Re: [g-a-devel] other question about the gnome-mag design

[Carlos Eduardo Rodrigues Diogenes <cerdiogenes yahoo com br>]

Bill Haneman wrote:

> Carlos Eduardo Rodrigues Diogenes wrote:
>
> > Hi Bill,
> >
> > After tinking a little with the gnome-mag code other question about 
> > it's design come in my mind.
> >
> > The question is: It isn't better to consider all the screen like 
> > source_bounds? 
>
>
> I think that what you mean is (please correct me if I am wrong), 
> "consider the entire source display to constitute the source bounds".  
> This does make sense when we use COMPOSITE, but it doesn't work today, 
> without COMPOSITE, when source and target are the same display.  If 
> source and target are different displays, gnome-mag already does what 
> you suggest.

Yes, you understand!!!

> The reason we do not consider the entire source display to be the 
> source bounds is because of two things: one, when we did this before, 
> users complained that the magnifier was "magnifying itself".  
> Secondly, the source bounds need to be returned to clients, like 
> gnopernicus, as the "usable source bounds", so that "proportional 
> mode" tracking and other client-side algorithms can be correctly 
> implemented.

Can you explain better what is "proportional mode"?

Carlos.

> One possibility which I think would be useful for split-screen 
> magnification, although it would not solve the 'proportional mode' 
> issue above, would be to allow gnome-mag to move its ROI into the 
> current target area, but suppress 'self-magnification' by replacing 
> those pixels explicitly with gray areas, rather than clipping as we do 
> now.  This would allow the source bounds to be 'non rectangular', 
> which would be useful for magnifying the bottom panel, for instance, 
> if the magnifier window is on the right-hand-side of the screen but 
> does not extend all the way to the bottom, and would be useful for 
> "quarter screen" magnification.
> However, doing this will require a sizeable source code patch, and its 
> priority has not been high enough to justify this work up until now.  
> I would certainly be happy to review a patch which did the above (used 
> fill-with-blank-pixels instead of clipping, to avoid self-magnification.
>
> best regards,
>
> Bill
>
> > This way we can track the pointer and only magnify the regions of the 
> > screen that aren't the magnifier window. Other thing that I think in 
> > this way is that we can verify if the user have the COMPOSITE 
> > extensions and magnify also when the pointer is over the magnifier 
> > screen, and if the COMPOSITE extension is not present we show an gray 
> > color like is done today when we run only the magnifier and the 
> > pointer are over the magnifier screen and in the corners of the screen.
> >
> > Thanks,
> > Carlos.
> > _______________________________________________