title: Basic rendering - onDraw() method question
body: <p>I am declaring a class that extends activity and an inner class that extends view and contains the onDraw() method, which also contains the invalidate() method. In my overriden onCreate() method I instantiate the outer class. My question is how the onDraw() method is called, since I never call it manually.</p>
  
  <p>PS: I understand this might be a simple java language trick - I admit I am not the best here!</p>