Re: Qt/gui on MacOSX (was: 4.0 release goals)

[Michael Goffioul]

On Mon, Nov 5, 2012 at 3:58 PM, Ben Abbott <address@hidden> wrote:

On Nov 5, 2012, at 3:50 PM, Michael Goffioul wrote:

> On Mon, Nov 5, 2012 at 3:45 PM, Ben Abbott <address@hidden> wrote:
> Octave exists during the call "QApplication application (argc, argv);"  at line 87 in libgui/src/octave-gui.cc
>
>  80 int
>  81 octave_start_gui (int argc, char *argv[])
>  82 {
>  83   dissociate_terminal ();
>  84
>  85   setenv ("GNUTERM", "qt", 1);
>  86
>  87   QApplication application (argc, argv);
>
> With lack of experience with c++, I don't know how to go further.
>
> It looks like yet another hard limitation of Mac OS X. If Qt decides to exit the app, there's probably a good reason for it, and it's also probably difficult (or impossible) to work around as-is. You might try to debug further with debug version of Qt, but I'm not sure it's worth. Now I'm wondering what can be done to make it work under Mac OS X. Maybe we should simple re-exec octave with a specific flag to avoid re-forking?
>
> Michael.

Gnuplot overcame the same (similar?) problem.  I asked Ethan Merritt for an overview.  See below.

Yes, I've read if from one of your previous mails, but that's not really a "solution". It involves running the graphics system in a separate process and communicate with the base program through pipes. That's typically what we tried to avoid by using a in-process separate thread.  Note that using that approach in gnuplot actually doubles the data transfer when using it from octave: first to transfer data from octave to gnuplot, then to transfer data from gnuplot to the separate process running the Qt terminal.

Michael.