How to set ontouch listener for something drawn using canvas: Android

Question

I have a custom view in which i am drawing one big circle and a small circle on the edge of this big circle.

I would like to move the small circle and so would like

Answer 1

You can get the rectangle of your touch point and the rectangle(position) of your inner circle and check if they cross over with the Intersects method.

http://docs.oracle.com/javase/7/docs/api/java/awt/Rectangle.html#intersects(java.awt.Rectangle)

Your canvas onTouchListener can do whatever it needs to do if the touchpoint intersect your circle.

e.g:

    // Create a rectangle from the point of touch
    Rect touchpoint = new Rect(x,y,10,10);

    // Create a rectangle from the postion of the circle.
    Rect myCircle=new Rect(10,10,20,20);

    if (Rect.intersects(myCircle,touchpoint)){
        Log.d("The circle was touched");
    }