FlashLightActivity

public class FlashLightActivity extends AppCompatActivity {

    private ImageButton mSwich;
    private boolean isFlashOn;
    private boolean isDeviceHasFlas;

    private MediaPlayer mMediaPlayer;


    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_flash_light);


        mSwich = (ImageButton) findViewById(R.id.btnSwitch);

        isDeviceHasFlas = getApplicationContext().getPackageManager()
                .hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);

        if (!isDeviceHasFlas) {
            AlertDialog alert = new AlertDialog.Builder(FlashLightActivity.this)
                    .create();
            alert.setTitle("Error");
            alert.setMessage("Sorry, your device doesn't support flash light!");
            alert.setButton("OK", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    finish();
                }
            });
            alert.show();
            return;
        }

        //getCamera();

        isFlashOn = false;

        toggleButtonImage();

        mSwich.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent i = new Intent(getApplicationContext(),FlashLightBackGroundService.class);
                if (isFlashOn) {
                    stopService(i);
                    toggleButtonImage();
                    isFlashOn = true;
                } else {
                    startService(i);
                    toggleButtonImage();
                    isFlashOn = true;
                }
            }
        });

    }

//    private void getCamera() {
//        if (mCamera == null) {
//            try {
//                mCamera = Camera.open();
//                mParams = mCamera.getParameters();
//            } catch (RuntimeException e) {
//                Log.e("Failed to Open. Error: ", e.getMessage());
//            }
//        }
//    }

//    private void turnOnFlash() {
//
//        if (!isFlashOn) {
//            if (mCamera == null || mParams == null) {
//                return;
//            }
//            mParams = mCamera.getParameters();
//            mParams.setFlashMode(mParams.FLASH_MODE_TORCH);
//            mCamera.setParameters(mParams);
//            mCamera.startPreview();
//            isFlashOn = true;
//
//            toggleButtonImage();
//        }
//
//    }

//    private void turnOffFlash() {
//        if (isFlashOn) {
//            if (mCamera == null || mParams == null) {
//                return;
//            }
//            mParams = mCamera.getParameters();
//            mParams.setFlashMode(mParams.FLASH_MODE_OFF);
//            mCamera.setParameters(mParams);
//            mCamera.stopPreview();
//            isFlashOn = false;
//
//            toggleButtonImage();
//        }
//    }

    private void toggleButtonImage() {
        if (isFlashOn) {
            mSwich.setImageResource(R.drawable.btn_switch_on);
            playSound();
        } else {
            mSwich.setImageResource(R.drawable.btn_switch_off);
            playSound();
        }
    }

    private void playSound() {

        if (isFlashOn) {
            mMediaPlayer = MediaPlayer.create(FlashLightActivity.this, R.raw.light_switch_off);
        } else {
            mMediaPlayer = MediaPlayer.create(FlashLightActivity.this, R.raw.light_switch_on);
        }
        mMediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {

            @Override
            public void onCompletion(MediaPlayer mp) {
                mp.release();
            }

        });
        mMediaPlayer.start();

    }


}