> 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 incrementally with one additional commit since the last revision: Review comments ------------- Changes: - all: https://git.openjdk.org/jdk/pull/20845/files - new: https://git.openjdk.org/jdk/pull/20845/files/83669d56..c2b4389e Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=20845&range=04 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20845&range=03-04 Stats: 15 lines in 2 files changed: 0 ins; 2 del; 13 mod Patch: https://git.openjdk.org/jdk/pull/20845.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/20845/head:pull/20845 PR: https://git.openjdk.org/jdk/pull/20845
