How to update Android Views upon modifications?

I have some methods in my View that modify some of the shapes that are drawn when called. In Java in order to make sure the component is updated I would call repaint(). Is there something that will make sure my view is updated correctly?

I had read somewhere that calling invalidate() in the onDraw() method would keep things up to date and therefore I wouldn't need to have something like repaint() in my methods that modify that shapes that are drawn.

Is this correct, or is there something else I have to do?

EDIT

To add in an example, a method I call in my view is:

public void setLineThickness(int thickness) {
    aLineThickness = thickness;

    if(aLineThicness > 1)
        //repaint();      - Okay in Java but not in Android

}