Apparently, I guess I made a new friend today.

All credit goes to this one guy named Marius Gedminas.

Here's what he had to.say on your clock build.



Four things come into mind:

** The background and foreground never changes; instead of rendering the SVG every time, render them into an offscreen buffer and blit the cached image in your expose event.

Something like http://old.nabble.com/Cairo-double-b...d22493956.html
but don't draw to the image surface on every frame; cache it if the widget size hasn't changed.

** Use timeout_add_seconds rather than timeout_add, that should be slightly more battery-efficient (multiple apps will get scheduled to wake up at the same time, rather than staggered throughout the second).

-- see http://library.gnome.org/devel/pygob...ut-add-seconds

** clip the drawing in the expose event handler to just the dirty area:

# Create the cairo context
cr = self.window.cairo_create()

# Restrict Cairo to the exposed area; avoid extra work
cr.rectangle(event.area.x, event.area.y,
event.area.width, event.area.height)
cr.clip()

-- from http://www.tortall.net/mu/wiki/PyGTKCairoTutorial

This will probably not matter much for Maemo where all windows are not overlapping, but then you can

** compute the dirty area in your timer interrupt and use queue_draw_area instead of queue_draw

This will let you draw less on every frame.

Hope that helps!