Bug 40788 [plan item] Configurable Next/Previous actions
Toolbar drop down, or editor specific control. Needs to be coordinated with Platform UI.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
public void selectionChanged(SelectionChangedEvent event) {
			doSelectionChanged(event);
		}
	}
	
	/*
	 * Link mode.  
	 */
	class MouseClickListener implements KeyListener, MouseListener, MouseMoveListener,
		FocusListener, PaintListener, IPropertyChangeListener, IDocumentListener, ITextInputListener {
		
		private boolean fActive;
		
		private IRegion fActiveRegion;
		
		private Position fRememberedPosition;
		
		private Cursor fCursor;
		
		
		private Color fColor;
		
		private int fKeyModifierMask;
		public void deactivate() {
			deactivate(false);
		}
		public void deactivate(boolean redrawAll) {
			if (!fActive)
				return;
			repairRepresentation(redrawAll);