gEDA-dev: Filechooser and component selector code

[Peter C.J. Clifton]

Hi,

I'm continuing work to split the component selector away from the 
file-chooser code in gschem. This will allow more divergence between those 
functions, and ought to allow better abstracted GTK+ programming.

My roadmap for this is:

1. Split x_fileselect.c into x_fileselect.c, and x_compselect.c, 
refactoring without re-writing too much. Unused data-structure members will 
be removed. (NEARLY DONE) 2. Re-write x_compselect.c to be a subclassed 
GTK+ widget 3. Consider re-writing x_fileselect.c to better abstract gschem 
operations from the GTK+ code. 4. Copy x_fileselect.c and adapt for 
gattrib. Perhaps ideally, we should have a place in libgeda for standard 
"gaf" widgets, dialogs etc.., and this code should be shared there.

Is it common / best practice to subclass a GTK+ file-chooser dialog, or 
simply to "use" it from within your code - like is done at the moment? 
Would we subclass each special case (Open, Saveas, Saveas with "Discard 
changes"), or provide one subclass which has methods to invoke all of them.

As part of the refactor in step 1, I was unable to help myself fixing the 
mess of "OPEN SAVEAS SAVEAS_NONE SAVEAS..." flags, leaving only "OPEN, 
SAVEAS, SAVEAS_CLOSE" as used in the code. It was only natural at this 
point to add the extra "if" statement to fix the "Discard changes" button 
is always offered in the save dialogs.

Regards

Peter Clifton