Merge changes I04d5e59f,Ia5fa3517

* changes:
  Update overflow button on theme change
  Empty overflow UI
diff --git a/packages/SystemUI/res/layout/bubble_overflow_activity.xml b/packages/SystemUI/res/layout/bubble_overflow_activity.xml
index 95f205a..481c4db 100644
--- a/packages/SystemUI/res/layout/bubble_overflow_activity.xml
+++ b/packages/SystemUI/res/layout/bubble_overflow_activity.xml
@@ -14,8 +14,45 @@
   ~ limitations under the License
   -->
 
-<androidx.recyclerview.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
-    android:id="@+id/bubble_overflow_recycler"
-    android:layout_gravity="center_horizontal"
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/bubble_overflow_container"
     android:layout_width="match_parent"
-    android:layout_height="wrap_content"/>
+    android:layout_height="match_parent"
+    android:orientation="vertical"
+    android:layout_gravity="center_horizontal">
+
+    <androidx.recyclerview.widget.RecyclerView
+        android:id="@+id/bubble_overflow_recycler"
+        android:layout_gravity="center_horizontal"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"/>
+
+    <LinearLayout
+        android:id="@+id/bubble_overflow_empty_state"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:orientation="vertical"
+        android:gravity="center">
+
+        <TextView
+            android:id="@+id/bubble_overflow_empty_title"
+            android:text="@string/bubble_overflow_empty_title"
+            android:fontFamily="@*android:string/config_bodyFontFamilyMedium"
+            android:textAppearance="@*android:style/TextAppearance.DeviceDefault.Body2"
+            android:textColor="?android:attr/textColorSecondary"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:gravity="center"/>
+
+        <TextView
+            android:id="@+id/bubble_overflow_empty_subtitle"
+            android:fontFamily="@*android:string/config_bodyFontFamily"
+            android:textAppearance="@*android:style/TextAppearance.DeviceDefault.Body2"
+            android:textColor="?android:attr/textColorSecondary"
+            android:text="@string/bubble_overflow_empty_subtitle"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:gravity="center"/>
+    </LinearLayout>
+</LinearLayout>
diff --git a/packages/SystemUI/res/values/strings.xml b/packages/SystemUI/res/values/strings.xml
index 6dd89d8..ef9e705 100644
--- a/packages/SystemUI/res/values/strings.xml
+++ b/packages/SystemUI/res/values/strings.xml
@@ -1780,6 +1780,12 @@
     <!-- [CHAR LIMIT=150] Notification Importance title: bubble level summary -->
     <string name="notification_channel_summary_bubble">Keeps your attention with a floating shortcut to this content.</string>
 
+    <!-- [CHAR LIMIT=NONE] Empty overflow title -->
+    <string name="bubble_overflow_empty_title">No recent bubbles</string>
+
+    <!-- [CHAR LIMIT=NONE] Empty overflow subtitle -->
+    <string name="bubble_overflow_empty_subtitle">Recently dismissed bubbles will appear here for easy retrieval.</string>
+
     <!-- Notification: Control panel: Label that displays when the app's notifications cannot be blocked. -->
     <string name="notification_unblockable_desc">These notifications can\'t be modified.</string>
 
diff --git a/packages/SystemUI/src/com/android/systemui/bubbles/BubbleExpandedView.java b/packages/SystemUI/src/com/android/systemui/bubbles/BubbleExpandedView.java
index 0d5261d..fe191f4 100644
--- a/packages/SystemUI/src/com/android/systemui/bubbles/BubbleExpandedView.java
+++ b/packages/SystemUI/src/com/android/systemui/bubbles/BubbleExpandedView.java
@@ -294,7 +294,8 @@
         ta.recycle();
 
         mPointerDrawable.setTint(bgColor);
-        if (ScreenDecorationsUtils.supportsRoundedCornersOnWindows(mContext.getResources())) {
+        if (mActivityView != null && ScreenDecorationsUtils.supportsRoundedCornersOnWindows(
+                mContext.getResources())) {
             mActivityView.setCornerRadius(cornerRadius);
         }
     }
diff --git a/packages/SystemUI/src/com/android/systemui/bubbles/BubbleOverflowActivity.java b/packages/SystemUI/src/com/android/systemui/bubbles/BubbleOverflowActivity.java
index 2d55a1d..f3cfa83 100644
--- a/packages/SystemUI/src/com/android/systemui/bubbles/BubbleOverflowActivity.java
+++ b/packages/SystemUI/src/com/android/systemui/bubbles/BubbleOverflowActivity.java
@@ -26,7 +26,10 @@
 import android.os.Bundle;
 import android.util.Log;
 import android.view.LayoutInflater;
+import android.view.View;
 import android.view.ViewGroup;
+import android.widget.LinearLayout;
+import android.widget.TextView;
 
 import androidx.recyclerview.widget.GridLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
@@ -46,6 +49,7 @@
 public class BubbleOverflowActivity extends Activity {
     private static final String TAG = TAG_WITH_CLASS_NAME ? "BubbleOverflowActivity" : TAG_BUBBLES;
 
+    private LinearLayout mEmptyState;
     private BubbleController mBubbleController;
     private BubbleOverflowAdapter mAdapter;
     private RecyclerView mRecyclerView;
@@ -64,6 +68,7 @@
         setBackgroundColor();
 
         mMaxBubbles = getResources().getInteger(R.integer.bubbles_max_rendered);
+        mEmptyState = findViewById(R.id.bubble_overflow_empty_state);
         mRecyclerView = findViewById(R.id.bubble_overflow_recycler);
         mRecyclerView.setLayoutManager(
                 new GridLayoutManager(getApplicationContext(),
@@ -73,9 +78,9 @@
                 mBubbleController::promoteBubbleFromOverflow);
         mRecyclerView.setAdapter(mAdapter);
 
-        updateData(mBubbleController.getOverflowBubbles());
+        onDataChanged(mBubbleController.getOverflowBubbles());
         mBubbleController.setOverflowCallback(() -> {
-            updateData(mBubbleController.getOverflowBubbles());
+            onDataChanged(mBubbleController.getOverflowBubbles());
         });
     }
 
@@ -87,7 +92,7 @@
         findViewById(android.R.id.content).setBackgroundColor(bgColor);
     }
 
-    void updateData(List<Bubble> bubbles) {
+    void onDataChanged(List<Bubble> bubbles) {
         mOverflowBubbles.clear();
         if (bubbles.size() > mMaxBubbles) {
             mOverflowBubbles.addAll(bubbles.subList(mMaxBubbles, bubbles.size()));
@@ -96,6 +101,12 @@
         }
         mAdapter.notifyDataSetChanged();
 
+        if (mOverflowBubbles.isEmpty()) {
+            mEmptyState.setVisibility(View.VISIBLE);
+        } else {
+            mEmptyState.setVisibility(View.GONE);
+        }
+
         if (DEBUG_OVERFLOW) {
             Log.d(TAG, "Updated overflow bubbles:\n" + BubbleDebugConfig.formatBubblesString(
                     mOverflowBubbles, /*selected*/ null));
diff --git a/packages/SystemUI/src/com/android/systemui/bubbles/BubbleStackView.java b/packages/SystemUI/src/com/android/systemui/bubbles/BubbleStackView.java
index acaf271..cff78cf 100644
--- a/packages/SystemUI/src/com/android/systemui/bubbles/BubbleStackView.java
+++ b/packages/SystemUI/src/com/android/systemui/bubbles/BubbleStackView.java
@@ -528,6 +528,12 @@
         mBubbleContainer.addView(mOverflowBtn, 0,
                 new FrameLayout.LayoutParams(WRAP_CONTENT, WRAP_CONTENT));
 
+        setOverflowBtnTheme();
+        mOverflowBtn.setVisibility(GONE);
+    }
+
+    // TODO(b/149146374) Propagate theme change to bubbles in overflow.
+    private void setOverflowBtnTheme() {
         TypedArray ta = mContext.obtainStyledAttributes(
                 new int[]{android.R.attr.colorBackgroundFloating});
         int bgColor = ta.getColor(0, Color.WHITE /* default */);
@@ -537,8 +543,6 @@
         ColorDrawable bg = new ColorDrawable(bgColor);
         AdaptiveIconDrawable adaptiveIcon = new AdaptiveIconDrawable(bg, fg);
         mOverflowBtn.setImageDrawable(adaptiveIcon);
-
-        mOverflowBtn.setVisibility(GONE);
     }
 
     void showExpandedViewContents(int displayId) {
@@ -568,6 +572,9 @@
      */
     public void onThemeChanged() {
         setUpFlyout();
+        if (BubbleExperimentConfig.allowBubbleOverflow(mContext)) {
+            setOverflowBtnTheme();
+        }
     }
 
     /** Respond to the phone being rotated by repositioning the stack and hiding any flyouts. */