Question

I have a code where I draw image:

class Panel extends View {

        public Panel(Context context) {
            super(context);
        }

        @Override
        public void onDraw(Canvas canvas) {
            Bitmap _scratch = BitmapFactory.decodeResource(getResources(), R.drawable.calvin_logo_small);
            canvas.drawColor(Color.WHITE);
            canvas.drawBitmap(_scratch, x-point, y-point, null);
        }
    }

How can I draw this image in my activity, but I don’t want to change may layout. I have layout: setContentView(R.layout.main); This is possible to draw in this lauout with canvas? I have this activity and this layout have a lot of components. I only want image in place where I click with canvas. This is idea. I start application where start activity with my setContentView(R.layout.main);. After that I click on the screen and canvas draw picture in place where I clicked. This is possible to do?

Answer 1

Your code should work. Just override the onTouchEvent() for the view, store the co-ordinates of the touch event in field variables and invalidate() the view so that onDraw() would be called. Use the co-ordinates in onDraw() to render the image as you’ve already done.

To improve performance, you can cache the bitmap if it’s not going to change.