Android example source code file (ResultReceiver.java)

This example Android source code file (ResultReceiver.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, bundle, creator, handler, iresultreceiver, myresultreceiver, myrunnable, parcelable, remoteexception, resultreceiver

The ResultReceiver.java Android example source code

/*
 * 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}.
 */
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 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 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];
        }
    };
}