Set the camera focus area in Android

Question

following several tutorials and examples I came up with the next algorithm to set the camera focus on a specific spot, the problem is that the camera completely ignores the spot

Answer 1

this work for me focus on camera 1 Api

@Override
public boolean onTouchEvent(MotionEvent event) {

        //variable for storing the time of first click
        //constant for defining the time duration between the click that can be considered as double-tap
        final int MAX_DURATION = 200;
        // handle single touch events
        if (action == MotionEvent.ACTION_UP) {
            handleFocus(event, params);
            startTime = System.currentTimeMillis();
        }

        else if (event.getAction() == MotionEvent.ACTION_DOWN) {

            if(System.currentTimeMillis() - startTime <= MAX_DURATION)
            {

                //capture image on Double Tap
                mCamera.autoFocus(ShotActivity_CameraActivity.this);


            }
        }
    }
    return true;

}

then this method to handle touch focus area

public void handleFocus(MotionEvent event, Camera.Parameters params) {
    int pointerId = event.getPointerId(0);
    int pointerIndex = event.findPointerIndex(pointerId);
    // Get the pointer's current position
    float x = event.getX(pointerIndex);
    float y = event.getY(pointerIndex);

    Rect touchRect = new Rect(
            (int) (x - 100),
            (int) (y - 100),
            (int) (x + 100),
            (int) (y + 100) );
    final Rect targetFocusRect = new Rect(
            touchRect.left * 2000/mTextureView.getWidth() - 1000,
            touchRect.top * 2000/mTextureView.getHeight() - 1000,
            touchRect.right * 2000/mTextureView.getWidth() - 1000,
            touchRect.bottom * 2000/mTextureView.getHeight() - 1000);

    List supportedFocusModes = params.getSupportedFocusModes();
    if (supportedFocusModes != null && supportedFocusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)) {
        try {
            List focusList = new ArrayList();
            Camera.Area focusArea = new Camera.Area(targetFocusRect, 1000);
            focusList.add(focusArea);


            params.setFocusAreas(focusList);
            params.setMeteringAreas(focusList);
            mCamera.setParameters(params);



           /* mCamera.autoFocus(this);*/
        } catch (Exception e) {
            e.printStackTrace();
            Log.i(TAG, "Unable to autofocus");
        }

    }
}

i hope this help