eliminating flicker in FvwnButtons and icons

I was curious if there is a way to eliminate flicker in various places in Fvwm, specifically FvwmButtons and icons. Flicker occurs in a few places, for instance:

  • My clock is powered by a FvwmScript that is updated every minute, that is swallowed inside a FvwmButton. Everytime it updates you can see a very quick flicker.

  • I have an image that sits inside a FvwmButton. I have it set so if I click on an area on my desktop this image will slide into view. The image slides in very clean, but when it stops there is a quick flicker, where I see the wallpaper underneath, then it looks fine.

  • I use Taviso’s thumbnail function for my icons. I also have a transparency set for each, so when I mouse-over the image it returns to being 100% opaque. When I mouse over another icon, when it returns from opaque to tansparent there is a flicker.

I’m assuming that all 3 of these problems are related to Fvwm’s repaint method. Is there an option to enable double buffering? Is this something that could be eliminated with a patch?

I am using the FlickeringMoveWorkaround, but I believe this is for a different issue anyways.

Hmm. I am not sure about eliminating it. Most of what you’re describing fall within the exposenotify events a lot of the apps will receive when they need to redraw themselves. This flicker is just something that’s “necessary” – especially when they’re within FvwmButtons, for instance.

Yes – that’s for ConfigureNotify.

– Thomas Adam

So, in your opinion, is this possible to fix with a little hacking on the Fvwm codebase, or would this be opening a huge can of worms?

I wouldn’t mind spending a little time going though the code to come up with a workaround, since I guess this must effect a lot of people, but unfortunatly I don’t have countless hours.

You could try if you really wanted, but it won’t be as easy as you think.

– Thomas Adam