Keyboard Accelerator implementation not MenuElement-aware

Name: boT120536 Date: 01/10/2001


Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.0-C)
Java HotSpot(TM) Client VM (build 1.3.0-C, mixed mode)

This is not a bug but a limitation in the implementation of the
processKeyBinding and processBindingForKeyStrokeRecursive methods of JMenuBar.
processKeyBinding is overridden from JComponent so that when the
KeyboardManager passes key events to any registered menubars through
processKeyBinding, it recursively scans through JMenus and JMenuItems, looking
for components that are registered for the event. All this allows keyboard
menu accelerators to work even when menus aren't visible...

The problem is that these overridden methods are implemented to recursively
scan JMenus and JMenuItems, specifically, instead of using the MenuElement
interface. So developers who make additional components that implement
MenuElement can't get accelerators to work properly. It seems easy instead to
recursively scan through MenuElements using the getSubElements and getComponent
methods of that interface. If the JMenuBar (and other Swing code, for that
matter) stuck to the MenuElement interface in cases like this, it would make
menu component development simpler (yes, I am in fact making a MenuElement that
is not a JMenuItem...).

So, instead of implementing the mentioned methods with 'instanceof JMenuItem'
and 'instanceof JMenu' expressions, please modify this code to use the
MenuElement interface, checking binding with something
like 'menuelement.getComponent().processKeyBinding(...)' (or give me the
possible good reason why it's not implemented that way to begin with :) Thanks!
(Review ID: 111589)
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