Hi Pavel,
Thanks for you reply. I have thought it through and have to have
this solution. The pain point is that these private access level
listeners are completely encapsulated. But there is another possible
fix that won't bother introducing cleanup api but would require
1. Make ComponentView.setComponentParent method become protected for
FormView to override (package level is not adequate because FormView
resides under a different package). This allows FormView instance to
determine de-registration condition.
2. Make ComponentView.c (private Invalidator c) become protected for
FormView to access.
It doesn't bring about new cleanup public api but make hidden
setComponentParent and c come to surface. Do you think it is preferable
than cleanup one? Or I would be more than glad to know another approach.
Best regards,
Frank
On 10/5/2012 8:39 PM, pavel porvatov wrote:
Hi Frank,
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.
You added new method in public API
(javax.swing.text.ComponentView#cleanup). Is it possible to fix the
problem without extending API? I don't think this method will be
useful for other people...
Thanks, Pavel
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
