Bug 17292 Inconsistent Undo behaviour for Cut/Copy/Paste in outline
Build 20020521 (freeze 1) 1) Open a java editor on some class 2) In the content outline, select a method and do Ctrl+X to cut 3) Notice in the menus, Edit->Undo and Refactor->Undo are disabled 4) Now select the type node in the content outline, and Ctrl+V to paste 5) Still, neither Undo action is enabled 6) Now click inside the editor area to give it focus. 7) Now "Edit->Undo" is possible. So, the problems are: 1) Undo is not consistent, it's available for Paste but not Cut. 2) Even when undo is possible, it only becomes enabled when the editor is activated.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaOutlinePage.java
}
				
				/*
				 * @see IContentProvider#inputChanged(Viewer, Object, Object)
				 */
				public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
					boolean isCU= (newInput instanceof ICompilationUnit);
									
					if (isCU && fListener == null) {
						fListener= new ElementChangedListener();
						JavaCore.addElementChangedListener(fListener);
					} else if (!isCU && fListener != null) {
						JavaCore.removeElementChangedListener(fListener);
						fListener= null;
					}
				}
			};
			
			
			class JavaOutlineViewer extends TreeViewer {
				
				/**
				 * Indicates an item which has been reused. At the point of
				 * its reuse it has been expanded. This field is used to
				 * communicate between <code>internalExpandToLevel</code> and
				 * <code>reuseTreeItem</code>.
				 */
				private Item fReusedExpandedItem;
				
				public JavaOutlineViewer(Tree tree) {