content: /*
   * 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.
   */
  
  package android.os;
  
  import com.android.internal.os.IResultReceiver;
  
  /**
   * Generic interface for receiving a callback result from someone.  Use this
   * by creating a subclass and implement {@link #onReceiveResult}, which you can
   * then pass to others and send through IPC, and receive results they
   * supply with {@link #send}.
   *
   * <p>Note: the implementation underneath is just a simple wrapper around
   * a {@link Binder} that is used to perform the communication.  This means
   * semantically you should treat it as such: this class does not impact process
   * lifecycle management (you must be using some higher-level component to tell
   * the system that your process needs to continue running), the connection will
   * break if your process goes away for any reason, etc.</p>
   */
  public class ResultReceiver implements Parcelable {
      final boolean mLocal;
      final Handler mHandler;
      
      IResultReceiver mReceiver;
      
      class MyRunnable implements Runnable {
          final int mResultCode;
          final Bundle mResultData;
          
          MyRunnable(int resultCode, Bundle resultData) {
              mResultCode = resultCode;
              mResultData = resultData;
          }
          
          public void run() {
              onReceiveResult(mResultCode, mResultData);
          }
      }
      
      class MyResultReceiver extends IResultReceiver.Stub {
          public void send(int resultCode, Bundle resultData) {
              if (mHandler != null) {
                  mHandler.post(new MyRunnable(resultCode, resultData));
              } else {
                  onReceiveResult(resultCode, resultData);
              }
          }
      }
      
      /**
       * Create a new ResultReceive to receive results.  Your
       * {@link #onReceiveResult} method will be called from the thread running
       * <var>handler</var> if given, or from an arbitrary thread if null.
       */
      public ResultReceiver(Handler handler) {
          mLocal = true;
          mHandler = handler;
      }
      
      /**
       * Deliver a result to this receiver.  Will call {@link #onReceiveResult},
       * always asynchronously if the receiver has supplied a Handler in which
       * to dispatch the result.
       * @param resultCode Arbitrary result code to deliver, as defined by you.
       * @param resultData Any additional data provided by you.
       */
      public void send(int resultCode, Bundle resultData) {
          if (mLocal) {
              if (mHandler != null) {
                  mHandler.post(new MyRunnable(resultCode, resultData));
              } else {
                  onReceiveResult(resultCode, resultData);
              }
              return;
          }
          
          if (mReceiver != null) {
              try {
                  mReceiver.send(resultCode, resultData);
              } catch (RemoteException e) {
              }
          }
      }
      
      /**
       * Override to receive results delivered to this object.
       * 
       * @param resultCode Arbitrary result code delivered by the sender, as
       * defined by the sender.
       * @param resultData Any additional data provided by the sender.
       */
      protected void onReceiveResult(int resultCode, Bundle resultData) {
      }
      
      public int describeContents() {
          return 0;
      }
  
      public void writeToParcel(Parcel out, int flags) {
          synchronized (this) {
              if (mReceiver == null) {
                  mReceiver = new MyResultReceiver();
              }
              out.writeStrongBinder(mReceiver.asBinder());
          }
      }
  
      ResultReceiver(Parcel in) {
          mLocal = false;
          mHandler = null;
          mReceiver = IResultReceiver.Stub.asInterface(in.readStrongBinder());
      }
      
      public static final @android.annotation.NonNull Parcelable.Creator<ResultReceiver> CREATOR
              = new Parcelable.Creator<ResultReceiver>() {
          public ResultReceiver createFromParcel(Parcel in) {
              return new ResultReceiver(in);
          }
          public ResultReceiver[] newArray(int size) {
              return new ResultReceiver[size];
          }
      };
  }
  