content: /*
   * 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.
   */
  
  package com.android.server.hdmi;
  
  import android.hardware.hdmi.HdmiDeviceInfo;
  import java.util.ArrayList;
  import java.util.Iterator;
  
  /**
   * Buffer storage to keep incoming messages for later processing. Used to
   * handle messages that arrive when the device is not ready. Useful when
   * keeping the messages from a connected device which are not discovered yet.
   */
  final class DelayedMessageBuffer {
      private final ArrayList<HdmiCecMessage> mBuffer = new ArrayList<>();
      private final HdmiCecLocalDevice mDevice;
  
      DelayedMessageBuffer(HdmiCecLocalDevice device) {
          mDevice = device;
      }
  
      /**
       * Add a new message to the buffer. The buffer keeps selected messages in
       * the order they are received.
       *
       * @param message {@link HdmiCecMessage} to add
       */
      void add(HdmiCecMessage message) {
          boolean buffered = true;
  
          // Note that all the messages are not handled in the same manner.
          // For &lt;Active Source&gt; we keep the latest one only.
          // TODO: This might not be the best way to choose the active source.
          //       Devise a better way to pick up the best one.
          switch (message.getOpcode()) {
              case Constants.MESSAGE_ACTIVE_SOURCE:
                  removeActiveSource();
                  mBuffer.add(message);
                  break;
              case Constants.MESSAGE_INITIATE_ARC:
              case Constants.MESSAGE_SET_SYSTEM_AUDIO_MODE:
                  mBuffer.add(message);
                  break;
              default:
                  buffered = false;
                  break;
          }
          if (buffered) {
              HdmiLogger.debug("Buffering message:" + message);
          }
      }
  
      private void removeActiveSource() {
          // Uses iterator to remove elements while looping through the list.
          for (Iterator<HdmiCecMessage> iter = mBuffer.iterator(); iter.hasNext(); ) {
              HdmiCecMessage message = iter.next();
              if (message.getOpcode() == Constants.MESSAGE_ACTIVE_SOURCE) {
                  iter.remove();
              }
          }
      }
  
      boolean isBuffered(int opcode) {
          for (HdmiCecMessage message : mBuffer) {
              if (message.getOpcode() == opcode) {
                  return true;
              }
          }
          return false;
      }
  
      void processAllMessages() {
          // Use the copied buffer.
          ArrayList<HdmiCecMessage> copiedBuffer = new ArrayList<>(mBuffer);
          mBuffer.clear();
          for (HdmiCecMessage message : copiedBuffer) {
              mDevice.onMessage(message);
              HdmiLogger.debug("Processing message:" + message);
          }
      }
  
      /**
       * Process messages from a given logical device. Called by
       * {@link NewDeviceAction} actions when they finish adding the device
       * information.
       * <p>&lt;Active Source&gt; is processed only when the TV input is ready.
       * If not, {@link #processActiveSource()} will be invoked later to handle it.
       *
       * @param address logical address of CEC device which the messages to process
       *        are associated with
       */
      void processMessagesForDevice(int address) {
          ArrayList<HdmiCecMessage> copiedBuffer = new ArrayList<>(mBuffer);
          mBuffer.clear();
          HdmiLogger.debug("Checking message for address:" + address);
          for (HdmiCecMessage message : copiedBuffer) {
              if (message.getSource() != address) {
                  mBuffer.add(message);
                  continue;
              }
              if (message.getOpcode() == Constants.MESSAGE_ACTIVE_SOURCE
                      && !mDevice.isInputReady(HdmiDeviceInfo.idForCecDevice(address))) {
                  mBuffer.add(message);
                  continue;
              }
              mDevice.onMessage(message);
              HdmiLogger.debug("Processing message:" + message);
          }
      }
  
      /**
       * Process &lt;Active Source&gt;.
       *
       * <p>The message has a dependency on TV input framework. Should be invoked
       * after we get the callback
       * {@link android.media.tv.TvInputManager.TvInputCallback#onInputAdded(String)}
       * to ensure the processing of the message takes effect when transformed
       * to input change callback.
       *
       * @param address logical address of the device to be the active source
       */
      void processActiveSource(int address) {
          ArrayList<HdmiCecMessage> copiedBuffer = new ArrayList<>(mBuffer);
          mBuffer.clear();
          for (HdmiCecMessage message : copiedBuffer) {
              if (message.getOpcode() == Constants.MESSAGE_ACTIVE_SOURCE
                      && message.getSource() == address) {
                  mDevice.onMessage(message);
                  HdmiLogger.debug("Processing message:" + message);
              } else {
                  mBuffer.add(message);
              }
          }
      }
  }
  