[Usability] Shortcut keys for EOG

[Jaap Haitsma <jaap haitsma org>]

Hi,

I cooked up a patch for EOG to use some extra shortcut keys mainly for 
accessing the previous or next image, on which I'd like to have your 
opinion concerning usability.

The patch and discussion about it can be found here: [1]

This is a short summary of the discussion there.

Current behavior of EOG in CVS
------------------------------

Currently EOG has the following accelerators for next image and prev image.

Next Image
  Ctrl+PageDown
  Spacebar
  Return

Prev Image
  Ctrl+PageUp
  Shift+Spacebar
  Shift+Return

User test
---------
I did a test with two users who are only familiar with Windows and not 
computer savvy. I used a patched version of EOG where I disabled all the 
shortcut keys. The thing they had to do is to go to the next image.

Both users never thought of using Ctrl+PageDown and always tried to use 
the arrow keys.

Proposed new behaviour
----------------------
So the main thing my patch does is when the complete image is visible it 
binds the arrow keys to previous and next slide. When the image is not 
completely visible the arrow keys scroll the image.

The goal of the patch is also to do the same as evince is currently doing

In more detail

Shortcuts that always work
  Prev Image
    Ctrl+Left (new)
    PageUp (new)
    Shift+Return
    Shift+SpaceBar
  Next Image
    Ctrl+Right (new)
    PageDown (new)
    Return
    SpaceBar
  First Image
    Ctrl+Home
    Home (new)
  Last Image
    Ctrl+End
    End (new)

 Shortcuts that work when the image is fully visible (i.e NO scrollbars
visible)
  Prev Image
    Left (new)
    Up (new)
  Next Image
    Right (new)
    Down (new)

2. Shortcuts that work when the image is NOT fully visible (i.e scrollbars
visible)
  Arrow keys pans the image

Question.
----------
What do you think about these changes from a usability point of view. It 
 would also be interesting that some more people did the same user test 
with non computer savvy people.


Jaap

[1] http://bugzilla.gnome.org/show_bug.cgi?id=310455#c12