2D Recents: Slightly darken header to differentiate from thumbnail

Bug: 34771148
Test: Locally on sw600dp device, sent screenshot to UX to confirm
Change-Id: I74282c6ed81d3b48d554f9acf55d4fafca2c73f4

packages/SystemUI/src/com/android/systemui/recents/RecentsImpl.java

@@ -646,6 +646,10 @@ public class RecentsImpl implements ActivityOptions.OnAnimationFinishedListener
                 synchronized (mHeaderBarLock) {
                     if (mHeaderBar.getMeasuredWidth() != taskViewWidth ||
                             mHeaderBar.getMeasuredHeight() != mTaskBarHeight) {
+                        if (mDummyStackView.useGridLayout()) {
+                            mHeaderBar.setShouldDarkenBackgroundColor(true);
+                            mHeaderBar.setNoUserInteractionState();
+                        }
                         mHeaderBar.forceLayout();
                         mHeaderBar.measure(
                                 MeasureSpec.makeMeasureSpec(taskViewWidth, MeasureSpec.EXACTLY),

packages/SystemUI/src/com/android/systemui/recents/views/TaskView.java

@@ -151,7 +151,7 @@ public class TaskView extends FixedSizeFrameLayout implements Task.TaskCallbacks
     @ViewDebug.ExportedProperty(deepExport=true, prefix="thumbnail_")
     protected TaskViewThumbnail mThumbnailView;
     @ViewDebug.ExportedProperty(deepExport=true, prefix="header_")
-    TaskViewHeader mHeaderView;
+    protected TaskViewHeader mHeaderView;
     private View mActionButtonView;
     private View mIncompatibleAppToastView;
     private TaskViewCallbacks mCb;

packages/SystemUI/src/com/android/systemui/recents/views/TaskViewHeader.java

@@ -91,6 +91,9 @@ public class TaskViewHeader extends FrameLayout
             if (mColor != color || Float.compare(mDimAlpha, dimAlpha) != 0) {
                 mColor = color;
                 mDimAlpha = dimAlpha;
+                if (mShouldDarkenBackgroundColor) {
+                    color = getSecondaryColor(color, false /* useLightOverlayColor */);
+                }
                 mBackgroundPaint.setColor(color);
 
                 ColorUtils.colorToHSL(color, mTmpHSL);
@@ -179,6 +182,10 @@ public class TaskViewHeader extends FrameLayout
     // Header dim, which is only used when task view hardware layers are not used
     private Paint mDimLayerPaint = new Paint();
 
+    // Whether the background color should be darkened to differentiate from the primary color.
+    // Used in grid layout.
+    private boolean mShouldDarkenBackgroundColor = false;
+
     private CountDownTimer mFocusTimerCountDown;
 
     public TaskViewHeader(Context context) {
@@ -442,6 +449,13 @@ public class TaskViewHeader extends FrameLayout
         }
     }
 
+    /**
+     * Sets whether the background color should be darkened to differentiate from the primary color.
+     */
+    public void setShouldDarkenBackgroundColor(boolean flag) {
+        mShouldDarkenBackgroundColor = flag;
+    }
+
     /**
      * Binds the bar view to the task.
      */
@@ -557,7 +571,7 @@ public class TaskViewHeader extends FrameLayout
      * Mark this task view that the user does has not interacted with the stack after a certain
      * time.
      */
-    void setNoUserInteractionState() {
+    public void setNoUserInteractionState() {
         mDismissButton.setVisibility(View.VISIBLE);
         mDismissButton.animate().cancel();
         mDismissButton.setAlpha(1f);

packages/SystemUI/src/com/android/systemui/recents/views/grid/GridTaskView.java

@@ -53,6 +53,7 @@ public class GridTaskView extends TaskView {
         mThumbnailView.setOverlayHeaderOnThumbnailActionBar(false);
         mThumbnailView.updateThumbnailScale();
         mThumbnailView.setTranslationY(mHeaderHeight);
+        mHeaderView.setShouldDarkenBackgroundColor(true);
     }
 
     @Override