On Tuesday 02 May 2006 03:55, Michael Gogins wrote:

> I'm not completely sure how Qt's GPL would play with Csound's LGPL.

It should not be a problem in a GPL licensed host application. A more
interesting issue is how well two separate toolkits (each with its own
event processing etc.) would coexist in the same process, assuming
that the discussion is still about solving the use of widget opcodes
in a GUI frontend. I think it is safest if the GUI frontend uses FLTK,
and both it and the widgets plugin use the same dynamic FLTK library.
If the host is able to perform both with and without using a separate
audio thread (I did implement this in my Csound GUI), and uses the
"FLTK_Flags" variable to control the threading behavior of the FLTK
plugin, then the widget opcodes should work reliably. It is also
possible to check "FLTK_Flags" after calling csoundCompile() to find
out if using a separate thread is safe (i.e. depending on whether
there are FLTK graphs or opcodes, or not), and then choose the threading
or non-threading mode automatically. So, here is a short summary of what
is needed:
  - use FLTK in the host application
  - use a dynamic FLTK library compiled with --enable-threads
  - do not use a separate audio thread when performing an orchestra
    that contains widget opcodes, or FLTK displays are enabled; it is
    still OK to offer a multi-threaded mode for non-FLTK orchestras
  - use "FLTK_Flags" to control the widgets plugin