Commit 9f70d5ea authored Jan 06, 2025 by Yifei Zhang

backnav: don't reset back tracker at start

- updateStartLocation will reset the BackTracker internal state and
  update the start position of the progress calculation
- Updating at animation start will cause a significant offset for small
  screen devices. This is especially obvious on Wear OS.
- Skipping will not cause a direct jump in animation. There is a visible
  spring effect when the animation catches up with back progress.

Bug: 381150378
Test: build & flash
Flag: EXEMPT, bug fix
Change-Id: I2fb1be277f328fc3ef556804c2bc6dbc02c68c29

parent 8b379c95

libs/WindowManager/Shell/src/com/android/wm/shell/back/BackAnimationController.java

+0 −1

Original line number	Diff line number	Diff line
		@@ -1093,7 +1093,6 @@ public class BackAnimationController implements RemoteCallable<BackAnimationCont
		() -> mShellExecutor.execute(this::onBackAnimationFinished));

		if (mApps.length >= 1) {
		mCurrentTracker.updateStartLocation();
		BackMotionEvent startEvent = mCurrentTracker.createStartEvent(mApps[0]);
		dispatchOnBackStarted(mActiveCallback, startEvent);
		if (startEvent.getSwipeEdge() == EDGE_NONE) {