updated java doc
diff --git a/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/IGaLayoutService.java b/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/IGaLayoutService.java
index 6135a07..91fd0e7 100644
--- a/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/IGaLayoutService.java
+++ b/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/IGaLayoutService.java
@@ -19,6 +19,9 @@
 import org.eclipse.graphiti.mm.pictograms.GraphicsAlgorithm;
 
 /**
+ * The interface IGaLayoutService provides convenient services for the
+ * calculation and change of the size and/or location of graphics algorithm.
+ * This makes it easier to write layout features.
  * 
  * @noimplement This interface is not intended to be implemented by clients.
  * @noextend This interface is not intended to be extended by clients.
@@ -31,8 +34,8 @@
 	 * Otherwise the size of the graphics algorithm is simply returned.
 	 * 
 	 * @param ga
-	 *            GraphicsAlgorithm
-	 * @return the i dimension
+	 *            graphics algorithm
+	 * @return the dimension of the given graphics algorithm
 	 */
 	public IDimension calculateSize(GraphicsAlgorithm ga);
 
@@ -42,102 +45,102 @@
 	 * Otherwise the size of the graphics algorithm is simply returned.
 	 * 
 	 * @param ga
-	 *            GraphicsAlgorithm
+	 *            graphics algorithm
 	 * @param considerLineWidth
-	 *            the consider line width
-	 * @return the i dimension
+	 *            if TRUE, the line width will be considered in the dimension
+	 * @return the dimension of the given graphics algorithm
 	 */
 	public IDimension calculateSize(GraphicsAlgorithm ga, boolean considerLineWidth);
 
 	/**
-	 * Changes the height of the given graphics algorithm.
+	 * Sets the height of the given graphics algorithm.
 	 * 
 	 * @param ga
-	 *            GraphicsAlgorithm
+	 *            graphics algorithm
 	 * @param height
-	 *            the height
+	 *            the new height
 	 */
 	public void setHeight(GraphicsAlgorithm ga, int height);
 
 	/**
-	 * Changes location and size of the given graphics algorithm.
+	 * Sets location and size of the given graphics algorithm.
 	 * 
 	 * @param ga
-	 *            GraphicsAlgorithm
+	 *            graphics algorithm
 	 * @param x
-	 *            the x
+	 *            the new x coordinate
 	 * @param y
-	 *            the y
+	 *            the new y coordinate
 	 * @param width
-	 *            the width
+	 *            the new width
 	 * @param height
-	 *            the height
+	 *            the new height
 	 */
 	public void setLocationAndSize(GraphicsAlgorithm ga, int x, int y, int width, int height);
 
 	/**
-	 * Changes location and size of the given graphics algorithm.
+	 * Sets location and size of the given graphics algorithm.
 	 * 
 	 * @param ga
-	 *            GraphicsAlgorithm
+	 *            graphics algorithm
 	 * @param x
-	 *            the x
+	 *            the new x coordinate
 	 * @param y
-	 *            the y
+	 *            the new y coordinate
 	 * @param width
-	 *            the width
+	 *            the new width
 	 * @param height
-	 *            the height
+	 *            the new height
 	 * @param avoidNegativeCoordinates
-	 *            the avoid negative coordinates
+	 *            if TRUE, a negative coordinate will automatically set to 0.
 	 */
 	public void setLocationAndSize(GraphicsAlgorithm ga, int x, int y, int width, int height, boolean avoidNegativeCoordinates);
 
 	/**
-	 * Changes location of the given graphics algorithm.
+	 * Sets the location of the given graphics algorithm.
 	 * 
 	 * @param ga
-	 *            GraphicsAlgorithm
+	 *            graphics algorithm
 	 * @param x
-	 *            the x
+	 *            the new x coordinate
 	 * @param y
-	 *            the y
+	 *            the new y coordinate
 	 */
 	public void setLocation(GraphicsAlgorithm ga, int x, int y);
 
 	/**
-	 * Changes location of the given graphics algorithm.
+	 * Sets the location of the given graphics algorithm.
 	 * 
 	 * @param ga
-	 *            GraphicsAlgorithm
+	 *            graphics algorithm
 	 * @param x
-	 *            the x
+	 *            the new x coordinate
 	 * @param y
-	 *            the y
+	 *            the new y coordinate
 	 * @param avoidNegativeCoordinates
-	 *            the avoid negative coordinates
+	 *            if TRUE, a negative coordinate will automatically set to 0.
 	 */
 	public void setLocation(GraphicsAlgorithm ga, int x, int y, boolean avoidNegativeCoordinates);
 
 	/**
-	 * Changes the size of the given graphics algorithm.
+	 * Sets the size of the given graphics algorithm.
 	 * 
 	 * @param ga
-	 *            GraphicsAlgorithm
+	 *            graphics algorithm
 	 * @param width
-	 *            the width
+	 *            the new width
 	 * @param height
-	 *            the height
+	 *            the new height
 	 */
 	public void setSize(GraphicsAlgorithm ga, int width, int height);
 
 	/**
-	 * Changes the width of the given graphics algorithm.
+	 * Sets the width of the given graphics algorithm.
 	 * 
 	 * @param ga
-	 *            GraphicsAlgorithm
+	 *            graphics algorithm
 	 * @param width
-	 *            the width
+	 *            the new width
 	 */
 	public void setWidth(GraphicsAlgorithm ga, int width);
 
diff --git a/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/IGaService.java b/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/IGaService.java
index aa94916..f98107e 100644
--- a/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/IGaService.java
+++ b/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/IGaService.java
@@ -32,6 +32,8 @@
 import org.eclipse.graphiti.util.IPredefinedRenderingStyle;
 
 /**
+ * The interface IGaService provides convenient services for the creation and
+ * layout of graphics algorithm.
  * 
  * @noimplement This interface is not intended to be implemented by clients.
  * @noextend This interface is not intended to be extended by clients.
diff --git a/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/ILayoutService.java b/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/ILayoutService.java
index f3fa879..fa962ed 100644
--- a/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/ILayoutService.java
+++ b/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/ILayoutService.java
@@ -16,6 +16,8 @@
 package org.eclipse.graphiti.services;
 
 /**
+ * The interface ILayoutService provides convenient services which are useful
+ * for writing layout features.
  * 
  * @noimplement This interface is not intended to be implemented by clients.
  * @noextend This interface is not intended to be extended by clients.
diff --git a/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/IPeLayoutService.java b/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/IPeLayoutService.java
index ddc376b..92bfd22 100644
--- a/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/IPeLayoutService.java
+++ b/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/IPeLayoutService.java
@@ -23,6 +23,8 @@
 import org.eclipse.graphiti.util.ILocationInfo;
 
 /**
+ * The interface IPeLayoutService provides services (e.g. query location info
+ * for a pictogram element) which makes it easier to write layout features.
  * 
  * @noimplement This interface is not intended to be implemented by clients.
  * @noextend This interface is not intended to be extended by clients.
@@ -33,15 +35,21 @@
 	 * Gets the connection midpoint.
 	 * 
 	 * @param c
-	 *            the c
+	 *            the connection
 	 * @param d
-	 *            the d
+	 *            a relative location on the connection (must be between 0 and
+	 *            1)
 	 * @return the connection midpoint
 	 */
 	ILocation getConnectionMidpoint(Connection c, double d);
 
 	/**
-	 * Returns the bounds of the GA, which is referenced by the anchor.
+	 * Returns the bounds of the graphics algorithm, which is referenced by the
+	 * anchor.
+	 * 
+	 * @param anchor
+	 *            the anchor
+	 * @return the bounds of the anchor graphics algorithm
 	 */
 	IRectangle getGaBoundsForAnchor(Anchor anchor);
 
@@ -53,7 +61,7 @@
 	 * @param shape
 	 *            the shape
 	 * @param x
-	 *            x coorsinate
+	 *            x coordinate
 	 * @param y
 	 *            y coordinate
 	 * @return the location info
diff --git a/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/IPeService.java b/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/IPeService.java
index fe255c3..4d6bfed 100644
--- a/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/IPeService.java
+++ b/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/services/IPeService.java
@@ -32,6 +32,8 @@
 import org.eclipse.graphiti.mm.pictograms.Shape;
 
 /**
+ * The interface IPeService provides convenient services for the creation and
+ * layout of pictogram elements.
  * 
  * @noimplement This interface is not intended to be implemented by clients.
  * @noextend This interface is not intended to be extended by clients.