diff --git a/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/gef/.ratings b/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/gef/.ratings
index 5697540ac6c14cb177229b94761a8447c8c97270..1d34bbdbe5589743708ede5f2b3471f31d496108 100644
--- a/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/gef/.ratings
+++ b/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/gef/.ratings
@@ -1,2 +1,2 @@
-ConnectionCompositionDropTargetListener.java ba861adbef5ca39644386be53826a939be5110a3 RED
-ElementCompositionDropTargetListener.java ab0fd4910f84790d72ec76ad20d87542019ed206 RED
+ConnectionCompositionDropTargetListener.java 502736cffbe766ee4df5fec44e90b6d9d49584a8 YELLOW
+ElementCompositionDropTargetListener.java 1fda888c2229eab3f20ea0d32be27520eeed9519 YELLOW
diff --git a/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/gef/ConnectionCompositionDropTargetListener.java b/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/gef/ConnectionCompositionDropTargetListener.java
index 556c06cd34fd67eefcf5bcaf1e9ecbf4428fb7da..381852ea10180afd9ff43c89cbc91227627e7374 100644
--- a/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/gef/ConnectionCompositionDropTargetListener.java
+++ b/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/gef/ConnectionCompositionDropTargetListener.java
@@ -25,7 +25,6 @@ import org.fortiss.tooling.kernel.service.IConnectionCompositorService;
 import org.fortiss.tooling.kernel.ui.dnd.CompositionServiceLocalDNDTransfer;
 import org.fortiss.tooling.kernel.ui.dnd.ConnectionCompositionSource;
 
-// TODO(SB,6) (x2)
 /**
  * This class implements a drop target listener for {@link EditPartViewer}s,
  * which creates {@link CreateConnectionCompositionRequest}s. The request
@@ -34,13 +33,10 @@ import org.fortiss.tooling.kernel.ui.dnd.ConnectionCompositionSource;
  * which completes the DND operation with the target information. It then relays
  * the completed DND operation to the {@link IConnectionCompositorService}.
  * <p>
- * This class mimics the behavior of the kernel's SWT-based
  * 
- * {@link ConnectionCompositionDropTargetAdapter}, but uses the GEF abstraction
  * {@link AbstractTransferDropTargetListener} super class.
  * 
  * @see RelayCreateCommandEditPolicyBase
- * @see ConnectionCompositionDropTargetAdapter
  * 
  * @author hoelzl
  */
@@ -68,14 +64,12 @@ public class ConnectionCompositionDropTargetListener extends AbstractTransferDro
 		ConnectionCompositionSource sourceData = null;
 		if(getCurrentEvent().data instanceof ConnectionCompositionSource) {
 			sourceData = (ConnectionCompositionSource)getCurrentEvent().data;
-			// TODO(SB,20)
 		} else if(CompositionServiceLocalDNDTransfer.getInstance().getObject() instanceof ConnectionCompositionSource) {
 			// there have been reports about SWT platform inconsistencies:
 			// on OSX getCurrentEvent().data might be null during dragging
 			// while it is not null on other platforms. Therefore, we use this
 			// fallback.
 			sourceData =
-			// TODO(SB,20)
 					(ConnectionCompositionSource)CompositionServiceLocalDNDTransfer.getInstance()
 							.getObject();
 		}
diff --git a/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/gef/ElementCompositionDropTargetListener.java b/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/gef/ElementCompositionDropTargetListener.java
index 5ec27bb544870d3845dfbe5614cdc9e0e0569ef0..cd5f5984a7da89a85f235e7a6b63a915e7f7bd90 100644
--- a/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/gef/ElementCompositionDropTargetListener.java
+++ b/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/gef/ElementCompositionDropTargetListener.java
@@ -25,7 +25,6 @@ import org.fortiss.tooling.kernel.service.IElementCompositorService;
 import org.fortiss.tooling.kernel.ui.dnd.CompositionServiceLocalDNDTransfer;
 import org.fortiss.tooling.kernel.ui.dnd.ElementCompositionSource;
 
-// TODO(SB,6) (x2)
 /**
  * This class implements a drop target listener for {@link EditPartViewer}s,
  * which creates {@link CreateElementCompositionRequest}s. The request contains
@@ -34,16 +33,14 @@ import org.fortiss.tooling.kernel.ui.dnd.ElementCompositionSource;
  * the DND operation with the target information. It then relays the completed
  * DND operation to the {@link IElementCompositorService}.
  * <p>
- * This class mimics the behavior of the kernel's SWT-based // TODO(SB,20)
  * 
- * {@link ElementCompositionDropTargetAdapter}, but uses the GEF abstraction
  * {@link AbstractTransferDropTargetListener} super class.
  * 
  * @see RelayCreateCommandEditPolicyBase
- * @see ElementCompositionDropTargetAdapter
  * 
  * @author hoelzl
  */
+
 public class ElementCompositionDropTargetListener extends AbstractTransferDropTargetListener {
 
 	/** Constructor. */
@@ -67,13 +64,11 @@ public class ElementCompositionDropTargetListener extends AbstractTransferDropTa
 		ElementCompositionSource sourceData = null;
 		if(getCurrentEvent().data instanceof ElementCompositionSource) {
 			sourceData = (ElementCompositionSource)getCurrentEvent().data;
-			// TODO(SB,20)
 		} else if(CompositionServiceLocalDNDTransfer.getInstance().getObject() instanceof ElementCompositionSource) {
 			// there have been reports about SWT platform inconsistencies:
 			// on OSX getCurrentEvent().data might be null during dragging
 			// while it is not null on other platforms. Therefore, we use this
 			// fallback.
-			// TODO(SB,20)
 			sourceData =
 					(ElementCompositionSource)CompositionServiceLocalDNDTransfer.getInstance()
 							.getObject();
diff --git a/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/jface/.ratings b/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/jface/.ratings
index b66c64bb4e660ac115a5965ba137298d05c0a389..22690d6274dc1b4d6eae0be87b2457c213f407e5 100644
--- a/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/jface/.ratings
+++ b/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/jface/.ratings
@@ -1 +1 @@
-ViewerElementCompositionDropAdapter.java 7f3adb61b8e7caba17e501a7260f72853f995606 RED
+ViewerElementCompositionDropAdapter.java 255646545e2c72055c1c090396525f21491f70e4 YELLOW
diff --git a/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/jface/ViewerElementCompositionDropAdapter.java b/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/jface/ViewerElementCompositionDropAdapter.java
index f74e3ceaba8fcd4afc38ab111848b1b025fee0ee..fe78ecb4854495f1fae994ad33dece9edb423650 100644
--- a/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/jface/ViewerElementCompositionDropAdapter.java
+++ b/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/dnd/jface/ViewerElementCompositionDropAdapter.java
@@ -24,24 +24,18 @@ import org.eclipse.jface.viewers.TreeViewer;
 import org.eclipse.jface.viewers.Viewer;
 import org.eclipse.jface.viewers.ViewerDropAdapter;
 import org.eclipse.swt.dnd.DND;
-import org.eclipse.swt.dnd.DropTargetAdapter;
 import org.eclipse.swt.dnd.DropTargetEvent;
 import org.eclipse.swt.dnd.Transfer;
 import org.eclipse.swt.dnd.TransferData;
 import org.fortiss.tooling.kernel.service.IElementCompositorService;
 import org.fortiss.tooling.kernel.ui.dnd.CompositionServiceLocalDNDTransfer;
-import org.fortiss.tooling.kernel.ui.util.DragAndDropUtils;
 
-//TODO(SB,6) (x2)
 /**
- * {@link ViewerDropAdapter} implementation for a JFace {@link TreeViewer}. This
- * implementation mimics the behavior of SWT-based {@link ElementCompositionDropTargetAdapter}, but
- * uses the JFace super class {@link ViewerDropAdapter} instead of SWT's {@link DropTargetAdapter}.
- * 
- * @see ElementCompositionDropTargetAdapter
- * 
+ * {@link ViewerDropAdapter} implementation for a JFace {@link TreeViewer}.
+ *
  * @author hoelzl
  */
+
 public class ViewerElementCompositionDropAdapter extends ViewerDropAdapter {
 
 	/** Remember the last target. */
@@ -77,15 +71,14 @@ public class ViewerElementCompositionDropAdapter extends ViewerDropAdapter {
 	public boolean performDrop(Object data) {
 		if(lastTarget instanceof EObject) {
 			final EObject target = (EObject)lastTarget;
-			// TODO(SB,25)
-			final EObject dropped = DragAndDropUtils.extractDroppedEObject(data);
-			// TODO(SB,20)
-			if(IElementCompositorService.getInstance().canCompose(target, dropped, null)) {
+			final EObject dropped = extractDroppedEObject(data);
+
+			IElementCompositorService instance = IElementCompositorService.getInstance();
+			if(instance.canCompose(target, dropped, null)) {
 				runAsCommand(target, new Runnable() {
 					@Override
 					public void run() {
-						// TODO(SB,20)
-						IElementCompositorService.getInstance().compose(target, dropped, null);
+						instance.compose(target, dropped, null);
 					}
 				});
 				return true;
diff --git a/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/editor/.ratings b/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/editor/.ratings
index cb8b8ff89c1f25ef5f8cb565142482ef03e5f69d..25505d025dfeb99e0dadb33892c120543a1fd521 100644
--- a/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/editor/.ratings
+++ b/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/editor/.ratings
@@ -7,4 +7,4 @@ DiagramKeyHandler.java 9c59eca862c9f878da7cbf7c220f26b38737095c GREEN
 FormsEditorBase.java 50934d36124dea9b16ac45fe3621d878afb48bc7 GREEN
 GEFEditorBase.java 7cc55eaf9c9ffa351b683512832273a4b54a3830 GREEN
 StyledTextCellEditor.java 3e678e4e8dbadb8463201bc62e7a67003acae8a8 GREEN
-TreeViewerEditorBase.java 8cff2f2c65d61d267513a787b76d991dda7ff317 GREEN
+TreeViewerEditorBase.java 5d2f159b59a1785cf118ac95cf4ad99b475efbe2 YELLOW
diff --git a/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/editor/TreeViewerEditorBase.java b/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/editor/TreeViewerEditorBase.java
index 57835acf40be7ffe17989c54743f0ebeadadeace..72c5464f74fc2d4f06bccfcf01ee2684997531e6 100644
--- a/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/editor/TreeViewerEditorBase.java
+++ b/org.fortiss.tooling.base.ui/trunk/src/org/fortiss/tooling/base/ui/editor/TreeViewerEditorBase.java
@@ -38,6 +38,7 @@ import org.fortiss.tooling.kernel.ui.extension.base.EditorBase;
  * 
  * @author hoelzl
  */
+
 public abstract class TreeViewerEditorBase<T extends EObject> extends EditorBase<T> {
 
 	/** Stores the {@link TreeViewer}. */