On Wed, May 16, 2007 at 04:40:53PM +0200, Helge Hafting wrote: ... > But bad drawing performance isn't the real problem here. The real > problem is that LyX keeps scrolling after I released the button. > It is as if LyX is able to notice the button release on time when > there > is some spare CPU, and struggles with noticing the release when > scrolling takes 100%cpu. > > Is LyX (or qt) checking for "scroll timer expired" before processing > mouse events? Or is there some kind of shortcut in the scroll > painting - > "if it already is time for doing more work, just do it and > don't bother checking pending events right now" ? > > Just guessing here - but the problem makes LyX hard to use. > I can't use continous scrolling to get where I want, because it > will overshoot. > > Even really bad drawing performance shouldn't cause this > overshooting. Bad drawing performance should merely > result in a slow LyX and 100% cpu usage.
I seem to recall that there was some code in the Qt X event handling code, precisely to handle this problem. Lars wrote this. But then it was decided that it could be removed... anyone remember? Something with coalescing of multiple keystroke events. - Martin
