Android Camera preview zoom using double finger touch
<p>I am trying to do zoom using double finger touch gesture in the camera preview mode. But i unable to do that. I have done that Zoom control on the ImageView and it's working fine. Now i want to do that in the camera preview mode i.e. when we start the camera we can able to do zooming using double finger gesture.</p>

<p>Below i an adding the code for double finger gesture for zooming the image.</p>

<pre><code>@Override
public boolean onTouch(View v, MotionEvent event) {
    // TODO Auto-generated method stub
    ImageView view = (ImageView) v;

    switch (event.getAction() &amp; MotionEvent.ACTION_MASK) {
    case MotionEvent.ACTION_DOWN:
        savedMatrix.set(matrix);
        start.set(event.getX(), event.getY());
        Log.d(TAG, "mode=DRAG");
        mode = DRAG;
        break;
    case MotionEvent.ACTION_POINTER_DOWN:
        oldDist = spacing(event);
        Log.d(TAG, "oldDist=" + oldDist);
        if (oldDist &gt; 10f) {
            savedMatrix.set(matrix);
            midPoint(mid, event);
            mode = ZOOM;
            Log.d(TAG, "mode=ZOOM");
        }
        break;
    case MotionEvent.ACTION_UP:
    case MotionEvent.ACTION_POINTER_UP:
        mode = NONE;
        Log.d(TAG, "mode=NONE");
        break;
    case MotionEvent.ACTION_MOVE:
        if (mode == DRAG) {

            // for draging the image

              matrix.set(savedMatrix); matrix.postTranslate(event.getX() -
              start.x, event.getY() - start.y);

            break;
        } else if (mode == ZOOM) {
            float newDist = spacing(event);
            Log.d(TAG, "newDist=" + newDist);
            if (newDist &gt; 10f) {
                matrix.set(savedMatrix);
                float scale = newDist / oldDist;
                matrix.postScale(scale, scale, mid.x, mid.y);
            }
        }
        break;
    }

    view.setImageMatrix(matrix);
    return true;
}
</code></pre>

<p>Please guide me how to do this gesture zoom control in camera preview.
atleast provide a tutorial link.</p>

<p>With Thanks
Vikash</p>
