Re: Emacs GTK scroll-bar flickering

[Jan D.]

Miles Bader wrote:
> On Fri, Mar 14, 2003 at 01:44:49PM +0100, Kai Gro?johann wrote:
>
> > Maybe I'm blind or something...
>
>
> I suspect that you're probably just using a GTK theme where it's less
> noticable; I use a pixmap theme (i.e., a bit slow to draw) with a lot of
> contrasty bits, which makes the flicker _very_ obvious.  With other themes
> (e.g. the default), it's not as obvious, but I can see that it's still
> happening.  Also, I suppose it may be related to the GTK version, etc.
>
> BTW, it's not just inserting characters at the end of the buffer that does
> it, it's essentially _every single command_ (it even flickers if you just let
> it sit there and do nothing!).

Internally in Emacs x_set_toolkit_scroll_bar_thumb gets called a lot, for 
example when the cursor moves.  One would think it should only be called when 
needed (i.e. anithing changed scrollbar-wise).  This coupled with the fact that 
scroll bar redraws in GTK seems to be particulary bad, makes the flicker 
happen.  I can just see it when opening a large file and pressing down arrow so 
the cursor goes from top to bottom rapidly.  I do not have a pixmap theme either.

I am reluctant to change how  x_set_toolkit_scroll_bar_thumb gets called as it 
might break something, so I added a fix for GTK instead.  Please try it. 
Scroll bar redraws have been a problem the whole time, for example, getting it 
to redraw when moving the scroll bar from the left to the right, getting it to 
clear the background (i.e. behind the thumb) when splitting a window, etc.

        Jan D.