content: package com.android.server.hdmi;
  
  /*
   * Copyright (C) 2014 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.
   */
  
  import android.hardware.hdmi.HdmiControlManager;
  import android.hardware.hdmi.HdmiPlaybackClient;
  import android.hardware.hdmi.HdmiPlaybackClient.DisplayStatusCallback;
  import android.hardware.hdmi.IHdmiControlCallback;
  import android.os.RemoteException;
  import android.util.Slog;
  
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * Feature action that queries the power status of other device. This action is initiated via
   * {@link HdmiPlaybackClient#queryDisplayStatus(DisplayStatusCallback)} from the Android system
   * working as playback device to get the power status of TV device.
   * <p>
   * Package-private, accessed by {@link HdmiControlService} only.
   */
  final class DevicePowerStatusAction extends HdmiCecFeatureAction {
      private static final String TAG = "DevicePowerStatusAction";
  
      // State in which the action is waiting for <Report Power Status>.
      private static final int STATE_WAITING_FOR_REPORT_POWER_STATUS = 1;
  
      private final int mTargetAddress;
      private final List<IHdmiControlCallback> mCallbacks = new ArrayList<>();
  
      static DevicePowerStatusAction create(HdmiCecLocalDevice source,
              int targetAddress, IHdmiControlCallback callback) {
          if (source == null || callback == null) {
              Slog.e(TAG, "Wrong arguments");
              return null;
          }
          return new DevicePowerStatusAction(source, targetAddress, callback);
      }
  
      private DevicePowerStatusAction(HdmiCecLocalDevice localDevice,
              int targetAddress, IHdmiControlCallback callback) {
          super(localDevice);
          mTargetAddress = targetAddress;
          addCallback(callback);
      }
  
      @Override
      boolean start() {
          queryDevicePowerStatus();
          mState = STATE_WAITING_FOR_REPORT_POWER_STATUS;
          addTimer(mState, HdmiConfig.TIMEOUT_MS);
          return true;
      }
  
      private void queryDevicePowerStatus() {
          sendCommand(HdmiCecMessageBuilder.buildGiveDevicePowerStatus(getSourceAddress(),
                  mTargetAddress));
      }
  
      @Override
      boolean processCommand(HdmiCecMessage cmd) {
          if (mState != STATE_WAITING_FOR_REPORT_POWER_STATUS
                 || mTargetAddress != cmd.getSource()) {
              return false;
          }
          if (cmd.getOpcode() == Constants.MESSAGE_REPORT_POWER_STATUS) {
              int status = cmd.getParams()[0];
              invokeCallback(status);
              finish();
              return true;
          }
          return false;
      }
  
      @Override
      void handleTimerEvent(int state) {
          if (mState != state) {
              return;
          }
          if (state == STATE_WAITING_FOR_REPORT_POWER_STATUS) {
              // Got no response from TV. Report status 'unknown'.
              invokeCallback(HdmiControlManager.POWER_STATUS_UNKNOWN);
              finish();
          }
      }
  
      public void addCallback(IHdmiControlCallback callback) {
          mCallbacks.add(callback);
      }
  
      private void invokeCallback(int result) {
          try {
              for (IHdmiControlCallback callback : mCallbacks) {
                  callback.onComplete(result);
              }
          } catch (RemoteException e) {
              Slog.e(TAG, "Callback failed:" + e);
          }
      }
  }
  