View.onDraw() — when does it get called?

Question

I put a Log.d() call into the onDraw() of my extended View, so I could see how often and when it\'s getting called. It gets called upon instantiation of the view, which is

Answer 1

• If you set a background drawable for a View, then the View will draw it for you before calling back to its onDraw() method.

• onAttachedToWindow () is called when the view is attached to a window. At this point it has a Surface and will start drawing. Note that this function is guaranteed to be called before onDraw(android.graphics.Canvas), however it may be called any time before the first onDraw -- including before or after onMeasure(int, int).

• invalidate() mark the area defined by dirty as needing to be drawn. If the view is visible, onDraw(android.graphics.Canvas) will be called at some point in the future.