Future plans and thoughts: 
(I'd be happy if you let me know your opinion.)
* text-wrap is necessary? If I can stop this, some codes become simpler.
E.g. currently text and line numbers are shown on the same (text)widget. 
This causes a performance issue. If I can stop text-wrap, line numbers 
can be shown on another (text)widget. It might become much faster.

* Gtkdiff is highly dependent on GtkText widget. 
Is it a better idea to create an own widget?

* Currently, I'm using the output from "diff -r". 
Formerly, I thought it is a good idea, but it might be better 
if gtkdiff itself traversed the directories. I'm not sure.

* More GNOME supports. Currently, gtkdiff uses only GNOME's GUI features. 
I hope to use GNOME's Object model features, too.

* patch(1) integration?


Todo:
 * Change the background color of whole line (now, only text part).
   I think I need to create a new widget (derived from GtkText) for this feature. 
   Any easier way?
 * how to show it, if blank line is in a different part?
   (This could be resolved by the feature above).
 * multiple windows (I like GNOME MDI, like ghex)
 * reload rc(?)
 * Keep window geometry and position.(session management?)
 * Drag & Drop?
 * More message translation. (If you can help me, let me know.)
 * property save is not intuitive. It's almost bug.
 * diff3(1) support
 * In two-pane view, I want to scroll both texts with keyboard.


Incompletely done:
 * column size of directory view, to make file name columns as wider as possible.
 * improve look&feel
 * Preference settings.
 * RCS(CVS) support. In my opinion, the other program, such as RCS (graphical) 
   front-end, should take care of RCS, and it should call gtkdiff. 
   If you're implementing such a program or a plan, I'd like you to let me know.


Personally, I don't need the following features, but you are welcome to do:
 * Show diff per characters
 * Inputbox for line number(optional).
 * Toolbar (Personally, I don't like toolbar, but the screen shot could be neat...).
   If you send me a patch, you also need to implement the feature to disable toolbar.


Internal issues:
 * Property instances, such DViewPref, FViewPres. These management is confused.
 * There are many exceptional code related to line number zero.
   Is it possible to avoid this by proper design?
 * style.c is necessary?
 * Rewrite using sigaction(2) instead of signal(2) for portability.
