @Domain Class Expression@ in @DynamicMappingFor@ elements (in properties views definitions) has been renamed into @Iterable Expression@.
 * <span class="label label-warning">Deprecated</span> The extension point @org.eclipse.sirius.diagram.ui.layoutDataManager@ is deprecated. It is replaced by the new extension point @org.eclipse.sirius.diagram.ui.formatDataManager@. The deprecated extension point will be removed in the next 5.0 Sirius major release. Several classes associated with this deprecated extension point are also deprecated (see Developer-Visible Changes for details).
 
@@ -126,6 +127,7 @@ h4. Changes in @org.eclipse.sirius.tests.swtbot.support@
 h4. Changes in @org.eclipse.sirius.properties@
 
 * <span class="label label-info">Modified</span> The property @domainClassExpression@ has been renamed into @iterableExpression@.
+* <span class="label label-info">Modified</span> The properties @fontSize@ and @labelFontSize@ have been renamed into @fontSizeExpression@ and @labelFontSizeExpression@ since both of them were already treated as expression.
 
 h4. Changes in @org.eclipse.sirius.ecore.extender@
 
diff --git a/plugins/org.eclipse.sirius.doc/doc/specifier/properties/Properties_View_Description.html b/plugins/org.eclipse.sirius.doc/doc/specifier/properties/Properties_View_Description.html
index 1815b7641e..854427f075 100644
--- a/plugins/org.eclipse.sirius.doc/doc/specifier/properties/Properties_View_Description.html
+++ b/plugins/org.eclipse.sirius.doc/doc/specifier/properties/Properties_View_Description.html
@@ -356,7 +356,7 @@
 				<em>Font name expression</em>: Is used to computes the name of the font to use.
 			</li>
 			<li>
-				<em>Font size</em>: Indicates the font size to use in points.
+				<em>Font size Expression</em>: Indicates the font size to use in points.
 			</li>
 			<li>
 				<em>Foreground color</em>: You can specify the foreground color using 
@@ -506,7 +506,7 @@
 				<em>Font Name Expression</em>: Is used to compute the name of the font to use for the text field.
 			</li>
 			<li>
-				<em>Font Size</em> : Indicates the font size to use in points.
+				<em>Font Size Expression</em> : Indicates the font size to use in points.
 			</li>
 			<li>
 				<em>Background Color</em>: You can specify the background color of the text field using 
@@ -587,7 +587,7 @@
 				<em>Font Name Expression</em>: Is used to compute the name of the font to use for the description.
 			</li>
 			<li>
-				<em>Font Size</em> : Indicates the font size to use in points.
+				<em>Font Size Expression</em> : Indicates the font size to use in points.
 			</li>
 			<li>
 				<em>Background Color</em>: You can specify the background color of the description using 
@@ -758,7 +758,7 @@
 				<em>Font Name Expression</em>: Is used to compute the name of the font to use for the text field.
 			</li>
 			<li>
-				<em>Font Size</em> : Indicates the font size to use in points.
+				<em>Font Size Expression</em> : Indicates the font size to use in points.
 			</li>
 			<li>
 				<em>Background Color</em>: You can specify the background color of the text field using 
@@ -974,7 +974,7 @@
 				<em>Label Font Name Expression</em>: Is used to compute the name of the font to use for the label.
 			</li>
 			<li>
-				<em>Label Font Size</em> : Indicates the font size to use in points.
+				<em>Label Font Size Expression</em> : Indicates the font size to use in points.
 			</li>
 			<li>
 				<em>Label Background Color</em>: You can specify the background color of the label using 
diff --git a/plugins/org.eclipse.sirius.doc/doc/specifier/properties/Properties_View_Description.textile b/plugins/org.eclipse.sirius.doc/doc/specifier/properties/Properties_View_Description.textile
index d698f37c30..e42880454e 100644
--- a/plugins/org.eclipse.sirius.doc/doc/specifier/properties/Properties_View_Description.textile
+++ b/plugins/org.eclipse.sirius.doc/doc/specifier/properties/Properties_View_Description.textile
@@ -116,7 +116,7 @@ For groups you can define the following style attributes:
 * _Bar style_ : Is used to define the section style. It exists 3 different styles : @TITLE BAR@, @SHORT TITLE BAR@, @NO TITLE@ (see the first table below for illusrations of these styles).
 * _Expanded by default_: This flag is used to define if the section should be expanded or collapsed.
 * _Font name expression_: Is used to computes the name of the font to use.
-* _Font size_: Indicates the font size to use in points.
+* _Font size Expression_: Indicates the font size to use in points.
 * _Foreground color_: You can specify the foreground color using "color":#colors sub-elements.
 * _Toggle style_: Is used to define the style of the toggle. It exists 3 different toggles : @TWISTIE@, @TREE NODE@, @NONE@ (see the second table below for illusrations of these styles).
 
@@ -172,7 +172,7 @@ See the "styles":#styling section for a general presentation of how styles are d
 
 One of the responsibility of texts styles is to describe how text fields will be formated. The following properties are available :
 * _Font Name Expression_: Is used to compute the name of the font to use for the text field.
-* _Font Size_ : Indicates the font size to use in points.
+* _Font Size Expression_ : Indicates the font size to use in points.
 * _Background Color_: You can specify the background color of the text field using "color":#colors sub-elements.
 * _Foreground Color_: You can specify the foreground color of the text field using "color":#colors sub-elements.
 * _Font Format_: Is used to specify the font style attributes (Bold and/or Italic and/or Underline and/or Strike through).
@@ -217,7 +217,7 @@ See the "styles":#styling section for a general presentation of how styles are d
 
 One of the responsibility of labels styles is to describe how descriptions will be formated. The following properties are available :
 * _Font Name Expression_: Is used to compute the name of the font to use for the description.
-* _Font Size_ : Indicates the font size to use in points.
+* _Font Size Expression_ : Indicates the font size to use in points.
 * _Background Color_: You can specify the background color of the description using "color":#colors sub-elements.
 * _Foreground Color_: You can specify the foreground color of the description using "color":#colors sub-elements.
 * _Font Format_: Is used to specify the font style attributes (Bold and/or Italic and/or Underline and/or Strike through).
@@ -310,7 +310,7 @@ See the "styles":#styling section for a general presentation of how styles are d
 
 One of the responsibility of hyperlinks styles is to describe how hyperlinks will be formated. The following properties are available :
 * _Font Name Expression_: Is used to compute the name of the font to use for the text field.
-* _Font Size_ : Indicates the font size to use in points.
+* _Font Size Expression_ : Indicates the font size to use in points.
 * _Background Color_: You can specify the background color of the text field using "color":#colors sub-elements.
 * _Font Format_: Is used to specify the font style attributes (Bold and/or Italic and/or Strike through).
 
@@ -419,7 +419,7 @@ h3(#widgets_styles). Widgets styles
 
 One of the responsibility of widgets styles is to describe how labels will be formated. The following properties are available :
 * _Label Font Name Expression_: Is used to compute the name of the font to use for the label.
-* _Label Font Size_ : Indicates the font size to use in points.
+* _Label Font Size Expression_ : Indicates the font size to use in points.
 * _Label Background Color_: You can specify the background color of the label using "color":#colors sub-elements.
 * _Label Foreground Color_: You can specify the foreground color of the label using "color":#colors sub-elements.
 * _Label Font Format_: Is used to specify the font style attributes (Bold and/or Italic and/or Underline and/or Strike through).
diff --git a/plugins/org.eclipse.sirius.editor.properties/plugin.xml b/plugins/org.eclipse.sirius.editor.properties/plugin.xml
index 335c427928..7b1a9d8bac 100644
--- a/plugins/org.eclipse.sirius.editor.properties/plugin.xml
+++ b/plugins/org.eclipse.sirius.editor.properties/plugin.xml
@@ -50,14 +50,14 @@
                class="org.eclipse.sirius.properties.editor.properties.sections.properties.groupstyle.GroupStyleBarStylePropertySection"
                id="properties.section.groupStyle.BarStyle"
                filter="org.eclipse.sirius.properties.editor.properties.filters.properties.groupstyle.GroupStyleBarStyleFilter"
-               afterSection="properties.section.groupStyle.FontSize"
+               afterSection="properties.section.groupStyle.FontSizeExpression"
                 tab="viewpoint.tab.general">
         <input type="org.eclipse.sirius.properties.GroupStyle"/>
       </propertySection>
   	  <propertySection
-               class="org.eclipse.sirius.properties.editor.properties.sections.properties.groupstyle.GroupStyleFontSizePropertySection"
-               id="properties.section.groupStyle.FontSize"
-               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.groupstyle.GroupStyleFontSizeFilter"
+               class="org.eclipse.sirius.properties.editor.properties.sections.properties.groupstyle.GroupStyleFontSizeExpressionPropertySection"
+               id="properties.section.groupStyle.FontSizeExpression"
+               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.groupstyle.GroupStyleFontSizeExpressionFilter"
                afterSection="properties.section.groupStyle.FontNameExpression"
                 tab="viewpoint.tab.general">
         <input type="org.eclipse.sirius.properties.GroupStyle"/>
@@ -97,14 +97,14 @@
                class="org.eclipse.sirius.properties.editor.properties.sections.properties.hyperlinkwidgetstyle.HyperlinkWidgetStyleBackgroundColorPropertySection"
                id="properties.section.hyperlinkWidgetStyle.BackgroundColor"
                filter="org.eclipse.sirius.properties.editor.properties.filters.properties.hyperlinkwidgetstyle.HyperlinkWidgetStyleBackgroundColorFilter"
-               afterSection="properties.section.hyperlinkWidgetStyle.FontSize"
+               afterSection="properties.section.hyperlinkWidgetStyle.FontSizeExpression"
                 tab="viewpoint.tab.general">
         <input type="org.eclipse.sirius.properties.HyperlinkWidgetStyle"/>
       </propertySection>
   	  <propertySection
-               class="org.eclipse.sirius.properties.editor.properties.sections.properties.hyperlinkwidgetstyle.HyperlinkWidgetStyleFontSizePropertySection"
-               id="properties.section.hyperlinkWidgetStyle.FontSize"
-               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.hyperlinkwidgetstyle.HyperlinkWidgetStyleFontSizeFilter"
+               class="org.eclipse.sirius.properties.editor.properties.sections.properties.hyperlinkwidgetstyle.HyperlinkWidgetStyleFontSizeExpressionPropertySection"
+               id="properties.section.hyperlinkWidgetStyle.FontSizeExpression"
+               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.hyperlinkwidgetstyle.HyperlinkWidgetStyleFontSizeExpressionFilter"
                afterSection="properties.section.hyperlinkWidgetStyle.FontNameExpression"
                 tab="viewpoint.tab.general">
         <input type="org.eclipse.sirius.properties.HyperlinkWidgetStyle"/>
@@ -136,14 +136,14 @@
                class="org.eclipse.sirius.properties.editor.properties.sections.properties.labelwidgetstyle.LabelWidgetStyleBackgroundColorPropertySection"
                id="properties.section.labelWidgetStyle.BackgroundColor"
                filter="org.eclipse.sirius.properties.editor.properties.filters.properties.labelwidgetstyle.LabelWidgetStyleBackgroundColorFilter"
-               afterSection="properties.section.labelWidgetStyle.FontSize"
+               afterSection="properties.section.labelWidgetStyle.FontSizeExpression"
                 tab="viewpoint.tab.general">
         <input type="org.eclipse.sirius.properties.LabelWidgetStyle"/>
       </propertySection>
   	  <propertySection
-               class="org.eclipse.sirius.properties.editor.properties.sections.properties.labelwidgetstyle.LabelWidgetStyleFontSizePropertySection"
-               id="properties.section.labelWidgetStyle.FontSize"
-               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.labelwidgetstyle.LabelWidgetStyleFontSizeFilter"
+               class="org.eclipse.sirius.properties.editor.properties.sections.properties.labelwidgetstyle.LabelWidgetStyleFontSizeExpressionPropertySection"
+               id="properties.section.labelWidgetStyle.FontSizeExpression"
+               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.labelwidgetstyle.LabelWidgetStyleFontSizeExpressionFilter"
                afterSection="properties.section.labelWidgetStyle.FontNameExpression"
                 tab="viewpoint.tab.general">
         <input type="org.eclipse.sirius.properties.LabelWidgetStyle"/>
@@ -156,7 +156,7 @@
         <input type="org.eclipse.sirius.properties.LabelWidgetStyle"/>
       </propertySection>
   	  <propertySection
-               class="org.eclipse.sirius.properties.editor.properties.sections.properties.textwidgetstyle.TextWidgetStyleFontFormatPropertySectionSpec"
+               class="org.eclipse.sirius.properties.editor.properties.sections.properties.textwidgetstyle.TextWidgetStyleFontFormatPropertySection"
                id="properties.section.textWidgetStyle.FontFormat"
                filter="org.eclipse.sirius.properties.editor.properties.filters.properties.textwidgetstyle.TextWidgetStyleFontFormatFilter"
                afterSection="properties.section.textWidgetStyle.ForegroundColor"
@@ -175,14 +175,14 @@
                class="org.eclipse.sirius.properties.editor.properties.sections.properties.textwidgetstyle.TextWidgetStyleBackgroundColorPropertySection"
                id="properties.section.textWidgetStyle.BackgroundColor"
                filter="org.eclipse.sirius.properties.editor.properties.filters.properties.textwidgetstyle.TextWidgetStyleBackgroundColorFilter"
-               afterSection="properties.section.textWidgetStyle.FontSize"
+               afterSection="properties.section.textWidgetStyle.FontSizeExpression"
                 tab="viewpoint.tab.general">
         <input type="org.eclipse.sirius.properties.TextWidgetStyle"/>
       </propertySection>
   	  <propertySection
-               class="org.eclipse.sirius.properties.editor.properties.sections.properties.textwidgetstyle.TextWidgetStyleFontSizePropertySection"
-               id="properties.section.textWidgetStyle.FontSize"
-               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.textwidgetstyle.TextWidgetStyleFontSizeFilter"
+               class="org.eclipse.sirius.properties.editor.properties.sections.properties.textwidgetstyle.TextWidgetStyleFontSizeExpressionPropertySection"
+               id="properties.section.textWidgetStyle.FontSizeExpression"
+               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.textwidgetstyle.TextWidgetStyleFontSizeExpressionFilter"
                afterSection="properties.section.textWidgetStyle.FontNameExpression"
                 tab="viewpoint.tab.general">
         <input type="org.eclipse.sirius.properties.TextWidgetStyle"/>
@@ -214,14 +214,14 @@
                class="org.eclipse.sirius.properties.editor.properties.sections.properties.widgetstyle.WidgetStyleLabelBackgroundColorPropertySection"
                id="properties.section.widgetStyle.LabelBackgroundColor"
                filter="org.eclipse.sirius.properties.editor.properties.filters.properties.widgetstyle.WidgetStyleLabelBackgroundColorFilter"
-               afterSection="properties.section.widgetStyle.LabelFontSize"
+               afterSection="properties.section.widgetStyle.LabelFontSizeExpression"
                 tab="viewpoint.tab.label">
         <input type="org.eclipse.sirius.properties.WidgetStyle"/>
       </propertySection>
   	  <propertySection
-               class="org.eclipse.sirius.properties.editor.properties.sections.properties.widgetstyle.WidgetStyleLabelFontSizePropertySection"
-               id="properties.section.widgetStyle.LabelFontSize"
-               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.widgetstyle.WidgetStyleLabelFontSizeFilter"
+               class="org.eclipse.sirius.properties.editor.properties.sections.properties.widgetstyle.WidgetStyleLabelFontSizeExpressionPropertySection"
+               id="properties.section.widgetStyle.LabelFontSizeExpression"
+               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.widgetstyle.WidgetStyleLabelFontSizeExpressionFilter"
                afterSection="properties.section.widgetStyle.LabelFontNameExpression"
                 tab="viewpoint.tab.label">
         <input type="org.eclipse.sirius.properties.WidgetStyle"/>
diff --git a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/groupstyle/GroupStyleFontSizeFilter.java b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/groupstyle/GroupStyleFontSizeExpressionFilter.java
index bef19c4433..d89a405f53 100644
--- a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/groupstyle/GroupStyleFontSizeFilter.java
+++ b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/groupstyle/GroupStyleFontSizeExpressionFilter.java
@@ -18,16 +18,16 @@ import org.eclipse.sirius.properties.PropertiesPackage;
 // End of user code specific imports
 
 /**
- * A filter for the fontSize property section.
+ * A filter for the fontSizeExpression property section.
  */
-public class GroupStyleFontSizeFilter extends ViewpointPropertyFilter {
+public class GroupStyleFontSizeExpressionFilter extends ViewpointPropertyFilter {
 
     /**
      * {@inheritDoc}
      */
     @Override
     protected EStructuralFeature getFeature() {
-        return PropertiesPackage.eINSTANCE.getGroupStyle_FontSize();
+        return PropertiesPackage.eINSTANCE.getGroupStyle_FontSizeExpression();
     }
 
     /**
diff --git a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/hyperlinkwidgetstyle/HyperlinkWidgetStyleFontSizeFilter.java b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/hyperlinkwidgetstyle/HyperlinkWidgetStyleFontSizeExpressionFilter.java
index 1664a3ba03..e29fb46b8f 100644
--- a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/hyperlinkwidgetstyle/HyperlinkWidgetStyleFontSizeFilter.java
+++ b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/hyperlinkwidgetstyle/HyperlinkWidgetStyleFontSizeExpressionFilter.java
@@ -18,16 +18,16 @@ import org.eclipse.sirius.properties.PropertiesPackage;
 // End of user code specific imports
 
 /**
- * A filter for the fontSize property section.
+ * A filter for the fontSizeExpression property section.
  */
-public class HyperlinkWidgetStyleFontSizeFilter extends ViewpointPropertyFilter {
+public class HyperlinkWidgetStyleFontSizeExpressionFilter extends ViewpointPropertyFilter {
 
     /**
      * {@inheritDoc}
      */
     @Override
     protected EStructuralFeature getFeature() {
-        return PropertiesPackage.eINSTANCE.getHyperlinkWidgetStyle_FontSize();
+        return PropertiesPackage.eINSTANCE.getHyperlinkWidgetStyle_FontSizeExpression();
     }
 
     /**
diff --git a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/labelwidgetstyle/LabelWidgetStyleFontSizeFilter.java b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/labelwidgetstyle/LabelWidgetStyleFontSizeExpressionFilter.java
index 64e5df2c50..84c6969e62 100644
--- a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/labelwidgetstyle/LabelWidgetStyleFontSizeFilter.java
+++ b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/labelwidgetstyle/LabelWidgetStyleFontSizeExpressionFilter.java
@@ -18,16 +18,16 @@ import org.eclipse.sirius.properties.PropertiesPackage;
 // End of user code specific imports
 
 /**
- * A filter for the fontSize property section.
+ * A filter for the fontSizeExpression property section.
  */
-public class LabelWidgetStyleFontSizeFilter extends ViewpointPropertyFilter {
+public class LabelWidgetStyleFontSizeExpressionFilter extends ViewpointPropertyFilter {
 
     /**
      * {@inheritDoc}
      */
     @Override
     protected EStructuralFeature getFeature() {
-        return PropertiesPackage.eINSTANCE.getLabelWidgetStyle_FontSize();
+        return PropertiesPackage.eINSTANCE.getLabelWidgetStyle_FontSizeExpression();
     }
 
     /**
diff --git a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/textwidgetstyle/TextWidgetStyleFontSizeFilter.java b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/textwidgetstyle/TextWidgetStyleFontSizeExpressionFilter.java
index 31ee94fb78..d1bb084ed2 100644
--- a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/textwidgetstyle/TextWidgetStyleFontSizeFilter.java
+++ b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/textwidgetstyle/TextWidgetStyleFontSizeExpressionFilter.java
@@ -18,16 +18,16 @@ import org.eclipse.sirius.properties.PropertiesPackage;
 // End of user code specific imports
 
 /**
- * A filter for the fontSize property section.
+ * A filter for the fontSizeExpression property section.
  */
-public class TextWidgetStyleFontSizeFilter extends ViewpointPropertyFilter {
+public class TextWidgetStyleFontSizeExpressionFilter extends ViewpointPropertyFilter {
 
     /**
      * {@inheritDoc}
      */
     @Override
     protected EStructuralFeature getFeature() {
-        return PropertiesPackage.eINSTANCE.getTextWidgetStyle_FontSize();
+        return PropertiesPackage.eINSTANCE.getTextWidgetStyle_FontSizeExpression();
     }
 
     /**
diff --git a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/widgetstyle/WidgetStyleLabelFontSizeFilter.java b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/widgetstyle/WidgetStyleLabelFontSizeExpressionFilter.java
index 213ac81f61..2d4d79dc30 100644
--- a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/widgetstyle/WidgetStyleLabelFontSizeFilter.java
+++ b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/widgetstyle/WidgetStyleLabelFontSizeExpressionFilter.java
@@ -18,16 +18,16 @@ import org.eclipse.sirius.properties.PropertiesPackage;
 // End of user code specific imports
 
 /**
- * A filter for the labelFontSize property section.
+ * A filter for the labelFontSizeExpression property section.
  */
-public class WidgetStyleLabelFontSizeFilter extends ViewpointPropertyFilter {
+public class WidgetStyleLabelFontSizeExpressionFilter extends ViewpointPropertyFilter {
 
     /**
      * {@inheritDoc}
      */
     @Override
     protected EStructuralFeature getFeature() {
-        return PropertiesPackage.eINSTANCE.getWidgetStyle_LabelFontSize();
+        return PropertiesPackage.eINSTANCE.getWidgetStyle_LabelFontSizeExpression();
     }
 
     /**
diff --git a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/groupstyle/GroupStyleFontSizePropertySection.java b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/groupstyle/GroupStyleFontSizeExpressionPropertySection.java
index 287c9db29b..4404cf8c48 100644
--- a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/groupstyle/GroupStyleFontSizePropertySection.java
+++ b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/groupstyle/GroupStyleFontSizeExpressionPropertySection.java
@@ -10,25 +10,35 @@
 package org.eclipse.sirius.properties.editor.properties.sections.properties.groupstyle;
 
 import org.eclipse.emf.ecore.EAttribute;
-import org.eclipse.sirius.editor.properties.sections.common.AbstractSpinnerPropertySection;
+import org.eclipse.sirius.editor.editorPlugin.SiriusEditor;
+import org.eclipse.sirius.editor.properties.sections.common.AbstractTextWithButtonPropertySection;
+import org.eclipse.sirius.editor.tools.api.assist.TypeContentProposalProvider;
+import org.eclipse.sirius.editor.tools.internal.presentation.TextWithContentProposalDialog;
 import org.eclipse.sirius.properties.PropertiesPackage;
+import org.eclipse.sirius.ui.tools.api.assist.ContentProposalClient;
+import org.eclipse.swt.events.SelectionAdapter;
+import org.eclipse.swt.events.SelectionEvent;
+import org.eclipse.swt.events.SelectionListener;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetPage;
 
+// End of user code imports
+
 /**
- * A section for the fontSize property of a GroupStyle object.
+ * A section for the fontSizeExpression property of a GroupStyle object.
  */
-public class GroupStyleFontSizePropertySection extends AbstractSpinnerPropertySection {
+public class GroupStyleFontSizeExpressionPropertySection extends AbstractTextWithButtonPropertySection implements ContentProposalClient {
+
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getDefaultLabelText()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getDefaultLabelText()
      */
     @Override
     protected String getDefaultLabelText() {
-        return "FontSize"; //$NON-NLS-1$
+        return "FontSizeExpression"; //$NON-NLS-1$
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getLabelText()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getLabelText()
      */
     @Override
     protected String getLabelText() {
@@ -41,72 +51,70 @@ public class GroupStyleFontSizePropertySection extends AbstractSpinnerPropertySe
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getFeature()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getFeature()
      */
     @Override
-    protected EAttribute getFeature() {
-        return PropertiesPackage.eINSTANCE.getGroupStyle_FontSize();
+    public EAttribute getFeature() {
+        return PropertiesPackage.eINSTANCE.getGroupStyle_FontSizeExpression();
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getFeatureAsInteger()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getFeatureValue(String)
      */
     @Override
-    protected String getFeatureAsText() {
-        String value = new String();
-        if (eObject.eGet(getFeature()) != null) {
-            value = toInteger(eObject.eGet(getFeature()).toString()).toString();
-        }
-        return value;
+    protected Object getFeatureValue(String newText) {
+        return newText;
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#isEqual(int)
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#isEqual(String)
      */
     @Override
     protected boolean isEqual(String newText) {
-        boolean equal = true;
-        if (toInteger(newText) != null) {
-            equal = getFeatureAsText().equals(toInteger(newText).toString());
-        } else {
-            refresh();
-        }
-        return equal;
+        return getFeatureAsText().equals(newText);
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getFeatureValue(int)
+     * {@inheritDoc}
      */
     @Override
-    protected Object getFeatureValue(String newText) {
-        return toInteger(newText);
+    public void createControls(Composite parent, TabbedPropertySheetPage tabbedPropertySheetPage) {
+        super.createControls(parent, tabbedPropertySheetPage);
+        /*
+         * We set the color as it's a InterpretedExpression
+         */
+        text.setBackground(SiriusEditor.getColorRegistry().get("yellow"));
+
+        TypeContentProposalProvider.bindPluginsCompletionProcessors(this, text);
+
+        // Start of user code create controls
+
+        // End of user code create controls
+
     }
 
-    /**
-     * Converts the given text to the integer it represents if applicable.
-     *
-     * @return The integer the given text represents if applicable,
-     *         <code>null</code> otherwise.
-     */
-    private Integer toInteger(String text) {
-        Integer integerValue = null;
-        try {
-            integerValue = new Integer(text);
-        } catch (NumberFormatException e) {
-            // Not a Integer
-        }
-        return integerValue;
+    @Override
+    protected SelectionListener createButtonListener() {
+        return new SelectionAdapter() {
+            @Override
+            public void widgetSelected(SelectionEvent e) {
+                TextWithContentProposalDialog dialog = new TextWithContentProposalDialog(composite.getShell(), GroupStyleFontSizeExpressionPropertySection.this, text.getText());
+                dialog.open();
+                text.setText(dialog.getResult());
+                handleTextModified();
+            }
+        };
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
-    public void createControls(Composite parent, TabbedPropertySheetPage tabbedPropertySheetPage) {
-        super.createControls(parent, tabbedPropertySheetPage);
+    protected String getPropertyDescription() {
+        return "";
+    }
 
-        // Start of user code create controls
+    // Start of user code user operations
 
-        // End of user code create controls
-    }
+    // End of user code user operations
 }
diff --git a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/hyperlinkwidgetstyle/HyperlinkWidgetStyleFontSizePropertySection.java b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/hyperlinkwidgetstyle/HyperlinkWidgetStyleFontSizeExpressionPropertySection.java
index b4b350b9c8..d2c72be352 100644
--- a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/hyperlinkwidgetstyle/HyperlinkWidgetStyleFontSizePropertySection.java
+++ b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/hyperlinkwidgetstyle/HyperlinkWidgetStyleFontSizeExpressionPropertySection.java
@@ -10,25 +10,36 @@
 package org.eclipse.sirius.properties.editor.properties.sections.properties.hyperlinkwidgetstyle;
 
 import org.eclipse.emf.ecore.EAttribute;
-import org.eclipse.sirius.editor.properties.sections.common.AbstractSpinnerPropertySection;
+import org.eclipse.sirius.editor.editorPlugin.SiriusEditor;
+import org.eclipse.sirius.editor.properties.sections.common.AbstractTextWithButtonPropertySection;
+import org.eclipse.sirius.editor.tools.api.assist.TypeContentProposalProvider;
+import org.eclipse.sirius.editor.tools.internal.presentation.TextWithContentProposalDialog;
 import org.eclipse.sirius.properties.PropertiesPackage;
+import org.eclipse.sirius.ui.tools.api.assist.ContentProposalClient;
+import org.eclipse.swt.events.SelectionAdapter;
+import org.eclipse.swt.events.SelectionEvent;
+import org.eclipse.swt.events.SelectionListener;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetPage;
 
+// End of user code imports
+
 /**
- * A section for the fontSize property of a HyperlinkWidgetStyle object.
+ * A section for the fontSizeExpression property of a HyperlinkWidgetStyle
+ * object.
  */
-public class HyperlinkWidgetStyleFontSizePropertySection extends AbstractSpinnerPropertySection {
+public class HyperlinkWidgetStyleFontSizeExpressionPropertySection extends AbstractTextWithButtonPropertySection implements ContentProposalClient {
+
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getDefaultLabelText()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getDefaultLabelText()
      */
     @Override
     protected String getDefaultLabelText() {
-        return "FontSize"; //$NON-NLS-1$
+        return "FontSizeExpression"; //$NON-NLS-1$
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getLabelText()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getLabelText()
      */
     @Override
     protected String getLabelText() {
@@ -41,72 +52,70 @@ public class HyperlinkWidgetStyleFontSizePropertySection extends AbstractSpinner
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getFeature()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getFeature()
      */
     @Override
-    protected EAttribute getFeature() {
-        return PropertiesPackage.eINSTANCE.getHyperlinkWidgetStyle_FontSize();
+    public EAttribute getFeature() {
+        return PropertiesPackage.eINSTANCE.getHyperlinkWidgetStyle_FontSizeExpression();
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getFeatureAsInteger()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getFeatureValue(String)
      */
     @Override
-    protected String getFeatureAsText() {
-        String value = new String();
-        if (eObject.eGet(getFeature()) != null) {
-            value = toInteger(eObject.eGet(getFeature()).toString()).toString();
-        }
-        return value;
+    protected Object getFeatureValue(String newText) {
+        return newText;
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#isEqual(int)
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#isEqual(String)
      */
     @Override
     protected boolean isEqual(String newText) {
-        boolean equal = true;
-        if (toInteger(newText) != null) {
-            equal = getFeatureAsText().equals(toInteger(newText).toString());
-        } else {
-            refresh();
-        }
-        return equal;
+        return getFeatureAsText().equals(newText);
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getFeatureValue(int)
+     * {@inheritDoc}
      */
     @Override
-    protected Object getFeatureValue(String newText) {
-        return toInteger(newText);
+    public void createControls(Composite parent, TabbedPropertySheetPage tabbedPropertySheetPage) {
+        super.createControls(parent, tabbedPropertySheetPage);
+        /*
+         * We set the color as it's a InterpretedExpression
+         */
+        text.setBackground(SiriusEditor.getColorRegistry().get("yellow"));
+
+        TypeContentProposalProvider.bindPluginsCompletionProcessors(this, text);
+
+        // Start of user code create controls
+
+        // End of user code create controls
+
     }
 
-    /**
-     * Converts the given text to the integer it represents if applicable.
-     *
-     * @return The integer the given text represents if applicable,
-     *         <code>null</code> otherwise.
-     */
-    private Integer toInteger(String text) {
-        Integer integerValue = null;
-        try {
-            integerValue = new Integer(text);
-        } catch (NumberFormatException e) {
-            // Not a Integer
-        }
-        return integerValue;
+    @Override
+    protected SelectionListener createButtonListener() {
+        return new SelectionAdapter() {
+            @Override
+            public void widgetSelected(SelectionEvent e) {
+                TextWithContentProposalDialog dialog = new TextWithContentProposalDialog(composite.getShell(), HyperlinkWidgetStyleFontSizeExpressionPropertySection.this, text.getText());
+                dialog.open();
+                text.setText(dialog.getResult());
+                handleTextModified();
+            }
+        };
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
-    public void createControls(Composite parent, TabbedPropertySheetPage tabbedPropertySheetPage) {
-        super.createControls(parent, tabbedPropertySheetPage);
+    protected String getPropertyDescription() {
+        return "";
+    }
 
-        // Start of user code create controls
+    // Start of user code user operations
 
-        // End of user code create controls
-    }
+    // End of user code user operations
 }
diff --git a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/labelwidgetstyle/LabelWidgetStyleFontSizePropertySection.java b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/labelwidgetstyle/LabelWidgetStyleFontSizeExpressionPropertySection.java
index e520ede0bf..e4dc8d8a8c 100644
--- a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/labelwidgetstyle/LabelWidgetStyleFontSizePropertySection.java
+++ b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/labelwidgetstyle/LabelWidgetStyleFontSizeExpressionPropertySection.java
@@ -10,25 +10,35 @@
 package org.eclipse.sirius.properties.editor.properties.sections.properties.labelwidgetstyle;
 
 import org.eclipse.emf.ecore.EAttribute;
-import org.eclipse.sirius.editor.properties.sections.common.AbstractSpinnerPropertySection;
+import org.eclipse.sirius.editor.editorPlugin.SiriusEditor;
+import org.eclipse.sirius.editor.properties.sections.common.AbstractTextWithButtonPropertySection;
+import org.eclipse.sirius.editor.tools.api.assist.TypeContentProposalProvider;
+import org.eclipse.sirius.editor.tools.internal.presentation.TextWithContentProposalDialog;
 import org.eclipse.sirius.properties.PropertiesPackage;
+import org.eclipse.sirius.ui.tools.api.assist.ContentProposalClient;
+import org.eclipse.swt.events.SelectionAdapter;
+import org.eclipse.swt.events.SelectionEvent;
+import org.eclipse.swt.events.SelectionListener;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetPage;
 
+// End of user code imports
+
 /**
- * A section for the fontSize property of a LabelWidgetStyle object.
+ * A section for the fontSizeExpression property of a LabelWidgetStyle object.
  */
-public class LabelWidgetStyleFontSizePropertySection extends AbstractSpinnerPropertySection {
+public class LabelWidgetStyleFontSizeExpressionPropertySection extends AbstractTextWithButtonPropertySection implements ContentProposalClient {
+
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getDefaultLabelText()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getDefaultLabelText()
      */
     @Override
     protected String getDefaultLabelText() {
-        return "FontSize"; //$NON-NLS-1$
+        return "FontSizeExpression"; //$NON-NLS-1$
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getLabelText()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getLabelText()
      */
     @Override
     protected String getLabelText() {
@@ -41,72 +51,70 @@ public class LabelWidgetStyleFontSizePropertySection extends AbstractSpinnerProp
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getFeature()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getFeature()
      */
     @Override
-    protected EAttribute getFeature() {
-        return PropertiesPackage.eINSTANCE.getLabelWidgetStyle_FontSize();
+    public EAttribute getFeature() {
+        return PropertiesPackage.eINSTANCE.getLabelWidgetStyle_FontSizeExpression();
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getFeatureAsInteger()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getFeatureValue(String)
      */
     @Override
-    protected String getFeatureAsText() {
-        String value = new String();
-        if (eObject.eGet(getFeature()) != null) {
-            value = toInteger(eObject.eGet(getFeature()).toString()).toString();
-        }
-        return value;
+    protected Object getFeatureValue(String newText) {
+        return newText;
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#isEqual(int)
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#isEqual(String)
      */
     @Override
     protected boolean isEqual(String newText) {
-        boolean equal = true;
-        if (toInteger(newText) != null) {
-            equal = getFeatureAsText().equals(toInteger(newText).toString());
-        } else {
-            refresh();
-        }
-        return equal;
+        return getFeatureAsText().equals(newText);
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getFeatureValue(int)
+     * {@inheritDoc}
      */
     @Override
-    protected Object getFeatureValue(String newText) {
-        return toInteger(newText);
+    public void createControls(Composite parent, TabbedPropertySheetPage tabbedPropertySheetPage) {
+        super.createControls(parent, tabbedPropertySheetPage);
+        /*
+         * We set the color as it's a InterpretedExpression
+         */
+        text.setBackground(SiriusEditor.getColorRegistry().get("yellow"));
+
+        TypeContentProposalProvider.bindPluginsCompletionProcessors(this, text);
+
+        // Start of user code create controls
+
+        // End of user code create controls
+
     }
 
-    /**
-     * Converts the given text to the integer it represents if applicable.
-     *
-     * @return The integer the given text represents if applicable,
-     *         <code>null</code> otherwise.
-     */
-    private Integer toInteger(String text) {
-        Integer integerValue = null;
-        try {
-            integerValue = new Integer(text);
-        } catch (NumberFormatException e) {
-            // Not a Integer
-        }
-        return integerValue;
+    @Override
+    protected SelectionListener createButtonListener() {
+        return new SelectionAdapter() {
+            @Override
+            public void widgetSelected(SelectionEvent e) {
+                TextWithContentProposalDialog dialog = new TextWithContentProposalDialog(composite.getShell(), LabelWidgetStyleFontSizeExpressionPropertySection.this, text.getText());
+                dialog.open();
+                text.setText(dialog.getResult());
+                handleTextModified();
+            }
+        };
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
-    public void createControls(Composite parent, TabbedPropertySheetPage tabbedPropertySheetPage) {
-        super.createControls(parent, tabbedPropertySheetPage);
+    protected String getPropertyDescription() {
+        return "";
+    }
 
-        // Start of user code create controls
+    // Start of user code user operations
 
-        // End of user code create controls
-    }
+    // End of user code user operations
 }
diff --git a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/textwidgetstyle/TextWidgetStyleFontSizePropertySection.java b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/textwidgetstyle/TextWidgetStyleFontSizeExpressionPropertySection.java
index b9bf786698..23394d1373 100644
--- a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/textwidgetstyle/TextWidgetStyleFontSizePropertySection.java
+++ b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/textwidgetstyle/TextWidgetStyleFontSizeExpressionPropertySection.java
@@ -10,25 +10,35 @@
 package org.eclipse.sirius.properties.editor.properties.sections.properties.textwidgetstyle;
 
 import org.eclipse.emf.ecore.EAttribute;
-import org.eclipse.sirius.editor.properties.sections.common.AbstractSpinnerPropertySection;
+import org.eclipse.sirius.editor.editorPlugin.SiriusEditor;
+import org.eclipse.sirius.editor.properties.sections.common.AbstractTextWithButtonPropertySection;
+import org.eclipse.sirius.editor.tools.api.assist.TypeContentProposalProvider;
+import org.eclipse.sirius.editor.tools.internal.presentation.TextWithContentProposalDialog;
 import org.eclipse.sirius.properties.PropertiesPackage;
+import org.eclipse.sirius.ui.tools.api.assist.ContentProposalClient;
+import org.eclipse.swt.events.SelectionAdapter;
+import org.eclipse.swt.events.SelectionEvent;
+import org.eclipse.swt.events.SelectionListener;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetPage;
 
+// End of user code imports
+
 /**
- * A section for the fontSize property of a TextWidgetStyle object.
+ * A section for the fontSizeExpression property of a TextWidgetStyle object.
  */
-public class TextWidgetStyleFontSizePropertySection extends AbstractSpinnerPropertySection {
+public class TextWidgetStyleFontSizeExpressionPropertySection extends AbstractTextWithButtonPropertySection implements ContentProposalClient {
+
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getDefaultLabelText()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getDefaultLabelText()
      */
     @Override
     protected String getDefaultLabelText() {
-        return "FontSize"; //$NON-NLS-1$
+        return "FontSizeExpression"; //$NON-NLS-1$
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getLabelText()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getLabelText()
      */
     @Override
     protected String getLabelText() {
@@ -41,72 +51,70 @@ public class TextWidgetStyleFontSizePropertySection extends AbstractSpinnerPrope
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getFeature()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getFeature()
      */
     @Override
-    protected EAttribute getFeature() {
-        return PropertiesPackage.eINSTANCE.getTextWidgetStyle_FontSize();
+    public EAttribute getFeature() {
+        return PropertiesPackage.eINSTANCE.getTextWidgetStyle_FontSizeExpression();
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getFeatureAsInteger()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getFeatureValue(String)
      */
     @Override
-    protected String getFeatureAsText() {
-        String value = new String();
-        if (eObject.eGet(getFeature()) != null) {
-            value = toInteger(eObject.eGet(getFeature()).toString()).toString();
-        }
-        return value;
+    protected Object getFeatureValue(String newText) {
+        return newText;
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#isEqual(int)
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#isEqual(String)
      */
     @Override
     protected boolean isEqual(String newText) {
-        boolean equal = true;
-        if (toInteger(newText) != null) {
-            equal = getFeatureAsText().equals(toInteger(newText).toString());
-        } else {
-            refresh();
-        }
-        return equal;
+        return getFeatureAsText().equals(newText);
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getFeatureValue(int)
+     * {@inheritDoc}
      */
     @Override
-    protected Object getFeatureValue(String newText) {
-        return toInteger(newText);
+    public void createControls(Composite parent, TabbedPropertySheetPage tabbedPropertySheetPage) {
+        super.createControls(parent, tabbedPropertySheetPage);
+        /*
+         * We set the color as it's a InterpretedExpression
+         */
+        text.setBackground(SiriusEditor.getColorRegistry().get("yellow"));
+
+        TypeContentProposalProvider.bindPluginsCompletionProcessors(this, text);
+
+        // Start of user code create controls
+
+        // End of user code create controls
+
     }
 
-    /**
-     * Converts the given text to the integer it represents if applicable.
-     *
-     * @return The integer the given text represents if applicable,
-     *         <code>null</code> otherwise.
-     */
-    private Integer toInteger(String text) {
-        Integer integerValue = null;
-        try {
-            integerValue = new Integer(text);
-        } catch (NumberFormatException e) {
-            // Not a Integer
-        }
-        return integerValue;
+    @Override
+    protected SelectionListener createButtonListener() {
+        return new SelectionAdapter() {
+            @Override
+            public void widgetSelected(SelectionEvent e) {
+                TextWithContentProposalDialog dialog = new TextWithContentProposalDialog(composite.getShell(), TextWidgetStyleFontSizeExpressionPropertySection.this, text.getText());
+                dialog.open();
+                text.setText(dialog.getResult());
+                handleTextModified();
+            }
+        };
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
-    public void createControls(Composite parent, TabbedPropertySheetPage tabbedPropertySheetPage) {
-        super.createControls(parent, tabbedPropertySheetPage);
+    protected String getPropertyDescription() {
+        return "";
+    }
 
-        // Start of user code create controls
+    // Start of user code user operations
 
-        // End of user code create controls
-    }
+    // End of user code user operations
 }
diff --git a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/widgetstyle/WidgetStyleLabelFontSizePropertySection.java b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/widgetstyle/WidgetStyleLabelFontSizeExpressionPropertySection.java
index 7a5d4d40e1..68d5983fb2 100644
--- a/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/widgetstyle/WidgetStyleLabelFontSizePropertySection.java
+++ b/plugins/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/widgetstyle/WidgetStyleLabelFontSizeExpressionPropertySection.java
@@ -10,25 +10,35 @@
 package org.eclipse.sirius.properties.editor.properties.sections.properties.widgetstyle;
 
 import org.eclipse.emf.ecore.EAttribute;
-import org.eclipse.sirius.editor.properties.sections.common.AbstractSpinnerPropertySection;
+import org.eclipse.sirius.editor.editorPlugin.SiriusEditor;
+import org.eclipse.sirius.editor.properties.sections.common.AbstractTextWithButtonPropertySection;
+import org.eclipse.sirius.editor.tools.api.assist.TypeContentProposalProvider;
+import org.eclipse.sirius.editor.tools.internal.presentation.TextWithContentProposalDialog;
 import org.eclipse.sirius.properties.PropertiesPackage;
+import org.eclipse.sirius.ui.tools.api.assist.ContentProposalClient;
+import org.eclipse.swt.events.SelectionAdapter;
+import org.eclipse.swt.events.SelectionEvent;
+import org.eclipse.swt.events.SelectionListener;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetPage;
 
+// End of user code imports
+
 /**
- * A section for the labelFontSize property of a WidgetStyle object.
+ * A section for the labelFontSizeExpression property of a WidgetStyle object.
  */
-public class WidgetStyleLabelFontSizePropertySection extends AbstractSpinnerPropertySection {
+public class WidgetStyleLabelFontSizeExpressionPropertySection extends AbstractTextWithButtonPropertySection implements ContentProposalClient {
+
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getDefaultLabelText()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getDefaultLabelText()
      */
     @Override
     protected String getDefaultLabelText() {
-        return "LabelFontSize"; //$NON-NLS-1$
+        return "LabelFontSizeExpression"; //$NON-NLS-1$
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getLabelText()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getLabelText()
      */
     @Override
     protected String getLabelText() {
@@ -41,72 +51,70 @@ public class WidgetStyleLabelFontSizePropertySection extends AbstractSpinnerProp
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getFeature()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getFeature()
      */
     @Override
-    protected EAttribute getFeature() {
-        return PropertiesPackage.eINSTANCE.getWidgetStyle_LabelFontSize();
+    public EAttribute getFeature() {
+        return PropertiesPackage.eINSTANCE.getWidgetStyle_LabelFontSizeExpression();
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getFeatureAsInteger()
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getFeatureValue(String)
      */
     @Override
-    protected String getFeatureAsText() {
-        String value = new String();
-        if (eObject.eGet(getFeature()) != null) {
-            value = toInteger(eObject.eGet(getFeature()).toString()).toString();
-        }
-        return value;
+    protected Object getFeatureValue(String newText) {
+        return newText;
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#isEqual(int)
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#isEqual(String)
      */
     @Override
     protected boolean isEqual(String newText) {
-        boolean equal = true;
-        if (toInteger(newText) != null) {
-            equal = getFeatureAsText().equals(toInteger(newText).toString());
-        } else {
-            refresh();
-        }
-        return equal;
+        return getFeatureAsText().equals(newText);
     }
 
     /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractSpinnerPropertySection#getFeatureValue(int)
+     * {@inheritDoc}
      */
     @Override
-    protected Object getFeatureValue(String newText) {
-        return toInteger(newText);
+    public void createControls(Composite parent, TabbedPropertySheetPage tabbedPropertySheetPage) {
+        super.createControls(parent, tabbedPropertySheetPage);
+        /*
+         * We set the color as it's a InterpretedExpression
+         */
+        text.setBackground(SiriusEditor.getColorRegistry().get("yellow"));
+
+        TypeContentProposalProvider.bindPluginsCompletionProcessors(this, text);
+
+        // Start of user code create controls
+
+        // End of user code create controls
+
     }
 
-    /**
-     * Converts the given text to the integer it represents if applicable.
-     *
-     * @return The integer the given text represents if applicable,
-     *         <code>null</code> otherwise.
-     */
-    private Integer toInteger(String text) {
-        Integer integerValue = null;
-        try {
-            integerValue = new Integer(text);
-        } catch (NumberFormatException e) {
-            // Not a Integer
-        }
-        return integerValue;
+    @Override
+    protected SelectionListener createButtonListener() {
+        return new SelectionAdapter() {
+            @Override
+            public void widgetSelected(SelectionEvent e) {
+                TextWithContentProposalDialog dialog = new TextWithContentProposalDialog(composite.getShell(), WidgetStyleLabelFontSizeExpressionPropertySection.this, text.getText());
+                dialog.open();
+                text.setText(dialog.getResult());
+                handleTextModified();
+            }
+        };
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
-    public void createControls(Composite parent, TabbedPropertySheetPage tabbedPropertySheetPage) {
-        super.createControls(parent, tabbedPropertySheetPage);
+    protected String getPropertyDescription() {
+        return "";
+    }
 
-        // Start of user code create controls
+    // Start of user code user operations
 
-        // End of user code create controls
-    }
+    // End of user code user operations
 }
diff --git a/plugins/org.eclipse.sirius.properties.edit/plugin.properties b/plugins/org.eclipse.sirius.properties.edit/plugin.properties
index 79dfdf8dc2..c8ac6305ea 100644
--- a/plugins/org.eclipse.sirius.properties.edit/plugin.properties
+++ b/plugins/org.eclipse.sirius.properties.edit/plugin.properties
@@ -109,22 +109,22 @@ _UI_LabelDescription_style_feature = Style
 _UI_TextWidgetStyle_type = Style
 _UI_LabelWidgetStyle_type = Style
 _UI_WidgetStyle_labelFontNameExpression_feature = Label Font Name Expression
-_UI_WidgetStyle_labelFontSize_feature = Label Font Size
+_UI_WidgetStyle_labelFontSizeExpression_feature = Label Font Size Expression
 _UI_WidgetStyle_labelBackgroundColor_feature = Label Background Color
 _UI_WidgetStyle_labelForegroundColor_feature = Label Foreground Color
 _UI_WidgetStyle_labelFontFormat_feature = Label Font Format
 _UI_TextWidgetStyle_fontNameExpression_feature = Font Name Expression
-_UI_TextWidgetStyle_fontSize_feature = Font Size
+_UI_TextWidgetStyle_fontSizeExpression_feature = Font Size Expression
 _UI_TextWidgetStyle_backgroundColor_feature = Background Color
 _UI_TextWidgetStyle_foregroundColor_feature = Foreground Color
 _UI_TextWidgetStyle_fontFormat_feature = Font Format
 _UI_LabelWidgetStyle_fontNameExpression_feature = Font Name Expression
-_UI_LabelWidgetStyle_fontSize_feature = Font Size
+_UI_LabelWidgetStyle_fontSizeExpression_feature = Font Size Expression
 _UI_LabelWidgetStyle_backgroundColor_feature = Background Color
 _UI_LabelWidgetStyle_foregroundColor_feature = Foreground Color
 _UI_LabelWidgetStyle_fontFormat_feature = Font Format
 _UI_HyperlinkWidgetStyle_fontNameExpression_feature = Font Name Expression
-_UI_HyperlinkWidgetStyle_fontSize_feature = Font Size
+_UI_HyperlinkWidgetStyle_fontSizeExpression_feature = Font Size Expression
 _UI_HyperlinkWidgetStyle_backgroundColor_feature = Background Color
 _UI_HyperlinkWidgetStyle_fontFormat_feature = Font Format
 _UI_CheckboxWidgetStyle_type = Style
@@ -194,7 +194,7 @@ _UI_GroupDescription_style_feature = Style
 _UI_GroupStyle_backgroundColor_feature = Background Color
 _UI_GroupStyle_foregroundColor_feature = Foreground Color
 _UI_GroupStyle_fontNameExpression_feature = Font Name Expression
-_UI_GroupStyle_fontSize_feature = Font Size
+_UI_GroupStyle_fontSizeExpression_feature = Font Size Expression
 _UI_GroupStyle_barStyle_feature = Bar Style
 _UI_GroupStyle_toggleStyle_feature = Toggle Style
 _UI_ToggleStyle_TWISTIE_literal = TWISTIE
diff --git a/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/GroupStyleItemProvider.java b/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/GroupStyleItemProvider.java
index cb12f27c0f..5a348815db 100644
--- a/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/GroupStyleItemProvider.java
+++ b/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/GroupStyleItemProvider.java
@@ -64,7 +64,7 @@ public class GroupStyleItemProvider extends ItemProviderAdapter
             addBackgroundColorPropertyDescriptor(object);
             addForegroundColorPropertyDescriptor(object);
             addFontNameExpressionPropertyDescriptor(object);
-            addFontSizePropertyDescriptor(object);
+            addFontSizeExpressionPropertyDescriptor(object);
             addBarStylePropertyDescriptor(object);
             addToggleStylePropertyDescriptor(object);
             addExpandedByDefaultPropertyDescriptor(object);
@@ -112,16 +112,16 @@ public class GroupStyleItemProvider extends ItemProviderAdapter
     }
 
     /**
-     * This adds a property descriptor for the Font Size feature. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * This adds a property descriptor for the Font Size Expression feature.
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      */
-    protected void addFontSizePropertyDescriptor(Object object) {
+    protected void addFontSizeExpressionPropertyDescriptor(Object object) {
         itemPropertyDescriptors
-                .add(createItemPropertyDescriptor(((ComposeableAdapterFactory) adapterFactory).getRootAdapterFactory(), getResourceLocator(), getString("_UI_GroupStyle_fontSize_feature"), //$NON-NLS-1$
-                        getString("_UI_PropertyDescriptor_description", "_UI_GroupStyle_fontSize_feature", "_UI_GroupStyle_type"), //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
-                        PropertiesPackage.Literals.GROUP_STYLE__FONT_SIZE, true, false, false, ItemPropertyDescriptor.INTEGRAL_VALUE_IMAGE, null, null));
+                .add(createItemPropertyDescriptor(((ComposeableAdapterFactory) adapterFactory).getRootAdapterFactory(), getResourceLocator(), getString("_UI_GroupStyle_fontSizeExpression_feature"), //$NON-NLS-1$
+                        getString("_UI_PropertyDescriptor_description", "_UI_GroupStyle_fontSizeExpression_feature", "_UI_GroupStyle_type"), //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+                        PropertiesPackage.Literals.GROUP_STYLE__FONT_SIZE_EXPRESSION, true, false, false, ItemPropertyDescriptor.GENERIC_VALUE_IMAGE, null, null));
     }
 
     /**
@@ -201,7 +201,7 @@ public class GroupStyleItemProvider extends ItemProviderAdapter
 
         switch (notification.getFeatureID(GroupStyle.class)) {
         case PropertiesPackage.GROUP_STYLE__FONT_NAME_EXPRESSION:
-        case PropertiesPackage.GROUP_STYLE__FONT_SIZE:
+        case PropertiesPackage.GROUP_STYLE__FONT_SIZE_EXPRESSION:
         case PropertiesPackage.GROUP_STYLE__BAR_STYLE:
         case PropertiesPackage.GROUP_STYLE__TOGGLE_STYLE:
         case PropertiesPackage.GROUP_STYLE__EXPANDED_BY_DEFAULT:
diff --git a/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/HyperlinkWidgetStyleItemProvider.java b/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/HyperlinkWidgetStyleItemProvider.java
index 5148e3892e..67e3b07c3e 100644
--- a/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/HyperlinkWidgetStyleItemProvider.java
+++ b/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/HyperlinkWidgetStyleItemProvider.java
@@ -53,7 +53,7 @@ public class HyperlinkWidgetStyleItemProvider extends WidgetStyleItemProvider {
             super.getPropertyDescriptors(object);
 
             addFontNameExpressionPropertyDescriptor(object);
-            addFontSizePropertyDescriptor(object);
+            addFontSizeExpressionPropertyDescriptor(object);
             addBackgroundColorPropertyDescriptor(object);
             addFontFormatPropertyDescriptor(object);
         }
@@ -74,16 +74,16 @@ public class HyperlinkWidgetStyleItemProvider extends WidgetStyleItemProvider {
     }
 
     /**
-     * This adds a property descriptor for the Font Size feature. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * This adds a property descriptor for the Font Size Expression feature.
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      */
-    protected void addFontSizePropertyDescriptor(Object object) {
-        itemPropertyDescriptors
-                .add(createItemPropertyDescriptor(((ComposeableAdapterFactory) adapterFactory).getRootAdapterFactory(), getResourceLocator(), getString("_UI_HyperlinkWidgetStyle_fontSize_feature"), //$NON-NLS-1$
-                        getString("_UI_PropertyDescriptor_description", "_UI_HyperlinkWidgetStyle_fontSize_feature", "_UI_HyperlinkWidgetStyle_type"), //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
-                        PropertiesPackage.Literals.HYPERLINK_WIDGET_STYLE__FONT_SIZE, true, false, false, ItemPropertyDescriptor.INTEGRAL_VALUE_IMAGE, null, null));
+    protected void addFontSizeExpressionPropertyDescriptor(Object object) {
+        itemPropertyDescriptors.add(createItemPropertyDescriptor(((ComposeableAdapterFactory) adapterFactory).getRootAdapterFactory(), getResourceLocator(),
+                getString("_UI_HyperlinkWidgetStyle_fontSizeExpression_feature"), //$NON-NLS-1$
+                getString("_UI_PropertyDescriptor_description", "_UI_HyperlinkWidgetStyle_fontSizeExpression_feature", "_UI_HyperlinkWidgetStyle_type"), //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+                PropertiesPackage.Literals.HYPERLINK_WIDGET_STYLE__FONT_SIZE_EXPRESSION, true, false, false, ItemPropertyDescriptor.GENERIC_VALUE_IMAGE, null, null));
     }
 
     /**
@@ -150,7 +150,7 @@ public class HyperlinkWidgetStyleItemProvider extends WidgetStyleItemProvider {
 
         switch (notification.getFeatureID(HyperlinkWidgetStyle.class)) {
         case PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_NAME_EXPRESSION:
-        case PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_SIZE:
+        case PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_SIZE_EXPRESSION:
         case PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_FORMAT:
             fireNotifyChanged(new ViewerNotification(notification, notification.getNotifier(), false, true));
             return;
diff --git a/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/LabelWidgetStyleItemProvider.java b/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/LabelWidgetStyleItemProvider.java
index 1ee7fee9b7..b992ef3330 100644
--- a/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/LabelWidgetStyleItemProvider.java
+++ b/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/LabelWidgetStyleItemProvider.java
@@ -53,7 +53,7 @@ public class LabelWidgetStyleItemProvider extends WidgetStyleItemProvider {
             super.getPropertyDescriptors(object);
 
             addFontNameExpressionPropertyDescriptor(object);
-            addFontSizePropertyDescriptor(object);
+            addFontSizeExpressionPropertyDescriptor(object);
             addBackgroundColorPropertyDescriptor(object);
             addForegroundColorPropertyDescriptor(object);
             addFontFormatPropertyDescriptor(object);
@@ -75,16 +75,16 @@ public class LabelWidgetStyleItemProvider extends WidgetStyleItemProvider {
     }
 
     /**
-     * This adds a property descriptor for the Font Size feature. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * This adds a property descriptor for the Font Size Expression feature.
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      */
-    protected void addFontSizePropertyDescriptor(Object object) {
-        itemPropertyDescriptors
-                .add(createItemPropertyDescriptor(((ComposeableAdapterFactory) adapterFactory).getRootAdapterFactory(), getResourceLocator(), getString("_UI_LabelWidgetStyle_fontSize_feature"), //$NON-NLS-1$
-                        getString("_UI_PropertyDescriptor_description", "_UI_LabelWidgetStyle_fontSize_feature", "_UI_LabelWidgetStyle_type"), //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
-                        PropertiesPackage.Literals.LABEL_WIDGET_STYLE__FONT_SIZE, true, false, false, ItemPropertyDescriptor.INTEGRAL_VALUE_IMAGE, null, null));
+    protected void addFontSizeExpressionPropertyDescriptor(Object object) {
+        itemPropertyDescriptors.add(
+                createItemPropertyDescriptor(((ComposeableAdapterFactory) adapterFactory).getRootAdapterFactory(), getResourceLocator(), getString("_UI_LabelWidgetStyle_fontSizeExpression_feature"), //$NON-NLS-1$
+                        getString("_UI_PropertyDescriptor_description", "_UI_LabelWidgetStyle_fontSizeExpression_feature", "_UI_LabelWidgetStyle_type"), //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+                        PropertiesPackage.Literals.LABEL_WIDGET_STYLE__FONT_SIZE_EXPRESSION, true, false, false, ItemPropertyDescriptor.GENERIC_VALUE_IMAGE, null, null));
     }
 
     /**
@@ -164,7 +164,7 @@ public class LabelWidgetStyleItemProvider extends WidgetStyleItemProvider {
 
         switch (notification.getFeatureID(LabelWidgetStyle.class)) {
         case PropertiesPackage.LABEL_WIDGET_STYLE__FONT_NAME_EXPRESSION:
-        case PropertiesPackage.LABEL_WIDGET_STYLE__FONT_SIZE:
+        case PropertiesPackage.LABEL_WIDGET_STYLE__FONT_SIZE_EXPRESSION:
         case PropertiesPackage.LABEL_WIDGET_STYLE__FONT_FORMAT:
             fireNotifyChanged(new ViewerNotification(notification, notification.getNotifier(), false, true));
             return;
diff --git a/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/TextWidgetStyleItemProvider.java b/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/TextWidgetStyleItemProvider.java
index 4223d4a5d7..d6c16bd05f 100644
--- a/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/TextWidgetStyleItemProvider.java
+++ b/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/TextWidgetStyleItemProvider.java
@@ -53,7 +53,7 @@ public class TextWidgetStyleItemProvider extends WidgetStyleItemProvider {
             super.getPropertyDescriptors(object);
 
             addFontNameExpressionPropertyDescriptor(object);
-            addFontSizePropertyDescriptor(object);
+            addFontSizeExpressionPropertyDescriptor(object);
             addBackgroundColorPropertyDescriptor(object);
             addForegroundColorPropertyDescriptor(object);
             addFontFormatPropertyDescriptor(object);
@@ -75,16 +75,16 @@ public class TextWidgetStyleItemProvider extends WidgetStyleItemProvider {
     }
 
     /**
-     * This adds a property descriptor for the Font Size feature. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * This adds a property descriptor for the Font Size Expression feature.
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      */
-    protected void addFontSizePropertyDescriptor(Object object) {
-        itemPropertyDescriptors
-                .add(createItemPropertyDescriptor(((ComposeableAdapterFactory) adapterFactory).getRootAdapterFactory(), getResourceLocator(), getString("_UI_TextWidgetStyle_fontSize_feature"), //$NON-NLS-1$
-                        getString("_UI_PropertyDescriptor_description", "_UI_TextWidgetStyle_fontSize_feature", "_UI_TextWidgetStyle_type"), //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
-                        PropertiesPackage.Literals.TEXT_WIDGET_STYLE__FONT_SIZE, true, false, false, ItemPropertyDescriptor.INTEGRAL_VALUE_IMAGE, null, null));
+    protected void addFontSizeExpressionPropertyDescriptor(Object object) {
+        itemPropertyDescriptors.add(
+                createItemPropertyDescriptor(((ComposeableAdapterFactory) adapterFactory).getRootAdapterFactory(), getResourceLocator(), getString("_UI_TextWidgetStyle_fontSizeExpression_feature"), //$NON-NLS-1$
+                        getString("_UI_PropertyDescriptor_description", "_UI_TextWidgetStyle_fontSizeExpression_feature", "_UI_TextWidgetStyle_type"), //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+                        PropertiesPackage.Literals.TEXT_WIDGET_STYLE__FONT_SIZE_EXPRESSION, true, false, false, ItemPropertyDescriptor.GENERIC_VALUE_IMAGE, null, null));
     }
 
     /**
@@ -164,7 +164,7 @@ public class TextWidgetStyleItemProvider extends WidgetStyleItemProvider {
 
         switch (notification.getFeatureID(TextWidgetStyle.class)) {
         case PropertiesPackage.TEXT_WIDGET_STYLE__FONT_NAME_EXPRESSION:
-        case PropertiesPackage.TEXT_WIDGET_STYLE__FONT_SIZE:
+        case PropertiesPackage.TEXT_WIDGET_STYLE__FONT_SIZE_EXPRESSION:
         case PropertiesPackage.TEXT_WIDGET_STYLE__FONT_FORMAT:
             fireNotifyChanged(new ViewerNotification(notification, notification.getNotifier(), false, true));
             return;
diff --git a/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/WidgetStyleItemProvider.java b/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/WidgetStyleItemProvider.java
index 13c9335581..b36cf7bf26 100644
--- a/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/WidgetStyleItemProvider.java
+++ b/plugins/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/WidgetStyleItemProvider.java
@@ -62,7 +62,7 @@ public class WidgetStyleItemProvider extends ItemProviderAdapter
             super.getPropertyDescriptors(object);
 
             addLabelFontNameExpressionPropertyDescriptor(object);
-            addLabelFontSizePropertyDescriptor(object);
+            addLabelFontSizeExpressionPropertyDescriptor(object);
             addLabelBackgroundColorPropertyDescriptor(object);
             addLabelForegroundColorPropertyDescriptor(object);
             addLabelFontFormatPropertyDescriptor(object);
@@ -84,16 +84,16 @@ public class WidgetStyleItemProvider extends ItemProviderAdapter
     }
 
     /**
-     * This adds a property descriptor for the Label Font Size feature. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * This adds a property descriptor for the Label Font Size Expression
+     * feature. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      */
-    protected void addLabelFontSizePropertyDescriptor(Object object) {
-        itemPropertyDescriptors
-                .add(createItemPropertyDescriptor(((ComposeableAdapterFactory) adapterFactory).getRootAdapterFactory(), getResourceLocator(), getString("_UI_WidgetStyle_labelFontSize_feature"), //$NON-NLS-1$
-                        getString("_UI_PropertyDescriptor_description", "_UI_WidgetStyle_labelFontSize_feature", "_UI_WidgetStyle_type"), //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
-                        PropertiesPackage.Literals.WIDGET_STYLE__LABEL_FONT_SIZE, true, false, false, ItemPropertyDescriptor.INTEGRAL_VALUE_IMAGE, null, null));
+    protected void addLabelFontSizeExpressionPropertyDescriptor(Object object) {
+        itemPropertyDescriptors.add(
+                createItemPropertyDescriptor(((ComposeableAdapterFactory) adapterFactory).getRootAdapterFactory(), getResourceLocator(), getString("_UI_WidgetStyle_labelFontSizeExpression_feature"), //$NON-NLS-1$
+                        getString("_UI_PropertyDescriptor_description", "_UI_WidgetStyle_labelFontSizeExpression_feature", "_UI_WidgetStyle_type"), //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+                        PropertiesPackage.Literals.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION, true, false, false, ItemPropertyDescriptor.GENERIC_VALUE_IMAGE, null, null));
     }
 
     /**
@@ -173,7 +173,7 @@ public class WidgetStyleItemProvider extends ItemProviderAdapter
 
         switch (notification.getFeatureID(WidgetStyle.class)) {
         case PropertiesPackage.WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION:
-        case PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE:
+        case PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION:
         case PropertiesPackage.WIDGET_STYLE__LABEL_FONT_FORMAT:
             fireNotifyChanged(new ViewerNotification(notification, notification.getNotifier(), false, true));
             return;
diff --git a/plugins/org.eclipse.sirius.properties/model/properties.ecore b/plugins/org.eclipse.sirius.properties/model/properties.ecore
index d8a5d63028..627f173565 100644
--- a/plugins/org.eclipse.sirius.properties/model/properties.ecore
+++ b/plugins/org.eclipse.sirius.properties/model/properties.ecore
@@ -288,7 +288,8 @@
   <eClassifiers xsi:type="ecore:EClass" name="WidgetStyle">
     <eStructuralFeatures xsi:type="ecore:EAttribute" name="labelFontNameExpression"
         eType="ecore:EDataType ../../org.eclipse.sirius/model/viewpoint.ecore#//description/InterpretedExpression"/>
-    <eStructuralFeatures xsi:type="ecore:EAttribute" name="labelFontSize" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EInt"/>
+    <eStructuralFeatures xsi:type="ecore:EAttribute" name="labelFontSizeExpression"
+        eType="ecore:EDataType ../../org.eclipse.sirius/model/viewpoint.ecore#//description/InterpretedExpression"/>
     <eStructuralFeatures xsi:type="ecore:EReference" name="labelBackgroundColor" eType="ecore:EClass ../../org.eclipse.sirius/model/viewpoint.ecore#//description/ColorDescription"/>
     <eStructuralFeatures xsi:type="ecore:EReference" name="labelForegroundColor" eType="ecore:EClass ../../org.eclipse.sirius/model/viewpoint.ecore#//description/ColorDescription"/>
     <eStructuralFeatures xsi:type="ecore:EAttribute" name="labelFontFormat" upperBound="4"
@@ -296,7 +297,7 @@
   </eClassifiers>
   <eClassifiers xsi:type="ecore:EClass" name="TextWidgetStyle" eSuperTypes="#//WidgetStyle">
     <eStructuralFeatures xsi:type="ecore:EAttribute" name="fontNameExpression" eType="ecore:EDataType ../../org.eclipse.sirius/model/viewpoint.ecore#//description/InterpretedExpression"/>
-    <eStructuralFeatures xsi:type="ecore:EAttribute" name="fontSize" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EInt"/>
+    <eStructuralFeatures xsi:type="ecore:EAttribute" name="fontSizeExpression" eType="ecore:EDataType ../../org.eclipse.sirius/model/viewpoint.ecore#//description/InterpretedExpression"/>
     <eStructuralFeatures xsi:type="ecore:EReference" name="backgroundColor" eType="ecore:EClass ../../org.eclipse.sirius/model/viewpoint.ecore#//description/ColorDescription"/>
     <eStructuralFeatures xsi:type="ecore:EReference" name="foregroundColor" eType="ecore:EClass ../../org.eclipse.sirius/model/viewpoint.ecore#//description/ColorDescription"/>
     <eStructuralFeatures xsi:type="ecore:EAttribute" name="fontFormat" upperBound="4"
@@ -304,7 +305,7 @@
   </eClassifiers>
   <eClassifiers xsi:type="ecore:EClass" name="LabelWidgetStyle" eSuperTypes="#//WidgetStyle">
     <eStructuralFeatures xsi:type="ecore:EAttribute" name="fontNameExpression" eType="ecore:EDataType ../../org.eclipse.sirius/model/viewpoint.ecore#//description/InterpretedExpression"/>
-    <eStructuralFeatures xsi:type="ecore:EAttribute" name="fontSize" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EInt"/>
+    <eStructuralFeatures xsi:type="ecore:EAttribute" name="fontSizeExpression" eType="ecore:EDataType ../../org.eclipse.sirius/model/viewpoint.ecore#//description/InterpretedExpression"/>
     <eStructuralFeatures xsi:type="ecore:EReference" name="backgroundColor" eType="ecore:EClass ../../org.eclipse.sirius/model/viewpoint.ecore#//description/ColorDescription"/>
     <eStructuralFeatures xsi:type="ecore:EReference" name="foregroundColor" eType="ecore:EClass ../../org.eclipse.sirius/model/viewpoint.ecore#//description/ColorDescription"/>
     <eStructuralFeatures xsi:type="ecore:EAttribute" name="fontFormat" upperBound="4"
@@ -318,7 +319,7 @@
   <eClassifiers xsi:type="ecore:EClass" name="ReferenceWidgetStyle" eSuperTypes="#//WidgetStyle"/>
   <eClassifiers xsi:type="ecore:EClass" name="HyperlinkWidgetStyle" eSuperTypes="#//WidgetStyle">
     <eStructuralFeatures xsi:type="ecore:EAttribute" name="fontNameExpression" eType="ecore:EDataType ../../org.eclipse.sirius/model/viewpoint.ecore#//description/InterpretedExpression"/>
-    <eStructuralFeatures xsi:type="ecore:EAttribute" name="fontSize" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EInt"/>
+    <eStructuralFeatures xsi:type="ecore:EAttribute" name="fontSizeExpression" eType="ecore:EDataType ../../org.eclipse.sirius/model/viewpoint.ecore#//description/InterpretedExpression"/>
     <eStructuralFeatures xsi:type="ecore:EReference" name="backgroundColor" eType="ecore:EClass ../../org.eclipse.sirius/model/viewpoint.ecore#//description/ColorDescription"/>
     <eStructuralFeatures xsi:type="ecore:EAttribute" name="fontFormat" upperBound="4"
         eType="ecore:EEnum ../../org.eclipse.sirius/model/viewpoint.ecore#//FontFormat"/>
@@ -327,7 +328,7 @@
     <eStructuralFeatures xsi:type="ecore:EReference" name="backgroundColor" eType="ecore:EClass ../../org.eclipse.sirius/model/viewpoint.ecore#//description/ColorDescription"/>
     <eStructuralFeatures xsi:type="ecore:EReference" name="foregroundColor" eType="ecore:EClass ../../org.eclipse.sirius/model/viewpoint.ecore#//description/ColorDescription"/>
     <eStructuralFeatures xsi:type="ecore:EAttribute" name="fontNameExpression" eType="ecore:EDataType ../../org.eclipse.sirius/model/viewpoint.ecore#//description/InterpretedExpression"/>
-    <eStructuralFeatures xsi:type="ecore:EAttribute" name="fontSize" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EInt"/>
+    <eStructuralFeatures xsi:type="ecore:EAttribute" name="fontSizeExpression" eType="ecore:EDataType ../../org.eclipse.sirius/model/viewpoint.ecore#//description/InterpretedExpression"/>
     <eStructuralFeatures xsi:type="ecore:EAttribute" name="barStyle" eType="#//TitleBarStyle"/>
     <eStructuralFeatures xsi:type="ecore:EAttribute" name="toggleStyle" eType="#//ToggleStyle"/>
     <eStructuralFeatures xsi:type="ecore:EAttribute" name="expandedByDefault" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EBoolean"/>
diff --git a/plugins/org.eclipse.sirius.properties/model/properties.genmodel b/plugins/org.eclipse.sirius.properties/model/properties.genmodel
index 4fcbfaa222..2841581626 100644
--- a/plugins/org.eclipse.sirius.properties/model/properties.genmodel
+++ b/plugins/org.eclipse.sirius.properties/model/properties.genmodel
@@ -173,21 +173,21 @@
     </genClasses>
     <genClasses ecoreClass="properties.ecore#//WidgetStyle">
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//WidgetStyle/labelFontNameExpression"/>
-      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//WidgetStyle/labelFontSize"/>
+      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//WidgetStyle/labelFontSizeExpression"/>
       <genFeatures notify="false" createChild="false" propertySortChoices="true" ecoreFeature="ecore:EReference properties.ecore#//WidgetStyle/labelBackgroundColor"/>
       <genFeatures notify="false" createChild="false" propertySortChoices="true" ecoreFeature="ecore:EReference properties.ecore#//WidgetStyle/labelForegroundColor"/>
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//WidgetStyle/labelFontFormat"/>
     </genClasses>
     <genClasses ecoreClass="properties.ecore#//TextWidgetStyle">
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//TextWidgetStyle/fontNameExpression"/>
-      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//TextWidgetStyle/fontSize"/>
+      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//TextWidgetStyle/fontSizeExpression"/>
       <genFeatures notify="false" createChild="false" propertySortChoices="true" ecoreFeature="ecore:EReference properties.ecore#//TextWidgetStyle/backgroundColor"/>
       <genFeatures notify="false" createChild="false" propertySortChoices="true" ecoreFeature="ecore:EReference properties.ecore#//TextWidgetStyle/foregroundColor"/>
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//TextWidgetStyle/fontFormat"/>
     </genClasses>
     <genClasses ecoreClass="properties.ecore#//LabelWidgetStyle">
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//LabelWidgetStyle/fontNameExpression"/>
-      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//LabelWidgetStyle/fontSize"/>
+      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//LabelWidgetStyle/fontSizeExpression"/>
       <genFeatures notify="false" createChild="false" propertySortChoices="true" ecoreFeature="ecore:EReference properties.ecore#//LabelWidgetStyle/backgroundColor"/>
       <genFeatures notify="false" createChild="false" propertySortChoices="true" ecoreFeature="ecore:EReference properties.ecore#//LabelWidgetStyle/foregroundColor"/>
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//LabelWidgetStyle/fontFormat"/>
@@ -200,7 +200,7 @@
     <genClasses ecoreClass="properties.ecore#//ReferenceWidgetStyle"/>
     <genClasses ecoreClass="properties.ecore#//HyperlinkWidgetStyle">
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//HyperlinkWidgetStyle/fontNameExpression"/>
-      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//HyperlinkWidgetStyle/fontSize"/>
+      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//HyperlinkWidgetStyle/fontSizeExpression"/>
       <genFeatures notify="false" createChild="false" propertySortChoices="true" ecoreFeature="ecore:EReference properties.ecore#//HyperlinkWidgetStyle/backgroundColor"/>
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//HyperlinkWidgetStyle/fontFormat"/>
     </genClasses>
@@ -208,7 +208,7 @@
       <genFeatures notify="false" createChild="false" propertySortChoices="true" ecoreFeature="ecore:EReference properties.ecore#//GroupStyle/backgroundColor"/>
       <genFeatures notify="false" createChild="false" propertySortChoices="true" ecoreFeature="ecore:EReference properties.ecore#//GroupStyle/foregroundColor"/>
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//GroupStyle/fontNameExpression"/>
-      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//GroupStyle/fontSize"/>
+      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//GroupStyle/fontSizeExpression"/>
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//GroupStyle/barStyle"/>
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//GroupStyle/toggleStyle"/>
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//GroupStyle/expandedByDefault"/>
diff --git a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/GroupStyle.java b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/GroupStyle.java
index f4232e090f..1b896f43bb 100644
--- a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/GroupStyle.java
+++ b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/GroupStyle.java
@@ -28,8 +28,8 @@ import org.eclipse.sirius.viewpoint.description.ColorDescription;
  * <em>Foreground Color</em>}</li>
  * <li>{@link org.eclipse.sirius.properties.GroupStyle#getFontNameExpression
  * <em>Font Name Expression</em>}</li>
- * <li>{@link org.eclipse.sirius.properties.GroupStyle#getFontSize
- * <em>Font Size</em>}</li>
+ * <li>{@link org.eclipse.sirius.properties.GroupStyle#getFontSizeExpression
+ * <em>Font Size Expression</em>}</li>
  * <li>{@link org.eclipse.sirius.properties.GroupStyle#getBarStyle
  * <em>Bar Style</em>}</li>
  * <li>{@link org.eclipse.sirius.properties.GroupStyle#getToggleStyle
@@ -136,34 +136,36 @@ public interface GroupStyle extends EObject {
     void setFontNameExpression(String value);
 
     /**
-     * Returns the value of the '<em><b>Font Size</b></em>' attribute. <!--
-     * begin-user-doc -->
+     * Returns the value of the '<em><b>Font Size Expression</b></em>'
+     * attribute. <!-- begin-user-doc -->
      * <p>
-     * If the meaning of the '<em>Font Size</em>' attribute isn't clear, there
-     * really should be more of a description here...
+     * If the meaning of the '<em>Font Size Expression</em>' attribute isn't
+     * clear, there really should be more of a description here...
      * </p>
      * <!-- end-user-doc -->
      *
-     * @return the value of the '<em>Font Size</em>' attribute.
-     * @see #setFontSize(int)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getGroupStyle_FontSize()
-     * @model
+     * @return the value of the '<em>Font Size Expression</em>' attribute.
+     * @see #setFontSizeExpression(String)
+     * @see org.eclipse.sirius.properties.PropertiesPackage#getGroupStyle_FontSizeExpression()
+     * @model dataType=
+     *        "org.eclipse.sirius.viewpoint.description.InterpretedExpression"
      * @generated
      */
-    int getFontSize();
+    String getFontSizeExpression();
 
     /**
      * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.GroupStyle#getFontSize
-     * <em>Font Size</em>}' attribute. <!-- begin-user-doc --> <!-- end-user-doc
-     * -->
+     * {@link org.eclipse.sirius.properties.GroupStyle#getFontSizeExpression
+     * <em>Font Size Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
      *
      * @param value
-     *            the new value of the '<em>Font Size</em>' attribute.
-     * @see #getFontSize()
+     *            the new value of the '<em>Font Size Expression</em>'
+     *            attribute.
+     * @see #getFontSizeExpression()
      * @generated
      */
-    void setFontSize(int value);
+    void setFontSizeExpression(String value);
 
     /**
      * Returns the value of the '<em><b>Bar Style</b></em>' attribute. The
diff --git a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/HyperlinkWidgetStyle.java b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/HyperlinkWidgetStyle.java
index 76dc538ed2..c7f63aa5f3 100644
--- a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/HyperlinkWidgetStyle.java
+++ b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/HyperlinkWidgetStyle.java
@@ -26,8 +26,9 @@ import org.eclipse.sirius.viewpoint.description.ColorDescription;
  * <li>
  * {@link org.eclipse.sirius.properties.HyperlinkWidgetStyle#getFontNameExpression
  * <em>Font Name Expression</em>}</li>
- * <li>{@link org.eclipse.sirius.properties.HyperlinkWidgetStyle#getFontSize
- * <em>Font Size</em>}</li>
+ * <li>
+ * {@link org.eclipse.sirius.properties.HyperlinkWidgetStyle#getFontSizeExpression
+ * <em>Font Size Expression</em>}</li>
  * <li>
  * {@link org.eclipse.sirius.properties.HyperlinkWidgetStyle#getBackgroundColor
  * <em>Background Color</em>}</li>
@@ -73,34 +74,36 @@ public interface HyperlinkWidgetStyle extends WidgetStyle {
     void setFontNameExpression(String value);
 
     /**
-     * Returns the value of the '<em><b>Font Size</b></em>' attribute. <!--
-     * begin-user-doc -->
+     * Returns the value of the '<em><b>Font Size Expression</b></em>'
+     * attribute. <!-- begin-user-doc -->
      * <p>
-     * If the meaning of the '<em>Font Size</em>' attribute isn't clear, there
-     * really should be more of a description here...
+     * If the meaning of the '<em>Font Size Expression</em>' attribute isn't
+     * clear, there really should be more of a description here...
      * </p>
      * <!-- end-user-doc -->
      *
-     * @return the value of the '<em>Font Size</em>' attribute.
-     * @see #setFontSize(int)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getHyperlinkWidgetStyle_FontSize()
-     * @model
+     * @return the value of the '<em>Font Size Expression</em>' attribute.
+     * @see #setFontSizeExpression(String)
+     * @see org.eclipse.sirius.properties.PropertiesPackage#getHyperlinkWidgetStyle_FontSizeExpression()
+     * @model dataType=
+     *        "org.eclipse.sirius.viewpoint.description.InterpretedExpression"
      * @generated
      */
-    int getFontSize();
+    String getFontSizeExpression();
 
     /**
      * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.HyperlinkWidgetStyle#getFontSize
-     * <em>Font Size</em>}' attribute. <!-- begin-user-doc --> <!-- end-user-doc
-     * -->
+     * {@link org.eclipse.sirius.properties.HyperlinkWidgetStyle#getFontSizeExpression
+     * <em>Font Size Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
      *
      * @param value
-     *            the new value of the '<em>Font Size</em>' attribute.
-     * @see #getFontSize()
+     *            the new value of the '<em>Font Size Expression</em>'
+     *            attribute.
+     * @see #getFontSizeExpression()
      * @generated
      */
-    void setFontSize(int value);
+    void setFontSizeExpression(String value);
 
     /**
      * Returns the value of the '<em><b>Background Color</b></em>' reference.
diff --git a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/LabelWidgetStyle.java b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/LabelWidgetStyle.java
index b58e5556b8..63448ab12c 100644
--- a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/LabelWidgetStyle.java
+++ b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/LabelWidgetStyle.java
@@ -26,8 +26,9 @@ import org.eclipse.sirius.viewpoint.description.ColorDescription;
  * <li>
  * {@link org.eclipse.sirius.properties.LabelWidgetStyle#getFontNameExpression
  * <em>Font Name Expression</em>}</li>
- * <li>{@link org.eclipse.sirius.properties.LabelWidgetStyle#getFontSize
- * <em>Font Size</em>}</li>
+ * <li>
+ * {@link org.eclipse.sirius.properties.LabelWidgetStyle#getFontSizeExpression
+ * <em>Font Size Expression</em>}</li>
  * <li>{@link org.eclipse.sirius.properties.LabelWidgetStyle#getBackgroundColor
  * <em>Background Color</em>}</li>
  * <li>{@link org.eclipse.sirius.properties.LabelWidgetStyle#getForegroundColor
@@ -74,34 +75,36 @@ public interface LabelWidgetStyle extends WidgetStyle {
     void setFontNameExpression(String value);
 
     /**
-     * Returns the value of the '<em><b>Font Size</b></em>' attribute. <!--
-     * begin-user-doc -->
+     * Returns the value of the '<em><b>Font Size Expression</b></em>'
+     * attribute. <!-- begin-user-doc -->
      * <p>
-     * If the meaning of the '<em>Font Size</em>' attribute isn't clear, there
-     * really should be more of a description here...
+     * If the meaning of the '<em>Font Size Expression</em>' attribute isn't
+     * clear, there really should be more of a description here...
      * </p>
      * <!-- end-user-doc -->
      *
-     * @return the value of the '<em>Font Size</em>' attribute.
-     * @see #setFontSize(int)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getLabelWidgetStyle_FontSize()
-     * @model
+     * @return the value of the '<em>Font Size Expression</em>' attribute.
+     * @see #setFontSizeExpression(String)
+     * @see org.eclipse.sirius.properties.PropertiesPackage#getLabelWidgetStyle_FontSizeExpression()
+     * @model dataType=
+     *        "org.eclipse.sirius.viewpoint.description.InterpretedExpression"
      * @generated
      */
-    int getFontSize();
+    String getFontSizeExpression();
 
     /**
      * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.LabelWidgetStyle#getFontSize
-     * <em>Font Size</em>}' attribute. <!-- begin-user-doc --> <!-- end-user-doc
-     * -->
+     * {@link org.eclipse.sirius.properties.LabelWidgetStyle#getFontSizeExpression
+     * <em>Font Size Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
      *
      * @param value
-     *            the new value of the '<em>Font Size</em>' attribute.
-     * @see #getFontSize()
+     *            the new value of the '<em>Font Size Expression</em>'
+     *            attribute.
+     * @see #getFontSizeExpression()
      * @generated
      */
-    void setFontSize(int value);
+    void setFontSizeExpression(String value);
 
     /**
      * Returns the value of the '<em><b>Background Color</b></em>' reference.
diff --git a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/PropertiesPackage.java b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/PropertiesPackage.java
index 793673f8f8..bc0793f878 100644
--- a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/PropertiesPackage.java
+++ b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/PropertiesPackage.java
@@ -1955,13 +1955,13 @@ public interface PropertiesPackage extends EPackage {
     int WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION = 0;
 
     /**
-     * The feature id for the '<em><b>Label Font Size</b></em>' attribute. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * The feature id for the '<em><b>Label Font Size Expression</b></em>'
+     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int WIDGET_STYLE__LABEL_FONT_SIZE = 1;
+    int WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION = 1;
 
     /**
      * The feature id for the '<em><b>Label Background Color</b></em>'
@@ -2021,13 +2021,13 @@ public interface PropertiesPackage extends EPackage {
     int TEXT_WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION;
 
     /**
-     * The feature id for the '<em><b>Label Font Size</b></em>' attribute. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * The feature id for the '<em><b>Label Font Size Expression</b></em>'
+     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int TEXT_WIDGET_STYLE__LABEL_FONT_SIZE = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE;
+    int TEXT_WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION;
 
     /**
      * The feature id for the '<em><b>Label Background Color</b></em>'
@@ -2066,13 +2066,13 @@ public interface PropertiesPackage extends EPackage {
     int TEXT_WIDGET_STYLE__FONT_NAME_EXPRESSION = PropertiesPackage.WIDGET_STYLE_FEATURE_COUNT + 0;
 
     /**
-     * The feature id for the '<em><b>Font Size</b></em>' attribute. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * The feature id for the '<em><b>Font Size Expression</b></em>' attribute.
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int TEXT_WIDGET_STYLE__FONT_SIZE = PropertiesPackage.WIDGET_STYLE_FEATURE_COUNT + 1;
+    int TEXT_WIDGET_STYLE__FONT_SIZE_EXPRESSION = PropertiesPackage.WIDGET_STYLE_FEATURE_COUNT + 1;
 
     /**
      * The feature id for the '<em><b>Background Color</b></em>' reference. <!--
@@ -2132,13 +2132,13 @@ public interface PropertiesPackage extends EPackage {
     int LABEL_WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION;
 
     /**
-     * The feature id for the '<em><b>Label Font Size</b></em>' attribute. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * The feature id for the '<em><b>Label Font Size Expression</b></em>'
+     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int LABEL_WIDGET_STYLE__LABEL_FONT_SIZE = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE;
+    int LABEL_WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION;
 
     /**
      * The feature id for the '<em><b>Label Background Color</b></em>'
@@ -2177,13 +2177,13 @@ public interface PropertiesPackage extends EPackage {
     int LABEL_WIDGET_STYLE__FONT_NAME_EXPRESSION = PropertiesPackage.WIDGET_STYLE_FEATURE_COUNT + 0;
 
     /**
-     * The feature id for the '<em><b>Font Size</b></em>' attribute. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * The feature id for the '<em><b>Font Size Expression</b></em>' attribute.
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int LABEL_WIDGET_STYLE__FONT_SIZE = PropertiesPackage.WIDGET_STYLE_FEATURE_COUNT + 1;
+    int LABEL_WIDGET_STYLE__FONT_SIZE_EXPRESSION = PropertiesPackage.WIDGET_STYLE_FEATURE_COUNT + 1;
 
     /**
      * The feature id for the '<em><b>Background Color</b></em>' reference. <!--
@@ -2243,13 +2243,13 @@ public interface PropertiesPackage extends EPackage {
     int CHECKBOX_WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION;
 
     /**
-     * The feature id for the '<em><b>Label Font Size</b></em>' attribute. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * The feature id for the '<em><b>Label Font Size Expression</b></em>'
+     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int CHECKBOX_WIDGET_STYLE__LABEL_FONT_SIZE = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE;
+    int CHECKBOX_WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION;
 
     /**
      * The feature id for the '<em><b>Label Background Color</b></em>'
@@ -2309,13 +2309,13 @@ public interface PropertiesPackage extends EPackage {
     int RADIO_WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION;
 
     /**
-     * The feature id for the '<em><b>Label Font Size</b></em>' attribute. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * The feature id for the '<em><b>Label Font Size Expression</b></em>'
+     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int RADIO_WIDGET_STYLE__LABEL_FONT_SIZE = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE;
+    int RADIO_WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION;
 
     /**
      * The feature id for the '<em><b>Label Background Color</b></em>'
@@ -2375,13 +2375,13 @@ public interface PropertiesPackage extends EPackage {
     int BUTTON_WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION;
 
     /**
-     * The feature id for the '<em><b>Label Font Size</b></em>' attribute. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * The feature id for the '<em><b>Label Font Size Expression</b></em>'
+     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int BUTTON_WIDGET_STYLE__LABEL_FONT_SIZE = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE;
+    int BUTTON_WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION;
 
     /**
      * The feature id for the '<em><b>Label Background Color</b></em>'
@@ -2441,13 +2441,13 @@ public interface PropertiesPackage extends EPackage {
     int SELECT_WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION;
 
     /**
-     * The feature id for the '<em><b>Label Font Size</b></em>' attribute. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * The feature id for the '<em><b>Label Font Size Expression</b></em>'
+     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int SELECT_WIDGET_STYLE__LABEL_FONT_SIZE = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE;
+    int SELECT_WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION;
 
     /**
      * The feature id for the '<em><b>Label Background Color</b></em>'
@@ -2507,13 +2507,13 @@ public interface PropertiesPackage extends EPackage {
     int CUSTOM_WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION;
 
     /**
-     * The feature id for the '<em><b>Label Font Size</b></em>' attribute. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * The feature id for the '<em><b>Label Font Size Expression</b></em>'
+     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int CUSTOM_WIDGET_STYLE__LABEL_FONT_SIZE = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE;
+    int CUSTOM_WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION;
 
     /**
      * The feature id for the '<em><b>Label Background Color</b></em>'
@@ -2693,13 +2693,13 @@ public interface PropertiesPackage extends EPackage {
     int REFERENCE_WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION;
 
     /**
-     * The feature id for the '<em><b>Label Font Size</b></em>' attribute. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * The feature id for the '<em><b>Label Font Size Expression</b></em>'
+     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int REFERENCE_WIDGET_STYLE__LABEL_FONT_SIZE = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE;
+    int REFERENCE_WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION;
 
     /**
      * The feature id for the '<em><b>Label Background Color</b></em>'
@@ -2759,13 +2759,13 @@ public interface PropertiesPackage extends EPackage {
     int HYPERLINK_WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION;
 
     /**
-     * The feature id for the '<em><b>Label Font Size</b></em>' attribute. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * The feature id for the '<em><b>Label Font Size Expression</b></em>'
+     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int HYPERLINK_WIDGET_STYLE__LABEL_FONT_SIZE = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE;
+    int HYPERLINK_WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION;
 
     /**
      * The feature id for the '<em><b>Label Background Color</b></em>'
@@ -2804,13 +2804,13 @@ public interface PropertiesPackage extends EPackage {
     int HYPERLINK_WIDGET_STYLE__FONT_NAME_EXPRESSION = PropertiesPackage.WIDGET_STYLE_FEATURE_COUNT + 0;
 
     /**
-     * The feature id for the '<em><b>Font Size</b></em>' attribute. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * The feature id for the '<em><b>Font Size Expression</b></em>' attribute.
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int HYPERLINK_WIDGET_STYLE__FONT_SIZE = PropertiesPackage.WIDGET_STYLE_FEATURE_COUNT + 1;
+    int HYPERLINK_WIDGET_STYLE__FONT_SIZE_EXPRESSION = PropertiesPackage.WIDGET_STYLE_FEATURE_COUNT + 1;
 
     /**
      * The feature id for the '<em><b>Background Color</b></em>' reference. <!--
@@ -2879,13 +2879,13 @@ public interface PropertiesPackage extends EPackage {
     int GROUP_STYLE__FONT_NAME_EXPRESSION = 2;
 
     /**
-     * The feature id for the '<em><b>Font Size</b></em>' attribute. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
+     * The feature id for the '<em><b>Font Size Expression</b></em>' attribute.
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int GROUP_STYLE__FONT_SIZE = 3;
+    int GROUP_STYLE__FONT_SIZE_EXPRESSION = 3;
 
     /**
      * The feature id for the '<em><b>Bar Style</b></em>' attribute. <!--
@@ -4852,15 +4852,17 @@ public interface PropertiesPackage extends EPackage {
 
     /**
      * Returns the meta object for the attribute '
-     * {@link org.eclipse.sirius.properties.WidgetStyle#getLabelFontSize
-     * <em>Label Font Size</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * {@link org.eclipse.sirius.properties.WidgetStyle#getLabelFontSizeExpression
+     * <em>Label Font Size Expression</em>}'. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
      *
-     * @return the meta object for the attribute '<em>Label Font Size</em>'.
-     * @see org.eclipse.sirius.properties.WidgetStyle#getLabelFontSize()
+     * @return the meta object for the attribute '
+     *         <em>Label Font Size Expression</em>'.
+     * @see org.eclipse.sirius.properties.WidgetStyle#getLabelFontSizeExpression()
      * @see #getWidgetStyle()
      * @generated
      */
-    EAttribute getWidgetStyle_LabelFontSize();
+    EAttribute getWidgetStyle_LabelFontSizeExpression();
 
     /**
      * Returns the meta object for the reference '
@@ -4932,15 +4934,17 @@ public interface PropertiesPackage extends EPackage {
 
     /**
      * Returns the meta object for the attribute '
-     * {@link org.eclipse.sirius.properties.TextWidgetStyle#getFontSize
-     * <em>Font Size</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * {@link org.eclipse.sirius.properties.TextWidgetStyle#getFontSizeExpression
+     * <em>Font Size Expression</em>}'. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
      *
-     * @return the meta object for the attribute '<em>Font Size</em>'.
-     * @see org.eclipse.sirius.properties.TextWidgetStyle#getFontSize()
+     * @return the meta object for the attribute '<em>Font Size Expression</em>
+     *         '.
+     * @see org.eclipse.sirius.properties.TextWidgetStyle#getFontSizeExpression()
      * @see #getTextWidgetStyle()
      * @generated
      */
-    EAttribute getTextWidgetStyle_FontSize();
+    EAttribute getTextWidgetStyle_FontSizeExpression();
 
     /**
      * Returns the meta object for the reference '
@@ -5008,15 +5012,17 @@ public interface PropertiesPackage extends EPackage {
 
     /**
      * Returns the meta object for the attribute '
-     * {@link org.eclipse.sirius.properties.LabelWidgetStyle#getFontSize
-     * <em>Font Size</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * {@link org.eclipse.sirius.properties.LabelWidgetStyle#getFontSizeExpression
+     * <em>Font Size Expression</em>}'. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
      *
-     * @return the meta object for the attribute '<em>Font Size</em>'.
-     * @see org.eclipse.sirius.properties.LabelWidgetStyle#getFontSize()
+     * @return the meta object for the attribute '<em>Font Size Expression</em>
+     *         '.
+     * @see org.eclipse.sirius.properties.LabelWidgetStyle#getFontSizeExpression()
      * @see #getLabelWidgetStyle()
      * @generated
      */
-    EAttribute getLabelWidgetStyle_FontSize();
+    EAttribute getLabelWidgetStyle_FontSizeExpression();
 
     /**
      * Returns the meta object for the reference '
@@ -5469,15 +5475,17 @@ public interface PropertiesPackage extends EPackage {
 
     /**
      * Returns the meta object for the attribute '
-     * {@link org.eclipse.sirius.properties.HyperlinkWidgetStyle#getFontSize
-     * <em>Font Size</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * {@link org.eclipse.sirius.properties.HyperlinkWidgetStyle#getFontSizeExpression
+     * <em>Font Size Expression</em>}'. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
      *
-     * @return the meta object for the attribute '<em>Font Size</em>'.
-     * @see org.eclipse.sirius.properties.HyperlinkWidgetStyle#getFontSize()
+     * @return the meta object for the attribute '<em>Font Size Expression</em>
+     *         '.
+     * @see org.eclipse.sirius.properties.HyperlinkWidgetStyle#getFontSizeExpression()
      * @see #getHyperlinkWidgetStyle()
      * @generated
      */
-    EAttribute getHyperlinkWidgetStyle_FontSize();
+    EAttribute getHyperlinkWidgetStyle_FontSizeExpression();
 
     /**
      * Returns the meta object for the reference '
@@ -5557,15 +5565,17 @@ public interface PropertiesPackage extends EPackage {
 
     /**
      * Returns the meta object for the attribute '
-     * {@link org.eclipse.sirius.properties.GroupStyle#getFontSize
-     * <em>Font Size</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * {@link org.eclipse.sirius.properties.GroupStyle#getFontSizeExpression
+     * <em>Font Size Expression</em>}'. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
      *
-     * @return the meta object for the attribute '<em>Font Size</em>'.
-     * @see org.eclipse.sirius.properties.GroupStyle#getFontSize()
+     * @return the meta object for the attribute '<em>Font Size Expression</em>
+     *         '.
+     * @see org.eclipse.sirius.properties.GroupStyle#getFontSizeExpression()
      * @see #getGroupStyle()
      * @generated
      */
-    EAttribute getGroupStyle_FontSize();
+    EAttribute getGroupStyle_FontSizeExpression();
 
     /**
      * Returns the meta object for the attribute '
@@ -6774,12 +6784,13 @@ public interface PropertiesPackage extends EPackage {
         EAttribute WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION = PropertiesPackage.eINSTANCE.getWidgetStyle_LabelFontNameExpression();
 
         /**
-         * The meta object literal for the '<em><b>Label Font Size</b></em>'
-         * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
+         * The meta object literal for the '
+         * <em><b>Label Font Size Expression</b></em>' attribute feature. <!--
+         * begin-user-doc --> <!-- end-user-doc -->
          *
          * @generated
          */
-        EAttribute WIDGET_STYLE__LABEL_FONT_SIZE = PropertiesPackage.eINSTANCE.getWidgetStyle_LabelFontSize();
+        EAttribute WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION = PropertiesPackage.eINSTANCE.getWidgetStyle_LabelFontSizeExpression();
 
         /**
          * The meta object literal for the '
@@ -6828,12 +6839,12 @@ public interface PropertiesPackage extends EPackage {
         EAttribute TEXT_WIDGET_STYLE__FONT_NAME_EXPRESSION = PropertiesPackage.eINSTANCE.getTextWidgetStyle_FontNameExpression();
 
         /**
-         * The meta object literal for the '<em><b>Font Size</b></em>' attribute
-         * feature. <!-- begin-user-doc --> <!-- end-user-doc -->
+         * The meta object literal for the '<em><b>Font Size Expression</b></em>
+         * ' attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
          *
          * @generated
          */
-        EAttribute TEXT_WIDGET_STYLE__FONT_SIZE = PropertiesPackage.eINSTANCE.getTextWidgetStyle_FontSize();
+        EAttribute TEXT_WIDGET_STYLE__FONT_SIZE_EXPRESSION = PropertiesPackage.eINSTANCE.getTextWidgetStyle_FontSizeExpression();
 
         /**
          * The meta object literal for the '<em><b>Background Color</b></em>'
@@ -6880,12 +6891,12 @@ public interface PropertiesPackage extends EPackage {
         EAttribute LABEL_WIDGET_STYLE__FONT_NAME_EXPRESSION = PropertiesPackage.eINSTANCE.getLabelWidgetStyle_FontNameExpression();
 
         /**
-         * The meta object literal for the '<em><b>Font Size</b></em>' attribute
-         * feature. <!-- begin-user-doc --> <!-- end-user-doc -->
+         * The meta object literal for the '<em><b>Font Size Expression</b></em>
+         * ' attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
          *
          * @generated
          */
-        EAttribute LABEL_WIDGET_STYLE__FONT_SIZE = PropertiesPackage.eINSTANCE.getLabelWidgetStyle_FontSize();
+        EAttribute LABEL_WIDGET_STYLE__FONT_SIZE_EXPRESSION = PropertiesPackage.eINSTANCE.getLabelWidgetStyle_FontSizeExpression();
 
         /**
          * The meta object literal for the '<em><b>Background Color</b></em>'
@@ -7254,12 +7265,12 @@ public interface PropertiesPackage extends EPackage {
         EAttribute HYPERLINK_WIDGET_STYLE__FONT_NAME_EXPRESSION = PropertiesPackage.eINSTANCE.getHyperlinkWidgetStyle_FontNameExpression();
 
         /**
-         * The meta object literal for the '<em><b>Font Size</b></em>' attribute
-         * feature. <!-- begin-user-doc --> <!-- end-user-doc -->
+         * The meta object literal for the '<em><b>Font Size Expression</b></em>
+         * ' attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
          *
          * @generated
          */
-        EAttribute HYPERLINK_WIDGET_STYLE__FONT_SIZE = PropertiesPackage.eINSTANCE.getHyperlinkWidgetStyle_FontSize();
+        EAttribute HYPERLINK_WIDGET_STYLE__FONT_SIZE_EXPRESSION = PropertiesPackage.eINSTANCE.getHyperlinkWidgetStyle_FontSizeExpression();
 
         /**
          * The meta object literal for the '<em><b>Background Color</b></em>'
@@ -7314,12 +7325,12 @@ public interface PropertiesPackage extends EPackage {
         EAttribute GROUP_STYLE__FONT_NAME_EXPRESSION = PropertiesPackage.eINSTANCE.getGroupStyle_FontNameExpression();
 
         /**
-         * The meta object literal for the '<em><b>Font Size</b></em>' attribute
-         * feature. <!-- begin-user-doc --> <!-- end-user-doc -->
+         * The meta object literal for the '<em><b>Font Size Expression</b></em>
+         * ' attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
          *
          * @generated
          */
-        EAttribute GROUP_STYLE__FONT_SIZE = PropertiesPackage.eINSTANCE.getGroupStyle_FontSize();
+        EAttribute GROUP_STYLE__FONT_SIZE_EXPRESSION = PropertiesPackage.eINSTANCE.getGroupStyle_FontSizeExpression();
 
         /**
          * The meta object literal for the '<em><b>Bar Style</b></em>' attribute
diff --git a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/TextWidgetStyle.java b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/TextWidgetStyle.java
index 1c394939ea..06fcc9370b 100644
--- a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/TextWidgetStyle.java
+++ b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/TextWidgetStyle.java
@@ -26,8 +26,9 @@ import org.eclipse.sirius.viewpoint.description.ColorDescription;
  * <li>
  * {@link org.eclipse.sirius.properties.TextWidgetStyle#getFontNameExpression
  * <em>Font Name Expression</em>}</li>
- * <li>{@link org.eclipse.sirius.properties.TextWidgetStyle#getFontSize
- * <em>Font Size</em>}</li>
+ * <li>
+ * {@link org.eclipse.sirius.properties.TextWidgetStyle#getFontSizeExpression
+ * <em>Font Size Expression</em>}</li>
  * <li>{@link org.eclipse.sirius.properties.TextWidgetStyle#getBackgroundColor
  * <em>Background Color</em>}</li>
  * <li>{@link org.eclipse.sirius.properties.TextWidgetStyle#getForegroundColor
@@ -74,34 +75,36 @@ public interface TextWidgetStyle extends WidgetStyle {
     void setFontNameExpression(String value);
 
     /**
-     * Returns the value of the '<em><b>Font Size</b></em>' attribute. <!--
-     * begin-user-doc -->
+     * Returns the value of the '<em><b>Font Size Expression</b></em>'
+     * attribute. <!-- begin-user-doc -->
      * <p>
-     * If the meaning of the '<em>Font Size</em>' attribute isn't clear, there
-     * really should be more of a description here...
+     * If the meaning of the '<em>Font Size Expression</em>' attribute isn't
+     * clear, there really should be more of a description here...
      * </p>
      * <!-- end-user-doc -->
      *
-     * @return the value of the '<em>Font Size</em>' attribute.
-     * @see #setFontSize(int)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getTextWidgetStyle_FontSize()
-     * @model
+     * @return the value of the '<em>Font Size Expression</em>' attribute.
+     * @see #setFontSizeExpression(String)
+     * @see org.eclipse.sirius.properties.PropertiesPackage#getTextWidgetStyle_FontSizeExpression()
+     * @model dataType=
+     *        "org.eclipse.sirius.viewpoint.description.InterpretedExpression"
      * @generated
      */
-    int getFontSize();
+    String getFontSizeExpression();
 
     /**
      * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.TextWidgetStyle#getFontSize
-     * <em>Font Size</em>}' attribute. <!-- begin-user-doc --> <!-- end-user-doc
-     * -->
+     * {@link org.eclipse.sirius.properties.TextWidgetStyle#getFontSizeExpression
+     * <em>Font Size Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
      *
      * @param value
-     *            the new value of the '<em>Font Size</em>' attribute.
-     * @see #getFontSize()
+     *            the new value of the '<em>Font Size Expression</em>'
+     *            attribute.
+     * @see #getFontSizeExpression()
      * @generated
      */
-    void setFontSize(int value);
+    void setFontSizeExpression(String value);
 
     /**
      * Returns the value of the '<em><b>Background Color</b></em>' reference.
diff --git a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/WidgetStyle.java b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/WidgetStyle.java
index e99c83de74..7fda1f44c6 100644
--- a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/WidgetStyle.java
+++ b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/WidgetStyle.java
@@ -27,8 +27,9 @@ import org.eclipse.sirius.viewpoint.description.ColorDescription;
  * <li>
  * {@link org.eclipse.sirius.properties.WidgetStyle#getLabelFontNameExpression
  * <em>Label Font Name Expression</em>}</li>
- * <li>{@link org.eclipse.sirius.properties.WidgetStyle#getLabelFontSize
- * <em>Label Font Size</em>}</li>
+ * <li>
+ * {@link org.eclipse.sirius.properties.WidgetStyle#getLabelFontSizeExpression
+ * <em>Label Font Size Expression</em>}</li>
  * <li>{@link org.eclipse.sirius.properties.WidgetStyle#getLabelBackgroundColor
  * <em>Label Background Color</em>}</li>
  * <li>{@link org.eclipse.sirius.properties.WidgetStyle#getLabelForegroundColor
@@ -75,34 +76,36 @@ public interface WidgetStyle extends EObject {
     void setLabelFontNameExpression(String value);
 
     /**
-     * Returns the value of the '<em><b>Label Font Size</b></em>' attribute.
-     * <!-- begin-user-doc -->
+     * Returns the value of the '<em><b>Label Font Size Expression</b></em>'
+     * attribute. <!-- begin-user-doc -->
      * <p>
-     * If the meaning of the '<em>Label Font Size</em>' attribute isn't clear,
-     * there really should be more of a description here...
+     * If the meaning of the '<em>Label Font Size Expression</em>' attribute
+     * isn't clear, there really should be more of a description here...
      * </p>
      * <!-- end-user-doc -->
      *
-     * @return the value of the '<em>Label Font Size</em>' attribute.
-     * @see #setLabelFontSize(int)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getWidgetStyle_LabelFontSize()
-     * @model
+     * @return the value of the '<em>Label Font Size Expression</em>' attribute.
+     * @see #setLabelFontSizeExpression(String)
+     * @see org.eclipse.sirius.properties.PropertiesPackage#getWidgetStyle_LabelFontSizeExpression()
+     * @model dataType=
+     *        "org.eclipse.sirius.viewpoint.description.InterpretedExpression"
      * @generated
      */
-    int getLabelFontSize();
+    String getLabelFontSizeExpression();
 
     /**
      * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.WidgetStyle#getLabelFontSize
-     * <em>Label Font Size</em>}' attribute. <!-- begin-user-doc --> <!--
-     * end-user-doc -->
+     * {@link org.eclipse.sirius.properties.WidgetStyle#getLabelFontSizeExpression
+     * <em>Label Font Size Expression</em>}' attribute. <!-- begin-user-doc -->
+     * <!-- end-user-doc -->
      *
      * @param value
-     *            the new value of the '<em>Label Font Size</em>' attribute.
-     * @see #getLabelFontSize()
+     *            the new value of the '<em>Label Font Size Expression</em>'
+     *            attribute.
+     * @see #getLabelFontSizeExpression()
      * @generated
      */
-    void setLabelFontSize(int value);
+    void setLabelFontSizeExpression(String value);
 
     /**
      * Returns the value of the '<em><b>Label Background Color</b></em>'
diff --git a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/GroupStyleImpl.java b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/GroupStyleImpl.java
index 6c14a1412a..055d1b94eb 100644
--- a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/GroupStyleImpl.java
+++ b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/GroupStyleImpl.java
@@ -38,8 +38,9 @@ import org.eclipse.sirius.viewpoint.description.ColorDescription;
  * <li>
  * {@link org.eclipse.sirius.properties.impl.GroupStyleImpl#getFontNameExpression
  * <em>Font Name Expression</em>}</li>
- * <li>{@link org.eclipse.sirius.properties.impl.GroupStyleImpl#getFontSize
- * <em>Font Size</em>}</li>
+ * <li>
+ * {@link org.eclipse.sirius.properties.impl.GroupStyleImpl#getFontSizeExpression
+ * <em>Font Size Expression</em>}</li>
  * <li>{@link org.eclipse.sirius.properties.impl.GroupStyleImpl#getBarStyle
  * <em>Bar Style</em>}</li>
  * <li>{@link org.eclipse.sirius.properties.impl.GroupStyleImpl#getToggleStyle
@@ -97,24 +98,26 @@ public class GroupStyleImpl extends MinimalEObjectImpl.Container implements Grou
     protected String fontNameExpression = GroupStyleImpl.FONT_NAME_EXPRESSION_EDEFAULT;
 
     /**
-     * The default value of the '{@link #getFontSize() <em>Font Size</em>}'
-     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * The default value of the '{@link #getFontSizeExpression()
+     * <em>Font Size Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
      *
-     * @see #getFontSize()
+     * @see #getFontSizeExpression()
      * @generated
      * @ordered
      */
-    protected static final int FONT_SIZE_EDEFAULT = 0;
+    protected static final String FONT_SIZE_EXPRESSION_EDEFAULT = null;
 
     /**
-     * The cached value of the '{@link #getFontSize() <em>Font Size</em>}'
-     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * The cached value of the '{@link #getFontSizeExpression()
+     * <em>Font Size Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
      *
-     * @see #getFontSize()
+     * @see #getFontSizeExpression()
      * @generated
      * @ordered
      */
-    protected int fontSize = GroupStyleImpl.FONT_SIZE_EDEFAULT;
+    protected String fontSizeExpression = GroupStyleImpl.FONT_SIZE_EXPRESSION_EDEFAULT;
 
     /**
      * The default value of the '{@link #getBarStyle() <em>Bar Style</em>}'
@@ -311,8 +314,8 @@ public class GroupStyleImpl extends MinimalEObjectImpl.Container implements Grou
      * @generated
      */
     @Override
-    public int getFontSize() {
-        return fontSize;
+    public String getFontSizeExpression() {
+        return fontSizeExpression;
     }
 
     /**
@@ -321,11 +324,11 @@ public class GroupStyleImpl extends MinimalEObjectImpl.Container implements Grou
      * @generated
      */
     @Override
-    public void setFontSize(int newFontSize) {
-        int oldFontSize = fontSize;
-        fontSize = newFontSize;
+    public void setFontSizeExpression(String newFontSizeExpression) {
+        String oldFontSizeExpression = fontSizeExpression;
+        fontSizeExpression = newFontSizeExpression;
         if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.GROUP_STYLE__FONT_SIZE, oldFontSize, fontSize));
+            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.GROUP_STYLE__FONT_SIZE_EXPRESSION, oldFontSizeExpression, fontSizeExpression));
         }
     }
 
@@ -421,8 +424,8 @@ public class GroupStyleImpl extends MinimalEObjectImpl.Container implements Grou
             return basicGetForegroundColor();
         case PropertiesPackage.GROUP_STYLE__FONT_NAME_EXPRESSION:
             return getFontNameExpression();
-        case PropertiesPackage.GROUP_STYLE__FONT_SIZE:
-            return getFontSize();
+        case PropertiesPackage.GROUP_STYLE__FONT_SIZE_EXPRESSION:
+            return getFontSizeExpression();
         case PropertiesPackage.GROUP_STYLE__BAR_STYLE:
             return getBarStyle();
         case PropertiesPackage.GROUP_STYLE__TOGGLE_STYLE:
@@ -450,8 +453,8 @@ public class GroupStyleImpl extends MinimalEObjectImpl.Container implements Grou
         case PropertiesPackage.GROUP_STYLE__FONT_NAME_EXPRESSION:
             setFontNameExpression((String) newValue);
             return;
-        case PropertiesPackage.GROUP_STYLE__FONT_SIZE:
-            setFontSize((Integer) newValue);
+        case PropertiesPackage.GROUP_STYLE__FONT_SIZE_EXPRESSION:
+            setFontSizeExpression((String) newValue);
             return;
         case PropertiesPackage.GROUP_STYLE__BAR_STYLE:
             setBarStyle((TitleBarStyle) newValue);
@@ -483,8 +486,8 @@ public class GroupStyleImpl extends MinimalEObjectImpl.Container implements Grou
         case PropertiesPackage.GROUP_STYLE__FONT_NAME_EXPRESSION:
             setFontNameExpression(GroupStyleImpl.FONT_NAME_EXPRESSION_EDEFAULT);
             return;
-        case PropertiesPackage.GROUP_STYLE__FONT_SIZE:
-            setFontSize(GroupStyleImpl.FONT_SIZE_EDEFAULT);
+        case PropertiesPackage.GROUP_STYLE__FONT_SIZE_EXPRESSION:
+            setFontSizeExpression(GroupStyleImpl.FONT_SIZE_EXPRESSION_EDEFAULT);
             return;
         case PropertiesPackage.GROUP_STYLE__BAR_STYLE:
             setBarStyle(GroupStyleImpl.BAR_STYLE_EDEFAULT);
@@ -513,8 +516,8 @@ public class GroupStyleImpl extends MinimalEObjectImpl.Container implements Grou
             return foregroundColor != null;
         case PropertiesPackage.GROUP_STYLE__FONT_NAME_EXPRESSION:
             return GroupStyleImpl.FONT_NAME_EXPRESSION_EDEFAULT == null ? fontNameExpression != null : !GroupStyleImpl.FONT_NAME_EXPRESSION_EDEFAULT.equals(fontNameExpression);
-        case PropertiesPackage.GROUP_STYLE__FONT_SIZE:
-            return fontSize != GroupStyleImpl.FONT_SIZE_EDEFAULT;
+        case PropertiesPackage.GROUP_STYLE__FONT_SIZE_EXPRESSION:
+            return GroupStyleImpl.FONT_SIZE_EXPRESSION_EDEFAULT == null ? fontSizeExpression != null : !GroupStyleImpl.FONT_SIZE_EXPRESSION_EDEFAULT.equals(fontSizeExpression);
         case PropertiesPackage.GROUP_STYLE__BAR_STYLE:
             return barStyle != GroupStyleImpl.BAR_STYLE_EDEFAULT;
         case PropertiesPackage.GROUP_STYLE__TOGGLE_STYLE:
@@ -539,8 +542,8 @@ public class GroupStyleImpl extends MinimalEObjectImpl.Container implements Grou
         StringBuffer result = new StringBuffer(super.toString());
         result.append(" (fontNameExpression: "); //$NON-NLS-1$
         result.append(fontNameExpression);
-        result.append(", fontSize: "); //$NON-NLS-1$
-        result.append(fontSize);
+        result.append(", fontSizeExpression: "); //$NON-NLS-1$
+        result.append(fontSizeExpression);
         result.append(", barStyle: "); //$NON-NLS-1$
         result.append(barStyle);
         result.append(", toggleStyle: "); //$NON-NLS-1$
diff --git a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/HyperlinkWidgetStyleImpl.java b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/HyperlinkWidgetStyleImpl.java
index 96fdd2f6d0..2ef4671961 100644
--- a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/HyperlinkWidgetStyleImpl.java
+++ b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/HyperlinkWidgetStyleImpl.java
@@ -35,8 +35,8 @@ import org.eclipse.sirius.viewpoint.description.ColorDescription;
  * {@link org.eclipse.sirius.properties.impl.HyperlinkWidgetStyleImpl#getFontNameExpression
  * <em>Font Name Expression</em>}</li>
  * <li>
- * {@link org.eclipse.sirius.properties.impl.HyperlinkWidgetStyleImpl#getFontSize
- * <em>Font Size</em>}</li>
+ * {@link org.eclipse.sirius.properties.impl.HyperlinkWidgetStyleImpl#getFontSizeExpression
+ * <em>Font Size Expression</em>}</li>
  * <li>
  * {@link org.eclipse.sirius.properties.impl.HyperlinkWidgetStyleImpl#getBackgroundColor
  * <em>Background Color</em>}</li>
@@ -71,24 +71,26 @@ public class HyperlinkWidgetStyleImpl extends WidgetStyleImpl implements Hyperli
     protected String fontNameExpression = HyperlinkWidgetStyleImpl.FONT_NAME_EXPRESSION_EDEFAULT;
 
     /**
-     * The default value of the '{@link #getFontSize() <em>Font Size</em>}'
-     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * The default value of the '{@link #getFontSizeExpression()
+     * <em>Font Size Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
      *
-     * @see #getFontSize()
+     * @see #getFontSizeExpression()
      * @generated
      * @ordered
      */
-    protected static final int FONT_SIZE_EDEFAULT = 0;
+    protected static final String FONT_SIZE_EXPRESSION_EDEFAULT = null;
 
     /**
-     * The cached value of the '{@link #getFontSize() <em>Font Size</em>}'
-     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * The cached value of the '{@link #getFontSizeExpression()
+     * <em>Font Size Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
      *
-     * @see #getFontSize()
+     * @see #getFontSizeExpression()
      * @generated
      * @ordered
      */
-    protected int fontSize = HyperlinkWidgetStyleImpl.FONT_SIZE_EDEFAULT;
+    protected String fontSizeExpression = HyperlinkWidgetStyleImpl.FONT_SIZE_EXPRESSION_EDEFAULT;
 
     /**
      * The cached value of the '{@link #getBackgroundColor()
@@ -160,8 +162,8 @@ public class HyperlinkWidgetStyleImpl extends WidgetStyleImpl implements Hyperli
      * @generated
      */
     @Override
-    public int getFontSize() {
-        return fontSize;
+    public String getFontSizeExpression() {
+        return fontSizeExpression;
     }
 
     /**
@@ -170,11 +172,11 @@ public class HyperlinkWidgetStyleImpl extends WidgetStyleImpl implements Hyperli
      * @generated
      */
     @Override
-    public void setFontSize(int newFontSize) {
-        int oldFontSize = fontSize;
-        fontSize = newFontSize;
+    public void setFontSizeExpression(String newFontSizeExpression) {
+        String oldFontSizeExpression = fontSizeExpression;
+        fontSizeExpression = newFontSizeExpression;
         if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_SIZE, oldFontSize, fontSize));
+            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_SIZE_EXPRESSION, oldFontSizeExpression, fontSizeExpression));
         }
     }
 
@@ -243,8 +245,8 @@ public class HyperlinkWidgetStyleImpl extends WidgetStyleImpl implements Hyperli
         switch (featureID) {
         case PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_NAME_EXPRESSION:
             return getFontNameExpression();
-        case PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_SIZE:
-            return getFontSize();
+        case PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_SIZE_EXPRESSION:
+            return getFontSizeExpression();
         case PropertiesPackage.HYPERLINK_WIDGET_STYLE__BACKGROUND_COLOR:
             if (resolve) {
                 return getBackgroundColor();
@@ -268,8 +270,8 @@ public class HyperlinkWidgetStyleImpl extends WidgetStyleImpl implements Hyperli
         case PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_NAME_EXPRESSION:
             setFontNameExpression((String) newValue);
             return;
-        case PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_SIZE:
-            setFontSize((Integer) newValue);
+        case PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_SIZE_EXPRESSION:
+            setFontSizeExpression((String) newValue);
             return;
         case PropertiesPackage.HYPERLINK_WIDGET_STYLE__BACKGROUND_COLOR:
             setBackgroundColor((ColorDescription) newValue);
@@ -293,8 +295,8 @@ public class HyperlinkWidgetStyleImpl extends WidgetStyleImpl implements Hyperli
         case PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_NAME_EXPRESSION:
             setFontNameExpression(HyperlinkWidgetStyleImpl.FONT_NAME_EXPRESSION_EDEFAULT);
             return;
-        case PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_SIZE:
-            setFontSize(HyperlinkWidgetStyleImpl.FONT_SIZE_EDEFAULT);
+        case PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_SIZE_EXPRESSION:
+            setFontSizeExpression(HyperlinkWidgetStyleImpl.FONT_SIZE_EXPRESSION_EDEFAULT);
             return;
         case PropertiesPackage.HYPERLINK_WIDGET_STYLE__BACKGROUND_COLOR:
             setBackgroundColor((ColorDescription) null);
@@ -316,8 +318,8 @@ public class HyperlinkWidgetStyleImpl extends WidgetStyleImpl implements Hyperli
         switch (featureID) {
         case PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_NAME_EXPRESSION:
             return HyperlinkWidgetStyleImpl.FONT_NAME_EXPRESSION_EDEFAULT == null ? fontNameExpression != null : !HyperlinkWidgetStyleImpl.FONT_NAME_EXPRESSION_EDEFAULT.equals(fontNameExpression);
-        case PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_SIZE:
-            return fontSize != HyperlinkWidgetStyleImpl.FONT_SIZE_EDEFAULT;
+        case PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_SIZE_EXPRESSION:
+            return HyperlinkWidgetStyleImpl.FONT_SIZE_EXPRESSION_EDEFAULT == null ? fontSizeExpression != null : !HyperlinkWidgetStyleImpl.FONT_SIZE_EXPRESSION_EDEFAULT.equals(fontSizeExpression);
         case PropertiesPackage.HYPERLINK_WIDGET_STYLE__BACKGROUND_COLOR:
             return backgroundColor != null;
         case PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_FORMAT:
@@ -340,8 +342,8 @@ public class HyperlinkWidgetStyleImpl extends WidgetStyleImpl implements Hyperli
         StringBuffer result = new StringBuffer(super.toString());
         result.append(" (fontNameExpression: "); //$NON-NLS-1$
         result.append(fontNameExpression);
-        result.append(", fontSize: "); //$NON-NLS-1$
-        result.append(fontSize);
+        result.append(", fontSizeExpression: "); //$NON-NLS-1$
+        result.append(fontSizeExpression);
         result.append(", fontFormat: "); //$NON-NLS-1$
         result.append(fontFormat);
         result.append(')');
diff --git a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/LabelWidgetStyleImpl.java b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/LabelWidgetStyleImpl.java
index 07f6218ef8..6b44fd4cc6 100644
--- a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/LabelWidgetStyleImpl.java
+++ b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/LabelWidgetStyleImpl.java
@@ -35,8 +35,8 @@ import org.eclipse.sirius.viewpoint.description.ColorDescription;
  * {@link org.eclipse.sirius.properties.impl.LabelWidgetStyleImpl#getFontNameExpression
  * <em>Font Name Expression</em>}</li>
  * <li>
- * {@link org.eclipse.sirius.properties.impl.LabelWidgetStyleImpl#getFontSize
- * <em>Font Size</em>}</li>
+ * {@link org.eclipse.sirius.properties.impl.LabelWidgetStyleImpl#getFontSizeExpression
+ * <em>Font Size Expression</em>}</li>
  * <li>
  * {@link org.eclipse.sirius.properties.impl.LabelWidgetStyleImpl#getBackgroundColor
  * <em>Background Color</em>}</li>
@@ -74,24 +74,26 @@ public class LabelWidgetStyleImpl extends WidgetStyleImpl implements LabelWidget
     protected String fontNameExpression = LabelWidgetStyleImpl.FONT_NAME_EXPRESSION_EDEFAULT;
 
     /**
-     * The default value of the '{@link #getFontSize() <em>Font Size</em>}'
-     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * The default value of the '{@link #getFontSizeExpression()
+     * <em>Font Size Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
      *
-     * @see #getFontSize()
+     * @see #getFontSizeExpression()
      * @generated
      * @ordered
      */
-    protected static final int FONT_SIZE_EDEFAULT = 0;
+    protected static final String FONT_SIZE_EXPRESSION_EDEFAULT = null;
 
     /**
-     * The cached value of the '{@link #getFontSize() <em>Font Size</em>}'
-     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * The cached value of the '{@link #getFontSizeExpression()
+     * <em>Font Size Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
      *
-     * @see #getFontSize()
+     * @see #getFontSizeExpression()
      * @generated
      * @ordered
      */
-    protected int fontSize = LabelWidgetStyleImpl.FONT_SIZE_EDEFAULT;
+    protected String fontSizeExpression = LabelWidgetStyleImpl.FONT_SIZE_EXPRESSION_EDEFAULT;
 
     /**
      * The cached value of the '{@link #getBackgroundColor()
@@ -174,8 +176,8 @@ public class LabelWidgetStyleImpl extends WidgetStyleImpl implements LabelWidget
      * @generated
      */
     @Override
-    public int getFontSize() {
-        return fontSize;
+    public String getFontSizeExpression() {
+        return fontSizeExpression;
     }
 
     /**
@@ -184,11 +186,11 @@ public class LabelWidgetStyleImpl extends WidgetStyleImpl implements LabelWidget
      * @generated
      */
     @Override
-    public void setFontSize(int newFontSize) {
-        int oldFontSize = fontSize;
-        fontSize = newFontSize;
+    public void setFontSizeExpression(String newFontSizeExpression) {
+        String oldFontSizeExpression = fontSizeExpression;
+        fontSizeExpression = newFontSizeExpression;
         if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.LABEL_WIDGET_STYLE__FONT_SIZE, oldFontSize, fontSize));
+            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.LABEL_WIDGET_STYLE__FONT_SIZE_EXPRESSION, oldFontSizeExpression, fontSizeExpression));
         }
     }
 
@@ -299,8 +301,8 @@ public class LabelWidgetStyleImpl extends WidgetStyleImpl implements LabelWidget
         switch (featureID) {
         case PropertiesPackage.LABEL_WIDGET_STYLE__FONT_NAME_EXPRESSION:
             return getFontNameExpression();
-        case PropertiesPackage.LABEL_WIDGET_STYLE__FONT_SIZE:
-            return getFontSize();
+        case PropertiesPackage.LABEL_WIDGET_STYLE__FONT_SIZE_EXPRESSION:
+            return getFontSizeExpression();
         case PropertiesPackage.LABEL_WIDGET_STYLE__BACKGROUND_COLOR:
             if (resolve) {
                 return getBackgroundColor();
@@ -329,8 +331,8 @@ public class LabelWidgetStyleImpl extends WidgetStyleImpl implements LabelWidget
         case PropertiesPackage.LABEL_WIDGET_STYLE__FONT_NAME_EXPRESSION:
             setFontNameExpression((String) newValue);
             return;
-        case PropertiesPackage.LABEL_WIDGET_STYLE__FONT_SIZE:
-            setFontSize((Integer) newValue);
+        case PropertiesPackage.LABEL_WIDGET_STYLE__FONT_SIZE_EXPRESSION:
+            setFontSizeExpression((String) newValue);
             return;
         case PropertiesPackage.LABEL_WIDGET_STYLE__BACKGROUND_COLOR:
             setBackgroundColor((ColorDescription) newValue);
@@ -357,8 +359,8 @@ public class LabelWidgetStyleImpl extends WidgetStyleImpl implements LabelWidget
         case PropertiesPackage.LABEL_WIDGET_STYLE__FONT_NAME_EXPRESSION:
             setFontNameExpression(LabelWidgetStyleImpl.FONT_NAME_EXPRESSION_EDEFAULT);
             return;
-        case PropertiesPackage.LABEL_WIDGET_STYLE__FONT_SIZE:
-            setFontSize(LabelWidgetStyleImpl.FONT_SIZE_EDEFAULT);
+        case PropertiesPackage.LABEL_WIDGET_STYLE__FONT_SIZE_EXPRESSION:
+            setFontSizeExpression(LabelWidgetStyleImpl.FONT_SIZE_EXPRESSION_EDEFAULT);
             return;
         case PropertiesPackage.LABEL_WIDGET_STYLE__BACKGROUND_COLOR:
             setBackgroundColor((ColorDescription) null);
@@ -383,8 +385,8 @@ public class LabelWidgetStyleImpl extends WidgetStyleImpl implements LabelWidget
         switch (featureID) {
         case PropertiesPackage.LABEL_WIDGET_STYLE__FONT_NAME_EXPRESSION:
             return LabelWidgetStyleImpl.FONT_NAME_EXPRESSION_EDEFAULT == null ? fontNameExpression != null : !LabelWidgetStyleImpl.FONT_NAME_EXPRESSION_EDEFAULT.equals(fontNameExpression);
-        case PropertiesPackage.LABEL_WIDGET_STYLE__FONT_SIZE:
-            return fontSize != LabelWidgetStyleImpl.FONT_SIZE_EDEFAULT;
+        case PropertiesPackage.LABEL_WIDGET_STYLE__FONT_SIZE_EXPRESSION:
+            return LabelWidgetStyleImpl.FONT_SIZE_EXPRESSION_EDEFAULT == null ? fontSizeExpression != null : !LabelWidgetStyleImpl.FONT_SIZE_EXPRESSION_EDEFAULT.equals(fontSizeExpression);
         case PropertiesPackage.LABEL_WIDGET_STYLE__BACKGROUND_COLOR:
             return backgroundColor != null;
         case PropertiesPackage.LABEL_WIDGET_STYLE__FOREGROUND_COLOR:
@@ -409,8 +411,8 @@ public class LabelWidgetStyleImpl extends WidgetStyleImpl implements LabelWidget
         StringBuffer result = new StringBuffer(super.toString());
         result.append(" (fontNameExpression: "); //$NON-NLS-1$
         result.append(fontNameExpression);
-        result.append(", fontSize: "); //$NON-NLS-1$
-        result.append(fontSize);
+        result.append(", fontSizeExpression: "); //$NON-NLS-1$
+        result.append(fontSizeExpression);
         result.append(", fontFormat: "); //$NON-NLS-1$
         result.append(fontFormat);
         result.append(')');
diff --git a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/PropertiesPackageImpl.java b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/PropertiesPackageImpl.java
index 5d68a2415d..15130f02a7 100644
--- a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/PropertiesPackageImpl.java
+++ b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/PropertiesPackageImpl.java
@@ -1730,7 +1730,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      * @generated
      */
     @Override
-    public EAttribute getWidgetStyle_LabelFontSize() {
+    public EAttribute getWidgetStyle_LabelFontSizeExpression() {
         return (EAttribute) widgetStyleEClass.getEStructuralFeatures().get(1);
     }
 
@@ -1790,7 +1790,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      * @generated
      */
     @Override
-    public EAttribute getTextWidgetStyle_FontSize() {
+    public EAttribute getTextWidgetStyle_FontSizeExpression() {
         return (EAttribute) textWidgetStyleEClass.getEStructuralFeatures().get(1);
     }
 
@@ -1850,7 +1850,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      * @generated
      */
     @Override
-    public EAttribute getLabelWidgetStyle_FontSize() {
+    public EAttribute getLabelWidgetStyle_FontSizeExpression() {
         return (EAttribute) labelWidgetStyleEClass.getEStructuralFeatures().get(1);
     }
 
@@ -2220,7 +2220,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      * @generated
      */
     @Override
-    public EAttribute getHyperlinkWidgetStyle_FontSize() {
+    public EAttribute getHyperlinkWidgetStyle_FontSizeExpression() {
         return (EAttribute) hyperlinkWidgetStyleEClass.getEStructuralFeatures().get(1);
     }
 
@@ -2290,7 +2290,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      * @generated
      */
     @Override
-    public EAttribute getGroupStyle_FontSize() {
+    public EAttribute getGroupStyle_FontSizeExpression() {
         return (EAttribute) groupStyleEClass.getEStructuralFeatures().get(3);
     }
 
@@ -2532,21 +2532,21 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
         widgetStyleEClass = createEClass(PropertiesPackage.WIDGET_STYLE);
         createEAttribute(widgetStyleEClass, PropertiesPackage.WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION);
-        createEAttribute(widgetStyleEClass, PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE);
+        createEAttribute(widgetStyleEClass, PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION);
         createEReference(widgetStyleEClass, PropertiesPackage.WIDGET_STYLE__LABEL_BACKGROUND_COLOR);
         createEReference(widgetStyleEClass, PropertiesPackage.WIDGET_STYLE__LABEL_FOREGROUND_COLOR);
         createEAttribute(widgetStyleEClass, PropertiesPackage.WIDGET_STYLE__LABEL_FONT_FORMAT);
 
         textWidgetStyleEClass = createEClass(PropertiesPackage.TEXT_WIDGET_STYLE);
         createEAttribute(textWidgetStyleEClass, PropertiesPackage.TEXT_WIDGET_STYLE__FONT_NAME_EXPRESSION);
-        createEAttribute(textWidgetStyleEClass, PropertiesPackage.TEXT_WIDGET_STYLE__FONT_SIZE);
+        createEAttribute(textWidgetStyleEClass, PropertiesPackage.TEXT_WIDGET_STYLE__FONT_SIZE_EXPRESSION);
         createEReference(textWidgetStyleEClass, PropertiesPackage.TEXT_WIDGET_STYLE__BACKGROUND_COLOR);
         createEReference(textWidgetStyleEClass, PropertiesPackage.TEXT_WIDGET_STYLE__FOREGROUND_COLOR);
         createEAttribute(textWidgetStyleEClass, PropertiesPackage.TEXT_WIDGET_STYLE__FONT_FORMAT);
 
         labelWidgetStyleEClass = createEClass(PropertiesPackage.LABEL_WIDGET_STYLE);
         createEAttribute(labelWidgetStyleEClass, PropertiesPackage.LABEL_WIDGET_STYLE__FONT_NAME_EXPRESSION);
-        createEAttribute(labelWidgetStyleEClass, PropertiesPackage.LABEL_WIDGET_STYLE__FONT_SIZE);
+        createEAttribute(labelWidgetStyleEClass, PropertiesPackage.LABEL_WIDGET_STYLE__FONT_SIZE_EXPRESSION);
         createEReference(labelWidgetStyleEClass, PropertiesPackage.LABEL_WIDGET_STYLE__BACKGROUND_COLOR);
         createEReference(labelWidgetStyleEClass, PropertiesPackage.LABEL_WIDGET_STYLE__FOREGROUND_COLOR);
         createEAttribute(labelWidgetStyleEClass, PropertiesPackage.LABEL_WIDGET_STYLE__FONT_FORMAT);
@@ -2565,7 +2565,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
         hyperlinkWidgetStyleEClass = createEClass(PropertiesPackage.HYPERLINK_WIDGET_STYLE);
         createEAttribute(hyperlinkWidgetStyleEClass, PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_NAME_EXPRESSION);
-        createEAttribute(hyperlinkWidgetStyleEClass, PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_SIZE);
+        createEAttribute(hyperlinkWidgetStyleEClass, PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_SIZE_EXPRESSION);
         createEReference(hyperlinkWidgetStyleEClass, PropertiesPackage.HYPERLINK_WIDGET_STYLE__BACKGROUND_COLOR);
         createEAttribute(hyperlinkWidgetStyleEClass, PropertiesPackage.HYPERLINK_WIDGET_STYLE__FONT_FORMAT);
 
@@ -2573,7 +2573,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
         createEReference(groupStyleEClass, PropertiesPackage.GROUP_STYLE__BACKGROUND_COLOR);
         createEReference(groupStyleEClass, PropertiesPackage.GROUP_STYLE__FOREGROUND_COLOR);
         createEAttribute(groupStyleEClass, PropertiesPackage.GROUP_STYLE__FONT_NAME_EXPRESSION);
-        createEAttribute(groupStyleEClass, PropertiesPackage.GROUP_STYLE__FONT_SIZE);
+        createEAttribute(groupStyleEClass, PropertiesPackage.GROUP_STYLE__FONT_SIZE_EXPRESSION);
         createEAttribute(groupStyleEClass, PropertiesPackage.GROUP_STYLE__BAR_STYLE);
         createEAttribute(groupStyleEClass, PropertiesPackage.GROUP_STYLE__TOGGLE_STYLE);
         createEAttribute(groupStyleEClass, PropertiesPackage.GROUP_STYLE__EXPANDED_BY_DEFAULT);
@@ -3005,8 +3005,8 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
         initEClass(widgetStyleEClass, WidgetStyle.class, "WidgetStyle", !EPackageImpl.IS_ABSTRACT, !EPackageImpl.IS_INTERFACE, EPackageImpl.IS_GENERATED_INSTANCE_CLASS); //$NON-NLS-1$
         initEAttribute(getWidgetStyle_LabelFontNameExpression(), theDescriptionPackage.getInterpretedExpression(), "labelFontNameExpression", null, 0, 1, WidgetStyle.class, !EPackageImpl.IS_TRANSIENT, //$NON-NLS-1$
                 !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
-        initEAttribute(getWidgetStyle_LabelFontSize(), ecorePackage.getEInt(), "labelFontSize", null, 0, 1, WidgetStyle.class, !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, //$NON-NLS-1$
-                EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
+        initEAttribute(getWidgetStyle_LabelFontSizeExpression(), theDescriptionPackage.getInterpretedExpression(), "labelFontSizeExpression", null, 0, 1, WidgetStyle.class, !EPackageImpl.IS_TRANSIENT, //$NON-NLS-1$
+                !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
         initEReference(getWidgetStyle_LabelBackgroundColor(), theDescriptionPackage.getColorDescription(), null, "labelBackgroundColor", null, 0, 1, WidgetStyle.class, !EPackageImpl.IS_TRANSIENT, //$NON-NLS-1$
                 !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_COMPOSITE, EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE, EPackageImpl.IS_UNIQUE,
                 !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
@@ -3019,8 +3019,8 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
         initEClass(textWidgetStyleEClass, TextWidgetStyle.class, "TextWidgetStyle", !EPackageImpl.IS_ABSTRACT, !EPackageImpl.IS_INTERFACE, EPackageImpl.IS_GENERATED_INSTANCE_CLASS); //$NON-NLS-1$
         initEAttribute(getTextWidgetStyle_FontNameExpression(), theDescriptionPackage.getInterpretedExpression(), "fontNameExpression", null, 0, 1, TextWidgetStyle.class, !EPackageImpl.IS_TRANSIENT, //$NON-NLS-1$
                 !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
-        initEAttribute(getTextWidgetStyle_FontSize(), ecorePackage.getEInt(), "fontSize", null, 0, 1, TextWidgetStyle.class, !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, //$NON-NLS-1$
-                EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
+        initEAttribute(getTextWidgetStyle_FontSizeExpression(), theDescriptionPackage.getInterpretedExpression(), "fontSizeExpression", null, 0, 1, TextWidgetStyle.class, !EPackageImpl.IS_TRANSIENT, //$NON-NLS-1$
+                !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
         initEReference(getTextWidgetStyle_BackgroundColor(), theDescriptionPackage.getColorDescription(), null, "backgroundColor", null, 0, 1, TextWidgetStyle.class, !EPackageImpl.IS_TRANSIENT, //$NON-NLS-1$
                 !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_COMPOSITE, EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE, EPackageImpl.IS_UNIQUE,
                 !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
@@ -3033,8 +3033,8 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
         initEClass(labelWidgetStyleEClass, LabelWidgetStyle.class, "LabelWidgetStyle", !EPackageImpl.IS_ABSTRACT, !EPackageImpl.IS_INTERFACE, EPackageImpl.IS_GENERATED_INSTANCE_CLASS); //$NON-NLS-1$
         initEAttribute(getLabelWidgetStyle_FontNameExpression(), theDescriptionPackage.getInterpretedExpression(), "fontNameExpression", null, 0, 1, LabelWidgetStyle.class, !EPackageImpl.IS_TRANSIENT, //$NON-NLS-1$
                 !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
-        initEAttribute(getLabelWidgetStyle_FontSize(), ecorePackage.getEInt(), "fontSize", null, 0, 1, LabelWidgetStyle.class, !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, //$NON-NLS-1$
-                EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
+        initEAttribute(getLabelWidgetStyle_FontSizeExpression(), theDescriptionPackage.getInterpretedExpression(), "fontSizeExpression", null, 0, 1, LabelWidgetStyle.class, !EPackageImpl.IS_TRANSIENT, //$NON-NLS-1$
+                !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
         initEReference(getLabelWidgetStyle_BackgroundColor(), theDescriptionPackage.getColorDescription(), null, "backgroundColor", null, 0, 1, LabelWidgetStyle.class, !EPackageImpl.IS_TRANSIENT, //$NON-NLS-1$
                 !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_COMPOSITE, EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE, EPackageImpl.IS_UNIQUE,
                 !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
@@ -3060,8 +3060,9 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
         initEAttribute(getHyperlinkWidgetStyle_FontNameExpression(), theDescriptionPackage.getInterpretedExpression(), "fontNameExpression", null, 0, 1, HyperlinkWidgetStyle.class, //$NON-NLS-1$
                 !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED,
                 EPackageImpl.IS_ORDERED);
-        initEAttribute(getHyperlinkWidgetStyle_FontSize(), ecorePackage.getEInt(), "fontSize", null, 0, 1, HyperlinkWidgetStyle.class, !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, //$NON-NLS-1$
-                EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
+        initEAttribute(getHyperlinkWidgetStyle_FontSizeExpression(), theDescriptionPackage.getInterpretedExpression(), "fontSizeExpression", null, 0, 1, HyperlinkWidgetStyle.class, //$NON-NLS-1$
+                !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED,
+                EPackageImpl.IS_ORDERED);
         initEReference(getHyperlinkWidgetStyle_BackgroundColor(), theDescriptionPackage.getColorDescription(), null, "backgroundColor", null, 0, 1, HyperlinkWidgetStyle.class, //$NON-NLS-1$
                 !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_COMPOSITE, EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE,
                 EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
@@ -3077,8 +3078,8 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
                 !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
         initEAttribute(getGroupStyle_FontNameExpression(), theDescriptionPackage.getInterpretedExpression(), "fontNameExpression", null, 0, 1, GroupStyle.class, !EPackageImpl.IS_TRANSIENT, //$NON-NLS-1$
                 !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
-        initEAttribute(getGroupStyle_FontSize(), ecorePackage.getEInt(), "fontSize", null, 0, 1, GroupStyle.class, !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, //$NON-NLS-1$
-                !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
+        initEAttribute(getGroupStyle_FontSizeExpression(), theDescriptionPackage.getInterpretedExpression(), "fontSizeExpression", null, 0, 1, GroupStyle.class, !EPackageImpl.IS_TRANSIENT, //$NON-NLS-1$
+                !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
         initEAttribute(getGroupStyle_BarStyle(), this.getTitleBarStyle(), "barStyle", null, 0, 1, GroupStyle.class, !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, //$NON-NLS-1$
                 !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
         initEAttribute(getGroupStyle_ToggleStyle(), this.getToggleStyle(), "toggleStyle", null, 0, 1, GroupStyle.class, !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, //$NON-NLS-1$
diff --git a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/TextWidgetStyleImpl.java b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/TextWidgetStyleImpl.java
index fff49dab8c..e490ddfdb2 100644
--- a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/TextWidgetStyleImpl.java
+++ b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/TextWidgetStyleImpl.java
@@ -34,8 +34,9 @@ import org.eclipse.sirius.viewpoint.description.ColorDescription;
  * <li>
  * {@link org.eclipse.sirius.properties.impl.TextWidgetStyleImpl#getFontNameExpression
  * <em>Font Name Expression</em>}</li>
- * <li>{@link org.eclipse.sirius.properties.impl.TextWidgetStyleImpl#getFontSize
- * <em>Font Size</em>}</li>
+ * <li>
+ * {@link org.eclipse.sirius.properties.impl.TextWidgetStyleImpl#getFontSizeExpression
+ * <em>Font Size Expression</em>}</li>
  * <li>
  * {@link org.eclipse.sirius.properties.impl.TextWidgetStyleImpl#getBackgroundColor
  * <em>Background Color</em>}</li>
@@ -73,24 +74,26 @@ public class TextWidgetStyleImpl extends WidgetStyleImpl implements TextWidgetSt
     protected String fontNameExpression = TextWidgetStyleImpl.FONT_NAME_EXPRESSION_EDEFAULT;
 
     /**
-     * The default value of the '{@link #getFontSize() <em>Font Size</em>}'
-     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * The default value of the '{@link #getFontSizeExpression()
+     * <em>Font Size Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
      *
-     * @see #getFontSize()
+     * @see #getFontSizeExpression()
      * @generated
      * @ordered
      */
-    protected static final int FONT_SIZE_EDEFAULT = 0;
+    protected static final String FONT_SIZE_EXPRESSION_EDEFAULT = null;
 
     /**
-     * The cached value of the '{@link #getFontSize() <em>Font Size</em>}'
-     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * The cached value of the '{@link #getFontSizeExpression()
+     * <em>Font Size Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
      *
-     * @see #getFontSize()
+     * @see #getFontSizeExpression()
      * @generated
      * @ordered
      */
-    protected int fontSize = TextWidgetStyleImpl.FONT_SIZE_EDEFAULT;
+    protected String fontSizeExpression = TextWidgetStyleImpl.FONT_SIZE_EXPRESSION_EDEFAULT;
 
     /**
      * The cached value of the '{@link #getBackgroundColor()
@@ -173,8 +176,8 @@ public class TextWidgetStyleImpl extends WidgetStyleImpl implements TextWidgetSt
      * @generated
      */
     @Override
-    public int getFontSize() {
-        return fontSize;
+    public String getFontSizeExpression() {
+        return fontSizeExpression;
     }
 
     /**
@@ -183,11 +186,11 @@ public class TextWidgetStyleImpl extends WidgetStyleImpl implements TextWidgetSt
      * @generated
      */
     @Override
-    public void setFontSize(int newFontSize) {
-        int oldFontSize = fontSize;
-        fontSize = newFontSize;
+    public void setFontSizeExpression(String newFontSizeExpression) {
+        String oldFontSizeExpression = fontSizeExpression;
+        fontSizeExpression = newFontSizeExpression;
         if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.TEXT_WIDGET_STYLE__FONT_SIZE, oldFontSize, fontSize));
+            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.TEXT_WIDGET_STYLE__FONT_SIZE_EXPRESSION, oldFontSizeExpression, fontSizeExpression));
         }
     }
 
@@ -298,8 +301,8 @@ public class TextWidgetStyleImpl extends WidgetStyleImpl implements TextWidgetSt
         switch (featureID) {
         case PropertiesPackage.TEXT_WIDGET_STYLE__FONT_NAME_EXPRESSION:
             return getFontNameExpression();
-        case PropertiesPackage.TEXT_WIDGET_STYLE__FONT_SIZE:
-            return getFontSize();
+        case PropertiesPackage.TEXT_WIDGET_STYLE__FONT_SIZE_EXPRESSION:
+            return getFontSizeExpression();
         case PropertiesPackage.TEXT_WIDGET_STYLE__BACKGROUND_COLOR:
             if (resolve) {
                 return getBackgroundColor();
@@ -328,8 +331,8 @@ public class TextWidgetStyleImpl extends WidgetStyleImpl implements TextWidgetSt
         case PropertiesPackage.TEXT_WIDGET_STYLE__FONT_NAME_EXPRESSION:
             setFontNameExpression((String) newValue);
             return;
-        case PropertiesPackage.TEXT_WIDGET_STYLE__FONT_SIZE:
-            setFontSize((Integer) newValue);
+        case PropertiesPackage.TEXT_WIDGET_STYLE__FONT_SIZE_EXPRESSION:
+            setFontSizeExpression((String) newValue);
             return;
         case PropertiesPackage.TEXT_WIDGET_STYLE__BACKGROUND_COLOR:
             setBackgroundColor((ColorDescription) newValue);
@@ -356,8 +359,8 @@ public class TextWidgetStyleImpl extends WidgetStyleImpl implements TextWidgetSt
         case PropertiesPackage.TEXT_WIDGET_STYLE__FONT_NAME_EXPRESSION:
             setFontNameExpression(TextWidgetStyleImpl.FONT_NAME_EXPRESSION_EDEFAULT);
             return;
-        case PropertiesPackage.TEXT_WIDGET_STYLE__FONT_SIZE:
-            setFontSize(TextWidgetStyleImpl.FONT_SIZE_EDEFAULT);
+        case PropertiesPackage.TEXT_WIDGET_STYLE__FONT_SIZE_EXPRESSION:
+            setFontSizeExpression(TextWidgetStyleImpl.FONT_SIZE_EXPRESSION_EDEFAULT);
             return;
         case PropertiesPackage.TEXT_WIDGET_STYLE__BACKGROUND_COLOR:
             setBackgroundColor((ColorDescription) null);
@@ -382,8 +385,8 @@ public class TextWidgetStyleImpl extends WidgetStyleImpl implements TextWidgetSt
         switch (featureID) {
         case PropertiesPackage.TEXT_WIDGET_STYLE__FONT_NAME_EXPRESSION:
             return TextWidgetStyleImpl.FONT_NAME_EXPRESSION_EDEFAULT == null ? fontNameExpression != null : !TextWidgetStyleImpl.FONT_NAME_EXPRESSION_EDEFAULT.equals(fontNameExpression);
-        case PropertiesPackage.TEXT_WIDGET_STYLE__FONT_SIZE:
-            return fontSize != TextWidgetStyleImpl.FONT_SIZE_EDEFAULT;
+        case PropertiesPackage.TEXT_WIDGET_STYLE__FONT_SIZE_EXPRESSION:
+            return TextWidgetStyleImpl.FONT_SIZE_EXPRESSION_EDEFAULT == null ? fontSizeExpression != null : !TextWidgetStyleImpl.FONT_SIZE_EXPRESSION_EDEFAULT.equals(fontSizeExpression);
         case PropertiesPackage.TEXT_WIDGET_STYLE__BACKGROUND_COLOR:
             return backgroundColor != null;
         case PropertiesPackage.TEXT_WIDGET_STYLE__FOREGROUND_COLOR:
@@ -408,8 +411,8 @@ public class TextWidgetStyleImpl extends WidgetStyleImpl implements TextWidgetSt
         StringBuffer result = new StringBuffer(super.toString());
         result.append(" (fontNameExpression: "); //$NON-NLS-1$
         result.append(fontNameExpression);
-        result.append(", fontSize: "); //$NON-NLS-1$
-        result.append(fontSize);
+        result.append(", fontSizeExpression: "); //$NON-NLS-1$
+        result.append(fontSizeExpression);
         result.append(", fontFormat: "); //$NON-NLS-1$
         result.append(fontFormat);
         result.append(')');
diff --git a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/WidgetStyleImpl.java b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/WidgetStyleImpl.java
index 0256859e07..1bac693ce4 100644
--- a/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/WidgetStyleImpl.java
+++ b/plugins/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/WidgetStyleImpl.java
@@ -36,8 +36,8 @@ import org.eclipse.sirius.viewpoint.description.ColorDescription;
  * {@link org.eclipse.sirius.properties.impl.WidgetStyleImpl#getLabelFontNameExpression
  * <em>Label Font Name Expression</em>}</li>
  * <li>
- * {@link org.eclipse.sirius.properties.impl.WidgetStyleImpl#getLabelFontSize
- * <em>Label Font Size</em>}</li>
+ * {@link org.eclipse.sirius.properties.impl.WidgetStyleImpl#getLabelFontSizeExpression
+ * <em>Label Font Size Expression</em>}</li>
  * <li>
  * {@link org.eclipse.sirius.properties.impl.WidgetStyleImpl#getLabelBackgroundColor
  * <em>Label Background Color</em>}</li>
@@ -75,26 +75,26 @@ public class WidgetStyleImpl extends MinimalEObjectImpl.Container implements Wid
     protected String labelFontNameExpression = WidgetStyleImpl.LABEL_FONT_NAME_EXPRESSION_EDEFAULT;
 
     /**
-     * The default value of the '{@link #getLabelFontSize()
-     * <em>Label Font Size</em>}' attribute. <!-- begin-user-doc --> <!--
-     * end-user-doc -->
+     * The default value of the '{@link #getLabelFontSizeExpression()
+     * <em>Label Font Size Expression</em>}' attribute. <!-- begin-user-doc -->
+     * <!-- end-user-doc -->
      *
-     * @see #getLabelFontSize()
+     * @see #getLabelFontSizeExpression()
      * @generated
      * @ordered
      */
-    protected static final int LABEL_FONT_SIZE_EDEFAULT = 0;
+    protected static final String LABEL_FONT_SIZE_EXPRESSION_EDEFAULT = null;
 
     /**
-     * The cached value of the '{@link #getLabelFontSize()
-     * <em>Label Font Size</em>}' attribute. <!-- begin-user-doc --> <!--
-     * end-user-doc -->
+     * The cached value of the '{@link #getLabelFontSizeExpression()
+     * <em>Label Font Size Expression</em>}' attribute. <!-- begin-user-doc -->
+     * <!-- end-user-doc -->
      *
-     * @see #getLabelFontSize()
+     * @see #getLabelFontSizeExpression()
      * @generated
      * @ordered
      */
-    protected int labelFontSize = WidgetStyleImpl.LABEL_FONT_SIZE_EDEFAULT;
+    protected String labelFontSizeExpression = WidgetStyleImpl.LABEL_FONT_SIZE_EXPRESSION_EDEFAULT;
 
     /**
      * The cached value of the '{@link #getLabelBackgroundColor()
@@ -178,8 +178,8 @@ public class WidgetStyleImpl extends MinimalEObjectImpl.Container implements Wid
      * @generated
      */
     @Override
-    public int getLabelFontSize() {
-        return labelFontSize;
+    public String getLabelFontSizeExpression() {
+        return labelFontSizeExpression;
     }
 
     /**
@@ -188,11 +188,11 @@ public class WidgetStyleImpl extends MinimalEObjectImpl.Container implements Wid
      * @generated
      */
     @Override
-    public void setLabelFontSize(int newLabelFontSize) {
-        int oldLabelFontSize = labelFontSize;
-        labelFontSize = newLabelFontSize;
+    public void setLabelFontSizeExpression(String newLabelFontSizeExpression) {
+        String oldLabelFontSizeExpression = labelFontSizeExpression;
+        labelFontSizeExpression = newLabelFontSizeExpression;
         if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE, oldLabelFontSize, labelFontSize));
+            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION, oldLabelFontSizeExpression, labelFontSizeExpression));
         }
     }
 
@@ -303,8 +303,8 @@ public class WidgetStyleImpl extends MinimalEObjectImpl.Container implements Wid
         switch (featureID) {
         case PropertiesPackage.WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION:
             return getLabelFontNameExpression();
-        case PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE:
-            return getLabelFontSize();
+        case PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION:
+            return getLabelFontSizeExpression();
         case PropertiesPackage.WIDGET_STYLE__LABEL_BACKGROUND_COLOR:
             if (resolve) {
                 return getLabelBackgroundColor();
@@ -333,8 +333,8 @@ public class WidgetStyleImpl extends MinimalEObjectImpl.Container implements Wid
         case PropertiesPackage.WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION:
             setLabelFontNameExpression((String) newValue);
             return;
-        case PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE:
-            setLabelFontSize((Integer) newValue);
+        case PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION:
+            setLabelFontSizeExpression((String) newValue);
             return;
         case PropertiesPackage.WIDGET_STYLE__LABEL_BACKGROUND_COLOR:
             setLabelBackgroundColor((ColorDescription) newValue);
@@ -361,8 +361,8 @@ public class WidgetStyleImpl extends MinimalEObjectImpl.Container implements Wid
         case PropertiesPackage.WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION:
             setLabelFontNameExpression(WidgetStyleImpl.LABEL_FONT_NAME_EXPRESSION_EDEFAULT);
             return;
-        case PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE:
-            setLabelFontSize(WidgetStyleImpl.LABEL_FONT_SIZE_EDEFAULT);
+        case PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION:
+            setLabelFontSizeExpression(WidgetStyleImpl.LABEL_FONT_SIZE_EXPRESSION_EDEFAULT);
             return;
         case PropertiesPackage.WIDGET_STYLE__LABEL_BACKGROUND_COLOR:
             setLabelBackgroundColor((ColorDescription) null);
@@ -387,8 +387,8 @@ public class WidgetStyleImpl extends MinimalEObjectImpl.Container implements Wid
         switch (featureID) {
         case PropertiesPackage.WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION:
             return WidgetStyleImpl.LABEL_FONT_NAME_EXPRESSION_EDEFAULT == null ? labelFontNameExpression != null : !WidgetStyleImpl.LABEL_FONT_NAME_EXPRESSION_EDEFAULT.equals(labelFontNameExpression);
-        case PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE:
-            return labelFontSize != WidgetStyleImpl.LABEL_FONT_SIZE_EDEFAULT;
+        case PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION:
+            return WidgetStyleImpl.LABEL_FONT_SIZE_EXPRESSION_EDEFAULT == null ? labelFontSizeExpression != null : !WidgetStyleImpl.LABEL_FONT_SIZE_EXPRESSION_EDEFAULT.equals(labelFontSizeExpression);
         case PropertiesPackage.WIDGET_STYLE__LABEL_BACKGROUND_COLOR:
             return labelBackgroundColor != null;
         case PropertiesPackage.WIDGET_STYLE__LABEL_FOREGROUND_COLOR:
@@ -413,8 +413,8 @@ public class WidgetStyleImpl extends MinimalEObjectImpl.Container implements Wid
         StringBuffer result = new StringBuffer(super.toString());
         result.append(" (labelFontNameExpression: "); //$NON-NLS-1$
         result.append(labelFontNameExpression);
-        result.append(", labelFontSize: "); //$NON-NLS-1$
-        result.append(labelFontSize);
+        result.append(", labelFontSizeExpression: "); //$NON-NLS-1$
+        result.append(labelFontSizeExpression);
         result.append(", labelFontFormat: "); //$NON-NLS-1$
         result.append(labelFontFormat);
         result.append(')');
diff --git a/plugins/org.eclipse.sirius.ui.properties/plugin.xml b/plugins/org.eclipse.sirius.ui.properties/plugin.xml
index 09226deea4..d99e5de794 100644
--- a/plugins/org.eclipse.sirius.ui.properties/plugin.xml
+++ b/plugins/org.eclipse.sirius.ui.properties/plugin.xml
@@ -74,5 +74,9 @@
            class="org.eclipse.sirius.ui.properties.internal.migration.DomainClassExpressionMigrationParticipant"
            kind="VSM">
      </participant>
+     <participant
+           class="org.eclipse.sirius.ui.properties.internal.migration.FontSizeMigrationParticipant"
+           kind="VSM">
+     </participant>
   </extension>
 </plugin>
diff --git a/plugins/org.eclipse.sirius.ui.properties/src/org/eclipse/sirius/ui/properties/internal/migration/FontSizeMigrationParticipant.java b/plugins/org.eclipse.sirius.ui.properties/src/org/eclipse/sirius/ui/properties/internal/migration/FontSizeMigrationParticipant.java
new file mode 100644
index 0000000000..c6d8c7c969
--- /dev/null
+++ b/plugins/org.eclipse.sirius.ui.properties/src/org/eclipse/sirius/ui/properties/internal/migration/FontSizeMigrationParticipant.java
@@ -0,0 +1,85 @@
+/*******************************************************************************
+ * Copyright (c) 2016 Obeo.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Obeo - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.sirius.ui.properties.internal.migration;
+
+import org.eclipse.emf.ecore.EAttribute;
+import org.eclipse.emf.ecore.EClass;
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.emf.ecore.EStructuralFeature;
+import org.eclipse.sirius.business.api.migration.AbstractVSMMigrationParticipant;
+import org.eclipse.sirius.properties.PropertiesPackage;
+import org.osgi.framework.Version;
+
+/**
+ * This migration participant is responsible for the migration of the fontSize
+ * and labelFontSize properties of the widget style, text widget style, label
+ * widget style, hyperlink widget style and group style.
+ * 
+ * @author sbegaudeau
+ */
+public class FontSizeMigrationParticipant extends AbstractVSMMigrationParticipant {
+
+    private static final Version MIGRATION_VERSION = new Version("11.0.0.201609011200"); //$NON-NLS-1$
+
+    /**
+     * The name of the property label font size.
+     */
+    private static final String LABEL_FONT_SIZE = "labelFontSize"; //$NON-NLS-1$
+
+    /**
+     * The name of the property font size.
+     */
+    private static final String FONT_SIZE = "fontSize"; //$NON-NLS-1$
+
+    @Override
+    public Version getMigrationVersion() {
+        return MIGRATION_VERSION;
+    }
+
+    @Override
+    public EStructuralFeature getAttribute(EClass eClass, String name, String loadedVersion) {
+        if (Version.parseVersion(loadedVersion).compareTo(MIGRATION_VERSION) < 0) {
+            EAttribute eAttribute = null;
+
+            if (PropertiesPackage.Literals.WIDGET_STYLE.isSuperTypeOf(eClass) && LABEL_FONT_SIZE.equals(name)) {
+                eAttribute = PropertiesPackage.Literals.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION;
+            } else if (PropertiesPackage.Literals.TEXT_WIDGET_STYLE.equals(eClass) && FONT_SIZE.equals(name)) {
+                eAttribute = PropertiesPackage.Literals.TEXT_WIDGET_STYLE__FONT_SIZE_EXPRESSION;
+            } else if (PropertiesPackage.Literals.LABEL_WIDGET_STYLE.equals(eClass) && FONT_SIZE.equals(name)) {
+                eAttribute = PropertiesPackage.Literals.LABEL_WIDGET_STYLE__FONT_SIZE_EXPRESSION;
+            } else if (PropertiesPackage.Literals.HYPERLINK_WIDGET_STYLE.equals(eClass) && FONT_SIZE.equals(name)) {
+                eAttribute = PropertiesPackage.Literals.HYPERLINK_WIDGET_STYLE__FONT_SIZE_EXPRESSION;
+            } else if (PropertiesPackage.Literals.GROUP_STYLE.equals(eClass) && FONT_SIZE.equals(name)) {
+                eAttribute = PropertiesPackage.Literals.GROUP_STYLE__FONT_SIZE_EXPRESSION;
+            }
+
+            if (eAttribute != null) {
+                return eAttribute;
+            }
+        }
+        return super.getAttribute(eClass, name, loadedVersion);
+    }
+
+    @Override
+    public Object getValue(EObject object, EStructuralFeature feature, Object value, String loadedVersion) {
+        boolean isFontSizeFeature = false;
+        isFontSizeFeature = isFontSizeFeature || PropertiesPackage.Literals.WIDGET_STYLE__LABEL_FONT_SIZE_EXPRESSION.equals(feature);
+        isFontSizeFeature = isFontSizeFeature || PropertiesPackage.Literals.TEXT_WIDGET_STYLE__FONT_SIZE_EXPRESSION.equals(feature);
+        isFontSizeFeature = isFontSizeFeature || PropertiesPackage.Literals.LABEL_WIDGET_STYLE__FONT_SIZE_EXPRESSION.equals(feature);
+        isFontSizeFeature = isFontSizeFeature || PropertiesPackage.Literals.HYPERLINK_WIDGET_STYLE__FONT_SIZE_EXPRESSION.equals(feature);
+        isFontSizeFeature = isFontSizeFeature || PropertiesPackage.Literals.GROUP_STYLE__FONT_SIZE_EXPRESSION.equals(feature);
+
+        if (isFontSizeFeature && value != null) {
+            return value.toString();
+        }
+        return super.getValue(object, feature, value, loadedVersion);
+    }
+}
diff --git a/plugins/org.eclipse.sirius.ui.properties/src/org/eclipse/sirius/ui/properties/internal/tabprovider/GroupStyleDescriptionConverter.java b/plugins/org.eclipse.sirius.ui.properties/src/org/eclipse/sirius/ui/properties/internal/tabprovider/GroupStyleDescriptionConverter.java
index d7ac3a3abe..de1585c998 100644
--- a/plugins/org.eclipse.sirius.ui.properties/src/org/eclipse/sirius/ui/properties/internal/tabprovider/GroupStyleDescriptionConverter.java
+++ b/plugins/org.eclipse.sirius.ui.properties/src/org/eclipse/sirius/ui/properties/internal/tabprovider/GroupStyleDescriptionConverter.java
@@ -56,7 +56,7 @@ public class GroupStyleDescriptionConverter extends AbstractDescriptionConverter
                 }
             }
             eefGroupStyle.setFontNameExpression(groupStyle.getFontNameExpression());
-            eefGroupStyle.setFontSizeExpression(Integer.toString(groupStyle.getFontSize()));
+            eefGroupStyle.setFontSizeExpression(groupStyle.getFontSizeExpression());
             eefGroupStyle.setBarStyle(EEF_TITLE_BAR_STYLE.get(groupStyle.getBarStyle().getValue()));
             eefGroupStyle.setToggleStyle(EEF_TOGGLE_STYLE.get(groupStyle.getToggleStyle().getValue()));
             eefGroupStyle.setExpandedByDefault(groupStyle.isExpandedByDefault());