text: /*
   * Copyright (C) 2009 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.
   */
  
  #ifndef ANDROID_MESSAGE_QUEUE_H
  #define ANDROID_MESSAGE_QUEUE_H
  
  #include <stdint.h>
  #include <errno.h>
  #include <sys/types.h>
  
  #include <utils/threads.h>
  #include <utils/Timers.h>
  #include <utils/Looper.h>
  
  #include <gui/DisplayEventReceiver.h>
  
  #include "Barrier.h"
  
  namespace android {
  
  class IDisplayEventConnection;
  class EventThread;
  class SurfaceFlinger;
  
  // ---------------------------------------------------------------------------
  
  class MessageBase : public MessageHandler
  {
  public:
      MessageBase();
      
      // return true if message has a handler
      virtual bool handler() = 0;
  
      // waits for the handler to be processed
      void wait() const { barrier.wait(); }
  
  protected:
      virtual ~MessageBase();
  
  private:
      virtual void handleMessage(const Message& message);
  
      mutable Barrier barrier;
  };
  
  // ---------------------------------------------------------------------------
  
  class MessageQueue {
      class Handler : public MessageHandler {
          enum {
              eventMaskInvalidate     = 0x1,
              eventMaskRefresh        = 0x2,
              eventMaskTransaction    = 0x4
          };
          MessageQueue& mQueue;
          int32_t mEventMask;
      public:
          Handler(MessageQueue& queue) : mQueue(queue), mEventMask(0) { }
          virtual void handleMessage(const Message& message);
          void dispatchRefresh();
          void dispatchInvalidate();
          void dispatchTransaction();
      };
  
      friend class Handler;
  
      sp<SurfaceFlinger> mFlinger;
      sp<Looper> mLooper;
      sp<EventThread> mEventThread;
      sp<IDisplayEventConnection> mEvents;
      sp<BitTube> mEventTube;
      sp<Handler> mHandler;
  
  
      static int cb_eventReceiver(int fd, int events, void* data);
      int eventReceiver(int fd, int events);
  
  public:
      enum {
          INVALIDATE  = 0,
          REFRESH     = 1,
          TRANSACTION = 2
      };
  
      MessageQueue();
      ~MessageQueue();
      void init(const sp<SurfaceFlinger>& flinger);
      void setEventThread(const sp<EventThread>& events);
  
      void waitMessage();
      status_t postMessage(const sp<MessageBase>& message, nsecs_t reltime=0);
  
      // sends INVALIDATE message at next VSYNC
      void invalidate();
      // sends REFRESH message at next VSYNC
      void refresh();
      // sends TRANSACTION message immediately
      void invalidateTransactionNow();
  };
  
  // ---------------------------------------------------------------------------
  
  }; // namespace android
  
  #endif /* ANDROID_MESSAGE_QUEUE_H */
  