Disabled components: to popup or not to popup context menu?

Question

Hi experts,
just noticed that Swing pops up a component menu on mouse click even if the component isn't enabled. Seems to contradict the general rule to not allow "active" interaction (vs. "passive" as f.i. still showing the tooltip, the distinction is probably freely invented but serves me well enough ;) with a disabled component.
Could half-way live with that - except that then all menu items need to be disabled individually. Another option would be to return a null componentPopup if disabled. Not generally applicable because requires subclassing. Yet another might be to force-inject a MouseListener into the rootPane: it would intercept and swallow the popup triggers if the target is disabled, otherwise delegate to the ui-installed listener.
Comments please?
Thanks
Jeanette

Answer 1

>
release is out (here's a screenshot: http://www.jyloo.com/news/?pubId=1297423104000 - commercial, though) - so have a bit more time right now to tackle this
What puzzled me most in your comments was:
>
(and set the show popup action enabled/disabled as well). because I expected that to be not a problem at all: RootPane's action in isEnabled(sender) first checks if the sender is the focusOwner and returns false if not. Disabled components cannot be focusOwner, so safe territory. Except ... they can, even if there are enabled focusable components around. Turns out that the KeyboardFocusManager isn't clever enough to keep transfering the focus when a whole bunch of components is disabled. Or maybe it's a timing issue, as focus transfers can be asynchronous, and/or are tricky anyway, don't know. Whatever, when disabling a bunch of components, it must be done in the inverse order of the focusTransferCycle ... and that's completely unmanageable except for most simple contexts, like focus cycle is the same as insertion order, than reversing disable loop is a brittle option
// before calling this, focus on parent.getComponent(0)
// the natural way of disabling the children
for (Component child: parent.getComponents()) {
     child.setEnabled(false);
// after the call, focus on parent.getComponent(1)
// inversing
for (int i = parent.getComponentCount() - 1; i >= 0; i--) {
   parent.getComponent(i).setEnabled(false);
// focus somewhere elseINCREDIBLE ...
overriding getComponentPopup to return null if disabled (as I did as a quick measure) is not really an option - don't want to override each and every component ;-) Another hook - not clean either, but at least manageable, might be a custom JPopupMenu: subclass and show only if enabled.
@override
public void show(Component invoker, int x, int y) {
    if (!invoker.isEnabled()) return;
    super.show(..)
}This still leaves the action enabled fooled - reports true because the invoker has a componentPopup - but then, a disable comp should be focusOwner anyway.
Cheers
Jeanette