[458349] Consolidate UI

Task-Url: https://bugs.eclipse.org/bugs/show_bug.cgi?id=458349

14 files changed, 269 insertions, 116 deletions

diff --git a/plugins/org.eclipse.emf.cdo.dawn.gmf/src/org/eclipse/emf/cdo/dawn/gmf/editors/impl/DawnGMFEditorSupport.java b/plugins/org.eclipse.emf.cdo.dawn.gmf/src/org/eclipse/emf/cdo/dawn/gmf/editors/impl/DawnGMFEditorSupport.java
index c79d2dd4ad..993f23c2c5 100644
--- a/plugins/org.eclipse.emf.cdo.dawn.gmf/src/org/eclipse/emf/cdo/dawn/gmf/editors/impl/DawnGMFEditorSupport.java
+++ b/plugins/org.eclipse.emf.cdo.dawn.gmf/src/org/eclipse/emf/cdo/dawn/gmf/editors/impl/DawnGMFEditorSupport.java
@@ -27,6 +27,7 @@ import org.eclipse.emf.cdo.transaction.CDOTransactionHandlerBase;
 import org.eclipse.emf.cdo.util.CDOUtil;
 import org.eclipse.emf.cdo.view.CDOView;
 
+import org.eclipse.emf.common.command.CommandStack;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.transaction.RecordingCommand;
 import org.eclipse.emf.transaction.TransactionalEditingDomain;
@@ -100,7 +101,8 @@ public class DawnGMFEditorSupport extends DawnAbstractEditorSupport
     super.rollback();
     final DiagramDocumentEditor diagramDocumentEditor = getDiagramEditor(getEditor());
     TransactionalEditingDomain editingDomain = diagramDocumentEditor.getEditingDomain();
-    editingDomain.getCommandStack().execute(new RecordingCommand(editingDomain)
+    CommandStack commandStack = editingDomain.getCommandStack();
+    commandStack.execute(new RecordingCommand(editingDomain)
     {
       @Override
       public void doExecute()
@@ -134,7 +136,8 @@ public class DawnGMFEditorSupport extends DawnAbstractEditorSupport
   {
     final DiagramDocumentEditor diagramDocumentEditor = getDiagramEditor(getEditor());
     TransactionalEditingDomain editingDomain = diagramDocumentEditor.getEditingDomain();
-    editingDomain.getCommandStack().execute(new RecordingCommand(editingDomain)
+    CommandStack commandStack = editingDomain.getCommandStack();
+    commandStack.execute(new RecordingCommand(editingDomain)
     {
       @Override
       public void doExecute()
diff --git a/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/ViewerUtil.java b/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/ViewerUtil.java
index db73b369c1..e2d500d98a 100644
--- a/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/ViewerUtil.java
+++ b/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/ViewerUtil.java
@@ -81,7 +81,7 @@ public final class ViewerUtil
 
   public static void refresh(final StructuredViewer viewer, final Object element, boolean async)
   {
-    refresh(viewer, element, true, false);
+    refresh(viewer, element, async, false);
   }
 
   public static void refresh(final StructuredViewer viewer, final Object element, boolean async,
diff --git a/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutContentProvider.java b/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutContentProvider.java
index 36c843ffe0..6d370e5c1c 100644
--- a/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutContentProvider.java
+++ b/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutContentProvider.java
@@ -21,9 +21,8 @@ import org.eclipse.emf.cdo.explorer.CDOExplorerManager;
 import org.eclipse.emf.cdo.explorer.CDOExplorerManager.ElementsChangedEvent;
 import org.eclipse.emf.cdo.explorer.CDOExplorerUtil;
 import org.eclipse.emf.cdo.explorer.checkouts.CDOCheckout;
-import org.eclipse.emf.cdo.explorer.checkouts.CDOCheckout.State;
 import org.eclipse.emf.cdo.explorer.checkouts.CDOCheckoutManager;
-import org.eclipse.emf.cdo.explorer.checkouts.CDOCheckoutManager.CheckoutOpenEvent;
+import org.eclipse.emf.cdo.explorer.checkouts.CDOCheckoutManager.CheckoutStateEvent;
 import org.eclipse.emf.cdo.explorer.ui.ViewerUtil;
 import org.eclipse.emf.cdo.explorer.ui.bundle.OM;
 import org.eclipse.emf.cdo.explorer.ui.checkouts.actions.OpenWithActionProvider;
@@ -43,6 +42,7 @@ import org.eclipse.net4j.util.ui.views.ItemProvider;
 import org.eclipse.emf.common.notify.Adapter;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.EStructuralFeature;
+import org.eclipse.emf.ecore.InternalEObject;
 import org.eclipse.emf.ecore.util.EcoreUtil;
 import org.eclipse.emf.edit.provider.ComposedAdapterFactory;
 import org.eclipse.emf.edit.provider.ITreeItemContentProvider;
@@ -126,24 +126,36 @@ public class CDOCheckoutContentProvider implements ICommonContentProvider, IProp
       {
         viewerRefresh.addNotification(null, true, true);
       }
-      else if (event instanceof CheckoutOpenEvent)
+      else if (event instanceof CheckoutStateEvent)
       {
-        CheckoutOpenEvent e = (CheckoutOpenEvent)event;
+        CheckoutStateEvent e = (CheckoutStateEvent)event;
         CDOCheckout checkout = e.getCheckout();
+        CDOCheckout.State state = e.getNewState();
 
-        if (!e.isOpen())
+        if (state == CDOCheckout.State.Opening)
         {
-          ViewerUtil.expand(viewer, checkout, false);
-        }
-
-        viewerRefresh.addNotification(checkout, true, true);
+          // Trigger hasChildren().
+          ViewerUtil.refresh(viewer, checkout);
 
-        if (e.isOpen())
-        {
+          // Trigger getChildren().
           ViewerUtil.expand(viewer, checkout, true);
         }
+        else
+        {
+          if (state == CDOCheckout.State.Closed)
+          {
+            ViewerUtil.expand(viewer, checkout, false);
+          }
+
+          viewerRefresh.addNotification(checkout, true, true);
+
+          if (state == CDOCheckout.State.Open)
+          {
+            ViewerUtil.expand(viewer, checkout, true);
+          }
 
-        updatePropertySheetPage(checkout);
+          updatePropertySheetPage(checkout);
+        }
       }
       else if (event instanceof CDOExplorerManager.ElementsChangedEvent)
       {
@@ -246,8 +258,6 @@ public class CDOCheckoutContentProvider implements ICommonContentProvider, IProp
 
   private final CDOCheckoutStateManager stateManager = new CDOCheckoutStateManager(this);
 
-  private final Map<CDOCheckout, CDOCheckout> openingCheckouts = new ConcurrentHashMap<CDOCheckout, CDOCheckout>();
-
   private final Map<Object, Object[]> childrenCache = new ConcurrentHashMap<Object, Object[]>();
 
   private String viewerID;
@@ -365,18 +375,20 @@ public class CDOCheckoutContentProvider implements ICommonContentProvider, IProp
       if (object instanceof CDOCheckout)
       {
         CDOCheckout checkout = (CDOCheckout)object;
-        if (!checkout.isOpen())
+        switch (checkout.getState())
         {
-          if (openingCheckouts.get(checkout) != null)
-          {
-            // This must be the ViewerUtil.Pending element.
-            return true;
-          }
-
+        case Closing:
+        case Closed:
           return false;
-        }
 
-        object = checkout.getRootObject();
+        case Opening:
+          // This must be the ViewerUtil.Pending element.
+          return true;
+
+        case Open:
+          object = checkout.getRootObject();
+          break;
+        }
       }
 
       if (object instanceof CDOElement)
@@ -473,18 +485,20 @@ public class CDOCheckoutContentProvider implements ICommonContentProvider, IProp
       if (object instanceof CDOCheckout)
       {
         checkout = (CDOCheckout)object;
-        if (!checkout.isOpen())
-        {
-          openingCheckout = openingCheckouts.remove(checkout);
-          if (openingCheckout == null)
-          {
-            return ViewerUtil.NO_CHILDREN;
-          }
-        }
 
-        if (openingCheckout == null)
+        switch (checkout.getState())
         {
+        case Closing:
+        case Closed:
+          return ViewerUtil.NO_CHILDREN;
+
+        case Opening:
+          openingCheckout = checkout;
+          break;
+
+        case Open:
           object = checkout.getRootObject();
+          break;
         }
       }
 
@@ -545,6 +559,21 @@ public class CDOCheckoutContentProvider implements ICommonContentProvider, IProp
               children = contentProvider.getChildren(finalObject);
             }
 
+            // Adjust possible legacy adapters.
+            for (int i = 0; i < children.length; i++)
+            {
+              Object child = children[i];
+              if (child instanceof InternalCDOObject)
+              {
+                InternalCDOObject cdoObject = (InternalCDOObject)child;
+                InternalEObject instance = cdoObject.cdoInternalInstance();
+                if (instance != cdoObject)
+                {
+                  children[i] = instance;
+                }
+              }
+            }
+
             children = CDOCheckoutContentModifier.Registry.INSTANCE.modifyChildren(finalObject, children);
             childrenCache.put(originalObject, children);
           }
@@ -851,17 +880,27 @@ public class CDOCheckoutContentProvider implements ICommonContentProvider, IProp
         Object element = ssel.getFirstElement();
         if (element instanceof CDOCheckout)
         {
-          CDOCheckout checkout = (CDOCheckout)element;
-          if (checkout.getState() == State.Closed)
+          final CDOCheckout checkout = (CDOCheckout)element;
+          if (checkout.getState() == CDOCheckout.State.Closed)
           {
-            // Mark this checkout as loading.
-            openingCheckouts.put(checkout, checkout);
-
-            // Trigger hasChildren().
-            ViewerUtil.refresh(viewer, checkout);
+            // Simulate CheckoutOpenHandler.
+            new Job("Open " + checkout.getLabel())
+            {
+              @Override
+              protected IStatus run(IProgressMonitor monitor)
+              {
+                try
+                {
+                  checkout.open();
+                }
+                catch (Exception ex)
+                {
+                  OM.LOG.error(ex);
+                }
 
-            // Trigger getChildren().
-            ViewerUtil.expand(viewer, checkout, true);
+                return Status.OK_STATUS;
+              }
+            }.schedule();
           }
         }
         else if (element instanceof CDOResourceNode)
diff --git a/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutEditorOpenerRegistry.java b/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutEditorOpenerRegistry.java
index 6abca20f71..9b7c14ba93 100644
--- a/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutEditorOpenerRegistry.java
+++ b/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutEditorOpenerRegistry.java
@@ -13,6 +13,7 @@ package org.eclipse.emf.cdo.explorer.ui.checkouts;
 import org.eclipse.emf.cdo.explorer.CDOExplorerUtil;
 import org.eclipse.emf.cdo.explorer.checkouts.CDOCheckout;
 import org.eclipse.emf.cdo.explorer.ui.bundle.OM;
+import org.eclipse.emf.cdo.transaction.CDOTransaction;
 import org.eclipse.emf.cdo.ui.CDOEditorUtil;
 import org.eclipse.emf.cdo.util.CDOURIUtil;
 import org.eclipse.emf.cdo.view.CDOView;
@@ -23,6 +24,7 @@ import org.eclipse.net4j.util.container.Container;
 import org.eclipse.net4j.util.om.OMPlatform;
 
 import org.eclipse.emf.common.util.URI;
+import org.eclipse.emf.spi.cdo.CDOMergingConflictResolver;
 
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IConfigurationElement;
@@ -219,6 +221,12 @@ public class CDOCheckoutEditorOpenerRegistry extends Container<CDOCheckoutEditor
       CDOCheckout checkout = CDOExplorerUtil.getCheckout(uri);
       final CDOView view = checkout.openView();
 
+      if (view instanceof CDOTransaction)
+      {
+        CDOTransaction transaction = (CDOTransaction)view;
+        transaction.options().addConflictResolver(new CDOMergingConflictResolver());
+      }
+
       final IEditorPart editor = openEditor(page, view, CDOURIUtil.extractResourcePath(uri));
       page.addPartListener(new IPartListener()
       {
diff --git a/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutState.java b/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutState.java
index 16ad823131..4840a6d2f8 100644
--- a/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutState.java
+++ b/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutState.java
@@ -22,6 +22,7 @@ import org.eclipse.emf.cdo.internal.ui.editor.CDOEditor;
 import org.eclipse.emf.cdo.ui.CDOEditorUtil;
 import org.eclipse.emf.cdo.ui.CDOLabelDecorator;
 import org.eclipse.emf.cdo.ui.CDOTreeExpansionAgent;
+import org.eclipse.emf.cdo.view.CDOView;
 
 import org.eclipse.net4j.util.event.IEvent;
 import org.eclipse.net4j.util.event.IListener;
@@ -76,16 +77,17 @@ public final class CDOCheckoutState
   {
     public void notifyEvent(IEvent event)
     {
-      if (event instanceof CDOCheckoutManager.CheckoutOpenEvent)
+      if (event instanceof CDOCheckoutManager.CheckoutStateEvent)
       {
-        CDOCheckoutManager.CheckoutOpenEvent e = (CDOCheckoutManager.CheckoutOpenEvent)event;
+        CDOCheckoutManager.CheckoutStateEvent e = (CDOCheckoutManager.CheckoutStateEvent)event;
         if (e.getCheckout() == checkout)
         {
-          if (e.isOpen())
+          CDOCheckout.State state = e.getNewState();
+          if (state == CDOCheckout.State.Open)
           {
             initTreeExpansionAgent();
           }
-          else
+          else if (state == CDOCheckout.State.Closed)
           {
             disposeTreeExpansionAgent();
           }
@@ -124,12 +126,26 @@ public final class CDOCheckoutState
     labelProvider = new LabelProvider(adapterFactory, resourceManager);
     labelProvider.addListener(eventBroker);
 
-    if (checkout.isOpen())
+    initTreeExpansionAgent();
+    CDOExplorerUtil.getCheckoutManager().addListener(checkoutManagerListener);
+  }
+
+  void inputChanged(TreeViewer newTreeViewer, Object oldInput, Object newInput)
+  {
+    contentProvider.inputChanged(newTreeViewer, oldInput, newInput);
+
+    if (treeExpansionAgent != null)
     {
-      initTreeExpansionAgent();
+      if (newTreeViewer != treeExpansionAgent.getViewer())
+      {
+        disposeTreeExpansionAgent();
+      }
     }
 
-    CDOExplorerUtil.getCheckoutManager().addListener(checkoutManagerListener);
+    if (newTreeViewer != null)
+    {
+      initTreeExpansionAgent();
+    }
   }
 
   public CDOCheckout getCheckout()
@@ -184,8 +200,18 @@ public final class CDOCheckoutState
 
   private void initTreeExpansionAgent()
   {
-    TreeViewer viewer = stateManager.getMainContentProvider().getViewer();
-    treeExpansionAgent = new CDOTreeExpansionAgent(checkout.getView(), viewer);
+    if (treeExpansionAgent == null)
+    {
+      CDOView view = checkout.getView();
+      if (view != null)
+      {
+        TreeViewer viewer = stateManager.getMainContentProvider().getViewer();
+        if (viewer != null)
+        {
+          treeExpansionAgent = new CDOTreeExpansionAgent(view, viewer);
+        }
+      }
+    }
   }
 
   /**
diff --git a/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutStateManager.java b/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutStateManager.java
index 88ec8c987a..f55718aefc 100644
--- a/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutStateManager.java
+++ b/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/CDOCheckoutStateManager.java
@@ -22,7 +22,6 @@ import org.eclipse.emf.edit.provider.ComposedAdapterFactory;
 import org.eclipse.jface.resource.JFaceResources;
 import org.eclipse.jface.resource.LocalResourceManager;
 import org.eclipse.jface.resource.ResourceManager;
-import org.eclipse.jface.viewers.IContentProvider;
 import org.eclipse.jface.viewers.TreeViewer;
 
 import java.util.HashMap;
@@ -103,8 +102,7 @@ public final class CDOCheckoutStateManager
 
     for (CDOCheckoutState state : getStates())
     {
-      IContentProvider contentProvider = state.getContentProvider();
-      contentProvider.inputChanged(newTreeViewer, oldInput, newInput);
+      state.inputChanged(newTreeViewer, oldInput, newInput);
     }
   }
 
diff --git a/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/wizards/CheckoutBranchPointPage.java b/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/wizards/CheckoutBranchPointPage.java
index e13b3a0daa..49ded02222 100644
--- a/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/wizards/CheckoutBranchPointPage.java
+++ b/plugins/org.eclipse.emf.cdo.explorer.ui/src/org/eclipse/emf/cdo/explorer/ui/checkouts/wizards/CheckoutBranchPointPage.java
@@ -99,7 +99,9 @@ public class CheckoutBranchPointPage extends CheckoutWizardPage
   @Override
   protected void createUI(Composite parent)
   {
-    branchPointComposite = new ComposeBranchPointComposite(parent, true, null)
+    CDOBranchPoint branchPoint = getBranchPoint();
+
+    branchPointComposite = new ComposeBranchPointComposite(parent, true, branchPoint)
     {
       @Override
       protected void timeStampError(String message)
diff --git a/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/explorer/checkouts/CDOCheckoutManager.java b/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/explorer/checkouts/CDOCheckoutManager.java
index b4bb2d3685..8c61877829 100644
--- a/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/explorer/checkouts/CDOCheckoutManager.java
+++ b/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/explorer/checkouts/CDOCheckoutManager.java
@@ -37,12 +37,14 @@ public interface CDOCheckoutManager extends CDOExplorerManager<CDOCheckout>
   /**
    * @author Eike Stepper
    */
-  public interface CheckoutOpenEvent extends IEvent
+  public interface CheckoutStateEvent extends IEvent
   {
     public CDOCheckoutManager getSource();
 
     public CDOCheckout getCheckout();
 
-    public boolean isOpen();
+    public CDOCheckout.State getOldState();
+
+    public CDOCheckout.State getNewState();
   }
 }
diff --git a/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/checkouts/CDOCheckoutImpl.java b/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/checkouts/CDOCheckoutImpl.java
index e282eeb6e4..0b90aa4e53 100644
--- a/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/checkouts/CDOCheckoutImpl.java
+++ b/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/checkouts/CDOCheckoutImpl.java
@@ -45,6 +45,7 @@ import org.eclipse.emf.common.util.URI;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.resource.ResourceSet;
 import org.eclipse.emf.ecore.resource.impl.ResourceSetImpl;
+import org.eclipse.emf.spi.cdo.InternalCDOObject;
 import org.eclipse.emf.spi.cdo.InternalCDOView;
 
 import java.io.File;
@@ -360,58 +361,77 @@ public abstract class CDOCheckoutImpl extends AbstractElement implements CDOChec
 
   public final void open()
   {
-    boolean opened = false;
+    CDOCheckoutManagerImpl manager = getManager();
+    State oldState = null;
+    State newState = null;
 
-    synchronized (this)
+    try
     {
-      if (!isOpen())
+      synchronized (this)
       {
-        try
-        {
-          state = State.Opening;
-
-          prepareOpen();
-          CDOSession session = ((CDORepositoryImpl)repository).openCheckout(this);
+        oldState = state;
 
-          view = openView(session);
-          view.addListener(new LifecycleEventAdapter()
+        if (!isOpen())
+        {
+          try
           {
-            @Override
-            protected void onDeactivated(ILifecycle lifecycle)
+            state = State.Opening;
+            if (manager != null)
             {
-              removeView(view);
-              close();
+              manager.fireCheckoutOpenEvent(this, null, oldState, state);
             }
-          });
 
-          configureView(view);
+            oldState = state;
 
-          rootObject = loadRootObject();
-          rootObject.eAdapters().add(this);
+            prepareOpen();
+            CDOSession session = ((CDORepositoryImpl)repository).openCheckout(this);
 
-          state = State.Open;
-        }
-        catch (RuntimeException ex)
-        {
-          state = State.Closed;
-          throw ex;
-        }
-        catch (Error ex)
-        {
-          state = State.Closed;
-          throw ex;
+            view = openView(session);
+            view.addListener(new LifecycleEventAdapter()
+            {
+              @Override
+              protected void onDeactivated(ILifecycle lifecycle)
+              {
+                removeView(view);
+                if (state != State.Closing)
+                {
+                  close();
+                }
+              }
+            });
+
+            configureView(view);
+
+            rootObject = loadRootObject();
+            rootObject.eAdapters().add(this);
+
+            state = State.Open;
+            newState = state;
+          }
+          catch (RuntimeException ex)
+          {
+            view = null;
+            rootObject = null;
+            state = State.Closed;
+            newState = state;
+            throw ex;
+          }
+          catch (Error ex)
+          {
+            view = null;
+            rootObject = null;
+            state = State.Closed;
+            newState = state;
+            throw ex;
+          }
         }
-
-        opened = true;
       }
     }
-
-    if (opened)
+    finally
     {
-      CDOCheckoutManagerImpl manager = getManager();
-      if (manager != null)
+      if (manager != null && oldState != null && newState != null && newState != oldState)
       {
-        manager.fireCheckoutOpenEvent(this, view, true);
+        manager.fireCheckoutOpenEvent(this, view, oldState, newState);
       }
     }
   }
@@ -467,7 +487,7 @@ public abstract class CDOCheckoutImpl extends AbstractElement implements CDOChec
       CDOCheckoutManagerImpl manager = getManager();
       if (manager != null)
       {
-        manager.fireCheckoutOpenEvent(this, oldView, false);
+        manager.fireCheckoutOpenEvent(this, oldView, State.Open, State.Closed);
       }
     }
   }
@@ -800,7 +820,8 @@ public abstract class CDOCheckoutImpl extends AbstractElement implements CDOChec
       rootID = view.getSession().getRepositoryInfo().getRootResourceID();
     }
 
-    return view.getObject(rootID);
+    InternalCDOObject cdoObject = (InternalCDOObject)view.getObject(rootID);
+    return cdoObject.cdoInternalInstance();
   }
 
   protected abstract CDOView openView(CDOSession session);
diff --git a/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/checkouts/CDOCheckoutManagerImpl.java b/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/checkouts/CDOCheckoutManagerImpl.java
index dcf84a489d..31a176a09b 100644
--- a/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/checkouts/CDOCheckoutManagerImpl.java
+++ b/plugins/org.eclipse.emf.cdo.explorer/src/org/eclipse/emf/cdo/internal/explorer/checkouts/CDOCheckoutManagerImpl.java
@@ -64,18 +64,21 @@ public class CDOCheckoutManagerImpl extends AbstractManager<CDOCheckout>implemen
     return newElement(properties);
   }
 
-  public void fireCheckoutOpenEvent(CDOCheckout checkout, CDOView view, boolean open)
+  public void fireCheckoutOpenEvent(CDOCheckout checkout, CDOView view, CDOCheckout.State oldState,
+      CDOCheckout.State newState)
   {
-    if (open)
+    switch (newState)
     {
+    case Open:
       viewMap.put(view, checkout);
-    }
-    else
-    {
+      break;
+
+    case Closed:
       viewMap.remove(view);
+      break;
     }
 
-    fireEvent(new CheckoutOpenEventImpl(this, checkout, open));
+    fireEvent(new CheckoutStateEventImpl(this, checkout, oldState, newState));
   }
 
   @Override
@@ -127,19 +130,23 @@ public class CDOCheckoutManagerImpl extends AbstractManager<CDOCheckout>implemen
   /**
    * @author Eike Stepper
    */
-  private static final class CheckoutOpenEventImpl extends Event implements CheckoutOpenEvent
+  private static final class CheckoutStateEventImpl extends Event implements CheckoutStateEvent
   {
     private static final long serialVersionUID = 1L;
 
     private final CDOCheckout checkout;
 
-    private final boolean open;
+    private final CDOCheckout.State oldState;
 
-    public CheckoutOpenEventImpl(CDOCheckoutManager repositoryManager, CDOCheckout checkout, boolean open)
+    private final CDOCheckout.State newState;
+
+    public CheckoutStateEventImpl(CDOCheckoutManager repositoryManager, CDOCheckout checkout,
+        CDOCheckout.State oldState, CDOCheckout.State newState)
     {
       super(repositoryManager);
       this.checkout = checkout;
-      this.open = open;
+      this.oldState = oldState;
+      this.newState = newState;
     }
 
     @Override
@@ -153,9 +160,20 @@ public class CDOCheckoutManagerImpl extends AbstractManager<CDOCheckout>implemen
       return checkout;
     }
 
-    public boolean isOpen()
+    public CDOCheckout.State getOldState()
+    {
+      return oldState;
+    }
+
+    public CDOCheckout.State getNewState()
+    {
+      return newState;
+    }
+
+    @Override
+    public String toString()
     {
-      return open;
+      return "CDOCheckoutState[" + checkout + ", " + oldState + " --> " + newState + "]";
     }
   }
 }
diff --git a/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/views/CDOTimeMachineView.java b/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/views/CDOTimeMachineView.java
index f07fd6a7e1..97d937c6ac 100644
--- a/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/views/CDOTimeMachineView.java
+++ b/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/internal/ui/views/CDOTimeMachineView.java
@@ -71,10 +71,7 @@ public class CDOTimeMachineView extends ViewPart implements ISelectionListener
   public void selectionChanged(IWorkbenchPart part, ISelection selection)
   {
     CDOView view = getView(selection);
-    if (view != null)
-    {
-      timeSlider.connect(view, null);
-    }
+    timeSlider.connect(view, null);
   }
 
   private CDOView getView(ISelection selection)
diff --git a/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/ui/CDOTreeExpansionAgent.java b/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/ui/CDOTreeExpansionAgent.java
index 657d6e8894..ed28b07434 100644
--- a/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/ui/CDOTreeExpansionAgent.java
+++ b/plugins/org.eclipse.emf.cdo.ui/src/org/eclipse/emf/cdo/ui/CDOTreeExpansionAgent.java
@@ -80,6 +80,16 @@ public class CDOTreeExpansionAgent
     }
   }
 
+  public final CDOView getView()
+  {
+    return view;
+  }
+
+  public final TreeViewer getViewer()
+  {
+    return viewer;
+  }
+
   public void setExpandedStates()
   {
     for (CDOID id : expandedIDs)
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/CDOElement.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/CDOElement.java
index e1b7a41fe2..57ba6b46c1 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/CDOElement.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/CDOElement.java
@@ -23,6 +23,7 @@ import org.eclipse.emf.common.util.EList;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.resource.Resource;
 import org.eclipse.emf.ecore.util.EcoreUtil;
+import org.eclipse.emf.spi.cdo.InternalCDOObject;
 
 import org.eclipse.core.runtime.IAdaptable;
 
@@ -45,7 +46,7 @@ public class CDOElement extends AdapterImpl implements IAdaptable
 
   public CDOElement(EObject delegate)
   {
-    this.delegate = delegate;
+    this.delegate = (EObject)getInstance(delegate);
   }
 
   public Object getDelegate()
@@ -70,6 +71,8 @@ public class CDOElement extends AdapterImpl implements IAdaptable
 
   public void addChild(Object child)
   {
+    child = getInstance(child);
+
     EList<Adapter> adapters = removeFrom(child);
     if (adapters != null)
     {
@@ -203,6 +206,17 @@ public class CDOElement extends AdapterImpl implements IAdaptable
     }
   }
 
+  private static Object getInstance(Object object)
+  {
+    if (object instanceof InternalCDOObject)
+    {
+      InternalCDOObject cdoObject = (InternalCDOObject)object;
+      object = cdoObject.cdoInternalInstance();
+    }
+
+    return object;
+  }
+
   /**
    * @author Eike Stepper
    * @since 4.4
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/CDOChangeSubscriptionAdapter.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/CDOChangeSubscriptionAdapter.java
index bd948d358a..bf22260635 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/CDOChangeSubscriptionAdapter.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/spi/cdo/CDOChangeSubscriptionAdapter.java
@@ -16,6 +16,7 @@ import org.eclipse.emf.cdo.view.CDOView;
 
 import org.eclipse.emf.common.notify.Adapter;
 import org.eclipse.emf.common.notify.impl.AdapterImpl;
+import org.eclipse.emf.common.util.EList;
 import org.eclipse.emf.ecore.EObject;
 
 import java.util.HashSet;
@@ -78,7 +79,21 @@ public class CDOChangeSubscriptionAdapter extends AdapterImpl
   {
     for (CDOObject notifier : notifiers)
     {
-      notifier.eAdapters().remove(this);
+      try
+      {
+        if (notifier != null)
+        {
+          EList<Adapter> adapters = notifier.eAdapters();
+          if (adapters != null)
+          {
+            adapters.remove(this);
+          }
+        }
+      }
+      catch (Exception ex)
+      {
+        //$FALL-THROUGH$
+      }
     }
 
     notifiers.clear();