1 files changed, 80 insertions, 0 deletions
diff --git a/plugins/org.eclipse.emf.cdo.ui.compare/src/org/eclipse/emf/cdo/ui/internal/compare/CompareWithPreviousVersionAction.java b/plugins/org.eclipse.emf.cdo.ui.compare/src/org/eclipse/emf/cdo/ui/internal/compare/CompareWithPreviousVersionAction.java
new file mode 100644
index 0000000000..055e01a9d0
--- /dev/null
+++ b/plugins/org.eclipse.emf.cdo.ui.compare/src/org/eclipse/emf/cdo/ui/internal/compare/CompareWithPreviousVersionAction.java
@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2004 - 2012 Eike Stepper (Berlin, Germany) and others.
+ * 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:
+ *    Eike Stepper - initial API and implementation
+ */
+package org.eclipse.emf.cdo.ui.internal.compare;
+
+import org.eclipse.emf.cdo.common.commit.CDOCommitInfo;
+import org.eclipse.emf.cdo.ui.compare.CDOCompareEditorUtil;
+
+import org.eclipse.core.runtime.IAdaptable;
+import org.eclipse.jface.action.IAction;
+import org.eclipse.jface.viewers.ISelection;
+import org.eclipse.jface.viewers.IStructuredSelection;
+import org.eclipse.ui.IObjectActionDelegate;
+import org.eclipse.ui.IWorkbenchPart;
+
+/**
+ * @author Eike Stepper
+ */
+public class CompareWithPreviousVersionAction implements IObjectActionDelegate
+{
+  private CDOCommitInfo commitInfo;
+
+  public CompareWithPreviousVersionAction()
+  {
+  }
+
+  public void setActivePart(IAction action, IWorkbenchPart targetPart)
+  {
+    // Do nothing
+  }
+
+  public void selectionChanged(IAction action, ISelection selection)
+  {
+    commitInfo = null;
+    if (selection instanceof IStructuredSelection)
+    {
+      Object selectedElement = ((IStructuredSelection)selection).getFirstElement();
+      if (selectedElement instanceof CDOCommitInfo)
+      {
+        commitInfo = getAdapter(selectedElement, CDOCommitInfo.class);
+      }
+    }
+  }
+
+  public void run(IAction action)
+  {
+    if (commitInfo != null)
+    {
+      CDOCompareEditorUtil.openDialog(commitInfo);
+    }
+  }
+
+  @SuppressWarnings("unchecked")
+  public static <T> T getAdapter(Object adaptable, Class<T> c)
+  {
+    if (c.isInstance(adaptable))
+    {
+      return (T)adaptable;
+    }
+
+    if (adaptable instanceof IAdaptable)
+    {
+      IAdaptable a = (IAdaptable)adaptable;
+      Object adapter = a.getAdapter(c);
+      if (c.isInstance(adapter))
+      {
+        return (T)adapter;
+      }
+    }
+
+    return null;
+  }
+}