On Jul 27, 2010, at 8:00 AM, Krzysztof Kosiński wrote:
579932 Too much states saved for undo/redo when using sliders https://bugs.launchpad.net/inkscape/+bug/579932
The easiest fix is to set the sliders to Gtk::UPDATE_DISCONTINUOUS update policy, but this will prevent the display from updating during the drag. Apparently there is no way in GTK right now to get the correct behavior!
There are a few ways to get good behavior. Some of these have come up for the color sliders. For this area the two big things to look at are using the might-be-more calls for undo and also to "debounce" the input from the slider so as to not trigger as many changes as the user moves things quickly.
While the former will probably give some of the best 'fix' for this bug, the latter has potential to significantly improve the user experience. When I applied this to the color sliders it technically became slower, but to the users it felt much faster. It trades of raw numeric crunching speed for improved responsiveness to the user.
But again, the root cause of the bug report appears to be from not using our proper under system calls. This may be direct or indirect. If it is the latter (function triggers events that calls functions that in turn register undo changes, etc.) then it might take a bit of cleanup to fix without breaking other cases.