Android 按两下power键不打开相机改为打开手电筒

MTK平台默认按两下power键打开相机的快捷手势，如今需求改为快捷打开手电筒，需要找到位置进行替换即可，写入节点，加入节点权限。

/frameworks/base/services/core/java/com/android/server/GestureLauncherService.java

//*/add pkg
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import android.util.Log;
//*/

  //*/add global variable opne flashlight to switch on/off
    private boolean mFlashlight = false;
     //*/

  if (launchCamera) {//两下power键打开相机
            /*/add,repalce double open camera with open flashlight
            launchCamera = handleCameraGesture(false ,
                    StatusBarManager.CAMERA_LAUNCH_SOURCE_POWER_DOUBLE_TAP);//1 // useWakelock
                    /*/
                    mFlashlight = !mFlashlight;
                    writeFlashLightFile(mFlashlight);
                    //*/
            if (launchCamera) {
                mMetricsLogger.action(MetricsEvent.ACTION_DOUBLE_TAP_POWER_CAMERA_GESTURE,
                        (int) powerTapInterval);
                mUiEventLogger.log(GestureLauncherEvent.GESTURE_CAMERA_DOUBLE_TAP_POWER);
            }
        } else if (launchEmergencyGesture) {//五下power键打开紧急拨号
            Slog.i(TAG, "Emergency gesture detected, launching.");
            launchEmergencyGesture = handleEmergencyGesture();
            mUiEventLogger.log(GestureLauncherEvent.GESTURE_EMERGENCY_TAP_POWER);
        }

 

     //*/add open flash method
    private static void writeFlashLightFile(boolean enable) {
        File file = new File("/sys/kernel/flash_cur/flash_cur");
        Writer writer = null;
        try {
            writer = new OutputStreamWriter(new FileOutputStream(file));
            if (enable) {
                writer.append("1");
            } else {
                writer.append("0");
            }
        } catch (FileNotFoundException e) {
        } catch (IOException e) {
        } finally {

            if (writer != null) {
                try {
                    writer.close();
                } catch (IOException e) {
                }
            }
        }
    }
    //*/