commit 08c956c781a7df2eccfe761258e585ed0e9d60b8
author Wenyu Fu <wenyufu@google.com> Tue Jan 09 03:30:24 2024
committer Chromium LUCI CQ <chromium-scoped@luci-project-accounts.iam.gserviceaccount.com> Tue Jan 09 03:30:24 2024
tree aa22f5d90c0f72da0c7c5fc6be8254616e80889a
parent cfd4a70f1402883544909f8b2634a5de34a4fda9

[TLDD] Refactor DragAnDropGlobalState APIs

Context: Drag events usually reach child view first and then propagate back to parent if child is unable to handle the event (ie: returns false). However, drag start / end events are sent to all drag listeners. These 2 events do no follow the same call order as other events - ie: they reach listeners in no specific order (verified through testing).

Since we need to clear static shared drag state on drag end, this leads to an issue where one listener could preemptively clear the state that is required by another listener. Saw issues with users flows due to this where dragSourceInstanceId in DragDropGlobalState was getting cleared early causing isDragSource call to return incorrect value.

To get around this issue, this CL introduces a concept of tracker token:
* The token is handed over to the creator of the global state instance (token is handed during startDragAndDrop).
* The global instance can only be obtained when passing the right token, or an drag event that has ACTION_DROP.
* The drag starter is responsible to release the global state at drag end.

This CL also wraps the entire ChromeDropDataAndroid into the global state, making it easier for adding more fields.

Fixed: 1514917
Change-Id: I889960787bfab3f3a9a294541330df68872ec3c3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5154244
Reviewed-by: Neil Coronado <nemco@google.com>
Reviewed-by: Theresa Sullivan <twellington@chromium.org>
Commit-Queue: Wenyu Fu <wenyufu@chromium.org>
Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#1244436}