screen turn off after using "WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON"

Question

I'm having problem allow the device to dim and turn off after using WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON.

I've built a recording camera and while recording I don't want the screen to turn off so I used the WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON and its work fine. The problem is that after recording (while still in the same activity) I wand to set the device to the previous state (after couple of seconds dim, after couple of seconds more then it completely off). I follow this android code:

https://developer.android.com/training/scheduling/wakelock.html

and its says to use getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON), but nothing happens and the screen is kept on.

Anyone knows how to let the screen turn off?

Here is my code:

 private View.OnClickListener startRecord=new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        if (isRecording) {
            // stop recording and release camera
            mMediaRecorder.stop();  // stop the recording
            releaseMediaRecorder(); // release the MediaRecorder object
            mCamera.lock();         // take camera access back from MediaRecorder

            // inform the user that recording has stopped

            isRecording = false;
            videoV.setAlpha(1f);
            videoV.setClickable(true);
            videoX.setAlpha(1f);
            videoX.setClickable(true);
            toggleRecord.setAlpha(0f);
            toggleRecord.setClickable(false);
            timerCountDown.cancel();//chancel timer counter
            animationCountDown.cancel();//chancel animation counter
            videoCountDown.setText("");
            videoCounterFrame.setBackgroundColor(Color.parseColor("#00000000"));  // set counter alpha to 0
            getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);  // after recording, allow screen turn off
        } else {
            // initialize video camera
            if (prepareVideoRecorder()) {
                // Camera is available and unlocked, MediaRecorder is prepared,
                // now you can start recording
                toggleRecord.setImageResource(R.drawable.vidcam_stop);
                mMediaRecorder.start();

                // inform the user that recording has started

                isRecording = true;
                videoCounterFrame.setBackgroundColor(Color.parseColor("#30000000"));//set alpha to 0.3
                //init two animations- first change animation from white to red and second the opposite
                final ValueAnimator colorAnimation = ValueAnimator.ofObject(new ArgbEvaluator(), Color.parseColor("#ffffff"), Color.parseColor("#f50f2b"));
                colorAnimation.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {

                    @Override
                    public void onAnimationUpdate(ValueAnimator animator) {
                        videoCountDown.setTextColor((Integer)animator.getAnimatedValue());
                    }

                });

                final ValueAnimator colorAnimation2 = ValueAnimator.ofObject(new ArgbEvaluator(), Color.parseColor("#f50f2b"), Color.parseColor("#ffffff"));
                colorAnimation2.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {

                    @Override
                    public void onAnimationUpdate(ValueAnimator animator) {
                        videoCountDown.setTextColor((Integer)animator.getAnimatedValue());
                    }

                });
                //start both counters
                timerCountDown=new CountDownTimer(121000, 100) {

                    public void onTick(long millisUntilFinished) {
                        Log.i("millis",millisUntilFinished+"");
                        if(TimeUnit.MILLISECONDS.toMinutes(millisUntilFinished)>0){
                            videoCountDown.setText(String.format("%d:%02d",
                                    TimeUnit.MILLISECONDS.toMinutes(millisUntilFinished),
                                    TimeUnit.MILLISECONDS.toSeconds(millisUntilFinished) -
                                            TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(millisUntilFinished))));
                        }else{

                            videoCountDown.setText((millisUntilFinished-1000)/1000+"");
                        }

                    }

                    public void onFinish() {
                        videoCountDown.setText("0");
                        toggleRecord.performClick();
                    }
                }.start();

                animationCountDown=new CountDownTimer(121000, 600) {

                    public void onTick(long millisUntilFinished) {
                        if(animationColorChange){
                            colorAnimation.start();
                            animationColorChange=false;
                        }else{
                            colorAnimation2.start();
                            animationColorChange=true;
                        }

                    }

                    @Override
                    public void onFinish() {
                        animationColorChange=true;
                    }

                }.start();

            } else {
                // prepare didn't work, release the camera
                releaseMediaRecorder();
                // inform user
            }
        }
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); // screen never goes to sleep while recording
    }
};

Answer 1

You Can use this tutorial to dim the light. Some snippets are :(brightness is an integer value)

  IHardwareService hardware = IHardwareService.Stub.asInterface(
  ServiceManager.getService("hardware"));
  if (hardware != null) {
    hardware.setScreenBacklight(brightness);
  }

Another Way is :

Settings.System.putInt(this.getContentResolver(),
    Settings.System.SCREEN_BRIGHTNESS, 20);

   WindowManager.LayoutParams lp = getWindow().getAttributes();
  lp.screenBrightness =0.2f;// 100 / 100.0f;
  getWindow().setAttributes(lp);

Answer 2

You could play with some View using in your xml the attribute keepScreenOn. In this way when the view is no more visible the flag is no more valid automatically. doc