As the sugar.tutorius.overlayer is currently implemented, it would be a matter of creating a widget similar to the overlayer.TextBubble but with a mask to capture events such as mouse clicks and setting its event mask to the non-interesting region. see http://pygtk.org/pygtk2reference/class-gtkwidget.html#method-gtkwidget--input-shape-combine-mask. How the "mask" is actually drawn could be with cairo.fill() with an alpha of, say 0.5f.
As the sugar.tutorius. overlayer is currently implemented, it would be a matter of creating a widget similar to the overlayer. TextBubble but with a mask to capture events such as mouse clicks and setting its event mask to the non-interesting region. see http:// pygtk.org/ pygtk2reference /class- gtkwidget. html#method- gtkwidget- -input- shape-combine- mask. How the "mask" is actually drawn could be with cairo.fill() with an alpha of, say 0.5f.