New magnifier UI: Input requested

Improvements to the magnifier preferences dialog have been suggested.  
A  mockup, courtesy of Allan Day, can be found at the following URL:
https://raw.github.com/gnome-design-team/gnome-mockups/master/system-settings/universal-access/zoom-and-filters.png

One of the additions is a check box labelled "Keep keyboard focus in  
view" that is on the left hand "Zoom" panel.  This is for toggling the 
activation of focus/caret tracking.

The gnome-shell magnifier supports tracking modes for widget focus,  
caret focus, and mouse pointer movement.  Furthermore, these are 
independent of each other.  However, the proposed dialog combines 
them.   The radio buttons above the check box list different mouse 
tracking  modes, i.e. "Push with pointer", "Follow pointer", and "Keep 
pointer  centered".  Whatever mode is set for the mouse will be used for 
both  focus and caret tracking.

The question is what do magnifier users want or need regarding tracking 
types?  Are there use cases for having the types of tracking independent 
of each other?  Or, if the user chooses "centered" for one,  that 
applies to all? We would really like user input.

To give a better idea of what this is about, I'll be the use case, 
since  I use a magnifier on occasion, and at a low magnification factor 
(1.75x).  My preference is "push" for mouse and caret tracking, but  
"centered" for focus tracking.

With respect to the mouse, I prefer it behave as close as possible to  
the non-magnifier experience.  On a standard desktop, the mouse moves,  
not the contents.  The mouse tracking mode that comes the closest to  
that experience is "push", where the contents do not move in the  
magnified view until the mouse abuts up against an edge. When it does,  
the contents do move, but only enough to bring them into view.

For myself, the text caret works in a similar way.  When using a word  
processor, the caret generally moves in small increments -- left, 
right,  up, and down --  and I prefer that the contents not move until 
they need to.

However, when using the keyboard to tab-navigate around the UI, widget 
focus frequently jumps over large distances.  For example, I may be 
near  the bottom of the screen editing a text document when I use 
alt+tab to  use the task switcher.  Focus moves (warps) to the centre of 
the screen,  far from where I was typing.  I need to reorientto the new 
screen contents (my point of regard, so to speak),  and, in my case, 
that is helped by centering the widget that just  acquired focus -- I 
prefer "centered" tracking for changes in widget  focus.  Trying to 
preserve little or no movement in the contents is  pointless here since 
focus is likely to move large distances.

Now, that's just me, and I stress that I am **not**putting my 
preferences  forward as any kind of standard.  In fact, quite the 
opposite.  Those  are my user preferences.  I fully expect other 
magnifier users to have different ones, and we would like to know yours 
so that we fully understand the needs and can incorporate them into the 
UI being designed: Do you use the same tracking mode for focus, caret, 
and mouse or different modes for each? And if you use different modes, why?

Thanks.

-- 
;;;;joseph.


'A: After all, it isn't rocket science.'
'K: Right. It's merely computer science.'
              - J. D. Klaun -