Size calculation for custom view?

Question

Android

There is actually a custom view, if you specify the exact dimensions or fill_parent for both properties (layout_width and layout_height) on layout-e, everything is OK, but if you specify wrap_content, the view is flattened to 0. Actually, as I understand it, you just need to rewrite a couple of methods for calculate the width-height, but where exactly, kick in the right direction.