Add API to specify background color for animations

To be used for new task transtion animations
(go/android-new-task-motion) to set a background color behind the
animations instead of showing the wallpaper.

Test: atest FlickerTests:TaskTransitionTest
Bug: 199507257
Change-Id: I7fabfdcaf90be63c11eb3b18d65259c620570cab

1 files changed, 14 insertions, 7 deletions

diff --git a/core/java/android/view/animation/Animation.java b/core/java/android/view/animation/Animation.java
index b1d618eff40a..b296d6f6a052 100644
--- a/core/java/android/view/animation/Animation.java
+++ b/core/java/android/view/animation/Animation.java
@@ -19,6 +19,7 @@ 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;
@@ -258,8 +259,6 @@ public abstract class Animation implements Cloneable {
 
         setZAdjustment(a.getInt(com.android.internal.R.styleable.Animation_zAdjustment, ZORDER_NORMAL));
 
-        setBackgroundColor(a.getInt(com.android.internal.R.styleable.Animation_background, 0));
-
         setDetachWallpaper(
                 a.getBoolean(com.android.internal.R.styleable.Animation_detachWallpaper, false));
         setShowWallpaper(
@@ -271,6 +270,15 @@ 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);
         }
@@ -632,16 +640,15 @@ public abstract class Animation implements Cloneable {
     }
 
     /**
-     * Set background behind animation.
+     * Set background behind an animation.
      *
-     * @param bg The background color.  If 0, no background.  Currently must
-     * be black, with any desired alpha level.
+     * @param bg The background color. If 0, no background.
      *
      * @deprecated None of window animations are running with background color.
      */
     @Deprecated
     public void setBackgroundColor(@ColorInt int bg) {
-        // The background color is not needed any more, do nothing.
+        mBackgroundColor = bg;
     }
 
     /**
@@ -803,7 +810,7 @@ public abstract class Animation implements Cloneable {
     @Deprecated
     @ColorInt
     public int getBackgroundColor() {
-        return 0;
+        return mBackgroundColor;
     }
 
     /**