commit 355cc15c17e209cb5c78c98b2ab259ab9153c53e
author Riddle Hsu <riddlehsu@google.com> Mon May 16 20:34:16 2022 +0800
committer Riddle Hsu <riddlehsu@google.com> Mon May 16 12:44:20 2022 +0000
tree 86436d6ec2c63351c6c862f940f730cd08770e9a
parent 6cfafc4b2bfcf95d2e9f7a16a4116e31d30ded4c

Reduce unnecessary redraw of wallpaper with shell transition

Wallpaper only needs to draw once in most of cases. It usually
only changes visibility, so the redraw doesn't make any effect
but the latency.

This may reduce ~20ms latency while swiping up to recents with
shell transition.

Also limit adjustWallpaperWindows for shell rotation in
ensureActivitiesVisible, because only shell rotation needs to
capture a closing state of wallpaper.

Bug: 231435331
Test: adb shell setprop persist.wm.debug.shell_transit 1; reboot
      adb shell wm logging enable-text WM_DEBUG_DRAW
      Swipe to recents and check there is no log "finishDrawing"
      of wallpaper.
Change-Id: Iee1bed1ebee986c096f930759571eb147abad56d

services/core/java/com/android/server/wm/DisplayContent.java

diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index 1f73a78..2dc163c 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -6080,7 +6080,8 @@
                 rootTask.ensureActivitiesVisible(starting, configChanges, preserveWindows,
                         notifyClients);
             });
-            if (mTransitionController.isCollecting()
+            if (mTransitionController.useShellTransitionsRotation()
+                    && mTransitionController.isCollecting()
                     && mWallpaperController.getWallpaperTarget() != null) {
                 // Also update wallpapers so that their requestedVisibility immediately reflects
                 // the changes to activity visibility.

services/core/java/com/android/server/wm/Transition.java

diff --git a/services/core/java/com/android/server/wm/Transition.java b/services/core/java/com/android/server/wm/Transition.java
index d5acf4f..56afc07 100644
--- a/services/core/java/com/android/server/wm/Transition.java
+++ b/services/core/java/com/android/server/wm/Transition.java
@@ -299,7 +299,12 @@
             }
         }
         if (mParticipants.contains(wc)) return;
-        mSyncEngine.addToSyncSet(mSyncId, wc);
+        // Wallpaper is like in a static drawn state unless display may have changes, so exclude
+        // the case to reduce transition latency waiting for the unchanged wallpaper to redraw.
+        final boolean needSyncDraw = !isWallpaper(wc) || mParticipants.contains(wc.mDisplayContent);
+        if (needSyncDraw) {
+            mSyncEngine.addToSyncSet(mSyncId, wc);
+        }
         ChangeInfo info = mChanges.get(wc);
         if (info == null) {
             info = new ChangeInfo(wc);