Bug 521958 - Added generic debug hover

And contribute it to Generic Editor

Signed-off-by: Mickael Istria <mistria@redhat.com>
Change-Id: Ic7cfd1e231b117a2837e543f6dbb535594179662

4 files changed, 611 insertions, 1 deletions

diff --git a/org.eclipse.debug.ui/META-INF/MANIFEST.MF b/org.eclipse.debug.ui/META-INF/MANIFEST.MF
index 96a9a5ea2..0a33f8db5 100644
--- a/org.eclipse.debug.ui/META-INF/MANIFEST.MF
+++ b/org.eclipse.debug.ui/META-INF/MANIFEST.MF
@@ -87,7 +87,8 @@ Require-Bundle: org.eclipse.core.expressions;bundle-version="[3.4.0,4.0.0)",
  org.eclipse.ui.editors;bundle-version="[3.5.0,4.0.0)",
  org.eclipse.core.runtime;bundle-version="[3.11.0,4.0.0)",
  org.eclipse.core.filesystem;bundle-version="[1.2.0,2.0.0)",
- org.eclipse.core.resources;bundle-version="[3.5.0,4.0.0)"
+ org.eclipse.core.resources;bundle-version="[3.5.0,4.0.0)",
+ org.eclipse.ui.genericeditor;bundle-version="1.1.0";resolution:=optional
 Bundle-ActivationPolicy: lazy
 Bundle-ClassPath: .
 Import-Package: com.ibm.icu.text,
diff --git a/org.eclipse.debug.ui/plugin.xml b/org.eclipse.debug.ui/plugin.xml
index 462029b25..4fa4d6646 100644
--- a/org.eclipse.debug.ui/plugin.xml
+++ b/org.eclipse.debug.ui/plugin.xml
@@ -3277,4 +3277,11 @@ M4 = Platform-specific fourth key
             description="%GroupLaunch.description">
       </launchConfigurationTabGroup>
    </extension>
+   <extension
+         point="org.eclipse.ui.genericeditor.hoverProviders">
+      <hoverProvider
+            class="org.eclipse.debug.internal.ui.hover.DebugTextHover"
+            contentType="org.eclipse.core.runtime.text">
+      </hoverProvider>
+   </extension>
 </plugin>
diff --git a/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/hover/DebugTextHover.java b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/hover/DebugTextHover.java
new file mode 100644
index 000000000..cd9d44217
--- /dev/null
+++ b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/hover/DebugTextHover.java
@@ -0,0 +1,131 @@
+package org.eclipse.debug.internal.ui.hover;
+
+import org.eclipse.core.runtime.Adapters;
+import org.eclipse.debug.core.DebugException;
+import org.eclipse.debug.core.model.IVariable;
+import org.eclipse.debug.internal.ui.DebugUIPlugin;
+import org.eclipse.jface.preference.IPreferenceStore;
+import org.eclipse.jface.text.BadLocationException;
+import org.eclipse.jface.text.IDocument;
+import org.eclipse.jface.text.IInformationControlCreator;
+import org.eclipse.jface.text.IRegion;
+import org.eclipse.jface.text.ITextHover;
+import org.eclipse.jface.text.ITextHoverExtension;
+import org.eclipse.jface.text.ITextHoverExtension2;
+import org.eclipse.jface.text.ITextViewer;
+import org.eclipse.jface.text.Region;
+import org.eclipse.jface.text.TextSelection;
+
+
+public class DebugTextHover implements ITextHover, ITextHoverExtension, ITextHoverExtension2 {
+
+	@Override
+	public IRegion getHoverRegion(ITextViewer textViewer, int offset) {
+		IVariable variable = getHoverInfo2(textViewer, new Region(offset, 0));
+		if (variable == null) {
+			return null;
+		}
+		// assumes variable.getName() is the name of the variable as used in the document
+		try {
+			IDocument document = textViewer.getDocument();
+			for (int prefix = Math.min(offset, variable.getName().length()); prefix >= 0 && document.getLength() > offset - prefix + variable.getName().length() ; prefix--) {
+				if (textViewer.getDocument().get(offset - prefix, variable.getName().length()).equals(variable.getName())) {
+					return new Region(offset - prefix, variable.getName().length());
+				}
+			}
+		} catch (DebugException | BadLocationException ex) {
+			DebugUIPlugin.log(ex);
+		}
+		return null;
+	}
+
+
+	@Override
+	public String getHoverInfo(ITextViewer textViewer, IRegion hoverRegion) {
+		if (textViewer == null || hoverRegion == null) {
+			return null;
+		}
+		Object object = getHoverInfo2(textViewer, hoverRegion);
+		if (object instanceof IVariable) {
+			IVariable var = (IVariable) object;
+			return getVariableText(var);
+		}
+		return null;
+	}
+
+	/**
+	 * Returns HTML text for the given variable
+	 */
+	private static String getVariableText(IVariable variable) {
+		try {
+			return replaceHTMLChars(variable.getValue().getValueString()) + "<br/>" + replaceHTMLChars(variable.getReferenceTypeName()); //$NON-NLS-1$
+		} catch (DebugException e) {
+			DebugUIPlugin.log(e);
+			return null;
+		}
+	}
+
+	/**
+	 * Replaces reserved HTML characters in the given string with
+	 * their escaped equivalents. This is to ensure that variable
+	 * values containing reserved characters are correctly displayed.
+     */
+    private static String replaceHTMLChars(String variableText) {
+        StringBuffer buffer= new StringBuffer(variableText.length());
+        char[] characters = variableText.toCharArray();
+        for (int i = 0; i < characters.length; i++) {
+            char character= characters[i];
+            switch (character) {
+            	case '<':
+            	    buffer.append("&lt;"); //$NON-NLS-1$
+            	    break;
+            	case '>':
+            	    buffer.append("&gt;"); //$NON-NLS-1$
+            	    break;
+            	case '&':
+            	    buffer.append("&amp;"); //$NON-NLS-1$
+            	    break;
+            	case '"':
+            	    buffer.append("&quot;"); //$NON-NLS-1$
+            	    break;
+            	default:
+            	    buffer.append(character);
+            }
+        }
+        return buffer.toString();
+    }
+
+	   /**
+     * Returns the value of this filters preference (on/off) for the given
+     * view.
+     *
+     * @param part
+     * @return boolean
+     */
+    public static boolean getBooleanPreferenceValue(String id, String preference) {
+        String compositeKey = id + "." + preference; //$NON-NLS-1$
+		IPreferenceStore store = DebugUIPlugin.getDefault().getPreferenceStore();
+        boolean value = false;
+        if (store.contains(compositeKey)) {
+            value = store.getBoolean(compositeKey);
+        } else {
+            value = store.getBoolean(preference);
+        }
+        return value;
+    }
+
+	@Override
+	public IInformationControlCreator getHoverControlCreator() {
+		return new ExpressionInformationControlCreator();
+	}
+
+	@Override
+	public IVariable getHoverInfo2(ITextViewer textViewer, IRegion hoverRegion) {
+		if (textViewer == null || hoverRegion == null) {
+			return null;
+		}
+		TextSelection sel = new TextSelection(textViewer.getDocument(), hoverRegion.getOffset(), hoverRegion.getLength());
+		return Adapters.adapt(sel, IVariable.class);
+	}
+
+}
diff --git a/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/hover/ExpressionInformationControlCreator.java b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/hover/ExpressionInformationControlCreator.java
new file mode 100644
index 000000000..980925a44
--- /dev/null
+++ b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/hover/ExpressionInformationControlCreator.java
@@ -0,0 +1,471 @@
+package org.eclipse.debug.internal.ui.hover;
+
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.debug.core.model.IVariable;
+import org.eclipse.debug.internal.ui.DebugUIPlugin;
+import org.eclipse.debug.internal.ui.SWTFactory;
+import org.eclipse.debug.internal.ui.model.elements.ElementContentProvider;
+import org.eclipse.debug.internal.ui.viewers.model.provisional.IChildrenUpdate;
+import org.eclipse.debug.internal.ui.viewers.model.provisional.IPresentationContext;
+import org.eclipse.debug.internal.ui.viewers.model.provisional.IViewerUpdate;
+import org.eclipse.debug.internal.ui.viewers.model.provisional.IViewerUpdateListener;
+import org.eclipse.debug.internal.ui.viewers.model.provisional.PresentationContext;
+import org.eclipse.debug.internal.ui.viewers.model.provisional.TreeModelViewer;
+import org.eclipse.debug.internal.ui.views.variables.details.DefaultDetailPane;
+import org.eclipse.debug.internal.ui.views.variables.details.DetailPaneProxy;
+import org.eclipse.debug.internal.ui.views.variables.details.IDetailPaneContainer;
+import org.eclipse.debug.ui.AbstractDebugView;
+import org.eclipse.debug.ui.IDebugUIConstants;
+import org.eclipse.jface.dialogs.IDialogSettings;
+import org.eclipse.jface.text.AbstractInformationControl;
+import org.eclipse.jface.text.IInformationControl;
+import org.eclipse.jface.text.IInformationControlCreator;
+import org.eclipse.jface.text.IInformationControlExtension2;
+import org.eclipse.jface.viewers.IStructuredSelection;
+import org.eclipse.jface.viewers.StructuredViewer;
+import org.eclipse.jface.viewers.TreePath;
+import org.eclipse.jface.viewers.TreeSelection;
+import org.eclipse.jface.viewers.ViewerFilter;
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.custom.SashForm;
+import org.eclipse.swt.events.SelectionEvent;
+import org.eclipse.swt.events.SelectionListener;
+import org.eclipse.swt.graphics.Color;
+import org.eclipse.swt.graphics.Point;
+import org.eclipse.swt.layout.GridData;
+import org.eclipse.swt.layout.GridLayout;
+import org.eclipse.swt.widgets.Composite;
+import org.eclipse.swt.widgets.Layout;
+import org.eclipse.swt.widgets.Shell;
+import org.eclipse.swt.widgets.Tree;
+import org.eclipse.ui.IWorkbenchPage;
+import org.eclipse.ui.IWorkbenchPartSite;
+import org.eclipse.ui.PlatformUI;
+
+/**
+ * Creates an information control to display an expression in a hover control.
+ *
+ * @noextend This class is not intended to be subclassed by clients.
+ *
+ * @since 3.3
+ */
+public class ExpressionInformationControlCreator implements IInformationControlCreator {
+
+	class ExpressionInformationControl extends AbstractInformationControl implements IInformationControlExtension2 {
+
+		/**
+		 * Dialog setting key for height
+		 */
+		private static final String HEIGHT = "HEIGHT"; //$NON-NLS-1$
+
+		/**
+		 * Dialog setting key for width.
+		 */
+		private static final String WIDTH = "WIDTH"; //$NON-NLS-1$
+
+		/**
+		 * Dialog setting key for tree sash weight
+		 */
+		private static final String SASH_WEIGHT_TREE = "SashWeightTree"; //$NON-NLS-1$
+
+		/**
+		 * Dialog setting key for details sash weight
+		 */
+		private static final String SASH_WEIGHT_DETAILS = "SashWeightDetails"; //$NON-NLS-1$
+
+		/**
+		 * Variable to display.
+		 */
+		private IVariable fVariable;
+
+		private IPresentationContext fContext;
+	    private TreeModelViewer fViewer;
+	    private SashForm fSashForm;
+	    private Composite fDetailPaneComposite;
+	    private DetailPaneProxy fDetailPane;
+	    private Tree fTree;
+
+		/**
+	     * Creates the content for the root element of the tree viewer in the hover
+	     */
+	    private class TreeRoot extends ElementContentProvider {
+			/* (non-Javadoc)
+			 * @see org.eclipse.debug.internal.ui.viewers.model.provisional.elements.ElementContentProvider#getChildCount(java.lang.Object, org.eclipse.debug.internal.ui.viewers.provisional.IPresentationContext)
+			 */
+			@Override
+			protected int getChildCount(Object element, IPresentationContext context, IViewerUpdate monitor) throws CoreException {
+				return 1;
+			}
+			/* (non-Javadoc)
+			 * @see org.eclipse.debug.internal.ui.viewers.model.provisional.elements.ElementContentProvider#getChildren(java.lang.Object, int, int, org.eclipse.debug.internal.ui.viewers.provisional.IPresentationContext)
+			 */
+			@Override
+			protected Object[] getChildren(Object parent, int index, int length, IPresentationContext context, IViewerUpdate monitor) throws CoreException {
+				return new Object[] { fVariable };
+			}
+
+			/* (non-Javadoc)
+			 * @see org.eclipse.debug.internal.ui.viewers.model.provisional.elements.ElementContentProvider#supportsContextId(java.lang.String)
+			 */
+			@Override
+			protected boolean supportsContextId(String id) {
+				return true;
+			}
+	    }
+
+		/**
+		 * Inner class implementing IDetailPaneContainer methods.  Handles changes to detail
+		 * pane and provides limited access to the detail pane proxy.
+		 */
+		private class DetailPaneContainer implements IDetailPaneContainer{
+
+			/* (non-Javadoc)
+			 * @see org.eclipse.debug.internal.ui.views.variables.details.IDetailPaneContainer#getCurrentPaneID()
+			 */
+			@Override
+			public String getCurrentPaneID() {
+				return fDetailPane.getCurrentPaneID();
+			}
+
+			/* (non-Javadoc)
+			 * @see org.eclipse.debug.internal.ui.views.variables.details.IDetailPaneContainer#getCurrentSelection()
+			 */
+			@Override
+			public IStructuredSelection getCurrentSelection() {
+				return (IStructuredSelection)fViewer.getSelection();
+			}
+
+			/* (non-Javadoc)
+			 * @see org.eclipse.debug.internal.ui.views.variables.details.IDetailPaneContainer#refreshDetailPaneContents()
+			 */
+			@Override
+			public void refreshDetailPaneContents() {
+				fDetailPane.display(getCurrentSelection());
+			}
+
+			/* (non-Javadoc)
+			 * @see org.eclipse.debug.internal.ui.views.variables.details.IDetailPaneContainer#getParentComposite()
+			 */
+			@Override
+			public Composite getParentComposite() {
+				return fDetailPaneComposite;
+			}
+
+			/* (non-Javadoc)
+			 * @see org.eclipse.debug.internal.ui.views.variables.details.IDetailPaneContainer#getWorkbenchPartSite()
+			 */
+			@Override
+			public IWorkbenchPartSite getWorkbenchPartSite() {
+				return null;
+			}
+
+			/* (non-Javadoc)
+			 * @see org.eclipse.debug.internal.ui.views.variables.details.IDetailPaneContainer#paneChanged(java.lang.String)
+			 */
+			@Override
+			public void paneChanged(String newPaneID) {
+				if (newPaneID.equals(DefaultDetailPane.ID)){
+					fDetailPane.getCurrentControl().setForeground(getShell().getDisplay().getSystemColor(SWT.COLOR_INFO_FOREGROUND));
+					fDetailPane.getCurrentControl().setBackground(getShell().getDisplay().getSystemColor(SWT.COLOR_INFO_BACKGROUND));
+				}
+			}
+
+		}
+
+		/**
+		 * Constructs a new control in the given shell.
+		 *
+		 * @param parentShell shell
+		 * @param resize whether resize is supported
+		 */
+		ExpressionInformationControl(Shell parentShell, boolean resize) {
+			super(parentShell, resize);
+			create();
+		}
+
+		/* (non-Javadoc)
+		 * @see org.eclipse.jface.text.AbstractInformationControl#computeSizeHint()
+		 */
+		@Override
+		public Point computeSizeHint() {
+			IDialogSettings settings = getDialogSettings(false);
+			if (settings != null) {
+				int x = getIntSetting(settings, WIDTH);
+				if (x > 0) {
+					int y = getIntSetting(settings, HEIGHT);
+					if (y > 0) {
+						return new Point(x,y);
+					}
+				}
+			}
+			return super.computeSizeHint();
+		}
+
+		/**
+		 * Returns the dialog settings for this hover or <code>null</code> if none
+		 *
+		 * @param create whether to create the settings
+		 */
+		private IDialogSettings getDialogSettings(boolean create) {
+			IDialogSettings settings = DebugUIPlugin.getDefault().getDialogSettings();
+			IDialogSettings section = settings.getSection(this.getClass().getName());
+			if (section == null & create) {
+				section = settings.addNewSection(this.getClass().getName());
+			}
+			return section;
+		}
+
+		/**
+		 * Returns an integer value in the given dialog settings or -1 if none.
+		 *
+		 * @param settings dialog settings
+		 * @param key key
+		 * @return value or -1 if not present
+		 */
+		private int getIntSetting(IDialogSettings settings, String key) {
+			try {
+				return settings.getInt(key);
+			} catch (NumberFormatException e) {
+				return -1;
+			}
+		}
+
+		/* (non-Javadoc)
+		 * @see org.eclipse.jface.text.AbstractInformationControl#dispose()
+		 */
+		@Override
+		public void dispose() {
+			persistSettings(getShell());
+            fContext.dispose();
+			super.dispose();
+		}
+
+		/**
+		 * Persists dialog settings.
+		 *
+		 * @param shell
+		 */
+		private void persistSettings(Shell shell) {
+			if (shell != null && !shell.isDisposed()) {
+				if (isResizable()) {
+					IDialogSettings settings = getDialogSettings(true);
+					Point size = shell.getSize();
+					settings.put(WIDTH, size.x);
+					settings.put(HEIGHT, size.y);
+					int[] weights = fSashForm.getWeights();
+					settings.put(SASH_WEIGHT_TREE, weights[0]);
+					settings.put(SASH_WEIGHT_DETAILS, weights[1]);
+				}
+			}
+		}
+
+		/* (non-Javadoc)
+		 * @see org.eclipse.jface.text.AbstractInformationControl#setVisible(boolean)
+		 */
+		@Override
+		public void setVisible(boolean visible) {
+			if (!visible) {
+				persistSettings(getShell());
+			}
+			super.setVisible(visible);
+		}
+
+		/* (non-Javadoc)
+		 * @see org.eclipse.jface.text.AbstractInformationControl#createContent(org.eclipse.swt.widgets.Composite)
+		 */
+		@Override
+		protected void createContent(Composite parent) {
+
+	        fSashForm = new SashForm(parent, parent.getStyle());
+	        fSashForm.setOrientation(SWT.VERTICAL);
+
+		    // update presentation context
+	        AbstractDebugView view = getViewToEmulate();
+	        fContext = new PresentationContext(IDebugUIConstants.ID_VARIABLE_VIEW);
+	        if (view != null) {
+	        	// copy over properties
+	        	IPresentationContext copy = ((TreeModelViewer)view.getViewer()).getPresentationContext();
+	        	String[] properties = copy.getProperties();
+	        	for (int i = 0; i < properties.length; i++) {
+					String key = properties[i];
+					fContext.setProperty(key, copy.getProperty(key));
+				}
+	        }
+
+	        fViewer = new TreeModelViewer(fSashForm, SWT.NO_TRIM | SWT.MULTI | SWT.VIRTUAL, fContext);
+	        fViewer.setAutoExpandLevel(1);
+
+	        if (view != null) {
+	        	// copy over filters
+	        	StructuredViewer structuredViewer = (StructuredViewer) view.getViewer();
+	            if (structuredViewer != null) {
+	                ViewerFilter[] filters = structuredViewer.getFilters();
+	                for (int i = 0; i < filters.length; i++) {
+	                    fViewer.addFilter(filters[i]);
+	                }
+	            }
+	        }
+
+	        fDetailPaneComposite = SWTFactory.createComposite(fSashForm, 1, 1, GridData.FILL_BOTH);
+	        Layout layout = fDetailPaneComposite.getLayout();
+	        if (layout instanceof GridLayout) {
+				GridLayout gl = (GridLayout) layout;
+				gl.marginHeight = 0;
+				gl.marginWidth = 0;
+			}
+
+	        fDetailPane = new DetailPaneProxy(new DetailPaneContainer());
+	        fDetailPane.display(null); // Bring up the default pane so the user doesn't see an empty composite
+
+	        fTree = fViewer.getTree();
+	        fTree.addSelectionListener(new SelectionListener() {
+	            @Override
+				public void widgetSelected(SelectionEvent e) {
+	            	fDetailPane.display((IStructuredSelection)fViewer.getSelection());
+	            }
+	            @Override
+				public void widgetDefaultSelected(SelectionEvent e) {}
+	        });
+
+	        initSashWeights();
+
+	        // add update listener to auto-select and display details of root expression
+	        fViewer.addViewerUpdateListener(new IViewerUpdateListener() {
+				@Override
+				public void viewerUpdatesComplete() {
+				}
+				@Override
+				public void viewerUpdatesBegin() {
+				}
+				@Override
+				public void updateStarted(IViewerUpdate update) {
+				}
+				@Override
+				public void updateComplete(IViewerUpdate update) {
+					if (update instanceof IChildrenUpdate) {
+						TreeSelection selection = new TreeSelection(new TreePath(new Object[]{fVariable}));
+						fViewer.setSelection(selection);
+						fDetailPane.display(selection);
+						fViewer.removeViewerUpdateListener(this);
+					}
+				}
+			});
+
+	        setForegroundColor(getShell().getDisplay().getSystemColor(SWT.COLOR_INFO_FOREGROUND));
+	        setBackgroundColor(getShell().getDisplay().getSystemColor(SWT.COLOR_INFO_BACKGROUND));
+		}
+
+
+		/**
+	     * Attempts to find an appropriate view to emulate, this will either be the
+	     * variables view or the expressions view.
+	     * @return a view to emulate or <code>null</code>
+	     */
+	    private AbstractDebugView getViewToEmulate() {
+			IWorkbenchPage page = PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage();
+	        AbstractDebugView expressionsView = (AbstractDebugView) page.findView(IDebugUIConstants.ID_EXPRESSION_VIEW);
+	        if (expressionsView != null && expressionsView.isVisible()) {
+	            return expressionsView;
+	        }
+	        AbstractDebugView variablesView = (AbstractDebugView) page.findView(IDebugUIConstants.ID_VARIABLE_VIEW);
+	        if (variablesView != null && variablesView.isVisible()) {
+	            return variablesView;
+	        }
+	        if (expressionsView != null) {
+	            return expressionsView;
+	        }
+	        return variablesView;
+	    }
+
+		/**
+	     * Initializes the sash form weights from the preference store (using default values if
+	     * no sash weights were stored previously).
+	     */
+	    protected void initSashWeights(){
+	    	IDialogSettings settings = getDialogSettings(false);
+	    	if (settings != null) {
+		    	int tree = getIntSetting(settings, SASH_WEIGHT_TREE);
+		    	if (tree > 0) {
+		    		int details = getIntSetting(settings, SASH_WEIGHT_DETAILS);
+		    		if (details > 0) {
+		    			fSashForm.setWeights(new int[]{tree, details});
+		    		}
+		    	}
+	    	}
+	    }
+
+	    /* (non-Javadoc)
+	     * @see org.eclipse.jface.text.AbstractInformationControl#setForegroundColor(org.eclipse.swt.graphics.Color)
+	     */
+	    @Override
+	    public void setForegroundColor(Color foreground) {
+	    	super.setForegroundColor(foreground);
+	    	fDetailPaneComposite.setForeground(foreground);
+	    	fTree.setForeground(foreground);
+	    }
+
+		/* (non-Javadoc)
+		 * @see org.eclipse.jface.text.AbstractInformationControl#setBackgroundColor(org.eclipse.swt.graphics.Color)
+		 */
+		@Override
+		public void setBackgroundColor(Color background) {
+			super.setBackgroundColor(background);
+			fDetailPaneComposite.setBackground(background);
+			fTree.setBackground(background);
+		}
+
+		/* (non-Javadoc)
+		 * @see org.eclipse.jface.text.AbstractInformationControl#setFocus()
+		 */
+		@Override
+		public void setFocus() {
+			super.setFocus();
+			fTree.setFocus();
+		}
+
+		/* (non-Javadoc)
+		 * @see org.eclipse.jface.text.IInformationControlExtension#hasContents()
+		 */
+		@Override
+		public boolean hasContents() {
+			return fVariable != null;
+		}
+
+		/* (non-Javadoc)
+		 * @see org.eclipse.jface.text.IInformationControlExtension2#setInput(java.lang.Object)
+		 */
+		@Override
+		public void setInput(Object input) {
+			if (input instanceof IVariable) {
+				fVariable = (IVariable) input;
+		        fViewer.setInput(new TreeRoot());
+			}
+		}
+
+		/* (non-Javadoc)
+		 * @see org.eclipse.jface.text.AbstractInformationControl#getInformationPresenterControlCreator()
+		 */
+		@Override
+		public IInformationControlCreator getInformationPresenterControlCreator() {
+			return new ExpressionInformationControlCreator() {
+				/* (non-Javadoc)
+				 * @see org.eclipse.jdt.internal.debug.ui.ExpressionInformationControlCreator#createInformationControl(org.eclipse.swt.widgets.Shell)
+				 */
+				@Override
+				public IInformationControl createInformationControl(Shell shell) {
+					return new ExpressionInformationControl(shell, true);
+				}
+			};
+		}
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.jface.text.IInformationControlCreator#createInformationControl(org.eclipse.swt.widgets.Shell)
+	 */
+	@Override
+	public IInformationControl createInformationControl(Shell parent) {
+		return new ExpressionInformationControl(parent, false);
+	}
+
+
+}