<Swing Dev> 7189299 DefaultButtonModel instance keeps stale listeners of JButton in case of multiple SwingUtilities.updateComponentTreeUI() calls

[Frank Ding]

Hi Pavel,
   Thanks for your comment.  I improved my fix again and uploaded to the 
following address
   http://cr.openjdk.java.net/~dingxmin/7189299/webrev.03/

   This revision offers a different approach where
1.  In ComponentView, setComponentParent method,  the best place that is 
entitled to detect de-registration condition because only in class 
ComponentView can var "Invalidator c" be accessed.
2.  If the condition is satisfied (this.getParent()==null && 
c.getParent() !=null), call a newly added protected method "cleanup" to 
let subclass do house clean up work.
3.  FormView.cleanup does the actual work of removing listeners from 
DefaultButtonModel.
4.  However, listener instances to be de-registered are protected 
members of AbstractButton, we need to have a JButton wrapper exposing 
these listeners, which leads to declaration of JButtonWrapper inner class.

   I think this time is much better than the reflection one.  Could you 
please take a took and give your comment?  I may need to refine javadoc 
of cleanup protected method later.

Thanks and best regards,
Frank

On 9/13/2012 7:50 PM, Pavel Porvatov wrote:
> Hi Frank,
>> Hi Pavel
>>   It's been a long time since last discussion.  Now I have a new 
>> approach to the issue.
>>   The basic idea is removing the listener pertaining to JButton 
>> instance from DefaultButtonModel when the corresponding FormView 
>> instance is about to retire.
>>
>>   The best place I can find in source code to achieve it is in 
>> FormView's super class ComponentView, method void setComponentParent.
>>   View p = getParent();
>>   if (p != null) {
>>      ....
>>   } else {
>>     // when p is null, it means the FormView instance is about to retire
>>     // deregister listener off shared DefaultButtonModel instance
>>   }
>>
>>   However, the biggest problem is that the listener to be removed is 
>> a private member of AbstractButton and the only way is holding the 
>> listener object and then calling various removeXXXListener on 
>> DefaultButtonModel with the listener being parameter.  I have to 
>> resort to reflection which makes it look more like a workaround. 
>> What's more, reflection introduces implementation dependency.
>>   In addition to the change to fix, I also updated its jtreg test 
>> case according to your comments.
>>   Could you please review it again @
>> http://cr.openjdk.java.net/~dingxmin/7189299/webrev.02
> We don't use reflection in the SWING library. Could you please try to 
> find another way of fix?
>
> Regards, Pavel
>