diff --git a/go/quickstep/res/drawable/empty_content_box.xml b/go/quickstep/res/drawable/empty_content_box.xml
new file mode 100644
index 0000000..a488388
--- /dev/null
+++ b/go/quickstep/res/drawable/empty_content_box.xml
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2019 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+<shape
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="rectangle">
+    <solid android:color="@android:color/transparent"/>
+    <stroke android:color="@android:color/white" android:width="4px"/>
+    <corners android:radius="2dp"/>
+</shape>
\ No newline at end of file
diff --git a/go/quickstep/src/com/android/quickstep/views/TaskLayerDrawable.java b/go/quickstep/src/com/android/quickstep/views/TaskLayerDrawable.java
new file mode 100644
index 0000000..3a23048
--- /dev/null
+++ b/go/quickstep/src/com/android/quickstep/views/TaskLayerDrawable.java
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.quickstep.views;
+
+import android.content.Context;
+import android.graphics.drawable.Drawable;
+import android.graphics.drawable.LayerDrawable;
+
+import androidx.annotation.NonNull;
+
+import com.android.launcher3.R;
+
+/**
+ * A layer drawable for task content that transitions between two drawables by crossfading. Similar
+ * to {@link android.graphics.drawable.TransitionDrawable} but allows callers to control transition
+ * progress and provides a default, empty drawable.
+ */
+public final class TaskLayerDrawable extends LayerDrawable {
+    private final Drawable mEmptyDrawable;
+
+    public TaskLayerDrawable(Context context) {
+        super(new Drawable[0]);
+
+        // Use empty drawable for both layers initially.
+        mEmptyDrawable = context.getResources().getDrawable(
+                R.drawable.empty_content_box, context.getTheme());
+        addLayer(mEmptyDrawable);
+        addLayer(mEmptyDrawable);
+        setTransitionProgress(1.0f);
+    }
+
+    /**
+     * Immediately set the front-most drawable layer.
+     *
+     * @param drawable drawable to set
+     */
+    public void setCurrentDrawable(@NonNull Drawable drawable) {
+        setDrawable(0, drawable);
+    }
+
+    /**
+     * Immediately reset the drawable to showing the empty drawable.
+     */
+    public void resetDrawable() {
+        setCurrentDrawable(mEmptyDrawable);
+    }
+
+    /**
+     * Prepare to start animating the transition by pushing the current drawable to the back and
+     * setting a new drawable to the front layer and making it invisible.
+     *
+     * @param endDrawable drawable to animate to
+     */
+    public void startNewTransition(@NonNull Drawable endDrawable) {
+        Drawable oldDrawable = getDrawable(0);
+        setDrawable(1, oldDrawable);
+        setDrawable(0, endDrawable);
+        setTransitionProgress(0.0f);
+    }
+
+    /**
+     * Set the progress of the transition animation to crossfade the two drawables.
+     *
+     * @param progress current transition progress between 0 (front view invisible) and 1
+     *                 (front view visible)
+     */
+    public void setTransitionProgress(float progress) {
+        if (progress > 1 || progress < 0) {
+            throw new IllegalArgumentException("Transition progress should be between 0 and 1");
+        }
+        int drawableAlpha = (int) (progress * 255);
+        getDrawable(0).setAlpha(drawableAlpha);
+        getDrawable(1).setAlpha(255 - drawableAlpha);
+        invalidateSelf();
+    }
+}