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
* Does not create a new control if one already exists.
 * <p>
 * Note that the menu is not expected to be dynamic.
 * </p>
 *
 * @param parent the parent control
 * @return the menu control
 */
public Menu createContextMenu(Control parent) {
	if (!menuExist()) {
		menu = new Menu(parent);
		initializeMenu();
	}
	return menu;
}
/**
 * Creates and returns an SWT menu bar control for this menu,
 * for use in the given shell, and installs all registered contributions.
 * Does not create a new control if one already exists.
 *
 * @param parent the parent shell
 * @return the menu control
 */
public Menu createMenuBar(Shell parent) {
	if (!menuExist()) {
		menu = new Menu(parent, SWT.BAR);
		update(false);
	}
	return menu;
}