The topwindow module offers an API for creating windows that are shown on top of other applications and managing the content of these windows. Images can be inserted into the windows and the background color, visibility, corner type and shadow of the window can be manipulated.
topwindow extension does not provide sophisticated drawing capabilities by any means but rather relies on services provided by the graphics extension: topwindow allows graphics Image objects to be put into the windows that are represented by TopWindow objects.
TopWindow object provides mainly only two services: TopWindow objects can be shown or hidden and Images can be put into the windows. However, several images can be added into one TopWindow object and several TopWindow objects can be created and shown. Since the images can be manipulated using the graphics extension this makes it possible to create many kind of content to the TopWindow objects.