<Swing Dev> Request for review 7155887: ComboBox does not paint focus correctly on GTK L&F

[Jonathan Lu]

Hi Pavel,

Here's the updated patch, including proposed solution for interior focus.
http://cr.openjdk.java.net/~luchsh/7155887_3/

In the orginal code as I understood, focus is only paint when 
!interiorFocus, in which case the background shadow and flatBox will 
shrink a bit to corperate with the outer focus whose size is same as the 
original component. My proposed solution is to shirink focus line for 
interior focus, but keep the same way of !interorFocus.

could you pls take a look?

On 03/27/2012 10:46 PM, Pavel Porvatov wrote:
> Hi Jonathan,
>
> What do you think about another solution: can we set component state 
> as SynthConstants.FOCUSED before paintTextBackground is invoked. 
> Another solution is to set state as "focused" for ComboBox renderer 
> like the following:
>
>         if ("ComboBox.renderer".equals(c.getName())) {
>             for (Component comboBoxParent = c.getParent(); 
> comboBoxParent != null; comboBoxParent = comboBoxParent.getParent()) {
>                 if (comboBoxParent instanceof JComboBox){
>                     if(comboBoxParent.hasFocus()){
>                         state |= SynthConstants.FOCUSED;
>                     }
>                     break;
>                 }
>             }
>         }
> without other changes in GTKPainter.java (actually there is some 
> problem with "interiorFocus", but it could be resolved....)
>
> See also my answers below.
>> Hi Pavel,
>>
>> Thanks for review, here's the new patch and my answers are inlined.
>> http://cr.openjdk.java.net/~luchsh/7155887_2/
>>
>> On 03/22/2012 10:24 PM, Pavel Porvatov wrote:
>>> Hi Jonathan,
>>>> Hi Swing-dev,
>>>>
>>>> ComboBox on linux GTK L&F does not works as gtk native 
>>>> applications, when get focused, the apperance of Java ComboBox 
>>>> remains unchanged but native GTK ComboBox control will have a 
>>>> outline to indicate it has got focused.
>>>>
>>>> The problem seems similar to bug
>>>> 6947671 ( http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6947671),
>>>> except that I did not reproduced the problem on Nimbus L&F, so 
>>>> another bug
>>>> 7155887 (http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7155887)
>>>> was created for this issue,
>>>>
>>>> And here's the proposed patch to fix this problem,
>>>> http://cr.openjdk.java.net/~luchsh/7155887/
>>>>
>>>> Could anybody please help to take a look?
>>> I have several comments about the patch:
>>>
>>> 1. "c.getName().equals("ComboBox.renderer")": I think we can get NPE 
>>> here
>> Yes, I've changed it to
>>
>> "ComboBox.renderer".equals(c.getName())
>>
>>>
>>> 2.
>>> +            for (Component comboBoxParent = c.getParent(); 
>>> comboBoxParent != null; comboBoxParent = comboBoxParent
>>> +                    .getParent()) {
>>> +                if (comboBoxParent instanceof JComboBox
>>> + && comboBoxParent.hasFocus()) {
>>> +                    comboBoxFocused = true;
>>> +                }
>>> +            }
>>>
>>> I'm not sure we should do such deep parent investigation. Why don't 
>>> you check first parent only?
>>>
>> javax.swing.CellRendererPane is inserted between the component and 
>> renderer, so if check only the first parent, it will retrieve a 
>> CellRendererPane object instead of JComboBox component. In the new 
>> patch, I added a break when JComboBox is encounterred so to make the 
>> effect similar to the first-parent-only approach.
> I found out the following code (see 
> com.sun.java.swing.plaf.gtk.GTKPainter#paintLabelBackground):
>         if (c instanceof ListCellRenderer &&
>                  container != null &&
>                  container.getParent() instanceof JComboBox ) {
>             ...
>         }
> I think we should use the same pattern
>>
>>> 3. "if (ENGINE.paintCachedImage(g, x, y, w, h, id, state) && 
>>> !comboBoxFocused)"
>>> If you are going to ignore ENGINE.paintCachedImage when 
>>> comboBoxFocused, then there is no need to invoke it at all
>>>
>> yes, in the new patch I've changed the order of these two checks.
>>> 4. "if (comboBoxFocused || focusSize > 0)"
>>> I'm not sure we should paint focus if focusSize == 0
>>>
>> I think there's no need to paint the focus if focusSize ==0, since 
>> the focus width and height arguements passed to JNI method 
>> native_paint_focus() will both be zero.
> That's what I meant! (may be my phrase was not clear enough)
> Your condition "if (comboBoxFocused || focusSize > 0)" allows to paint 
> focus even if focusSize == 0...
>
Oh, sorry for my misunderstanding, the previous patch indeed got such a 
problem, but it may not be in the new patch.
> Regards, Pavel

Thanks and best regards!

- Jonathan