On Tue, 5 Nov 2024 22:29:08 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 five additional
> commits since the last revision:
>
> - Update fix to resolve button pressed appearance. Handle review comments
> - Merge branch 'master' into 6672644/focusScroll
> - Initial commit
> - Review comments
> - Initial commit
src/java.desktop/share/classes/javax/swing/plaf/basic/BasicScrollBarUI.java
line 524:
> 522: * @return a keyboard focus listener
> 523: */
> 524: protected KeyboardFocusListener createKeyboardFocusListener(){
Suggestion:
protected KeyboardFocusListener createKeyboardFocusListener() {
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/20845#discussion_r1830429465
