towards MR2: update to new backend

Splitting MediaDeviceManager out of MediaControlPanel. This will make it
easier to integrate
MediaRouter2Manager#getRoutingSessionForMediaController.

Bug: 155266917
Test: atest tests/src/com/android/systemui/media/MediaDeviceManagerTest.kt
Test: atest tests/src/com/android/systemui/media/MediaDataCombineLatestTest.java
Test: manual - switch route between phone, headphones and cast and check
output switcher chip in the player.

Change-Id: Ibe6a7e41bd8fb0f0976d1c1c7f2f94cfc4fc6f5e

13 files changed, 730 insertions, 176 deletions

diff --git a/packages/SystemUI/src/com/android/systemui/media/LocalMediaManagerFactory.kt b/packages/SystemUI/src/com/android/systemui/media/LocalMediaManagerFactory.kt
new file mode 100644
index 000000000000..94a0835f22f8
--- /dev/null
+++ b/packages/SystemUI/src/com/android/systemui/media/LocalMediaManagerFactory.kt
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2020 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.systemui.media
+
+import android.content.Context
+
+import com.android.settingslib.bluetooth.LocalBluetoothManager
+import com.android.settingslib.media.InfoMediaManager
+import com.android.settingslib.media.LocalMediaManager
+
+import javax.inject.Inject
+
+/**
+ * Factory to create [LocalMediaManager] objects.
+ */
+class LocalMediaManagerFactory @Inject constructor(
+    private val context: Context,
+    private val localBluetoothManager: LocalBluetoothManager?
+) {
+    /** Creates a [LocalMediaManager] for the given package. */
+    fun create(packageName: String): LocalMediaManager {
+        return InfoMediaManager(context, packageName, null, localBluetoothManager).run {
+            LocalMediaManager(context, localBluetoothManager, this, packageName)
+        }
+    }
+}
diff --git a/packages/SystemUI/src/com/android/systemui/media/MediaControlPanel.java b/packages/SystemUI/src/com/android/systemui/media/MediaControlPanel.java
index aee7a4649d08..f90798bd30b8 100644
--- a/packages/SystemUI/src/com/android/systemui/media/MediaControlPanel.java
+++ b/packages/SystemUI/src/com/android/systemui/media/MediaControlPanel.java
@@ -41,7 +41,6 @@ import android.util.Log;
 import android.view.View;
 import android.widget.ImageButton;
 import android.widget.ImageView;
-import android.widget.LinearLayout;
 import android.widget.SeekBar;
 import android.widget.TextView;
 
@@ -56,14 +55,11 @@ import androidx.core.graphics.drawable.RoundedBitmapDrawable;
 import androidx.core.graphics.drawable.RoundedBitmapDrawableFactory;
 
 import com.android.settingslib.Utils;
-import com.android.settingslib.media.LocalMediaManager;
-import com.android.settingslib.media.MediaDevice;
 import com.android.settingslib.media.MediaOutputSliceConstants;
 import com.android.settingslib.widget.AdaptiveIcon;
 import com.android.systemui.R;
 import com.android.systemui.plugins.ActivityStarter;
 import com.android.systemui.qs.QSMediaBrowser;
-import com.android.systemui.util.Assert;
 import com.android.systemui.util.concurrency.DelayableExecutor;
 
 import org.jetbrains.annotations.NotNull;
@@ -77,7 +73,6 @@ import java.util.concurrent.Executor;
  */
 public class MediaControlPanel {
     private static final String TAG = "MediaControlPanel";
-    @Nullable private final LocalMediaManager mLocalMediaManager;
 
     // Button IDs for QS controls
     static final int[] ACTION_IDS = {
@@ -100,7 +95,6 @@ public class MediaControlPanel {
     private MediaSession.Token mToken;
     private MediaController mController;
     private int mBackgroundColor;
-    private MediaDevice mDevice;
     protected ComponentName mServiceComponent;
     private boolean mIsRegistered = false;
     private List<KeyFrames> mKeyFrames;
@@ -113,7 +107,6 @@ public class MediaControlPanel {
     public static final String MEDIA_PREFERENCE_KEY = "browser_components";
     private SharedPreferences mSharedPrefs;
     private boolean mCheckedForResumption = false;
-    private boolean mIsRemotePlayback;
     private QSMediaBrowser mQSMediaBrowser;
 
     private final MediaController.Callback mSessionCallback = new MediaController.Callback() {
@@ -122,7 +115,6 @@ public class MediaControlPanel {
             Log.d(TAG, "session destroyed");
             mController.unregisterCallback(mSessionCallback);
             clearControls();
-            makeInactive();
         }
         @Override
         public void onPlaybackStateChanged(PlaybackState state) {
@@ -130,31 +122,6 @@ public class MediaControlPanel {
             if (s == PlaybackState.STATE_NONE) {
                 Log.d(TAG, "playback state change will trigger resumption, state=" + state);
                 clearControls();
-                makeInactive();
-            }
-        }
-    };
-
-    private final LocalMediaManager.DeviceCallback mDeviceCallback =
-            new LocalMediaManager.DeviceCallback() {
-        @Override
-        public void onDeviceListUpdate(List<MediaDevice> devices) {
-            if (mLocalMediaManager == null) {
-                return;
-            }
-            MediaDevice currentDevice = mLocalMediaManager.getCurrentConnectedDevice();
-            // Check because this can be called several times while changing devices
-            if (mDevice == null || !mDevice.equals(currentDevice)) {
-                mDevice = currentDevice;
-                updateDevice(mDevice);
-            }
-        }
-
-        @Override
-        public void onSelectedDeviceStateChanged(MediaDevice device, int state) {
-            if (mDevice == null || !mDevice.equals(device)) {
-                mDevice = device;
-                updateDevice(mDevice);
             }
         }
     };
@@ -162,16 +129,13 @@ public class MediaControlPanel {
     /**
      * Initialize a new control panel
      * @param context
-     * @param routeManager Manager used to listen for device change events.
      * @param foregroundExecutor foreground executor
      * @param backgroundExecutor background executor, used for processing artwork
      * @param activityStarter activity starter
      */
-    public MediaControlPanel(Context context, @Nullable LocalMediaManager routeManager,
-            Executor foregroundExecutor, DelayableExecutor backgroundExecutor,
-            ActivityStarter activityStarter) {
+    public MediaControlPanel(Context context, Executor foregroundExecutor,
+            DelayableExecutor backgroundExecutor, ActivityStarter activityStarter) {
         mContext = context;
-        mLocalMediaManager = routeManager;
         mForegroundExecutor = foregroundExecutor;
         mBackgroundExecutor = backgroundExecutor;
         mActivityStarter = activityStarter;
@@ -183,7 +147,6 @@ public class MediaControlPanel {
         if (mSeekBarObserver != null) {
             mSeekBarViewModel.getProgress().removeObserver(mSeekBarObserver);
         }
-        makeInactive();
     }
 
     private void loadDimens() {
@@ -318,30 +281,67 @@ public class MediaControlPanel {
         artistText.setText(data.getArtist());
 
         // Transfer chip
-        if (mLocalMediaManager != null) {
-            mViewHolder.getSeamless().setVisibility(View.VISIBLE);
-            setVisibleAndAlpha(collapsedSet, R.id.media_seamless, true /*visible */);
-            setVisibleAndAlpha(expandedSet, R.id.media_seamless, true /*visible */);
-            updateDevice(mLocalMediaManager.getCurrentConnectedDevice());
-            mViewHolder.getSeamless().setOnClickListener(v -> {
-                final Intent intent = new Intent()
-                        .setAction(MediaOutputSliceConstants.ACTION_MEDIA_OUTPUT)
-                        .putExtra(MediaOutputSliceConstants.EXTRA_PACKAGE_NAME,
-                                mController.getPackageName())
-                        .putExtra(MediaOutputSliceConstants.KEY_MEDIA_SESSION_TOKEN, mToken);
-                mActivityStarter.startActivity(intent, false, true /* dismissShade */,
-                        Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
-            });
-        } else {
-            Log.d(TAG, "LocalMediaManager is null. Not binding output chip for pkg=" + pkgName);
-        }
+        mViewHolder.getSeamless().setVisibility(View.VISIBLE);
+        setVisibleAndAlpha(collapsedSet, R.id.media_seamless, true /*visible */);
+        setVisibleAndAlpha(expandedSet, R.id.media_seamless, true /*visible */);
+        mViewHolder.getSeamless().setOnClickListener(v -> {
+            final Intent intent = new Intent()
+                    .setAction(MediaOutputSliceConstants.ACTION_MEDIA_OUTPUT)
+                    .putExtra(MediaOutputSliceConstants.EXTRA_PACKAGE_NAME,
+                            mController.getPackageName())
+                    .putExtra(MediaOutputSliceConstants.KEY_MEDIA_SESSION_TOKEN, mToken);
+            mActivityStarter.startActivity(intent, false, true /* dismissShade */,
+                    Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
+        });
+        final boolean isRemotePlayback;
         PlaybackInfo playbackInfo = mController.getPlaybackInfo();
         if (playbackInfo != null) {
-            mIsRemotePlayback = playbackInfo.getPlaybackType() == PlaybackInfo.PLAYBACK_TYPE_REMOTE;
+            isRemotePlayback = playbackInfo.getPlaybackType() == PlaybackInfo.PLAYBACK_TYPE_REMOTE;
         } else {
             Log.d(TAG, "PlaybackInfo was null. Defaulting to local playback.");
-            mIsRemotePlayback = false;
+            isRemotePlayback = false;
+        }
+
+        ImageView iconView = mViewHolder.getSeamlessIcon();
+        TextView deviceName = mViewHolder.getSeamlessText();
+
+        // Update the outline color
+        RippleDrawable bkgDrawable = (RippleDrawable) mViewHolder.getSeamless().getBackground();
+        GradientDrawable rect = (GradientDrawable) bkgDrawable.getDrawable(0);
+        rect.setStroke(2, deviceName.getCurrentTextColor());
+        rect.setColor(Color.TRANSPARENT);
+
+        if (isRemotePlayback) {
+            mViewHolder.getSeamless().setEnabled(false);
+            // TODO(b/156875717): setEnabled should cause the alpha to change.
+            mViewHolder.getSeamless().setAlpha(0.38f);
+            iconView.setImageResource(R.drawable.ic_hardware_speaker);
+            iconView.setVisibility(View.VISIBLE);
+            deviceName.setText(R.string.media_seamless_remote_device);
+        } else if (data.getDevice() != null && data.getDevice().getIcon() != null
+                && data.getDevice().getName() != null) {
+            mViewHolder.getSeamless().setEnabled(true);
+            mViewHolder.getSeamless().setAlpha(1f);
+            Drawable icon = data.getDevice().getIcon();
+            iconView.setVisibility(View.VISIBLE);
+
+            if (icon instanceof AdaptiveIcon) {
+                AdaptiveIcon aIcon = (AdaptiveIcon) icon;
+                aIcon.setBackgroundColor(mBackgroundColor);
+                iconView.setImageDrawable(aIcon);
+            } else {
+                iconView.setImageDrawable(icon);
+            }
+            deviceName.setText(data.getDevice().getName());
+        } else {
+            // Reset to default
+            Log.w(TAG, "device is null. Not binding output chip.");
+            mViewHolder.getSeamless().setEnabled(true);
+            mViewHolder.getSeamless().setAlpha(1f);
+            iconView.setVisibility(View.GONE);
+            deviceName.setText(com.android.internal.R.string.ext_media_seamless_action);
         }
+
         List<Integer> actionsWhenCollapsed = data.getActionsToShowInCompact();
         // Media controls
         int i = 0;
@@ -382,8 +382,6 @@ public class MediaControlPanel {
         // Set up long press menu
         // TODO: b/156036025 bring back media guts
 
-        makeActive();
-
         // Update both constraint sets to regenerate the animation.
         mViewHolder.getPlayer().updateState(R.id.collapsed, collapsedSet);
         mViewHolder.getPlayer().updateState(R.id.expanded, expandedSet);
@@ -515,60 +513,6 @@ public class MediaControlPanel {
     }
 
     /**
-     * Update the current device information
-     * @param device device information to display
-     */
-    private void updateDevice(MediaDevice device) {
-        mForegroundExecutor.execute(() -> {
-            updateChipInternal(device);
-        });
-    }
-
-    private void updateChipInternal(MediaDevice device) {
-        if (mViewHolder == null) {
-            return;
-        }
-        ImageView iconView = mViewHolder.getSeamlessIcon();
-        TextView deviceName = mViewHolder.getSeamlessText();
-
-        // Update the outline color
-        LinearLayout viewLayout = (LinearLayout) mViewHolder.getSeamless();
-        RippleDrawable bkgDrawable = (RippleDrawable) viewLayout.getBackground();
-        GradientDrawable rect = (GradientDrawable) bkgDrawable.getDrawable(0);
-        rect.setStroke(2, deviceName.getCurrentTextColor());
-        rect.setColor(Color.TRANSPARENT);
-
-        if (mIsRemotePlayback) {
-            mViewHolder.getSeamless().setEnabled(false);
-            mViewHolder.getSeamless().setAlpha(0.38f);
-            iconView.setImageResource(R.drawable.ic_hardware_speaker);
-            iconView.setVisibility(View.VISIBLE);
-            deviceName.setText(R.string.media_seamless_remote_device);
-        } else if (device != null) {
-            mViewHolder.getSeamless().setEnabled(true);
-            mViewHolder.getSeamless().setAlpha(1f);
-            Drawable icon = device.getIcon();
-            iconView.setVisibility(View.VISIBLE);
-
-            if (icon instanceof AdaptiveIcon) {
-                AdaptiveIcon aIcon = (AdaptiveIcon) icon;
-                aIcon.setBackgroundColor(mBackgroundColor);
-                iconView.setImageDrawable(aIcon);
-            } else {
-                iconView.setImageDrawable(icon);
-            }
-            deviceName.setText(device.getName());
-        } else {
-            // Reset to default
-            Log.d(TAG, "device is null. Not binding output chip.");
-            mViewHolder.getSeamless().setEnabled(true);
-            mViewHolder.getSeamless().setAlpha(1f);
-            iconView.setVisibility(View.GONE);
-            deviceName.setText(com.android.internal.R.string.ext_media_seamless_action);
-        }
-    }
-
-    /**
      * Puts controls into a resumption state if possible, or calls removePlayer if no component was
      * found that could resume playback
      */
@@ -642,27 +586,6 @@ public class MediaControlPanel {
         set.setAlpha(actionId, visible ? 1.0f : 0.0f);
     }
 
-    private void makeActive() {
-        Assert.isMainThread();
-        if (!mIsRegistered) {
-            if (mLocalMediaManager != null) {
-                mLocalMediaManager.registerCallback(mDeviceCallback);
-                mLocalMediaManager.startScan();
-            }
-            mIsRegistered = true;
-        }
-    }
-
-    private void makeInactive() {
-        Assert.isMainThread();
-        if (mIsRegistered) {
-            if (mLocalMediaManager != null) {
-                mLocalMediaManager.stopScan();
-                mLocalMediaManager.unregisterCallback(mDeviceCallback);
-            }
-            mIsRegistered = false;
-        }
-    }
     /**
      * Verify that we can connect to the given component with a MediaBrowser, and if so, add that
      * component to the list of resumption components
diff --git a/packages/SystemUI/src/com/android/systemui/media/MediaData.kt b/packages/SystemUI/src/com/android/systemui/media/MediaData.kt
index 85965d03a096..41d411019921 100644
--- a/packages/SystemUI/src/com/android/systemui/media/MediaData.kt
+++ b/packages/SystemUI/src/com/android/systemui/media/MediaData.kt
@@ -34,7 +34,8 @@ data class MediaData(
     val actionsToShowInCompact: List<Int>,
     val packageName: String?,
     val token: MediaSession.Token?,
-    val clickIntent: PendingIntent?
+    val clickIntent: PendingIntent?,
+    val device: MediaDeviceData?
 )
 
 /** State of a media action. */
@@ -43,3 +44,9 @@ data class MediaAction(
     val intent: PendingIntent?,
     val contentDescription: CharSequence?
 )
+
+/** State of the media device. */
+data class MediaDeviceData(
+    val icon: Drawable?,
+    val name: String?
+)
diff --git a/packages/SystemUI/src/com/android/systemui/media/MediaDataCombineLatest.kt b/packages/SystemUI/src/com/android/systemui/media/MediaDataCombineLatest.kt
new file mode 100644
index 000000000000..cce9838bb8e2
--- /dev/null
+++ b/packages/SystemUI/src/com/android/systemui/media/MediaDataCombineLatest.kt
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2020 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.systemui.media
+
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * Combines updates from [MediaDataManager] with [MediaDeviceManager].
+ */
+@Singleton
+class MediaDataCombineLatest @Inject constructor(
+    private val dataSource: MediaDataManager,
+    private val deviceSource: MediaDeviceManager
+) {
+    private val listeners: MutableSet<MediaDataManager.Listener> = mutableSetOf()
+    private val entries: MutableMap<String, Pair<MediaData?, MediaDeviceData?>> = mutableMapOf()
+
+    init {
+        dataSource.addListener(object : MediaDataManager.Listener {
+            override fun onMediaDataLoaded(key: String, data: MediaData) {
+                entries[key] = data to entries[key]?.second
+                update(key)
+            }
+            override fun onMediaDataRemoved(key: String) {
+                remove(key)
+            }
+        })
+        deviceSource.addListener(object : MediaDeviceManager.Listener {
+            override fun onMediaDeviceChanged(key: String, data: MediaDeviceData?) {
+                entries[key] = entries[key]?.first to data
+                update(key)
+            }
+            override fun onKeyRemoved(key: String) {
+                remove(key)
+            }
+        })
+    }
+
+    /**
+     * Add a listener for [MediaData] changes that has been combined with latest [MediaDeviceData].
+     */
+    fun addListener(listener: MediaDataManager.Listener) = listeners.add(listener)
+
+    /**
+     * Remove a listener registered with addListener.
+     */
+    fun removeListener(listener: MediaDataManager.Listener) = listeners.remove(listener)
+
+    private fun update(key: String) {
+        val (entry, device) = entries[key] ?: null to null
+        if (entry != null && device != null) {
+            val data = entry.copy(device = device)
+            listeners.forEach {
+                it.onMediaDataLoaded(key, data)
+            }
+        }
+    }
+
+    private fun remove(key: String) {
+        entries.remove(key)?.let {
+            listeners.forEach {
+                it.onMediaDataRemoved(key)
+            }
+        }
+    }
+}
diff --git a/packages/SystemUI/src/com/android/systemui/media/MediaDataManager.kt b/packages/SystemUI/src/com/android/systemui/media/MediaDataManager.kt
index f950d41f02b1..8cbe3ecf5387 100644
--- a/packages/SystemUI/src/com/android/systemui/media/MediaDataManager.kt
+++ b/packages/SystemUI/src/com/android/systemui/media/MediaDataManager.kt
@@ -55,7 +55,19 @@ private const val LUMINOSITY_THRESHOLD = 0.05f
 private const val SATURATION_MULTIPLIER = 0.8f
 
 private val LOADING = MediaData(false, 0, null, null, null, null, null,
-        emptyList(), emptyList(), null, null, null)
+        emptyList(), emptyList(), null, null, null, null)
+
+fun isMediaNotification(sbn: StatusBarNotification): Boolean {
+    if (!sbn.notification.hasMediaSession()) {
+        return false
+    }
+    val notificationStyle = sbn.notification.notificationStyle
+    if (Notification.DecoratedMediaCustomViewStyle::class.java.equals(notificationStyle) ||
+            Notification.MediaStyle::class.java.equals(notificationStyle)) {
+        return true
+    }
+    return false
+}
 
 /**
  * A class that facilitates management and loading of Media Data, ready for binding.
@@ -72,7 +84,7 @@ class MediaDataManager @Inject constructor(
     private val mediaEntries: LinkedHashMap<String, MediaData> = LinkedHashMap()
 
     fun onNotificationAdded(key: String, sbn: StatusBarNotification) {
-        if (isMediaNotification(sbn)) {
+        if (Utils.useQsMediaPlayer(context) && isMediaNotification(sbn)) {
             if (!mediaEntries.containsKey(key)) {
                 mediaEntries.put(key, LOADING)
             }
@@ -204,7 +216,7 @@ class MediaDataManager @Inject constructor(
         foregroundExecutor.execute {
             onMediaDataLoaded(key, MediaData(true, bgColor, app, smallIconDrawable, artist, song,
                     artWorkIcon, actionIcons, actionsToShowCollapsed, sbn.packageName, token,
-                    notif.contentIntent))
+                    notif.contentIntent, null))
         }
     }
 
@@ -270,21 +282,6 @@ class MediaDataManager @Inject constructor(
         }
     }
 
-    private fun isMediaNotification(sbn: StatusBarNotification): Boolean {
-        if (!Utils.useQsMediaPlayer(context)) {
-            return false
-        }
-        if (!sbn.notification.hasMediaSession()) {
-            return false
-        }
-        val notificationStyle = sbn.notification.notificationStyle
-        if (Notification.DecoratedMediaCustomViewStyle::class.java.equals(notificationStyle) ||
-                Notification.MediaStyle::class.java.equals(notificationStyle)) {
-            return true
-        }
-        return false
-    }
-
     /**
      * Are there any media notifications active?
      */
diff --git a/packages/SystemUI/src/com/android/systemui/media/MediaDeviceManager.kt b/packages/SystemUI/src/com/android/systemui/media/MediaDeviceManager.kt
new file mode 100644
index 000000000000..2d16e2930365
--- /dev/null
+++ b/packages/SystemUI/src/com/android/systemui/media/MediaDeviceManager.kt
@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) 2020 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.systemui.media
+
+import android.content.Context
+import android.service.notification.StatusBarNotification
+import com.android.settingslib.media.LocalMediaManager
+import com.android.settingslib.media.MediaDevice
+import com.android.systemui.dagger.qualifiers.Main
+import java.util.concurrent.Executor
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * Provides information about the route (ie. device) where playback is occurring.
+ */
+@Singleton
+class MediaDeviceManager @Inject constructor(
+    private val context: Context,
+    private val localMediaManagerFactory: LocalMediaManagerFactory,
+    private val featureFlag: MediaFeatureFlag,
+    @Main private val fgExecutor: Executor
+) {
+    private val listeners: MutableSet<Listener> = mutableSetOf()
+    private val entries: MutableMap<String, Token> = mutableMapOf()
+
+    /**
+     * Add a listener for changes to the media route (ie. device).
+     */
+    fun addListener(listener: Listener) = listeners.add(listener)
+
+    /**
+     * Remove a listener that has been registered with addListener.
+     */
+    fun removeListener(listener: Listener) = listeners.remove(listener)
+
+    fun onNotificationAdded(key: String, sbn: StatusBarNotification) {
+        if (featureFlag.enabled && isMediaNotification(sbn)) {
+            var tok = entries[key]
+            if (tok == null) {
+                tok = Token(key, localMediaManagerFactory.create(sbn.packageName))
+                entries[key] = tok
+                tok.start()
+            }
+        } else {
+            onNotificationRemoved(key)
+        }
+    }
+
+    fun onNotificationRemoved(key: String) {
+        val token = entries.remove(key)
+        token?.stop()
+        token?.let {
+            listeners.forEach {
+                it.onKeyRemoved(key)
+            }
+        }
+    }
+
+    private fun processDevice(key: String, device: MediaDevice?) {
+        val data = MediaDeviceData(device?.icon, device?.name)
+        listeners.forEach {
+            it.onMediaDeviceChanged(key, data)
+        }
+    }
+
+    interface Listener {
+        /** Called when the route has changed for a given notification. */
+        fun onMediaDeviceChanged(key: String, data: MediaDeviceData?)
+        /** Called when the notification was removed. */
+        fun onKeyRemoved(key: String)
+    }
+
+    private inner class Token(
+        val key: String,
+        val localMediaManager: LocalMediaManager
+    ) : LocalMediaManager.DeviceCallback {
+        private var current: MediaDevice? = null
+            set(value) {
+                if (value != field) {
+                    field = value
+                    processDevice(key, value)
+                }
+            }
+        fun start() {
+            localMediaManager.registerCallback(this)
+            localMediaManager.startScan()
+            current = localMediaManager.getCurrentConnectedDevice()
+        }
+        fun stop() {
+            localMediaManager.stopScan()
+            localMediaManager.unregisterCallback(this)
+        }
+        override fun onDeviceListUpdate(devices: List<MediaDevice>?) = fgExecutor.execute {
+            current = localMediaManager.getCurrentConnectedDevice()
+        }
+        override fun onSelectedDeviceStateChanged(device: MediaDevice, state: Int) {
+            fgExecutor.execute {
+                current = device
+            }
+        }
+    }
+}
diff --git a/packages/SystemUI/src/com/android/systemui/media/MediaFeatureFlag.kt b/packages/SystemUI/src/com/android/systemui/media/MediaFeatureFlag.kt
new file mode 100644
index 000000000000..75eb33da64d8
--- /dev/null
+++ b/packages/SystemUI/src/com/android/systemui/media/MediaFeatureFlag.kt
@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2020 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.systemui.media
+
+import android.content.Context
+import com.android.systemui.util.Utils
+import javax.inject.Inject
+
+/**
+ * Provides access to the current value of the feature flag.
+ */
+class MediaFeatureFlag @Inject constructor(private val context: Context) {
+    val enabled
+        get() = Utils.useQsMediaPlayer(context)
+}
diff --git a/packages/SystemUI/src/com/android/systemui/media/MediaViewManager.kt b/packages/SystemUI/src/com/android/systemui/media/MediaViewManager.kt
index 8db9dcc1ecec..17e8404fe705 100644
--- a/packages/SystemUI/src/com/android/systemui/media/MediaViewManager.kt
+++ b/packages/SystemUI/src/com/android/systemui/media/MediaViewManager.kt
@@ -6,9 +6,6 @@ import android.view.View
 import android.view.ViewGroup
 import android.widget.HorizontalScrollView
 import android.widget.LinearLayout
-import com.android.settingslib.bluetooth.LocalBluetoothManager
-import com.android.settingslib.media.InfoMediaManager
-import com.android.settingslib.media.LocalMediaManager
 import com.android.systemui.R
 import com.android.systemui.dagger.qualifiers.Background
 import com.android.systemui.dagger.qualifiers.Main
@@ -30,10 +27,9 @@ class MediaViewManager @Inject constructor(
     private val context: Context,
     @Main private val foregroundExecutor: Executor,
     @Background private val backgroundExecutor: DelayableExecutor,
-    private val localBluetoothManager: LocalBluetoothManager?,
     private val visualStabilityManager: VisualStabilityManager,
     private val activityStarter: ActivityStarter,
-    mediaManager: MediaDataManager
+    mediaManager: MediaDataCombineLatest
 ) {
     private var playerWidth: Int = 0
     private var playerWidthPlusPadding: Int = 0
@@ -42,7 +38,7 @@ class MediaViewManager @Inject constructor(
     val mediaCarousel: HorizontalScrollView
     private val mediaContent: ViewGroup
     private val mediaPlayers: MutableMap<String, MediaControlPanel> = mutableMapOf()
-    private val visualStabilityCallback : VisualStabilityManager.Callback
+    private val visualStabilityCallback: VisualStabilityManager.Callback
     private var activeMediaIndex: Int = 0
     private var needsReordering: Boolean = false
     private var scrollIntoCurrentMedia: Int = 0
@@ -151,15 +147,8 @@ class MediaViewManager @Inject constructor(
     private fun updateView(key: String, data: MediaData) {
         var existingPlayer = mediaPlayers[key]
         if (existingPlayer == null) {
-            // Set up listener for device changes
-            // TODO: integrate with MediaTransferManager?
-            val imm = InfoMediaManager(context, data.packageName,
-                    null /* notification */, localBluetoothManager)
-            val routeManager = LocalMediaManager(context, localBluetoothManager,
-                    imm, data.packageName)
-
-            existingPlayer = MediaControlPanel(context, routeManager, foregroundExecutor,
-                    backgroundExecutor, activityStarter)
+            existingPlayer = MediaControlPanel(context, foregroundExecutor, backgroundExecutor,
+                    activityStarter)
             existingPlayer.attach(PlayerViewHolder.create(LayoutInflater.from(context),
                     mediaContent))
             mediaPlayers[key] = existingPlayer
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/NotificationMediaManager.java b/packages/SystemUI/src/com/android/systemui/statusbar/NotificationMediaManager.java
index 0fa1f553c1f3..8ed69d8fb982 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/NotificationMediaManager.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/NotificationMediaManager.java
@@ -53,6 +53,7 @@ import com.android.systemui.Interpolators;
 import com.android.systemui.colorextraction.SysuiColorExtractor;
 import com.android.systemui.dagger.qualifiers.Main;
 import com.android.systemui.media.MediaDataManager;
+import com.android.systemui.media.MediaDeviceManager;
 import com.android.systemui.plugins.statusbar.StatusBarStateController;
 import com.android.systemui.statusbar.dagger.StatusBarModule;
 import com.android.systemui.statusbar.notification.NotificationEntryListener;
@@ -218,7 +219,8 @@ public class NotificationMediaManager implements Dumpable {
             KeyguardBypassController keyguardBypassController,
             @Main DelayableExecutor mainExecutor,
             DeviceConfigProxy deviceConfig,
-            MediaDataManager mediaDataManager) {
+            MediaDataManager mediaDataManager,
+            MediaDeviceManager mediaDeviceManager) {
         mContext = context;
         mMediaArtworkProcessor = mediaArtworkProcessor;
         mKeyguardBypassController = keyguardBypassController;
@@ -239,11 +241,13 @@ public class NotificationMediaManager implements Dumpable {
             @Override
             public void onPendingEntryAdded(NotificationEntry entry) {
                 mediaDataManager.onNotificationAdded(entry.getKey(), entry.getSbn());
+                mediaDeviceManager.onNotificationAdded(entry.getKey(), entry.getSbn());
             }
 
             @Override
             public void onPreEntryUpdated(NotificationEntry entry) {
                 mediaDataManager.onNotificationAdded(entry.getKey(), entry.getSbn());
+                mediaDeviceManager.onNotificationAdded(entry.getKey(), entry.getSbn());
             }
 
             @Override
@@ -264,6 +268,7 @@ public class NotificationMediaManager implements Dumpable {
                     int reason) {
                 onNotificationRemoved(entry.getKey());
                 mediaDataManager.onNotificationRemoved(entry.getKey());
+                mediaDeviceManager.onNotificationRemoved(entry.getKey());
             }
         });
 
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/dagger/StatusBarDependenciesModule.java b/packages/SystemUI/src/com/android/systemui/statusbar/dagger/StatusBarDependenciesModule.java
index 8c9ce500e3ea..ac2a9c118672 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/dagger/StatusBarDependenciesModule.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/dagger/StatusBarDependenciesModule.java
@@ -24,6 +24,7 @@ import com.android.internal.statusbar.IStatusBarService;
 import com.android.systemui.bubbles.BubbleController;
 import com.android.systemui.dagger.qualifiers.Main;
 import com.android.systemui.media.MediaDataManager;
+import com.android.systemui.media.MediaDeviceManager;
 import com.android.systemui.plugins.statusbar.StatusBarStateController;
 import com.android.systemui.statusbar.ActionClickLogger;
 import com.android.systemui.statusbar.CommandQueue;
@@ -101,7 +102,8 @@ public interface StatusBarDependenciesModule {
             KeyguardBypassController keyguardBypassController,
             @Main DelayableExecutor mainExecutor,
             DeviceConfigProxy deviceConfigProxy,
-            MediaDataManager mediaDataManager) {
+            MediaDataManager mediaDataManager,
+            MediaDeviceManager mediaDeviceManager) {
         return new NotificationMediaManager(
                 context,
                 statusBarLazy,
@@ -111,7 +113,8 @@ public interface StatusBarDependenciesModule {
                 keyguardBypassController,
                 mainExecutor,
                 deviceConfigProxy,
-                mediaDataManager);
+                mediaDataManager,
+                mediaDeviceManager);
     }
 
     /** */
diff --git a/packages/SystemUI/tests/src/com/android/systemui/media/MediaControlPanelTest.kt b/packages/SystemUI/tests/src/com/android/systemui/media/MediaControlPanelTest.kt
index 60d15a8fb480..e8fb41a18ce9 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/media/MediaControlPanelTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/media/MediaControlPanelTest.kt
@@ -18,6 +18,8 @@ package com.android.systemui.media
 
 import android.content.res.ColorStateList
 import android.graphics.Color
+import android.graphics.drawable.GradientDrawable
+import android.graphics.drawable.RippleDrawable
 import android.media.MediaMetadata
 import android.media.session.MediaSession
 import android.media.session.PlaybackState
@@ -104,7 +106,7 @@ public class MediaControlPanelTest : SysuiTestCase() {
 
         activityStarter = mock(ActivityStarter::class.java)
 
-        player = MediaControlPanel(context, null, fgExecutor, bgExecutor, activityStarter)
+        player = MediaControlPanel(context, fgExecutor, bgExecutor, activityStarter)
 
         // Mock out a view holder for the player to attach to.
         holder = mock(PlayerViewHolder::class.java)
@@ -129,6 +131,9 @@ public class MediaControlPanelTest : SysuiTestCase() {
         artistText = TextView(context)
         whenever(holder.artistText).thenReturn(artistText)
         seamless = FrameLayout(context)
+        val seamlessBackground = mock(RippleDrawable::class.java)
+        seamless.setBackground(seamlessBackground)
+        whenever(seamlessBackground.getDrawable(0)).thenReturn(mock(GradientDrawable::class.java))
         whenever(holder.seamless).thenReturn(seamless)
         seamlessIcon = ImageView(context)
         whenever(holder.seamlessIcon).thenReturn(seamlessIcon)
@@ -176,7 +181,7 @@ public class MediaControlPanelTest : SysuiTestCase() {
     @Test
     fun bindWhenUnattached() {
         val state = MediaData(true, BG_COLOR, APP, null, ARTIST, TITLE, null, emptyList(),
-                emptyList(), PACKAGE, null, null)
+                emptyList(), PACKAGE, null, null, MediaDeviceData(null, DEVICE_NAME))
         player.bind(state)
         assertThat(player.isPlaying()).isFalse()
     }
@@ -185,7 +190,8 @@ public class MediaControlPanelTest : SysuiTestCase() {
     fun bindText() {
         player.attach(holder)
         val state = MediaData(true, BG_COLOR, APP, null, ARTIST, TITLE, null, emptyList(),
-                emptyList(), PACKAGE, session.getSessionToken(), null)
+                emptyList(), PACKAGE, session.getSessionToken(), null,
+                MediaDeviceData(null, DEVICE_NAME))
         player.bind(state)
         assertThat(appName.getText()).isEqualTo(APP)
         assertThat(titleText.getText()).isEqualTo(TITLE)
@@ -196,7 +202,8 @@ public class MediaControlPanelTest : SysuiTestCase() {
     fun bindBackgroundColor() {
         player.attach(holder)
         val state = MediaData(true, BG_COLOR, APP, null, ARTIST, TITLE, null, emptyList(),
-                emptyList(), PACKAGE, session.getSessionToken(), null)
+                emptyList(), PACKAGE, session.getSessionToken(), null,
+                MediaDeviceData(null, DEVICE_NAME))
         player.bind(state)
         assertThat(background.getBackgroundTintList()).isEqualTo(ColorStateList.valueOf(BG_COLOR))
     }
diff --git a/packages/SystemUI/tests/src/com/android/systemui/media/MediaDataCombineLatestTest.java b/packages/SystemUI/tests/src/com/android/systemui/media/MediaDataCombineLatestTest.java
new file mode 100644
index 000000000000..64a180f8aaab
--- /dev/null
+++ b/packages/SystemUI/tests/src/com/android/systemui/media/MediaDataCombineLatestTest.java
@@ -0,0 +1,161 @@
+/*
+ * Copyright (C) 2020 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.systemui.media;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.Mockito.any;
+import static org.mockito.Mockito.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+
+import android.graphics.Color;
+import android.testing.AndroidTestingRunner;
+import android.testing.TestableLooper;
+
+import androidx.test.filters.SmallTest;
+
+import com.android.systemui.SysuiTestCase;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Mock;
+
+import java.util.ArrayList;
+
+@SmallTest
+@RunWith(AndroidTestingRunner.class)
+@TestableLooper.RunWithLooper
+public class MediaDataCombineLatestTest extends SysuiTestCase {
+
+    private static final String KEY = "TEST_KEY";
+    private static final String APP = "APP";
+    private static final String PACKAGE = "PKG";
+    private static final int BG_COLOR = Color.RED;
+    private static final String ARTIST = "ARTIST";
+    private static final String TITLE = "TITLE";
+    private static final String DEVICE_NAME = "DEVICE_NAME";
+
+    private MediaDataCombineLatest mManager;
+
+    @Mock private MediaDataManager mDataSource;
+    @Mock private MediaDeviceManager mDeviceSource;
+    @Mock private MediaDataManager.Listener mListener;
+
+    private MediaDataManager.Listener mDataListener;
+    private MediaDeviceManager.Listener mDeviceListener;
+
+    private MediaData mMediaData;
+    private MediaDeviceData mDeviceData;
+
+    @Before
+    public void setUp() {
+        mDataSource = mock(MediaDataManager.class);
+        mDeviceSource = mock(MediaDeviceManager.class);
+        mListener = mock(MediaDataManager.Listener.class);
+
+        mManager = new MediaDataCombineLatest(mDataSource, mDeviceSource);
+
+        mDataListener = captureDataListener();
+        mDeviceListener = captureDeviceListener();
+
+        mManager.addListener(mListener);
+
+        mMediaData = new MediaData(true, BG_COLOR, APP, null, ARTIST, TITLE, null,
+                new ArrayList<>(), new ArrayList<>(), PACKAGE, null, null, null);
+        mDeviceData = new MediaDeviceData(null, DEVICE_NAME);
+    }
+
+    @Test
+    public void eventNotEmittedWithoutDevice() {
+        // WHEN data source emits an event without device data
+        mDataListener.onMediaDataLoaded(KEY, mMediaData);
+        // THEN an event isn't emitted
+        verify(mListener, never()).onMediaDataLoaded(eq(KEY), any());
+    }
+
+    @Test
+    public void eventNotEmittedWithoutMedia() {
+        // WHEN device source emits an event without media data
+        mDeviceListener.onMediaDeviceChanged(KEY, mDeviceData);
+        // THEN an event isn't emitted
+        verify(mListener, never()).onMediaDataLoaded(eq(KEY), any());
+    }
+
+    @Test
+    public void emitEventAfterDeviceFirst() {
+        // GIVEN that a device event has already been received
+        mDeviceListener.onMediaDeviceChanged(KEY, mDeviceData);
+        // WHEN media event is received
+        mDataListener.onMediaDataLoaded(KEY, mMediaData);
+        // THEN the listener receives a combined event
+        ArgumentCaptor<MediaData> captor = ArgumentCaptor.forClass(MediaData.class);
+        verify(mListener).onMediaDataLoaded(eq(KEY), captor.capture());
+        assertThat(captor.getValue().getDevice()).isNotNull();
+    }
+
+    @Test
+    public void emitEventAfterMediaFirst() {
+        // GIVEN that media event has already been received
+        mDataListener.onMediaDataLoaded(KEY, mMediaData);
+        // WHEN device event is received
+        mDeviceListener.onMediaDeviceChanged(KEY, mDeviceData);
+        // THEN the listener receives a combined event
+        ArgumentCaptor<MediaData> captor = ArgumentCaptor.forClass(MediaData.class);
+        verify(mListener).onMediaDataLoaded(eq(KEY), captor.capture());
+        assertThat(captor.getValue().getDevice()).isNotNull();
+    }
+
+    @Test
+    public void mediaDataRemoved() {
+        // WHEN media data is removed without first receiving device or data
+        mDataListener.onMediaDataRemoved(KEY);
+        // THEN a removed event isn't emitted
+        verify(mListener, never()).onMediaDataRemoved(eq(KEY));
+    }
+
+    @Test
+    public void mediaDataRemovedAfterMediaEvent() {
+        mDataListener.onMediaDataLoaded(KEY, mMediaData);
+        mDataListener.onMediaDataRemoved(KEY);
+        verify(mListener).onMediaDataRemoved(eq(KEY));
+    }
+
+    @Test
+    public void mediaDataRemovedAfterDeviceEvent() {
+        mDeviceListener.onMediaDeviceChanged(KEY, mDeviceData);
+        mDataListener.onMediaDataRemoved(KEY);
+        verify(mListener).onMediaDataRemoved(eq(KEY));
+    }
+
+    private MediaDataManager.Listener captureDataListener() {
+        ArgumentCaptor<MediaDataManager.Listener> captor = ArgumentCaptor.forClass(
+                MediaDataManager.Listener.class);
+        verify(mDataSource).addListener(captor.capture());
+        return captor.getValue();
+    }
+
+    private MediaDeviceManager.Listener captureDeviceListener() {
+        ArgumentCaptor<MediaDeviceManager.Listener> captor = ArgumentCaptor.forClass(
+                MediaDeviceManager.Listener.class);
+        verify(mDeviceSource).addListener(captor.capture());
+        return captor.getValue();
+    }
+}
diff --git a/packages/SystemUI/tests/src/com/android/systemui/media/MediaDeviceManagerTest.kt b/packages/SystemUI/tests/src/com/android/systemui/media/MediaDeviceManagerTest.kt
new file mode 100644
index 000000000000..ac6b5f6bca66
--- /dev/null
+++ b/packages/SystemUI/tests/src/com/android/systemui/media/MediaDeviceManagerTest.kt
@@ -0,0 +1,195 @@
+/*
+ * Copyright (C) 2020 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.systemui.media
+
+import android.app.Notification
+import android.media.MediaMetadata
+import android.media.session.MediaSession
+import android.media.session.PlaybackState
+import android.os.Process
+import android.service.notification.StatusBarNotification
+import android.testing.AndroidTestingRunner
+import android.testing.TestableLooper
+import androidx.test.filters.SmallTest
+
+import com.android.settingslib.media.LocalMediaManager
+import com.android.settingslib.media.MediaDevice
+import com.android.systemui.SysuiTestCase
+import com.android.systemui.util.concurrency.FakeExecutor
+import com.android.systemui.util.time.FakeSystemClock
+
+import com.google.common.truth.Truth.assertThat
+
+import org.junit.After
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.ArgumentCaptor
+import org.mockito.Mock
+import org.mockito.Mockito
+import org.mockito.Mockito.any
+import org.mockito.Mockito.mock
+import org.mockito.Mockito.never
+import org.mockito.Mockito.verify
+import org.mockito.Mockito.`when` as whenever
+
+private const val KEY = "TEST_KEY"
+private const val PACKAGE = "PKG"
+private const val SESSION_KEY = "SESSION_KEY"
+private const val SESSION_ARTIST = "SESSION_ARTIST"
+private const val SESSION_TITLE = "SESSION_TITLE"
+private const val DEVICE_NAME = "DEVICE_NAME"
+
+private fun <T> eq(value: T): T = Mockito.eq(value) ?: value
+
+@SmallTest
+@RunWith(AndroidTestingRunner::class)
+@TestableLooper.RunWithLooper
+public class MediaDeviceManagerTest : SysuiTestCase() {
+
+    private lateinit var manager: MediaDeviceManager
+
+    @Mock private lateinit var lmmFactory: LocalMediaManagerFactory
+    @Mock private lateinit var lmm: LocalMediaManager
+    @Mock private lateinit var featureFlag: MediaFeatureFlag
+    private lateinit var fakeExecutor: FakeExecutor
+
+    @Mock private lateinit var device: MediaDevice
+    private lateinit var session: MediaSession
+    private lateinit var metadataBuilder: MediaMetadata.Builder
+    private lateinit var playbackBuilder: PlaybackState.Builder
+    private lateinit var notifBuilder: Notification.Builder
+    private lateinit var sbn: StatusBarNotification
+
+    @Before
+    fun setup() {
+        lmmFactory = mock(LocalMediaManagerFactory::class.java)
+        lmm = mock(LocalMediaManager::class.java)
+        device = mock(MediaDevice::class.java)
+        whenever(device.name).thenReturn(DEVICE_NAME)
+        whenever(lmmFactory.create(PACKAGE)).thenReturn(lmm)
+        whenever(lmm.getCurrentConnectedDevice()).thenReturn(device)
+        featureFlag = mock(MediaFeatureFlag::class.java)
+        whenever(featureFlag.enabled).thenReturn(true)
+
+        fakeExecutor = FakeExecutor(FakeSystemClock())
+
+        manager = MediaDeviceManager(context, lmmFactory, featureFlag, fakeExecutor)
+
+        // Create a media sesssion and notification for testing.
+        metadataBuilder = MediaMetadata.Builder().apply {
+            putString(MediaMetadata.METADATA_KEY_ARTIST, SESSION_ARTIST)
+            putString(MediaMetadata.METADATA_KEY_TITLE, SESSION_TITLE)
+        }
+        playbackBuilder = PlaybackState.Builder().apply {
+            setState(PlaybackState.STATE_PAUSED, 6000L, 1f)
+            setActions(PlaybackState.ACTION_PLAY)
+        }
+        session = MediaSession(context, SESSION_KEY).apply {
+            setMetadata(metadataBuilder.build())
+            setPlaybackState(playbackBuilder.build())
+        }
+        session.setActive(true)
+        notifBuilder = Notification.Builder(context, "NONE").apply {
+            setContentTitle(SESSION_TITLE)
+            setContentText(SESSION_ARTIST)
+            setSmallIcon(android.R.drawable.ic_media_pause)
+            setStyle(Notification.MediaStyle().setMediaSession(session.getSessionToken()))
+        }
+        sbn = StatusBarNotification(PACKAGE, PACKAGE, 0, "TAG", Process.myUid(), 0, 0,
+                notifBuilder.build(), Process.myUserHandle(), 0)
+    }
+
+    @After
+    fun tearDown() {
+        session.release()
+    }
+
+    @Test
+    fun removeUnknown() {
+        manager.onNotificationRemoved("unknown")
+    }
+
+    @Test
+    fun addNotification() {
+        manager.onNotificationAdded(KEY, sbn)
+        verify(lmmFactory).create(PACKAGE)
+    }
+
+    @Test
+    fun featureDisabled() {
+        whenever(featureFlag.enabled).thenReturn(false)
+        manager.onNotificationAdded(KEY, sbn)
+        verify(lmmFactory, never()).create(PACKAGE)
+    }
+
+    @Test
+    fun addAndRemoveNotification() {
+        manager.onNotificationAdded(KEY, sbn)
+        manager.onNotificationRemoved(KEY)
+        verify(lmm).unregisterCallback(any())
+    }
+
+    @Test
+    fun deviceListUpdate() {
+        val listener = mock(MediaDeviceManager.Listener::class.java)
+        manager.addListener(listener)
+        manager.onNotificationAdded(KEY, sbn)
+        val deviceCallback = captureCallback()
+        // WHEN the device list changes
+        deviceCallback.onDeviceListUpdate(mutableListOf(device))
+        assertThat(fakeExecutor.runAllReady()).isEqualTo(1)
+        // THEN the update is dispatched to the listener
+        val captor = ArgumentCaptor.forClass(MediaDeviceData::class.java)
+        verify(listener).onMediaDeviceChanged(eq(KEY), captor.capture())
+        val data = captor.getValue()
+        assertThat(data.name).isEqualTo(DEVICE_NAME)
+    }
+
+    @Test
+    fun selectedDeviceStateChanged() {
+        val listener = mock(MediaDeviceManager.Listener::class.java)
+        manager.addListener(listener)
+        manager.onNotificationAdded(KEY, sbn)
+        val deviceCallback = captureCallback()
+        // WHEN the selected device changes state
+        deviceCallback.onSelectedDeviceStateChanged(device, 1)
+        assertThat(fakeExecutor.runAllReady()).isEqualTo(1)
+        // THEN the update is dispatched to the listener
+        val captor = ArgumentCaptor.forClass(MediaDeviceData::class.java)
+        verify(listener).onMediaDeviceChanged(eq(KEY), captor.capture())
+        val data = captor.getValue()
+        assertThat(data.name).isEqualTo(DEVICE_NAME)
+    }
+
+    @Test
+    fun listenerReceivesKeyRemoved() {
+        manager.onNotificationAdded(KEY, sbn)
+        val listener = mock(MediaDeviceManager.Listener::class.java)
+        manager.addListener(listener)
+        // WHEN the notification is removed
+        manager.onNotificationRemoved(KEY)
+        // THEN the listener receives key removed event
+        verify(listener).onKeyRemoved(eq(KEY))
+    }
+
+    fun captureCallback(): LocalMediaManager.DeviceCallback {
+        val captor = ArgumentCaptor.forClass(LocalMediaManager.DeviceCallback::class.java)
+        verify(lmm).registerCallback(captor.capture())
+        return captor.getValue()
+    }
+}