Stop relying on background color attribute to set task transition background

Because the background attribute used to have a different use some apps still set it and it means we could run transitions with unexpected background colors

Test: Existing

Bug: 200763116
Change-Id: Id42f52760cb9a681c6c33f3c261d7db5e2f71af3

core/java/android/view/animation/Animation.java

@@ -19,7 +19,6 @@ package android.view.animation;
 import android.annotation.AnimRes;
 import android.annotation.ColorInt;
 import android.annotation.InterpolatorRes;
-import android.app.ActivityThread;
 import android.compat.annotation.UnsupportedAppUsage;
 import android.content.Context;
 import android.content.res.TypedArray;
@@ -270,15 +269,6 @@ public abstract class Animation implements Cloneable {
 
         a.recycle();
 
-        Context uiContext = ActivityThread.currentActivityThread().getSystemUiContext();
-        TypedArray uiStyledAttrs = uiContext
-                .obtainStyledAttributes(attrs, com.android.internal.R.styleable.Animation);
-
-        setBackgroundColor(
-                uiStyledAttrs.getColor(com.android.internal.R.styleable.Animation_background, 0));
-
-        uiStyledAttrs.recycle();
-
         if (resID > 0) {
             setInterpolator(context, resID);
         }

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

@@ -32,6 +32,10 @@ import static android.os.UserHandle.USER_NULL;
 import static android.view.SurfaceControl.Transaction;
 import static android.view.WindowManager.LayoutParams.INVALID_WINDOW_TYPE;
 import static android.view.WindowManager.TRANSIT_CHANGE;
+import static android.view.WindowManager.TRANSIT_OLD_TASK_CLOSE;
+import static android.view.WindowManager.TRANSIT_OLD_TASK_OPEN;
+import static android.view.WindowManager.TRANSIT_OLD_TASK_TO_BACK;
+import static android.view.WindowManager.TRANSIT_OLD_TASK_TO_FRONT;
 
 import static com.android.internal.protolog.ProtoLogGroup.WM_DEBUG_APP_TRANSITIONS;
 import static com.android.internal.protolog.ProtoLogGroup.WM_DEBUG_APP_TRANSITIONS_ANIM;
@@ -61,10 +65,13 @@ import static com.android.server.wm.WindowManagerService.logWithStack;
 import static com.android.server.wm.WindowStateAnimator.ROOT_TASK_CLIP_AFTER_ANIM;
 
 import android.annotation.CallSuper;
+import android.annotation.ColorInt;
 import android.annotation.IntDef;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
+import android.app.ActivityThread;
 import android.app.WindowConfiguration;
+import android.content.Context;
 import android.content.pm.ActivityInfo;
 import android.content.res.Configuration;
 import android.graphics.Point;
@@ -90,6 +97,7 @@ import android.view.animation.Animation;
 import android.window.IWindowContainerToken;
 import android.window.WindowContainerToken;
 
+import com.android.internal.R;
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.protolog.common.ProtoLog;
 import com.android.internal.util.ToBooleanFunction;
@@ -2814,24 +2822,23 @@ class WindowContainer<E extends WindowContainer> extends ConfigurationContainer<
             }
 
             TaskDisplayArea taskDisplayArea = getTaskDisplayArea();
-            int backgroundColor = adapter.getBackgroundColor();
+            boolean isSettingBackgroundColor = taskDisplayArea != null
+                    && isTransitionWithBackgroundColor(transit);
 
-            boolean shouldSetBackgroundColor = taskDisplayArea != null && backgroundColor != 0;
+            if (isSettingBackgroundColor) {
+                Context uiContext = ActivityThread.currentActivityThread().getSystemUiContext();
+                @ColorInt int backgroundColor = uiContext.getColor(R.color.overview_background);
 
-            if (shouldSetBackgroundColor) {
                 taskDisplayArea.setBackgroundColor(backgroundColor);
             }
 
-            Runnable clearColorBackground = () -> {
+            final Runnable cleanUpCallback = isSettingBackgroundColor
-                if (shouldSetBackgroundColor) {
+                    ? taskDisplayArea::clearBackgroundColor : () -> {};
-                    taskDisplayArea.clearBackgroundColor();
-                }
-            };
 
             startAnimation(getPendingTransaction(), adapter, !isVisible(),
                     ANIMATION_TYPE_APP_TRANSITION,
-                    (type, anim) -> clearColorBackground.run(),
+                    (type, anim) -> cleanUpCallback.run(),
-                    clearColorBackground);
+                    cleanUpCallback);
 
             if (adapter.getShowWallpaper()) {
                 getDisplayContent().pendingLayoutChanges |= FINISH_LAYOUT_REDO_WALLPAPER;
@@ -2843,6 +2850,13 @@ class WindowContainer<E extends WindowContainer> extends ConfigurationContainer<
         }
     }
 
+    private boolean isTransitionWithBackgroundColor(@TransitionOldType int transit) {
+        return transit == TRANSIT_OLD_TASK_OPEN
+                || transit == TRANSIT_OLD_TASK_CLOSE
+                || transit == TRANSIT_OLD_TASK_TO_FRONT
+                || transit == TRANSIT_OLD_TASK_TO_BACK;
+    }
+
     final SurfaceAnimationRunner getSurfaceAnimationRunner() {
         return mWmService.mSurfaceAnimationRunner;
     }