Blur the background of aosp notification panel

Adds a blur to the panel itself, not the rest of the screen.

Bug: 174025821
Test: manual
Change-Id: Ia9df8f9f042dab55ba54eec741f9579c0208ac9b

packages/SystemUI/res/layout/tv_notification_panel.xml

@@ -20,7 +20,7 @@
     android:layout_width="@dimen/tv_notification_panel_width"
     android:layout_height="match_parent"
     android:layout_gravity="end"
-    android:background="@color/tv_notification_background_color"
+    android:background="@android:color/transparent"
     android:orientation="vertical">
 
     <TextView

packages/SystemUI/res/values/colors_tv.xml

@@ -34,6 +34,7 @@
     <color name="tv_volume_dialog_seek_bar_fill">#FFF8F9FA</color>
     <color name="tv_volume_dialog_accent">#FFDADCE0</color>
 
-    <color name="tv_notification_background_color">#383838</color>
+    <color name="tv_notification_default_background_color">#383838</color>
+    <color name="tv_notification_blur_background_color">#a0383838</color>
     <color name="tv_notification_text_color">#FFFFFF</color>
 </resources>

packages/SystemUI/res/values/dimens_tv.xml

@@ -16,4 +16,5 @@
   -->
 <resources>
     <dimen name="tv_notification_panel_width">360dp</dimen>
+    <dimen name="tv_notification_blur_radius">100dp</dimen>
 </resources>

packages/SystemUI/res/values/styles_tv.xml

@@ -30,5 +30,6 @@
         <item name="android:backgroundDimEnabled">false</item>
         <item name="android:windowNoTitle">true</item>
         <item name="android:windowContentOverlay">@null</item>
+        <item name="android:windowIsFloating">true</item>
     </style>
 </resources>

packages/SystemUI/src/com/android/systemui/statusbar/tv/notifications/TvNotificationPanelActivity.java

@@ -20,15 +20,19 @@ import android.annotation.NonNull;
 import android.app.Activity;
 import android.app.NotificationManager;
 import android.content.Intent;
+import android.graphics.drawable.ColorDrawable;
 import android.os.Bundle;
 import android.service.notification.StatusBarNotification;
 import android.util.SparseArray;
+import android.view.Gravity;
 import android.view.View;
 
 import androidx.leanback.widget.VerticalGridView;
 
 import com.android.systemui.R;
 
+import java.util.function.Consumer;
+
 import javax.inject.Inject;
 
 /**
@@ -42,6 +46,7 @@ public class TvNotificationPanelActivity extends Activity implements
     private VerticalGridView mNotificationListView;
     private View mNotificationPlaceholder;
     private boolean mPanelAlreadyOpen = false;
+    private final Consumer<Boolean> mBlurConsumer = this::enableBlur;
 
     @Inject
     public TvNotificationPanelActivity(TvNotificationHandler tvNotificationHandler) {
@@ -102,6 +107,33 @@ public class TvNotificationPanelActivity extends Activity implements
         return false;
     }
 
+    @Override
+    public void onAttachedToWindow() {
+        super.onAttachedToWindow();
+        getWindow().setGravity(Gravity.END);
+        getWindowManager().addCrossWindowBlurEnabledListener(mBlurConsumer);
+    }
+
+    private void enableBlur(boolean enabled) {
+        if (enabled) {
+            int blurRadius = getResources().getDimensionPixelSize(
+                    R.dimen.tv_notification_blur_radius);
+            getWindow().setBackgroundDrawable(
+                    new ColorDrawable(getColor(R.color.tv_notification_blur_background_color)));
+            getWindow().setBackgroundBlurRadius(blurRadius);
+        } else {
+            getWindow().setBackgroundDrawable(
+                    new ColorDrawable(getColor(R.color.tv_notification_default_background_color)));
+            getWindow().setBackgroundBlurRadius(0);
+        }
+    }
+
+    @Override
+    public void onDetachedFromWindow() {
+        super.onDetachedFromWindow();
+        getWindowManager().removeCrossWindowBlurEnabledListener(mBlurConsumer);
+    }
+
     @Override
     public void onDestroy() {
         super.onDestroy();