Bug 26221 [Perspectives] Noticeable menubar "flash" when switching perspectives
Build 20021113 Note this is Windows XP. Open a Java Perspective. Open a Java Browsing Perspective. Switch back and forth between the two. On my XP machine I can visibly see the menu bar "shrink" as menu items are removed, then "expand" as menu items are added. It actually looks like it's animated. Anyway, very noticeable and somewhat strange since I'm switching between two perspectives that have the same base menus (i.e., the menu bar for each perspective is the same).
bundles/org.eclipse.jface/src/org/eclipse/jface/action/MenuManager.java
*/
public boolean getRemoveAllWhenShown() {
	return removeAllWhenShown;
}
/**
 * Notifies all listeners that this menu is about to appear.
 */
private void handleAboutToShow() {
	if (removeAllWhenShown)
		removeAll();
	fireAboutToShow(this);
	update(false,true);
}
/**
 * Returns whether this menu manager contains an <code>ActionContributionItem</code>
 * that defines an accelerator (short cut).
 *
 * @return <code>true</code> if there are accelerators, and <code>false</code>
 *  if not
 */
private boolean hasAccelerator() {
	IContributionItem[] items = getItems();
	for (int i = 0; i < items.length; ++i) {
		if (items[i] instanceof ActionContributionItem) {
			IAction action = ((ActionContributionItem) items[i]).getAction();
			if (action.getAccelerator() != 0)
				return true;
		}
	}
	return false;