Widgets are double buffered by default; you can use this function
to turn off the buffering. “Double buffered” simply means that
Window.beginDrawFrame and Window.endDrawFrame are called
automatically around expose events sent to the
widget. Window.beginDrawFrame diverts all drawing to a widget's
window to an offscreen buffer, and Window.endDrawFrame draws the
buffer to the screen. The result is that users see the window
update in one smooth step, and don’t see individual graphics
primitives being rendered.
In very simple terms, double buffered widgets don’t flicker,
so you would only use this function to turn off double buffering
if you had special needs and really knew what you were doing.
Note: if you turn off double-buffering, you have to handle
expose events, since even the clearing to the background color or
pixmap will not happen automatically (as it is done in
Window.beginDrawFrame).
In 3.10 GTK and GDK have been restructured for translucent drawing. Since
then expose events for double-buffered widgets are culled into a single
event to the toplevel GDK window. If you now unset double buffering, you
will cause a separate rendering pass for every widget. This will likely
cause rendering problems - in particular related to stacking - and usually
increases rendering times significantly.
Widgets are double buffered by default; you can use this function to turn off the buffering. “Double buffered” simply means that Window.beginDrawFrame and Window.endDrawFrame are called automatically around expose events sent to the widget. Window.beginDrawFrame diverts all drawing to a widget's window to an offscreen buffer, and Window.endDrawFrame draws the buffer to the screen. The result is that users see the window update in one smooth step, and don’t see individual graphics primitives being rendered.
In very simple terms, double buffered widgets don’t flicker, so you would only use this function to turn off double buffering if you had special needs and really knew what you were doing.
Note: if you turn off double-buffering, you have to handle expose events, since even the clearing to the background color or pixmap will not happen automatically (as it is done in Window.beginDrawFrame).
In 3.10 GTK and GDK have been restructured for translucent drawing. Since then expose events for double-buffered widgets are culled into a single event to the toplevel GDK window. If you now unset double buffering, you will cause a separate rendering pass for every widget. This will likely cause rendering problems - in particular related to stacking - and usually increases rendering times significantly.