Grab key scrolling

Jim Gettys jg at laptop.org
Tue Apr 17 11:31:33 EDT 2007


Eben,

I think we're going to have to take a two prong approach:
  1) something short term, the best we can figure out to do with what's
in hand.
  2) fix X...  What we want to do is entirely reasonable, and that it is
difficult is a bug in the design.
                              - Jim


On Tue, 2007-04-17 at 09:50 -0400, Eben Eliason wrote:
> > 1 Scroll events can only be horizontal or vertical, you can't move
> > diagonally for example.
> 
> This seems like the biggest issue, as diagonal scrolling is one of the
> main benefits of the grab approach.  Still, I really want something
> mapped to that key.  To clarify, will this even properly generate
> horizontal or vertical events?  Does it really know that left to right
> is different than top to bottom?
> 
> > 2 The precision is limited since you can only move of a certain step.
> 
> This is true, but it's not as big an issue to me.  I've worked with
> scroll events before, and the event usually just contains a delta
> value.  This delta can be handled in any way the handler wants, and so
> can easily be scaled up or down, or capped at some max and min values.
> 
> > The fact that they are already supported by applications it's clearly a
> > big plus though. Maybe for Gen1 we could implement something using
> > scrolling events and for later releases aim to add better semantics to
> > X. Eben what do you think?
> 
> So, I guess the answer is that if this is the best we can do for now,
> then we should try it out.  Lack of diagonal scrolling is a big reason
> to look for a better way, though.
> 
> - Eben
-- 
Jim Gettys
One Laptop Per Child




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