Widget Transparency in PyGTK?

What is the best way to have transparency of specific widgets in a PyGTK application开发者_Python百科? I do not want to use themes because the transparency of each of the widgets will be changing through animation.

The only thing I can find is to use cairo to draw widgets with an Alpha, but I can't figure out how to do this. Is there perhaps a better way to do this as well?

Thanks!

Assuming that your program runs under composition manager, you could get per-widget transparency by manipulating widget's X window. Look at gtk.gdk.Window.set_opacity().

Note, it is not gtk.Window; you can get this object by getting its window property (buttonWidget.window), but only when widget is realized and only when widget does handle events -- gtk.Label does not have its own X window for instance.

If you need to work also when you don't have composition manager, drawing your widgets by yourself is the only option -- but you don't necessarily have to use cairo; drawing pixel by pixel on the bare X window will also work.