<Swing Dev> [9] Review request for 8136998: JComboBox prevents wheel mouse scrolling of JScrollPane

[Alexey Ivanov]

Hi Alex,

It makes sense, thanks.

Updated webrev: http://cr.openjdk.java.net/~aivanov/8136998/jdk9/webrev.01/


Regards,
Alexey

On 17.05.2016 20:18, Alexander Potochkin wrote:
> Hello Alexey
>
> The scrollerMouseWheelListener field is only initialized in the 
> installScrollerListeners() method
> which is called from the protected configureScroller().
>
> So if a customer UI delegate overrides configureScroller() method,
> the scrollerMouseWheelListener may not be initialized.
>
> Could you add the null checks?
>
> Thanks
> alexp
>
> On 5/11/2016 17:29, Alexey Ivanov wrote:
>> Hello Swing team,
>>
>> Could you please review the fix for jdk9:
>>     bug: https://bugs.openjdk.java.net/browse/JDK-8136998
>>     webrev: http://cr.openjdk.java.net/~aivanov/8136998/jdk9/webrev.00/
>>
>>
>> Problem description:
>> When JComboBox is added into a JScrollPane, scroll pane is not 
>> scrolled by mouse wheel if mouse over JComboBox.
>>
>> The fix to https://bugs.openjdk.java.net/browse/JDK-8033069 added 
>> MouseWheelListener to JComboBox, and combo box consumes MOUSE_WHEEL 
>> events therefore these events do not reach JScrollPane beneath 
>> JComboBox.
>>
>> The fix:
>> Remove MouseWheelListener from JComboBox. To prevent the combo box 
>> popup from being closed by rotating mouse wheel over the JComboBox, 
>> MouseWheelListener is added when the popup is about to be displayed 
>> and is removed when the popup is about to be hidden.
>>
>>
>> Regards,
>> Alexey
>