:: Re: [DNG] Building w/ gtk2 vs gtk3
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Author: Arnt Gulbrandsen
Date:  
To: dng
Subject: Re: [DNG] Building w/ gtk2 vs gtk3
Hendrik Boom writes:
> One thing I'm wondering about with GTK3 -- does GTK3 have the annoying
> 16-bit limitation on pixel counts? That has bitten me with GTK2. It
> severely limits one's scrolling range.


JFYI, it's not actually severe. Looks that way until you've crossed it,
that's all.

There's an easy workaround: Scroll in n-pixels steps instead of pixels. If
you scroll in, say, 16-pixel steps, users won't notice the loss of
accuracy, but you'll have an 19-bit or 20-bit range (the 16-bit limit is
sometimes 15-bit because of sign bits). But it doesn't help you, because an
19-bit range is so large that users lose the ability to use the scrollbar
effectively. Dragging the scrollbar one or a few pixels is an unmanageably
large jump on the model. At a 19-bit range with a 900-pixel scrollbar+view,
a single-pixel movement of the scrollbar moves the view by two thirds of
the window.

I think this workaround is so little-used and little-known precisely
because it doesn't help. It just bypasses the 16-bit limitation and
immediately gives you another, much less tractable, problem.

Arnt