How does Rainlendar achieve transparency with wxWidgets

Question

Rainlendar is a fantastic cross platform calendar program that is written with wxWidgets. How does it achieve the transparency effect? Does anyone have any example code which demonstrates the transparency effect?

Answer 1

My guess is that they could be using a wxScreenDC to draw directly to the screen (while preserving the background contents). Unlike receiving paint events or erase events, you create a wxScreenDC on the stack at your choosing, which means that you need to refresh yourself (most likely via a timer of some sort). If you don't, background applications will eventually repaint themselves over your wxScreenDC contents.

Here's the API listing

EDIT: Just to clarify, usage (besides the need to call StartDrawingOnTop and EndDrawingOnTop) is identical to any other wxDC.

Answer 2

wxTopLevelWindow::SetTransparent() method may be what you need.