Android example source code file (VibratorService.java)

This example Android source code file (VibratorService.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, broadcastreceiver, content, context, handler, ibinder, intentfilter, linkedlist, os, requires, runnable, securityexception, string, tag, util, utilities, utils, vibratethread, vibration, vibratorservice

The VibratorService.java Android example source code

/*
 * Copyright (C) 2008 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;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.os.Handler;
import android.os.IVibratorService;
import android.os.PowerManager;
import android.os.Process;
import android.os.RemoteException;
import android.os.IBinder;
import android.os.Binder;
import android.os.SystemClock;
import android.util.Slog;

import java.util.LinkedList;
import java.util.ListIterator;

public class VibratorService extends IVibratorService.Stub {
    private static final String TAG = "VibratorService";

    private final LinkedList<Vibration> mVibrations;
    private Vibration mCurrentVibration;

    private class Vibration implements IBinder.DeathRecipient {
        private final IBinder mToken;
        private final long    mTimeout;
        private final long    mStartTime;
        private final long[]  mPattern;
        private final int     mRepeat;

        Vibration(IBinder token, long millis) {
            this(token, millis, null, 0);
        }

        Vibration(IBinder token, long[] pattern, int repeat) {
            this(token, 0, pattern, repeat);
        }

        private Vibration(IBinder token, long millis, long[] pattern,
                int repeat) {
            mToken = token;
            mTimeout = millis;
            mStartTime = SystemClock.uptimeMillis();
            mPattern = pattern;
            mRepeat = repeat;
        }

        public void binderDied() {
            synchronized (mVibrations) {
                mVibrations.remove(this);
                if (this == mCurrentVibration) {
                    doCancelVibrateLocked();
                    startNextVibrationLocked();
                }
            }
        }

        public boolean hasLongerTimeout(long millis) {
            if (mTimeout == 0) {
                // This is a pattern, return false to play the simple
                // vibration.
                return false;
            }
            if ((mStartTime + mTimeout)
                    < (SystemClock.uptimeMillis() + millis)) {
                // If this vibration will end before the time passed in, let
                // the new vibration play.
                return false;
            }
            return true;
        }
    }

    VibratorService(Context context) {
        // Reset the hardware to a default state, in case this is a runtime
        // restart instead of a fresh boot.
        vibratorOff();

        mContext = context;
        PowerManager pm = (PowerManager)context.getSystemService(
                Context.POWER_SERVICE);
        mWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, TAG);
        mWakeLock.setReferenceCounted(true);

        mVibrations = new LinkedList<Vibration>();

        IntentFilter filter = new IntentFilter();
        filter.addAction(Intent.ACTION_SCREEN_OFF);
        context.registerReceiver(mIntentReceiver, filter);
    }

    public void vibrate(long milliseconds, IBinder token) {
        if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.VIBRATE)
                != PackageManager.PERMISSION_GRANTED) {
            throw new SecurityException("Requires VIBRATE permission");
        }
        // We're running in the system server so we cannot crash. Check for a
        // timeout of 0 or negative. This will ensure that a vibration has
        // either a timeout of > 0 or a non-null pattern.
        if (milliseconds <= 0 || (mCurrentVibration != null
                && mCurrentVibration.hasLongerTimeout(milliseconds))) {
            // Ignore this vibration since the current vibration will play for
            // longer than milliseconds.
            return;
        }
        Vibration vib = new Vibration(token, milliseconds);
        synchronized (mVibrations) {
            removeVibrationLocked(token);
            doCancelVibrateLocked();
            mCurrentVibration = vib;
            startVibrationLocked(vib);
        }
    }

    private boolean isAll0(long[] pattern) {
        int N = pattern.length;
        for (int i = 0; i < N; i++) {
            if (pattern[i] != 0) {
                return false;
            }
        }
        return true;
    }

    public void vibratePattern(long[] pattern, int repeat, IBinder token) {
        if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.VIBRATE)
                != PackageManager.PERMISSION_GRANTED) {
            throw new SecurityException("Requires VIBRATE permission");
        }
        // so wakelock calls will succeed
        long identity = Binder.clearCallingIdentity();
        try {
            if (false) {
                String s = "";
                int N = pattern.length;
                for (int i=0; i<N; i++) {
                    s += " " + pattern[i];
                }
                Slog.i(TAG, "vibrating with pattern: " + s);
            }

            // we're running in the server so we can't fail
            if (pattern == null || pattern.length == 0
                    || isAll0(pattern)
                    || repeat >= pattern.length || token == null) {
                return;
            }

            Vibration vib = new Vibration(token, pattern, repeat);
            try {
                token.linkToDeath(vib, 0);
            } catch (RemoteException e) {
                return;
            }

            synchronized (mVibrations) {
                removeVibrationLocked(token);
                doCancelVibrateLocked();
                if (repeat >= 0) {
                    mVibrations.addFirst(vib);
                    startNextVibrationLocked();
                } else {
                    // A negative repeat means that this pattern is not meant
                    // to repeat. Treat it like a simple vibration.
                    mCurrentVibration = vib;
                    startVibrationLocked(vib);
                }
            }
        }
        finally {
            Binder.restoreCallingIdentity(identity);
        }
    }

    public void cancelVibrate(IBinder token) {
        mContext.enforceCallingOrSelfPermission(
                android.Manifest.permission.VIBRATE,
                "cancelVibrate");

        // so wakelock calls will succeed
        long identity = Binder.clearCallingIdentity();
        try {
            synchronized (mVibrations) {
                final Vibration vib = removeVibrationLocked(token);
                if (vib == mCurrentVibration) {
                    doCancelVibrateLocked();
                    startNextVibrationLocked();
                }
            }
        }
        finally {
            Binder.restoreCallingIdentity(identity);
        }
    }

    private final Runnable mVibrationRunnable = new Runnable() {
        public void run() {
            synchronized (mVibrations) {
                doCancelVibrateLocked();
                startNextVibrationLocked();
            }
        }
    };

    // Lock held on mVibrations
    private void doCancelVibrateLocked() {
        if (mThread != null) {
            synchronized (mThread) {
                mThread.mDone = true;
                mThread.notify();
            }
            mThread = null;
        }
        vibratorOff();
        mH.removeCallbacks(mVibrationRunnable);
    }

    // Lock held on mVibrations
    private void startNextVibrationLocked() {
        if (mVibrations.size() <= 0) {
            return;
        }
        mCurrentVibration = mVibrations.getFirst();
        startVibrationLocked(mCurrentVibration);
    }

    // Lock held on mVibrations
    private void startVibrationLocked(final Vibration vib) {
        if (vib.mTimeout != 0) {
            vibratorOn(vib.mTimeout);
            mH.postDelayed(mVibrationRunnable, vib.mTimeout);
        } else {
            // mThread better be null here. doCancelVibrate should always be
            // called before startNextVibrationLocked or startVibrationLocked.
            mThread = new VibrateThread(vib);
            mThread.start();
        }
    }

    // Lock held on mVibrations
    private Vibration removeVibrationLocked(IBinder token) {
        ListIterator<Vibration> iter = mVibrations.listIterator(0);
        while (iter.hasNext()) {
            Vibration vib = iter.next();
            if (vib.mToken == token) {
                iter.remove();
                return vib;
            }
        }
        // We might be looking for a simple vibration which is only stored in
        // mCurrentVibration.
        if (mCurrentVibration != null && mCurrentVibration.mToken == token) {
            return mCurrentVibration;
        }
        return null;
    }

    private class VibrateThread extends Thread {
        final Vibration mVibration;
        boolean mDone;

        VibrateThread(Vibration vib) {
            mVibration = vib;
            mWakeLock.acquire();
        }

        private void delay(long duration) {
            if (duration > 0) {
                long bedtime = SystemClock.uptimeMillis();
                do {
                    try {
                        this.wait(duration);
                    }
                    catch (InterruptedException e) {
                    }
                    if (mDone) {
                        break;
                    }
                    duration = duration
                            - SystemClock.uptimeMillis() - bedtime;
                } while (duration > 0);
            }
        }

        public void run() {
            Process.setThreadPriority(Process.THREAD_PRIORITY_URGENT_DISPLAY);
            synchronized (this) {
                int index = 0;
                long[] pattern = mVibration.mPattern;
                int len = pattern.length;
                int repeat = mVibration.mRepeat;
                long duration = 0;

                while (!mDone) {
                    // add off-time duration to any accumulated on-time duration
                    if (index < len) {
                        duration += pattern[index++];
                    }

                    // sleep until it is time to start the vibrator
                    delay(duration);
                    if (mDone) {
                        break;
                    }

                    if (index < len) {
                        // read on-time duration and start the vibrator
                        // duration is saved for delay() at top of loop
                        duration = pattern[index++];
                        if (duration > 0) {
                            VibratorService.this.vibratorOn(duration);
                        }
                    } else {
                        if (repeat < 0) {
                            break;
                        } else {
                            index = repeat;
                            duration = 0;
                        }
                    }
                }
                mWakeLock.release();
            }
            synchronized (mVibrations) {
                if (mThread == this) {
                    mThread = null;
                }
                if (!mDone) {
                    // If this vibration finished naturally, start the next
                    // vibration.
                    mVibrations.remove(mVibration);
                    startNextVibrationLocked();
                }
            }
        }
    };

    BroadcastReceiver mIntentReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {
            if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
                synchronized (mVibrations) {
                    doCancelVibrateLocked();
                    mVibrations.clear();
                }
            }
        }
    };

    private Handler mH = new Handler();

    private final Context mContext;
    private final PowerManager.WakeLock mWakeLock;

    volatile VibrateThread mThread;

    native static void vibratorOn(long milliseconds);
    native static void vibratorOff();
}