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[200407271830; j2sdk1.4.2_05] 1.Create new JFrame form and add the JButton to it 2.Select the button in component inspector 3.In properties panel select Events category 4.Click to edit actionPerformed and press Enter 5.Exception dialog appears (see ide.log)
Created attachment 16517 [details] Ide.log attached
There is no exception when I'm running on j2sdk1.5b59 -> adding JDK_SPECIFIC keyword.
I obtained these NPEs also in the following way: 1. Invoke Open action on some form. 2. Invoke Edit action on another form. 3. Move mouse over editor. It seems to be caused by form group close. The corresponding code was changed by mkleint (FormEditorSupport revision 151) as a fix of issue 45666. When I remove the invokeLater introduced by this fix then the exception is not thrown => reassigning to Milos.
as i mentioned in the 45666 bug, my fix to form module was considered simplified. you should reevaluate the way you open/close window groups. the stacktrace of the NPEs doesn't look like it could be linked the invoke later stuff. it's a mere conicidence IMHO. I will look into it.
j2sdk1.4.2_01 and nb build 200407291800. Cannot reproduce using any of these scenarios. given the stacktrace ends in sun private packages and there's nothing from netbeans there, I'd say it's a jdk bug in that particular version. I have to reiterate that postponing the form group closing cannot have a direct effect on the exception. reassigning back, please look in the jdk bug db and file it as a bug if it's not there already.
This is a JDK bug #5057174 (attempt to access already cleared peer of some component). The bug is exposed by mkleint's invokeLater (the peer is already cleared, but the component still has focus?). No workaround is mentioned in the bug evaluation, but another invokeLater seems to help :-). Feel free to reopen the issue if the workaround fails somewhere.
Verified in 20040812; j2sdk1.5.0-beta3-b59 - the exception is doesn't appear to me now.
I think I managed to make the window system reentry-safe. (thus window system methods can be safely called from the componentShowing() and componentHiding() callbacks) Can you guys try removing the invokeLater() calls and see if everything works correctly?
It seems to work fine without the invokeLater() calls by now. I have removed them.