I'll add here sotg from an off-list msg; In fact we have the position given by the touchscreen : [ x(t) ; y(t) ] speed is: [ (x(t') - x(t)) / (t' -t) ; (y(t') - y(t)) / (t' -t) ] - friction_factor*(t' - t)
... Where the friction_factor is in [0 ; 1] If we want acceleration, then we have to integrate the equation once. Shit, i gotta look into my college courses, it's terrible how fast it fades away :-p I'm not sure we really need to take acceleration into account. The changes to bring to the standard gtk scrolling are: - consider the list as scrollable (not just the scroll item) - change the scrolling "stop" behaviour (when the user stops touching the screen) like this: if (last_cursor_speed > 0), continue_scrolling(last_cursor_speed) - when touching the moving list again, stop the scrolling immediately - addition of friction may be a plus, for a more "wheel-of-fortune"-like experience _______________________________________________ OpenMoko community mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/community
