Implement MediaOutputSlice

Implement MediaOutputSlice that used to show the MediaDevice list and
switch the device to transfer the media.

Bug: 121083246
Test: make -j RunSettingsRoboTests
Change-Id: I0d57cc75ca1fc8eae2d943819f84b1ec8b608255

src/com/android/settings/media/MediaDeviceUpdateWorker.java

@@ -0,0 +1,107 @@
+/*
+ * 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.settings.media;
+
+import android.content.Context;
+import android.net.Uri;
+
+import androidx.annotation.VisibleForTesting;
+
+import com.android.settings.slices.SliceBackgroundWorker;
+import com.android.settingslib.media.LocalMediaManager;
+import com.android.settingslib.media.MediaDevice;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * SliceBackgroundWorker for get MediaDevice list and handle MediaDevice state change event.
+ */
+public class MediaDeviceUpdateWorker extends SliceBackgroundWorker
+        implements LocalMediaManager.DeviceCallback {
+
+    private final Context mContext;
+    private final List<MediaDevice> mMediaDevices = new ArrayList<>();
+
+    private String mPackageName;
+
+    @VisibleForTesting
+    LocalMediaManager mLocalMediaManager;
+
+    public MediaDeviceUpdateWorker(Context context, Uri uri) {
+        super(context, uri);
+        mContext = context;
+    }
+
+    public void setPackageName(String packageName) {
+        mPackageName = packageName;
+    }
+
+    @Override
+    protected void onSlicePinned() {
+        mMediaDevices.clear();
+        if (mLocalMediaManager == null) {
+            mLocalMediaManager = new LocalMediaManager(mContext, mPackageName, null);
+        }
+
+        mLocalMediaManager.registerCallback(this);
+        mLocalMediaManager.startScan();
+    }
+
+    @Override
+    protected void onSliceUnpinned() {
+        mLocalMediaManager.unregisterCallback(this);
+        mLocalMediaManager.stopScan();
+    }
+
+    @Override
+    public void close() {
+
+    }
+
+    @Override
+    public void onDeviceListUpdate(List<MediaDevice> devices) {
+        buildMediaDevices(devices);
+        notifySliceChange();
+    }
+
+    private void buildMediaDevices(List<MediaDevice> devices) {
+        mMediaDevices.clear();
+        mMediaDevices.addAll(devices);
+    }
+
+    @Override
+    public void onSelectedDeviceStateChanged(MediaDevice device, int state) {
+        notifySliceChange();
+    }
+
+    public List<MediaDevice> getMediaDevices() {
+        return new ArrayList<>(mMediaDevices);
+    }
+
+    public void connectDevice(MediaDevice device) {
+        mLocalMediaManager.connectDevice(device);
+    }
+
+    public MediaDevice getMediaDeviceById(String id) {
+        return mLocalMediaManager.getMediaDeviceById(mMediaDevices, id);
+    }
+
+    public MediaDevice getCurrentConnectedMediaDevice() {
+        return mLocalMediaManager.getCurrentConnectedDevice();
+    }
+}