On Thu, 21 Nov 2024 16:51:12 GMT, Damon Nguyen <[email protected]> wrote:

>> In a JComboBox, if the user opens the dropdown list and clicks and holds the 
>> down-button, then ALT-TABs to switch focus, when the user re-focuses the 
>> frame with the JComboBox and opens the dropdown list again, the list will 
>> still be scrolling even though the down-button isn't pressed.
>> 
>> This isn't OS or L&F specific, although Aqua L&F does not have any 
>> directional arrows in the dropdown list (and is thus exempt). This led me to 
>> believe it could be handled in BasicComboBoxUI where focusLost and focusGain 
>> are used or isPopupVisible but the scroll behavior cannot be altered here. 
>> Likewise for BasicComboPopup where `autoscroll` is used. However, this 
>> behavior isn't related to autoscroll and is actually found in the JScrollbar 
>> of the JScrollpane inside of the JComboBox. The timer for the scroll action 
>> starts but is never stopped if focus is lost, so a new listener is created 
>> and used. The proposed solution uses `KeyboardFocusManager` to track the 
>> focus owner. The listener stops the `scrollTimer` when the `focusOwner` 
>> property is changed. With this change, the list no longer automatically 
>> scrolls when re-focused and instead opens normally.
>> 
>> The included test is manual due to the need to confirm that the list still 
>> scrolls after ALT-TABing. The L&F is set to Metal since it is the 
>> cross-platform lookandfeel and has directional buttons for the JScrollPane 
>> list.
>
> Damon Nguyen has updated the pull request with a new target base due to a 
> merge or a rebase. The incremental webrev excludes the unrelated changes 
> brought in by the merge/rebase. The pull request contains 10 additional 
> commits since the last revision:
> 
>  - Review comments
>  - Merge branch 'master' into 6672644/focusScroll
>  - isPressed check and set
>  - Review comments
>  - Add space
>  - Update fix to resolve button pressed appearance. Handle review comments
>  - Merge branch 'master' into 6672644/focusScroll
>  - Initial commit
>  - Review comments
>  - Initial commit

Marked as reviewed by psadhukhan (Reviewer).

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

PR Review: https://git.openjdk.org/jdk/pull/20845#pullrequestreview-2453493835

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