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
* @return <code>true</code> if enabled, and
 *   <code>false</code> if disabled
 */
public boolean isEnabled() {
	return true;
}
/* (non-Javadoc)
 * Method declared on IContributionItem.
 */
public boolean isGroupMarker() {
	return false;
}
/* (non-Javadoc)
 * Method declared on IContributionItem.
 */
public boolean isSeparator() {
	return false;
}
/* (non-Javadoc)
 * Method declared on IContributionItem.
 */
public boolean isSubstituteFor(IContributionItem item) {
	return this.equals(item);
}
/* (non-Javadoc)
 * Method declared on IContributionItem.
 */
public boolean isVisible() {
	return visible;
}