new Treeview feature discussion

[Stefan Kost <ensonic hora-obscura de>]

hi,

I currently look intensively at the GtkTreeview widget source to make it do what 
I need. The reason for this mail is that I hope to get pointers how to do it 
with existing API or get feedback of how to add it to the widget (if it makes 
sense). Further I am interested if anyone else needs it and if there are apps 
out there that do similar stuff already.
I start with a description of my use scenario:

I have tabular data - vertical data is time, horizontal data is categories. in 
the cells are item-names from the categories.
First column has the timestamps and the last column eats remaining space.
Entering items need to be fast and not interrupting navigation.
Right to the Treview is a list of items for the category the cursor is in 
together with the assigned keyname:
a -> item 1
b -> item 2
This when pressing 'a' in a cell it puts 'item 1' in there.

Now to the problems:

1.) I don't want the focus/cursor mark to go to the first-column (with the 
position labels). The cells are INERT, but that is currently unused information.
Generally I am a bit confused by the use of the terminology focus, cursor and 
selection. Focus is for me the part the receives input. Cursor is the part that 
can be edited.
Thus I need a way to constrain the curios for the editable area. JRB pointed out 
in yesterdays meeting that for accessibillity reasons all cells can receive the 
focus. I understand that otherwise information contained in there, such as 
labels can be read. The question then is how to unify that with usability. A 
user who can see, don't want the focus to go to such cells.
The problems even gets worser with scenarios as such:

  ooooo
  oo#oo    o focusable cell
  o#o#o    # inert cell
  oo#oo
  ooooo

now image on clicks the middle cell and thus pus focus there. If we'd use 
selection-mode=browse, the middle row would be selected. Now one presses cursor 
up. If that should select the line above, what should happen to the 
focus/cursor? Or should it jump two lines up?

2.) I need rectangular selections. AFAIK currently one can only select whole 
rows. Selection functions don't seems to help here.

4.) Finally a minor issue. The cell focus currently is drawn around the cell 
content. That looks well for check boxes, but odd for cells that contain text.
There it changes the size for each cell. If making the cursor fill the cell, it 
looks good for text but a bit odd for e.g. check boxes.


Below are the related bugzilla entries - the first is a real bug imho. The 
others are debatable and related to the scenarios described above.

http://bugzilla.gnome.org/show_bug.cgi?id=169463
http://bugzilla.gnome.org/show_bug.cgi?id=164464
http://bugzilla.gnome.org/show_bug.cgi?id=169464
http://bugzilla.gnome.org/show_bug.cgi?id=302153

Ciao
  Stefan