KEYNAV:GtkCombo and Accessibility (bug 53579)

["Padraig O'Briain" <Padraig Obriain Sun COM>]

When the input field of a dropdown combo box has focus and the list is not
currently displayed, pressing Alt+down arrow should drop down the list. 
(Currently this is done by pressing Enter).  

<POB> I found that the Enter key seemed to put a carriage return in the 
entry field of the combo and the Return key caused the list to be dropped down.
I assume that this is because activate_default is not set for the GtkEntry
widget in the GtkCombo.
</POB>

If the current contents of the entry field match an entry in the list, that
list entry should be given focus.  Otherwise no entry in the list should be
given focus until you press the down arrow a second time.

<POB> This works correctly. </POB>

The keyboard focus within the list should be changeable by using:

- up and down arrow keys to select previous and next entry respectively

<POB> This works correctly, assuming that the item names are unique. </POB>

- PageUp to select the top item currently visible, then the top item on the
previous "page" if pressed again

<POB> This works correctly. </POB>
 
- PageDn to select the bottom item currently visible, then the bottom item
on the next "page" if pressed again

<POB> This works correctly. </POB>
 
- Home and End to select the first and last item in list respectively

<POB> Home and End seems to scroll the list items left and right respectively.
</POB>

- Typing any printable character to select the next item in the list
starting with that character.  (Should ideally work with "select the next
item in the list starting with the 'n' characters I just typed", too, as MS
Windows does.  But that's more work as it would require a global timeout
setting which would have to be adjustable somewhere to cope with people who
can only type slowly-- which is something Windows doesn't provide, I don't
think).

<POB> This feature does not exist. </POB>.

While the list is being displayed, pressing Enter should select the
currently-focused item and hide the list, leaving keyboard focus on the
combo box's entry field.  (If the list is rolled up, pressing Enter should
activate the default button in the window, if there is one, otherwise do
nothing.)

<POB> Pressing Enter works as described while the list is displayed but as
noted above does not work correctly when the list is rolled up. </POB>

The user's currently-enforced cut, copy and paste keyboard accelerators
should be supported in the input field.

[Check http://developer.gnome.org/projects/gap/keyboardnav.html for any
later proposals that may not have filtered through to this bug report yet]