Proposal for a unified GUI to support Motif/Gtk/(Qt?)

[R. Bernstein]

Sounds great -  sounds ambitious! Good luck!

Peter Wainwright writes:
 > Proposal for a unified GUI to support Motif/Gtk/(Qt?)
 > +++++++++++++++++++++++++++++++++++++++++++++++++++++
 > 
 > In order to support Gtk, without dropping the existing Motif interface
 > or forking the project, I have begun to experiment with a unified O-O
 > toolkit interface under the "gddd" branch.
 > 
 > The gddd branch now has preliminary support for three GUI interfaces:
 > 
 > (1) Motif(Xm) : The old procedural Motif interface.
 >     This is selected by ./configure without arguments.
 >     The macros IF_MOTIF and IF_XM are defined in config.h.
 > 
 > (2) Motif(Xmmm) : The new object-oriented Motif wrapper.
 >     This is selected by ./configure --with-xmmm.
 >     The macros IF_MOTIF and IF_XMMM are defined in config.h.
 > 
 > (3) Gtk(GtkX) : The object-oriented Gtk wrapper.
 >     This is selected by ./configure --with-gtk.
 >     None of the above macros is defined.
 > 
 > At the end of the rewrite, the following conditions should be true
 > - as far as possible :-)
 > 
 > (i) The old and new Motif interfaces will provide the same
 >     functionality.  Then the old interface (#ifdef IF_XM sections)
 >     can be dropped.  At present these sections are left as a fallback
 >     and to show the old code for comparison purposes.
 > 
 > (ii) The Xmmm and GtkX interfaces will be isomorphic.  Then a single
 >      macro in config.h will be used to switch between Motif and Gtk
 >      versions:
 >      #define GUI Xmmm     ... OR ...
 >      #define GUI GtkX
 > 
 > The unified interface will look very much like Gtkmm, the C++
 > object-oriented interface to Gtk, but with minimal modifications which
 > are required to support Motif (and possibly Qt in future).
 > 
 > In the meantime, the transition from Xm to Xmmm will be done
 > incrementally. Widget handles will be stored as instances of a new
 > template class Xmmm::WidgetPtr<Xmmm::CLASS>.  This has conversion
 > operators which allow it to be used wherever an Xmmm::CLASS* is
 > required OR an Xt Widget is required.  This type of widget handle is
 > automatically converted to the appropriate type whether it is used in
 > a new-style O-O method call or an old-style Xm... or Xt... call.
 > 
 > The GtkX namespace is a thin wrapper over Gtkmm, provided for
 > compatibility with Xmmm.  The main difference is that Gtkmm widgets
 > are created, and THEN added to the parent in a separate call.  This
 > cannot be done in the unified GUI, since Widgets cannot be reparented
 > in the Xt architecture.  Thus the parent widget must be passed to the
 > constructor.  Also, a Widget name is mandatory in order to allow the
 > Xt resource mechanism to work.  Constructors in GtkX/Xmmm therefore
 > follow this pattern:
 > 
 > GUI::CLASS::CLASS(GUI::Widget &parent, const char *name, ...);
 > 
 > 
 > As an example of how this might work (remember, IF_XM marks the old
 > interface for comparison purposes), here are some fragments from
 > SourceView.C:
 > 
 > 
 > #if !defined(IF_XM)
 > #include <GUI/WidgetPtr.h>
 > #include <GUI/RadioBox.h>
 > #include <GUI/SelectionDialog.h>
 > #include <GUI/RadioButton.h>
 > #endif
 > 
 > ...
 > 
 > #if defined(IF_XM)
 > Widget SourceView::register_dialog_w         = 0;
 > #else
 > GUI::WidgetPtr<GUI::SelectionDialog> SourceView::register_dialog_w = 0;
 > #endif
 > 
 > ...
 > 
 > #if defined(IF_XM)
 > Widget SourceView::int_registers_w           = 0;
 > Widget SourceView::all_registers_w           = 0;
 > #else
 > GUI::WidgetPtr<GUI::RadioButton> SourceView::int_registers_w = 0;
 > GUI::WidgetPtr<GUI::RadioButton> SourceView::all_registers_w = 0;
 > #endif
 > 
 > ...
 > 
 > #if defined(IF_XM)
 >     arg = 0;
 >     XtSetArg(args[arg], XmNautoUnmanage, False); arg++;
 >     register_dialog_w = 
 >      verify(createTopLevelSelectionDialog(parent, "register_dialog", args,
 > arg));
 > #elif defined(IF_XMMM)
 >     register_dialog_w = 
 >      new GUI::SelectionDialog(parent, "register_dialog");
 > #else // Gtk
 >     register_dialog_w = 
 >      new GUI::SelectionDialog(*parent, "register_dialog");
 > #endif
 > 
 > ...
 > 
 > #if defined(IF_XM)
 >     arg = 0;
 >     Widget box = XmCreateRadioBox(register_dialog_w, XMST("box"), args,
 > arg);
 >     XtManageChild(box);
 > #else
 >     GUI::WidgetPtr<GUI::RadioBox> box = new
 > GUI::RadioBox(*register_dialog_w, "box", GUI::ORIENTATION_HORIZONTAL);
 >     box->show();
 > #endif
 > 
 > #if defined(IF_XM)
 >     arg = 0;
 >     XtSetArg(args[arg], XmNset, !all_registers); arg++;
 >     int_registers_w = 
 >      XmCreateToggleButton(box, XMST("int_registers"), args, arg);
 >     XtManageChild(int_registers_w);
 > #else
 >     int_registers_w =
 >      new GUI::RadioButton(*box, "int_registers");
 >     int_registers_w->set_active(!all_registers);
 >     int_registers_w->show();
 > #endif
 >     
 > 
 > #if defined(IF_XM)
 >     arg = 0;
 >     XtSetArg(args[arg], XmNset, all_registers); arg++;
 >     all_registers_w = 
 >      XmCreateToggleButton(box, XMST("all_registers"), args, arg);
 >     XtManageChild(all_registers_w);
 > #else // NOT IF_XM
 >     all_registers_w =
 >      new GUI::RadioButton(*box, "all_registers");
 >     all_registers_w->set_active(all_registers);
 >     all_registers_w->show();
 > #endif // IF_XM
 > 
 > #if defined(IF_XM)
 >     XtAddCallback(int_registers_w, XmNvalueChangedCallback,
 > sourceSetIntRegistersCB, XtPointer(0));
 >     XtAddCallback(all_registers_w, XmNvalueChangedCallback,
 > sourceSetAllRegistersCB, XtPointer(0));
 > #else
 > 
 > int_registers_w->signal_toggled().connect(sigc::bind(sigc::ptr_fun(sourceSetIntRegistersCB),
 >  int_registers_w));
 > 
 > all_registers_w->signal_toggled().connect(sigc::bind(sigc::ptr_fun(sourceSetAllRegistersCB),
 >  all_registers_w));
 > #endif
 > 
 > 
 > 
 > Peter Wainwright
 > 
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