WindowManager.LayoutParams and screenBrightness

I have some problem with WindowManager.LayoutParams. I need to poweroff and poweron the screen using the proximity sensors. The proximity sensor is OK, but layoutParams doesn't work

    public void setBright(float value) {
    Window mywindow = getWindow();
    WindowManager.LayoutParams lp = mywindow.getAttributes();
    lp.screenBrightness = value;
    lp.buttonBrightness = value;

    if (value != WindowManager.LayoutParams.BRIGHTNESS_OVERRIDE_OFF) {
        lp.flags |= WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON;
    }

    mywindow.setAttributes(lp);
}

The screen poweroff correctly. But if I use setBright(WindowManager.LayoutParams.BRIGHTNESS_OVERRIDE_NONE) the screen remains black. I also tri开发者_Go百科ed using wakeLock

private void powerOnScreen() {
    setBright(WindowManager.LayoutParams.BRIGHTNESS_OVERRIDE_NONE);

    onResume();
    if (!wakeLock.isHeld())
        wakeLock.acquire();
}

where wakeLock is:

PowerManager powerManager = (PowerManager) getSystemService(Context.POWER_SERVICE);
    wakeLock = powerManager.newWakeLock(
            PowerManager.SCREEN_DIM_WAKE_LOCK
            | PowerManager.ON_AFTER_RELEASE,
            "MY_TAG");

but it still doesn't work. Any idea? Target platform is Android 2.2

Seems you should add the flag PowerManager.ACQUIRE_CAUSES_WAKEUP into newWakeLock call.

EDIT: That snippet worked for me:

        boolean isScreenOff = !powerManager.isScreenOn();
        if (isScreenOff) {
            Window window = getWindow();

            if (window != null) {
                window.addFlags(WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD
                        | WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
            }

            stopTimeDialogListener.wakeLock = powerManager
                    .newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK
                            | PowerManager.ACQUIRE_CAUSES_WAKEUP
                            | PowerManager.ON_AFTER_RELEASE, "TIMING_ALARM");
            stopTimeDialogListener.wakeLock.acquire();

            try {
                long screenOffDelay = Settings.System.getLong(
                        getContentResolver(),
                        Settings.System.SCREEN_OFF_TIMEOUT);

                new Timer().schedule(
                        stopTimeDialogListener.releaseWakeLock,
                        screenOffDelay);

            } catch (SettingNotFoundException e) {
            }
        }