Android example source code file (Power.java)

This example Android source code file (Power.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, brightness_dim, brightness_low_battery, brightness_off, brightness_on, deprecated, full_wake_lock, io, ioexception, low_battery_threshold, os, partial_wake_lock, power, string

The Power.java Android example source code

/*
 * Copyright (C) 2007 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 java.io.IOException;
import android.os.ServiceManager;

/**
 * Class that provides access to some of the power management functions.
 *
 * {@hide}
 */
public class Power
{
    // can't instantiate this class
    private Power()
    {
    }

    /**
     * Wake lock that ensures that the CPU is running.  The screen might
     * not be on.
     */
    public static final int PARTIAL_WAKE_LOCK = 1;

    /**
     * Wake lock that ensures that the screen is on.
     */
    public static final int FULL_WAKE_LOCK = 2;

    public static native void acquireWakeLock(int lock, String id);
    public static native void releaseWakeLock(String id);

    /**
     * Brightness value for fully off
     */
    public static final int BRIGHTNESS_OFF = 0;

    /**
     * Brightness value for dim backlight
     */
    public static final int BRIGHTNESS_DIM = 20;

    /**
     * Brightness value for fully on
     */
    public static final int BRIGHTNESS_ON = 255;

    /**
     * Brightness value to use when battery is low
     */
    public static final int BRIGHTNESS_LOW_BATTERY = 10;

    /**
     * Threshold for BRIGHTNESS_LOW_BATTERY (percentage)
     * Screen will stay dim if battery level is <= LOW_BATTERY_THRESHOLD
     */
    public static final int LOW_BATTERY_THRESHOLD = 10;

    /**
     * Turn the screen on or off
     *
     * @param on Whether you want the screen on or off
     */
    public static native int setScreenState(boolean on);

    public static native int setLastUserActivityTimeout(long ms);

    /**
     * Low-level function turn the device off immediately, without trying
     * to be clean.  Most people should use
     * {@link android.internal.app.ShutdownThread} for a clean shutdown.
     *
     * @deprecated
     * @hide
     */
    @Deprecated
    public static native void shutdown();

    /**
     * Reboot the device.
     * @param reason code to pass to the kernel (e.g. "recovery"), or null.
     *
     * @throws IOException if reboot fails for some reason (eg, lack of
     *         permission)
     */
    public static void reboot(String reason) throws IOException
    {
        rebootNative(reason);
    }

    private static native void rebootNative(String reason) throws IOException ;
}