Reduce unnecessary collecting for wallpaper with shell transition

The adjustWallpaperWindows is a heavy operation (including assigning
layer), and it has no direct relation with ensure visibility of task.
Especially if there are several tasks, it may increase overhead with
dozens milliseconds in a transition. The original problem should be
fixed by collecting wallpaper token instead of window state.
(Because Transition only recognizes wallpaper by token)

Also
 - Reduce re-assigning layer if visibility is not changed.
 - Collect wallpaper token only when the requested visibility is
   different, that reduces lots of checking transition participants.
 - Update wallpaper visibility before playing transition, which is
   similar to legacy adjustWallpaperWindowsForAppTransitionIfNeeded.

Bug: 206487939
Bug: 187461719
Test: WallpaperControllerTests#testWallpaperTokenVisibility
Test: adb shell setprop  persist.debug.shell_transit 1; reboot
      Check 3 cases:
      1. Rotate display -> latency reduced.
      2. Launch app in different orientation from home
         -> wallpaper is not rotated.
      3. Launch an opaque app from home and it launches a
         non-opaque app immediately -> wallpaper should not flash.
Change-Id: I1819f6aad23eb103f97c9d33bc2ad68db0e6c4ed

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

@@ -139,9 +139,6 @@ class EnsureActivitiesVisibleHelper {
                 setActivityVisibilityState(child.asActivityRecord(), starting, resumeTopActivity);
             }
         }
-        if (mTaskFragment.mTransitionController.isShellTransitionsEnabled()) {
-            mTaskFragment.getDisplayContent().mWallpaperController.adjustWallpaperWindows();
-        }
     }
 
     private void setActivityVisibilityState(ActivityRecord r, ActivityRecord starting,

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

@@ -244,11 +244,11 @@ class Transition extends Binder implements BLASTSyncEngine.TransactionReadyListe
         }
         mParticipants.add(wc);
         if (info.mShowWallpaper) {
-            // Collect the wallpaper so it is part of the sync set.
+            // Collect the wallpaper token (for isWallpaper(wc)) so it is part of the sync set.
-            final WindowContainer wallpaper =
+            final WindowState wallpaper =
                     wc.getDisplayContent().mWallpaperController.getTopVisibleWallpaper();
             if (wallpaper != null) {
-                collect(wallpaper);
+                collect(wallpaper.mToken);
             }
         }
     }
@@ -495,25 +495,35 @@ class Transition extends Binder implements BLASTSyncEngine.TransactionReadyListe
             Slog.e(TAG, "Unexpected Sync ID " + syncId + ". Expected " + mSyncId);
             return;
         }
-        int displayId = DEFAULT_DISPLAY;
+        boolean hasWallpaper = false;
-        for (WindowContainer container : mParticipants) {
+        DisplayContent dc = null;
-            if (container.mDisplayContent == null) continue;
+        for (int i = mParticipants.size() - 1; i >= 0; --i) {
-            displayId = container.mDisplayContent.getDisplayId();
+            final WindowContainer<?> wc = mParticipants.valueAt(i);
+            if (dc == null && wc.mDisplayContent != null) {
+                dc = wc.mDisplayContent;
             }
+            if (!hasWallpaper && isWallpaper(wc)) {
+                hasWallpaper = true;
+            }
+        }
+        if (dc == null) dc = mController.mAtm.mRootWindowContainer.getDefaultDisplay();
 
         if (mState == STATE_ABORT) {
             mController.abort(this);
-            mController.mAtm.mRootWindowContainer.getDisplayContent(displayId)
+            dc.getPendingTransaction().merge(transaction);
-                    .getPendingTransaction().merge(transaction);
             mSyncId = -1;
             mOverrideOptions = null;
             return;
         }
+        // Ensure that wallpaper visibility is updated with the latest wallpaper target.
+        if (hasWallpaper) {
+            dc.mWallpaperController.adjustWallpaperWindows();
+        }
 
         mState = STATE_PLAYING;
         mController.moveToPlaying(this);
 
-        if (mController.mAtm.mTaskSupervisor.getKeyguardController().isKeyguardLocked(displayId)) {
+        if (dc.isKeyguardLocked()) {
             mFlags |= TRANSIT_FLAG_KEYGUARD_LOCKED;
         }
 
@@ -523,9 +533,9 @@ class Transition extends Binder implements BLASTSyncEngine.TransactionReadyListe
         info.setAnimationOptions(mOverrideOptions);
 
         // TODO(b/188669821): Move to animation impl in shell.
-        handleLegacyRecentsStartBehavior(displayId, info);
+        handleLegacyRecentsStartBehavior(dc, info);
 
-        handleNonAppWindowsInTransition(displayId, mType, mFlags);
+        handleNonAppWindowsInTransition(dc, mType, mFlags);
 
         reportStartReasonsToLogger();
 
@@ -627,14 +637,11 @@ class Transition extends Binder implements BLASTSyncEngine.TransactionReadyListe
     }
 
     /** @see RecentsAnimationController#attachNavigationBarToApp */
-    private void handleLegacyRecentsStartBehavior(int displayId, TransitionInfo info) {
+    private void handleLegacyRecentsStartBehavior(DisplayContent dc, TransitionInfo info) {
         if ((mFlags & TRANSIT_FLAG_IS_RECENTS) == 0) {
             return;
         }
-        final DisplayContent dc =
+        mRecentsDisplayId = dc.mDisplayId;
-                mController.mAtm.mRootWindowContainer.getDisplayContent(displayId);
-        if (dc == null) return;
-        mRecentsDisplayId = displayId;
 
         // Recents has an input-consumer to grab input from the "live tile" app. Set that up here
         final InputConsumerImpl recentsAnimationInputConsumer =
@@ -679,7 +686,7 @@ class Transition extends Binder implements BLASTSyncEngine.TransactionReadyListe
         // Find the top-most non-home, closing app.
         for (int i = 0; i < info.getChanges().size(); ++i) {
             final TransitionInfo.Change c = info.getChanges().get(i);
-            if (c.getTaskInfo() == null || c.getTaskInfo().displayId != displayId
+            if (c.getTaskInfo() == null || c.getTaskInfo().displayId != mRecentsDisplayId
                     || c.getTaskInfo().getActivityType() != ACTIVITY_TYPE_STANDARD
                     || !(c.getMode() == TRANSIT_CLOSE || c.getMode() == TRANSIT_TO_BACK)) {
                 continue;
@@ -710,7 +717,7 @@ class Transition extends Binder implements BLASTSyncEngine.TransactionReadyListe
             t.setLayer(navSurfaceControl, Integer.MAX_VALUE);
         }
         if (mController.mStatusBar != null) {
-            mController.mStatusBar.setNavigationBarLumaSamplingEnabled(displayId, false);
+            mController.mStatusBar.setNavigationBarLumaSamplingEnabled(mRecentsDisplayId, false);
         }
     }
 
@@ -760,13 +767,8 @@ class Transition extends Binder implements BLASTSyncEngine.TransactionReadyListe
         }
     }
 
-    private void handleNonAppWindowsInTransition(int displayId,
+    private void handleNonAppWindowsInTransition(@NonNull DisplayContent dc,
             @TransitionType int transit, @TransitionFlags int flags) {
-        final DisplayContent dc =
-                mController.mAtm.mRootWindowContainer.getDisplayContent(displayId);
-        if (dc == null) {
-            return;
-        }
         if ((transit == TRANSIT_KEYGUARD_GOING_AWAY
                 || (flags & TRANSIT_FLAG_KEYGUARD_GOING_AWAY) != 0)
                 && !WindowManagerService.sEnableRemoteKeyguardGoingAwayAnimation) {

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

@@ -611,8 +611,9 @@ class WallpaperController {
     private void updateWallpaperTokens(boolean visible) {
         for (int curTokenNdx = mWallpaperTokens.size() - 1; curTokenNdx >= 0; curTokenNdx--) {
             final WallpaperWindowToken token = mWallpaperTokens.get(curTokenNdx);
-            token.updateWallpaperWindows(visible);
+            if (token.updateWallpaperWindows(visible)) {
-            token.getDisplayContent().assignWindowLayers(false);
+                token.mDisplayContent.assignWindowLayers(false /* setLayoutNeeded */);
+            }
         }
     }
 

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

@@ -104,18 +104,21 @@ class WallpaperWindowToken extends WindowToken {
         }
     }
 
-    void updateWallpaperWindows(boolean visible) {
+    /** Returns {@code true} if visibility is changed. */
+    boolean updateWallpaperWindows(boolean visible) {
+        boolean changed = false;
         if (isVisible() != visible) {
             ProtoLog.d(WM_DEBUG_WALLPAPER, "Wallpaper token %s visible=%b",
                     token, visible);
             setVisibility(visible);
+            changed = true;
         }
-        final WallpaperController wallpaperController = mDisplayContent.mWallpaperController;
         if (mTransitionController.isShellTransitionsEnabled()) {
-            return;
+            return changed;
         }
 
-        final WindowState wallpaperTarget = wallpaperController.getWallpaperTarget();
+        final WindowState wallpaperTarget =
+                mDisplayContent.mWallpaperController.getWallpaperTarget();
 
         if (visible && wallpaperTarget != null) {
             final RecentsAnimationController recentsAnimationController =
@@ -137,6 +140,7 @@ class WallpaperWindowToken extends WindowToken {
         }
 
         setVisible(visible);
+        return changed;
     }
 
     private void setVisible(boolean visible) {
@@ -155,10 +159,12 @@ class WallpaperWindowToken extends WindowToken {
      * transition. In that situation, make sure to call {@link #commitVisibility} when done.
      */
     void setVisibility(boolean visible) {
+        if (mVisibleRequested != visible) {
             // Before setting mVisibleRequested so we can track changes.
             mTransitionController.collect(this);
 
             setVisibleRequested(visible);
+        }
 
         // If in a transition, defer commits for activities that are going invisible
         if (!visible && (mTransitionController.inTransition()

services/tests/wmtests/src/com/android/server/wm/WallpaperControllerTests.java

@@ -54,7 +54,6 @@ import android.view.RoundedCorners;
 import android.view.Surface;
 import android.view.SurfaceControl;
 import android.view.WindowManager;
-import android.window.ITransitionPlayer;
 
 import androidx.test.filters.SmallTest;
 
@@ -313,11 +312,7 @@ public class WallpaperControllerTests extends WindowTestsBase {
         wallpaperWindow.setHasSurface(true);
 
         // Set-up mock shell transitions
-        final IBinder mockBinder = mock(IBinder.class);
+        registerTestTransitionPlayer();
-        final ITransitionPlayer mockPlayer = mock(ITransitionPlayer.class);
-        doReturn(mockBinder).when(mockPlayer).asBinder();
-        mWm.mAtmService.getTransitionController().registerTransitionPlayer(mockPlayer,
-                null /* appThread */);
 
         Transition transit =
                 mWm.mAtmService.getTransitionController().createTransition(TRANSIT_OPEN);
@@ -338,10 +333,21 @@ public class WallpaperControllerTests extends WindowTestsBase {
         assertFalse(token.isVisibleRequested());
         assertTrue(token.isVisible());
 
-        transit.onTransactionReady(transit.getSyncId(), mock(SurfaceControl.Transaction.class));
+        final SurfaceControl.Transaction t = mock(SurfaceControl.Transaction.class);
-        transit.finishTransition();
+        token.finishSync(t, false /* cancel */);
+        transit.onTransactionReady(transit.getSyncId(), t);
+        dc.mTransitionController.finishTransition(transit);
         assertFalse(wallpaperWindow.isVisible());
         assertFalse(token.isVisible());
+
+        // Assume wallpaper was visible. When transaction is ready without wallpaper target,
+        // wallpaper should be requested to be invisible.
+        token.setVisibility(true);
+        transit = dc.mTransitionController.createTransition(TRANSIT_CLOSE);
+        dc.mTransitionController.collect(token);
+        transit.onTransactionReady(transit.getSyncId(), t);
+        assertFalse(token.isVisibleRequested());
+        assertTrue(token.isVisible());
     }
 
     private WindowState createWallpaperTargetWindow(DisplayContent dc) {