Movable image within a circle

Question

In this image, circle is static one. Rectangle image is in behind of this circle. I need to move,zoom out, zoom in and pan the rectangle image within this circle. How to achieve this?

Give me suggestions how to do this.

Thanks in advance

Answer 1

Follow the Guidelines to do so:

1. Take Relative Layout
2. Add ImageView in This layout.
3. Now add Circle Shape Image in it.

example:

      <RelativeLayout>
         <ImageView /> // image which have to apply movement.
         <ImaeView />  // circle shape
      </RelativeLayout>

Then Apply below code to use movement of Imageview.

Implements Activity with OnTouchListener, Then

         img.setonTouchListener(this);



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


        // make the image scalable as a matrix
        view.setScaleType(ImageView.ScaleType.MATRIX);
        float scale;

        // Handle touch events here...
        switch (event.getAction() & MotionEvent.ACTION_MASK) {

        case MotionEvent.ACTION_DOWN: //first finger down only
           savedMatrix.set(matrix);
           start.set(event.getX(), event.getY());
           Log.d(TAG, "mode=DRAG" );
           mode = DRAG;
           break;
        case MotionEvent.ACTION_UP: //first finger lifted
        case MotionEvent.ACTION_POINTER_UP: //second finger lifted
           mode = NONE;
           Log.d(TAG, "mode=NONE" );
           break;
        case MotionEvent.ACTION_POINTER_DOWN: //second finger down
           oldDist = spacing(event); // calculates the distance between two points where user touched.
           Log.d(TAG, "oldDist=" + oldDist);
           // minimal distance between both the fingers
           if (oldDist > 5f) {
              savedMatrix.set(matrix);
              midPoint(mid, event); // sets the mid-point of the straight line between two points where user touched. 
              mode = ZOOM;
              Log.d(TAG, "mode=ZOOM" );
           }
           break;

        case MotionEvent.ACTION_MOVE: 
           if (mode == DRAG) 
           { //movement of first finger
              matrix.set(savedMatrix);
              if (view.getLeft() >= -392)
              {
                 matrix.postTranslate(event.getX() - start.x, event.getY() - start.y);
              }
           }
           else if (mode == ZOOM) { //pinch zooming
              float newDist = spacing(event);
              Log.d(TAG, "newDist=" + newDist);
              if (newDist > 5f) {
                 matrix.set(savedMatrix);
                 scale = newDist/oldDist; //thinking I need to play around with this value to limit it**
                 matrix.postScale(scale, scale, mid.x, mid.y);
              }
           }
           break;
        }

        // Perform the transformation
        view.setImageMatrix(matrix);

        return true; // indicate event was handled
     }

     private float spacing(MotionEvent event) {
        float x = event.getX(0) - event.getX(1);
        float y = event.getY(0) - event.getY(1);
        return FloatMath.sqrt(x * x + y * y);
     }

     private void midPoint(PointF point, MotionEvent event) {
        float x = event.getX(0) + event.getX(1);
        float y = event.getY(0) + event.getY(1);
        point.set(x / 2, y / 2);
     }

Hope this will help you, Its easy Task.