Re: [RFC] Common library for Git GUIs

Hi,

On Feb 16, 2009, at 9:24 PM, Jan Hudec wrote:

What it should use:

- It should probably be in C++ or C, with bindings for at least Perl,
  Python, Ruby, C#(CLR) and Java. The bindings can be done either  
with Swig,
  or using some base library that already has them.

It should be either C++ or C. If you want git devvers to work on it too,
you'll probably want to go with C.

  I think Java or CLR, while more portable, would not be appropriate  
because
  there is no standard way to combine them with other languages like  
Perl,
  Python and Ruby and those languages are still superior for the UI
  programming itself. I somewhat prefer C++, because polymorphism  
and some
  template tools would be useful here, but I am open to arguments.

I think JGit is pretty far along for someone who wants to create a Java
GUI.

   - Bindings for languages. We can use Swig, but it has e.g. no  
support for
     callbacks, so having portable runtime with already existing  
bindings
     that support this would be an advantage.

I'd say bindings are pretty easy to create yourself.

Portable runtime options:

So what do you people think would be best? I see several options:

- QtCore

  Qt seems to be the most popular library among Git GUI writers and  
since
  version 4.5 will be LGPL, so it will be allowed to link with  
anything.
  It is also probably the most portable one. On the downside, it's  
rather
  large and it's language bindings are a bit worse (the garbage  
collector
  integration was a bit bad last time I looked).

- Glib

  This is C based, so the core could be in plain C. It is also quite  
modular
  and has very good support for bindings to various languages. On the
  downside it's a bit less portable and less used among the existing  
guis.
  C would mean more work, but we could probably save some of it by  
using
  gob2 (g object builder)

- STL + Boost

  I don't have experience with it, though I read some of the  
documentation.
  It should be sensibly portable. I know it has python bindings, the  
rest
  would probably have to be dealt with using swig.

None of these, if you want any GUI's to use it. Noone is going to
create a Gtk / Cocoa / Windows app that depends on Qt. Nobody wants
to use Boost in any situation and Glib, while being smaller than the
rest, is also difficult as it isn't shipped with many OS's, for example
OS X.

- POSIX + Msys on Windows

  I guess it would technically be usable, but I think it would be  
rather lot
  of additional work. It would probably be quite lightweight, though.

I think lightweight is the way to go. If you go for C++, you can also  
use
the STL.

But, isn't this time spent better on getting libgit2 off the ground?