Android example source code file (LightsService.java)

This example Android source code file (LightsService.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_mode_user, content, context, exception, fileinputstream, fileoutputstream, flashlight, handler, io, light, light_flash_hardware, light_flash_none, light_id_count, light_id_wifi, lightsservice, os, string, util, utilities

The LightsService.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.Context;
import android.content.pm.PackageManager;
import android.os.Handler;
import android.os.IHardwareService;
import android.os.ServiceManager;
import android.os.Message;
import android.util.Slog;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;

public class LightsService {
    private static final String TAG = "LightsService";

    static final int LIGHT_ID_BACKLIGHT = 0;
    static final int LIGHT_ID_KEYBOARD = 1;
    static final int LIGHT_ID_BUTTONS = 2;
    static final int LIGHT_ID_BATTERY = 3;
    static final int LIGHT_ID_NOTIFICATIONS = 4;
    static final int LIGHT_ID_ATTENTION = 5;
    static final int LIGHT_ID_BLUETOOTH = 6;
    static final int LIGHT_ID_WIFI = 7;
    static final int LIGHT_ID_COUNT = 8;

    static final int LIGHT_FLASH_NONE = 0;
    static final int LIGHT_FLASH_TIMED = 1;
    static final int LIGHT_FLASH_HARDWARE = 2;

    /**
     * Light brightness is managed by a user setting.
     */
    static final int BRIGHTNESS_MODE_USER = 0;

    /**
     * Light brightness is managed by a light sensor.
     */
    static final int BRIGHTNESS_MODE_SENSOR = 1;

    private final Light mLights[] = new Light[LIGHT_ID_COUNT];

    public final class Light {

        private Light(int id) {
            mId = id;
        }

        public void setBrightness(int brightness) {
            setBrightness(brightness, BRIGHTNESS_MODE_USER);
        }

        public void setBrightness(int brightness, int brightnessMode) {
            synchronized (this) {
                int color = brightness & 0x000000ff;
                color = 0xff000000 | (color << 16) | (color << 8) | color;
                setLightLocked(color, LIGHT_FLASH_NONE, 0, 0, brightnessMode);
            }
        }

        public void setColor(int color) {
            synchronized (this) {
                setLightLocked(color, LIGHT_FLASH_NONE, 0, 0, 0);
            }
        }

        public void setFlashing(int color, int mode, int onMS, int offMS) {
            synchronized (this) {
                setLightLocked(color, mode, onMS, offMS, BRIGHTNESS_MODE_USER);
            }
        }


        public void pulse() {
            pulse(0x00ffffff, 7);
        }

        public void pulse(int color, int onMS) {
            synchronized (this) {
                if (mColor == 0 && !mFlashing) {
                    setLightLocked(color, LIGHT_FLASH_HARDWARE, onMS, 1000, BRIGHTNESS_MODE_USER);
                    mH.sendMessageDelayed(Message.obtain(mH, 1, this), onMS);
                }
            }
        }

        public void turnOff() {
            synchronized (this) {
                setLightLocked(0, LIGHT_FLASH_NONE, 0, 0, 0);
            }
        }

        private void stopFlashing() {
            synchronized (this) {
                setLightLocked(mColor, LIGHT_FLASH_NONE, 0, 0, BRIGHTNESS_MODE_USER);
            }
        }

        private void setLightLocked(int color, int mode, int onMS, int offMS, int brightnessMode) {
            if (color != mColor || mode != mMode || onMS != mOnMS || offMS != mOffMS) {
                mColor = color;
                mMode = mode;
                mOnMS = onMS;
                mOffMS = offMS;
                setLight_native(mNativePointer, mId, color, mode, onMS, offMS, brightnessMode);
            }
        }

        private int mId;
        private int mColor;
        private int mMode;
        private int mOnMS;
        private int mOffMS;
        private boolean mFlashing;
    }

    /* This class implements an obsolete API that was removed after eclair and re-added during the
     * final moments of the froyo release to support flashlight apps that had been using the private
     * IHardwareService API. This is expected to go away in the next release.
     */
    private final IHardwareService.Stub mLegacyFlashlightHack = new IHardwareService.Stub() {

        private static final String FLASHLIGHT_FILE = "/sys/class/leds/spotlight/brightness";

        public boolean getFlashlightEnabled() {
            try {
                FileInputStream fis = new FileInputStream(FLASHLIGHT_FILE);
                int result = fis.read();
                fis.close();
                return (result != '0');
            } catch (Exception e) {
                Slog.e(TAG, "getFlashlightEnabled failed", e);
                return false;
            }
        }

        public void setFlashlightEnabled(boolean on) {
            if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.FLASHLIGHT)
                    != PackageManager.PERMISSION_GRANTED &&
                    mContext.checkCallingOrSelfPermission(android.Manifest.permission.HARDWARE_TEST)
                    != PackageManager.PERMISSION_GRANTED) {
                throw new SecurityException("Requires FLASHLIGHT or HARDWARE_TEST permission");
            }
            try {
                FileOutputStream fos = new FileOutputStream(FLASHLIGHT_FILE);
                byte[] bytes = new byte[2];
                bytes[0] = (byte)(on ? '1' : '0');
                bytes[1] = '\n';
                fos.write(bytes);
                fos.close();
            } catch (Exception e) {
                Slog.e(TAG, "setFlashlightEnabled failed", e);
            }
        }
    };

    LightsService(Context context) {

        mNativePointer = init_native();
        mContext = context;

        ServiceManager.addService("hardware", mLegacyFlashlightHack);

        for (int i = 0; i < LIGHT_ID_COUNT; i++) {
            mLights[i] = new Light(i);
        }
    }

    protected void finalize() throws Throwable {
        finalize_native(mNativePointer);
        super.finalize();
    }

    public Light getLight(int id) {
        return mLights[id];
    }

    private Handler mH = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            Light light = (Light)msg.obj;
            light.stopFlashing();
        }
    };

    private static native int init_native();
    private static native void finalize_native(int ptr);

    private static native void setLight_native(int ptr, int light, int color, int mode,
            int onMS, int offMS, int brightnessMode);

    private final Context mContext;

    private int mNativePointer;
}