Bug 63420 [R21PRES] Flash on tab switch
bundles/org.eclipse.ui.presentations.r21/src/org/eclipse/ui/internal/presentations/R21BasicStackPresentation.java
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.ToolBar;
import org.eclipse.swt.widgets.ToolItem;
import org.eclipse.ui.IMemento;
import org.eclipse.ui.IPropertyListener;
import org.eclipse.ui.internal.IWorkbenchConstants;
import org.eclipse.ui.internal.IWorkbenchGraphicConstants;
import org.eclipse.ui.internal.WorkbenchImages;
import org.eclipse.ui.internal.dnd.DragUtil;
import org.eclipse.ui.internal.presentations.r21.R21Colors;
import org.eclipse.ui.internal.presentations.r21.R21PresentationMessages;
import org.eclipse.ui.internal.presentations.r21.widgets.CTabItem;
import org.eclipse.ui.internal.presentations.r21.widgets.R21PaneFolder;
import org.eclipse.ui.internal.util.Util;
import org.eclipse.ui.presentations.IPartMenu;
import org.eclipse.ui.presentations.IPresentablePart;
import org.eclipse.ui.presentations.IPresentationSerializer;
import org.eclipse.ui.presentations.IStackPresentationSite;
import org.eclipse.ui.presentations.PresentationUtil;
import org.eclipse.ui.presentations.StackDropResult;
import org.eclipse.ui.presentations.StackPresentation;
/**
 * Base class for StackPresentations that display IPresentableParts in a
 * CTabFolder.
 * 
 * @since 3.0
 */
public class R21BasicStackPresentation extends StackPresentation {