RFR: 6318027: BasicScrollBarUI does not disable timer when enclosing frame is disabled. [v8]

[Abhishek Kumar]

On Tue, 20 Aug 2024 11:30:06 GMT, Prasanta Sadhukhan <psadhukhan at openjdk.org> wrote:

>> Issue is
>> BasicScrollBarUI.ArrowButtonListener starts a timer in mousePressed(), and stops it in mouseReleased(). If the frame containing the scrollbar is disabled between the MOUSE_PRESSED and the MOUSE_RELEASED events, the mouseReleased() method is never called. If the frame is then re-enabled, the still-running timer causes it to scroll all the way to the end.
>> Fix is to check if [ArrowButtonListener.handledEvent](https://github.com/openjdk/jdk/blame/ee839b7f0ebe471d3877cddd2c87019ccb8ee5ae/src/java.desktop/share/classes/javax/swing/plaf/basic/BasicScrollBarUI.java#L1567) is still set when ActionEvent is processed then stop the timer and reset this variable.
>> 
>> CI testing is green and also SwingSet2 JScrollPane scrolling with this modification..
>
> Prasanta Sadhukhan has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Sort imports

Ran the test and verified the latest fix on different platforms (mac, windows and linux). It works as expected and looks good to me now.

-------------

Marked as reviewed by abhiscxk (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/20346#pullrequestreview-2249722192