Fluid: hiding MergeBack form the main menu.

Hiding menuitem if option is not available.
Also testing the new FL_BEFORE_MENU event.

fluid/CMakeLists.txt

@@ -61,6 +61,7 @@ set(CPPFILES
   rsrcs/pixmaps.cxx
   tools/autodoc.cxx
   tools/filename.cxx
+  widgets/App_Menu_Bar.cxx
   widgets/Code_Editor.cxx
   widgets/Code_Viewer.cxx
   widgets/Text_Viewer.cxx
@@ -112,6 +113,7 @@ set(HEADERFILES
   rsrcs/pixmaps.h
   tools/autodoc.h
   tools/filename.h
+  widgets/App_Menu_Bar.h
   widgets/Code_Editor.h
   widgets/Code_Viewer.h
   widgets/Text_Viewer.h

fluid/Fluid.cxx

@@ -36,6 +36,7 @@
 #include "panels/about_panel.h"
 #include "rsrcs/pixmaps.h"
 #include "tools/autodoc.h"
+#include "widgets/App_Menu_Bar.h"
 #include "widgets/Node_Browser.h"
 
 #include <FL/Fl.H>
@@ -44,7 +45,6 @@
 #include <FL/platform.H> // for fl_open_callback
 #endif
 #include <FL/Fl_Help_Dialog.H>
-#include <FL/Fl_Menu_Bar.H>
 #include <FL/Fl_PNG_Image.H>
 #include <FL/Fl_Native_File_Chooser.H>
 #include <FL/Fl_Printer.H>
@@ -1157,7 +1157,7 @@ void Application::make_main_window() {
     o->box(FL_FLAT_BOX);
     o->tooltip("Double-click to view or change an item.");
     main_window->resizable(o);
-    main_menubar = new Fl_Menu_Bar(0,0,BROWSERWIDTH,MENUHEIGHT);
+    main_menubar = new fld::widget::App_Menu_Bar(0,0,BROWSERWIDTH,MENUHEIGHT);
     main_menubar->menu(main_menu);
     // quick access to all dynamic menu items
     save_item = (Fl_Menu_Item*)main_menubar->find_item(menu_file_save_cb);

fluid/Fluid.h

@@ -50,6 +50,9 @@ namespace fld {
 namespace app {
 class Layout_List;
 }
+namespace widget {
+class App_Menu_Bar;
+}
 
 /**
  Indicate the storage location for tools like layout suites and shell macros.
@@ -117,7 +120,7 @@ public: // Member Variables
   // TODO: make this into a class: app::GUI
   Fl_Window *main_window { nullptr };
   static Fl_Menu_Item main_menu[];
-  Fl_Menu_Bar *main_menubar { nullptr };
+  fld::widget::App_Menu_Bar *main_menubar { nullptr };
   Fl_Menu_Item *save_item { nullptr };
   Fl_Menu_Item *history_item { nullptr };
   Fl_Menu_Item *widgetbin_item { nullptr };

fluid/app/Snap_Action.cxx

@@ -22,9 +22,9 @@
 #include "nodes/Group_Node.h"
 #include "nodes/Window_Node.h"
 #include "panels/settings_panel.h"
+#include "widgets/App_Menu_Bar.h"
 
 #include <FL/fl_draw.H>
-#include <FL/Fl_Menu_Bar.H>
 #include <FL/fl_string_functions.h>
 
 #include <math.h>

fluid/app/shell_command.cxx

@@ -102,9 +102,9 @@
 #include "io/Project_Reader.h"
 #include "io/Project_Writer.h"
 #include "panels/settings_panel.h"
+#include "widgets/App_Menu_Bar.h"
 
 #include <FL/Fl_Double_Window.H>
-#include <FL/Fl_Menu_Bar.H>
 #include <FL/fl_message.H>
 #include <FL/fl_string_functions.h>
 

fluid/tools/autodoc.cxx

@@ -27,13 +27,13 @@
 #include "panels/function_panel.h"
 #include "panels/settings_panel.h"
 #include "panels/codeview_panel.h"
+#include "widgets/App_Menu_Bar.h"
 #include "widgets/Node_Browser.h"
 
 #include <FL/Enumerations.H>
 #include <FL/fl_draw.H>
 #include <FL/Fl_Image_Surface.H>
 #include <FL/Fl_PNG_Image.H>
-#include <FL/Fl_Menu_Bar.H>
 
 extern Fl_Double_Window *settings_window;
 

fluid/widgets/App_Menu_Bar.cxx

@@ -0,0 +1,59 @@
+//
+// Application Menu Bar widget for the Fast Light Tool Kit (FLTK).
+//
+// Copyright 2025 by Bill Spitzak and others.
+//
+// This library is free software. Distribution and use rights are outlined in
+// the file "COPYING" which should have been included with this file.  If this
+// file is missing or damaged, see the license at:
+//
+//     https://www.fltk.org/COPYING.php
+//
+// Please see the following page on how to report bugs and issues:
+//
+//     https://www.fltk.org/bugs.php
+//
+
+//
+// Include necessary headers...
+//
+
+#include "widgets/App_Menu_Bar.h"
+
+#include "Fluid.h"
+#include "Project.h"
+
+using namespace fld;
+using namespace fld::widget;
+
+extern void mergeback_cb(Fl_Widget *, void *);
+
+/**
+ Create a fld::widget::App_Menu_Bar widget.
+ \param[in] X, Y, W, H position and size of the widget
+ \param[in] L optional label
+ */
+App_Menu_Bar::App_Menu_Bar(int X, int Y, int W, int H, const char *L)
+: Fl_Menu_Bar(X, Y, W, H, L)
+{
+}
+
+/**
+ Set menu item visibility and active state before menu pops up.
+ */
+int App_Menu_Bar::handle(int event)
+{
+  Fl_Menu_Item *mi = nullptr;
+  if (event == FL_BEFORE_MENU) {
+    mi = (Fl_Menu_Item*)find_item(mergeback_cb);
+    if (mi && Fluid.proj.write_mergeback_data)
+      mi->show();
+    else
+      mi->hide();
+    return 1;
+  } else {
+    return Fl_Menu_Bar::handle(event);
+  }
+}
+
+

fluid/widgets/App_Menu_Bar.h

@@ -0,0 +1,41 @@
+//
+// Application Menu Bar widget for the Fast Light Tool Kit (FLTK).
+//
+// Copyright 2025 by Bill Spitzak and others.
+//
+// This library is free software. Distribution and use rights are outlined in
+// the file "COPYING" which should have been included with this file.  If this
+// file is missing or damaged, see the license at:
+//
+//     https://www.fltk.org/COPYING.php
+//
+// Please see the following page on how to report bugs and issues:
+//
+//     https://www.fltk.org/bugs.php
+//
+
+#ifndef FLUID_WIDGETS_APP_MENU_BAR_H
+#define FLUID_WIDGETS_APP_MENU_BAR_H
+
+//
+// Include necessary headers...
+//
+
+#include <FL/Fl_Menu_Bar.H>
+
+namespace fld {
+namespace widget {
+
+/**
+ A text viewer with an additional highlighting color scheme.
+ */
+class App_Menu_Bar : public Fl_Menu_Bar {
+public:
+  App_Menu_Bar(int X, int Y, int W, int H, const char *L = nullptr);
+  int handle(int event) override;
+};
+
+} // namespace widget
+} // namespace fld
+
+#endif // FLUID_WIDGETS_APP_MENU_BAR_H