Fluid: restructuring and rejuvenation of the source code.

* Add classes for application and project
* Removed all globals from Fluid.h
* Extracting args and project history into their own classes
* Moving globals into Application class
* Initialize values inside headers for some classes.
* Undo functionality wrapped in a class inside Project.
* File reader and writer are now linked to a project.
* Avoid global project access
* Nodes (former Types) will be managed by a new Tree class.
* Removed static members (hidden globals) form Node/Fl_Type.
* Adding Tree iterator.
* Use nullptr instead of 0, NULL, or 0L
* Renamed Fl_..._Type to ..._Node, FL_OVERRIDE -> override
* Renaming ..._type to ...::prototype
* Splitting Widget Panel into multiple files.
* Moved callback code into widget panel file.
* Cleaning up Fluid_Image -> Image_asset
* Moving Fd_Snap_Action into new namespace fld::app::Snap_Action etc.
* Moved mergeback into proj folder.
* `enum ID` is now `enum class Type`.

2 files changed, 74 insertions, 74 deletions

diff --git a/fluid/rsrcs/pixmaps.cxx b/fluid/rsrcs/pixmaps.cxx
index dbcebe043..640cf79d9 100644
--- a/fluid/rsrcs/pixmaps.cxx
+++ b/fluid/rsrcs/pixmaps.cxx
@@ -1,7 +1,7 @@
 //
-// Fluid Image management for the Fast Light Tool Kit (FLTK).
+// Fluid GUI Image code for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2023 by Bill Spitzak and others.
+// Copyright 1998-2025 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
@@ -16,7 +16,7 @@
 
 #include "rsrcs/pixmaps.h"
 
-#include "nodes/Fl_Type.h"
+#include "nodes/Node.h"
 
 #include <FL/Fl_Pixmap.H>
 
@@ -90,7 +90,7 @@ Fl_Pixmap *protected_pixmap;
 Fl_Pixmap *invisible_pixmap;
 Fl_Pixmap *compressed_pixmap;
 
-Fl_Pixmap *pixmap[ID_Max_] = { NULL };
+Fl_Pixmap *pixmap[(int)Type::Max_] = { nullptr };
 
 /**
  Draw a zoom cross pointing in all four diagonal directions
@@ -152,74 +152,74 @@ void loadPixmaps()
   invisible_pixmap = new Fl_Pixmap(invisible_xpm); invisible_pixmap->scale(16, 16);
   compressed_pixmap = new Fl_Pixmap(compressed_xpm); compressed_pixmap->scale(16, 16);
 
-  pixmap[ID_Window] = tmp = new Fl_Pixmap(flWindow_xpm); tmp->scale(16, 16);
-  pixmap[ID_Button] = tmp = new Fl_Pixmap(flButton_xpm); tmp->scale(16, 16);
-  pixmap[ID_Check_Button] = tmp = new Fl_Pixmap(flCheckButton_xpm); tmp->scale(16, 16);
-  pixmap[ID_Round_Button] = tmp = new Fl_Pixmap(flRoundButton_xpm); tmp->scale(16, 16);
-
-  pixmap[ID_Box] = tmp = new Fl_Pixmap(flBox_xpm); tmp->scale(16, 16);
-  pixmap[ID_Group] = tmp = new Fl_Pixmap(flGroup_xpm); tmp->scale(16, 16);
-  pixmap[ID_Function] = tmp = new Fl_Pixmap(flFunction_xpm); tmp->scale(16, 16);
-  pixmap[ID_Code] = tmp = new Fl_Pixmap(flCode_xpm); tmp->scale(16, 16);
-  pixmap[ID_CodeBlock] = tmp = new Fl_Pixmap(flCodeBlock_xpm); tmp->scale(16, 16);
-  pixmap[ID_Decl] = tmp = new Fl_Pixmap(flDeclaration_xpm); tmp->scale(16, 16);
-
-  pixmap[ID_DeclBlock] = tmp = new Fl_Pixmap(flDeclarationBlock_xpm); tmp->scale(16, 16);
-  pixmap[ID_Class] = tmp = new Fl_Pixmap(flClass_xpm); tmp->scale(16, 16);
-  pixmap[ID_Tabs] = tmp = new Fl_Pixmap(flTabs_xpm); tmp->scale(16, 16);
-  pixmap[ID_Input] = tmp = new Fl_Pixmap(flInput_xpm); tmp->scale(16, 16);
-  pixmap[ID_Choice] = tmp = new Fl_Pixmap(flChoice_xpm); tmp->scale(16, 16);
-
-  pixmap[ID_Menu_Item] = tmp = new Fl_Pixmap(flMenuitem_xpm); tmp->scale(16, 16);
-  pixmap[ID_Menu_Bar] = tmp = new Fl_Pixmap(flMenubar_xpm); tmp->scale(16, 16);
-  pixmap[ID_Submenu] = tmp = new Fl_Pixmap(flSubmenu_xpm); tmp->scale(16, 16);
-  pixmap[ID_Scroll] = tmp = new Fl_Pixmap(flScroll_xpm); tmp->scale(16, 16);
-  pixmap[ID_Tile] = tmp = new Fl_Pixmap(flTile_xpm); tmp->scale(16, 16);
-  pixmap[ID_Wizard] = tmp = new Fl_Pixmap(flWizard_xpm); tmp->scale(16, 16);
-
-  pixmap[ID_Pack] = tmp = new Fl_Pixmap(flPack_xpm); tmp->scale(16, 16);
-  pixmap[ID_Return_Button] = tmp = new Fl_Pixmap(flReturnButton_xpm); tmp->scale(16, 16);
-  pixmap[ID_Light_Button] = tmp = new Fl_Pixmap(flLightButton_xpm); tmp->scale(16, 16);
-  pixmap[ID_Repeat_Button] = tmp = new Fl_Pixmap(flRepeatButton_xpm); tmp->scale(16, 16);
-  pixmap[ID_Menu_Button] = tmp = new Fl_Pixmap(flMenuButton_xpm); tmp->scale(16, 16);
-
-  pixmap[ID_Output] = tmp = new Fl_Pixmap(flOutput_xpm); tmp->scale(16, 16);
-  pixmap[ID_Text_Display] = tmp = new Fl_Pixmap(flTextDisplay_xpm); tmp->scale(16, 16);
-  pixmap[ID_Text_Editor] = tmp = new Fl_Pixmap(flTextEdit_xpm); tmp->scale(16, 16);
-  pixmap[ID_File_Input] = tmp = new Fl_Pixmap(flFileInput_xpm); tmp->scale(16, 16);
-  pixmap[ID_Browser] = tmp = new Fl_Pixmap(flBrowser_xpm); tmp->scale(16, 16);
-
-  pixmap[ID_Check_Browser] = tmp = new Fl_Pixmap(flCheckBrowser_xpm); tmp->scale(16, 16);
-  pixmap[ID_File_Browser] = tmp = new Fl_Pixmap(flFileBrowser_xpm); tmp->scale(16, 16);
-  pixmap[ID_Clock] = tmp = new Fl_Pixmap(flClock_xpm); tmp->scale(16, 16);
-  pixmap[ID_Help_View] = tmp = new Fl_Pixmap(flHelp_xpm); tmp->scale(16, 16);
-  pixmap[ID_Progress] = tmp = new Fl_Pixmap(flProgress_xpm); tmp->scale(16, 16);
-
-  pixmap[ID_Slider] = tmp = new Fl_Pixmap(flSlider_xpm); tmp->scale(16, 16);
-  pixmap[ID_Scrollbar] = tmp = new Fl_Pixmap(flScrollBar_xpm); tmp->scale(16, 16);
-  pixmap[ID_Value_Slider] = tmp = new Fl_Pixmap(flValueSlider_xpm); tmp->scale(16, 16);
-  pixmap[ID_Adjuster] = tmp = new Fl_Pixmap(flAdjuster_xpm); tmp->scale(16, 16);
-  pixmap[ID_Counter] = tmp = new Fl_Pixmap(flCounter_xpm); tmp->scale(16, 16);
-
-  pixmap[ID_Dial] = tmp = new Fl_Pixmap(flDial_xpm); tmp->scale(16, 16);
-  pixmap[ID_Roller] = tmp = new Fl_Pixmap(flRoller_xpm); tmp->scale(16, 16);
-  pixmap[ID_Value_Input] = tmp = new Fl_Pixmap(flValueInput_xpm); tmp->scale(16, 16);
-  pixmap[ID_Value_Output] = tmp = new Fl_Pixmap(flValueOutput_xpm); tmp->scale(16, 16);
-  pixmap[ID_Comment] = tmp = new Fl_Pixmap(flComment_xpm); tmp->scale(16, 16);
-
-  pixmap[ID_Spinner] = tmp = new Fl_Pixmap(flSpinner_xpm); tmp->scale(16, 16);
-  pixmap[ID_Widget_Class] = tmp = new Fl_Pixmap(flWidgetClass_xpm); tmp->scale(16, 16);
-  pixmap[ID_Data] = tmp = new Fl_Pixmap(flData_xpm); tmp->scale(16, 16);
-  pixmap[ID_Tree] = tmp = new Fl_Pixmap(flTree_xpm); tmp->scale(16, 16);
-  pixmap[ID_Table] = tmp = new Fl_Pixmap(flTable_xpm); tmp->scale(16, 16);
-
-  pixmap[ID_Terminal] = tmp = new Fl_Pixmap(flSimpleTerminal_xpm); tmp->scale(16, 16);
-  pixmap[ID_Input_Choice] = tmp = new Fl_Pixmap(flInputChoice_xpm); tmp->scale(16, 16);
-  pixmap[ID_Checkbox_Menu_Item] = tmp = new Fl_Pixmap(flCheckMenuitem_xpm); tmp->scale(16, 16);
-  pixmap[ID_Radio_Menu_Item] = tmp = new Fl_Pixmap(flRadioMenuitem_xpm); tmp->scale(16, 16);
-
-  pixmap[ID_Flex] = tmp = new Fl_Pixmap(flFlex_xpm); tmp->scale(16, 16);
-  pixmap[ID_Grid] = tmp = new Fl_Pixmap(flGrid_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Window] = tmp = new Fl_Pixmap(flWindow_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Button] = tmp = new Fl_Pixmap(flButton_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Check_Button] = tmp = new Fl_Pixmap(flCheckButton_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Round_Button] = tmp = new Fl_Pixmap(flRoundButton_xpm); tmp->scale(16, 16);
+
+  pixmap[(int)Type::Box] = tmp = new Fl_Pixmap(flBox_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Group] = tmp = new Fl_Pixmap(flGroup_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Function] = tmp = new Fl_Pixmap(flFunction_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Code] = tmp = new Fl_Pixmap(flCode_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::CodeBlock] = tmp = new Fl_Pixmap(flCodeBlock_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Decl] = tmp = new Fl_Pixmap(flDeclaration_xpm); tmp->scale(16, 16);
+
+  pixmap[(int)Type::DeclBlock] = tmp = new Fl_Pixmap(flDeclarationBlock_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Class] = tmp = new Fl_Pixmap(flClass_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Tabs] = tmp = new Fl_Pixmap(flTabs_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Input] = tmp = new Fl_Pixmap(flInput_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Choice] = tmp = new Fl_Pixmap(flChoice_xpm); tmp->scale(16, 16);
+
+  pixmap[(int)Type::Menu_Item] = tmp = new Fl_Pixmap(flMenuitem_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Menu_Bar] = tmp = new Fl_Pixmap(flMenubar_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Submenu] = tmp = new Fl_Pixmap(flSubmenu_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Scroll] = tmp = new Fl_Pixmap(flScroll_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Tile] = tmp = new Fl_Pixmap(flTile_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Wizard] = tmp = new Fl_Pixmap(flWizard_xpm); tmp->scale(16, 16);
+
+  pixmap[(int)Type::Pack] = tmp = new Fl_Pixmap(flPack_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Return_Button] = tmp = new Fl_Pixmap(flReturnButton_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Light_Button] = tmp = new Fl_Pixmap(flLightButton_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Repeat_Button] = tmp = new Fl_Pixmap(flRepeatButton_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Menu_Button] = tmp = new Fl_Pixmap(flMenuButton_xpm); tmp->scale(16, 16);
+
+  pixmap[(int)Type::Output] = tmp = new Fl_Pixmap(flOutput_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Text_Display] = tmp = new Fl_Pixmap(flTextDisplay_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Text_Editor] = tmp = new Fl_Pixmap(flTextEdit_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::File_Input] = tmp = new Fl_Pixmap(flFileInput_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Browser] = tmp = new Fl_Pixmap(flBrowser_xpm); tmp->scale(16, 16);
+
+  pixmap[(int)Type::Check_Browser] = tmp = new Fl_Pixmap(flCheckBrowser_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::File_Browser] = tmp = new Fl_Pixmap(flFileBrowser_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Clock] = tmp = new Fl_Pixmap(flClock_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Help_View] = tmp = new Fl_Pixmap(flHelp_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Progress] = tmp = new Fl_Pixmap(flProgress_xpm); tmp->scale(16, 16);
+
+  pixmap[(int)Type::Slider] = tmp = new Fl_Pixmap(flSlider_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Scrollbar] = tmp = new Fl_Pixmap(flScrollBar_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Value_Slider] = tmp = new Fl_Pixmap(flValueSlider_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Adjuster] = tmp = new Fl_Pixmap(flAdjuster_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Counter] = tmp = new Fl_Pixmap(flCounter_xpm); tmp->scale(16, 16);
+
+  pixmap[(int)Type::Dial] = tmp = new Fl_Pixmap(flDial_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Roller] = tmp = new Fl_Pixmap(flRoller_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Value_Input] = tmp = new Fl_Pixmap(flValueInput_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Value_Output] = tmp = new Fl_Pixmap(flValueOutput_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Comment] = tmp = new Fl_Pixmap(flComment_xpm); tmp->scale(16, 16);
+
+  pixmap[(int)Type::Spinner] = tmp = new Fl_Pixmap(flSpinner_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Widget_Class] = tmp = new Fl_Pixmap(flWidgetClass_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Data] = tmp = new Fl_Pixmap(flData_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Tree] = tmp = new Fl_Pixmap(flTree_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Table] = tmp = new Fl_Pixmap(flTable_xpm); tmp->scale(16, 16);
+
+  pixmap[(int)Type::Terminal] = tmp = new Fl_Pixmap(flSimpleTerminal_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Input_Choice] = tmp = new Fl_Pixmap(flInputChoice_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Checkbox_Menu_Item] = tmp = new Fl_Pixmap(flCheckMenuitem_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Radio_Menu_Item] = tmp = new Fl_Pixmap(flRadioMenuitem_xpm); tmp->scale(16, 16);
+
+  pixmap[(int)Type::Flex] = tmp = new Fl_Pixmap(flFlex_xpm); tmp->scale(16, 16);
+  pixmap[(int)Type::Grid] = tmp = new Fl_Pixmap(flGrid_xpm); tmp->scale(16, 16);
 
   fl_add_symbol("fd_zoom", fd_zoom, 1);
 }
diff --git a/fluid/rsrcs/pixmaps.h b/fluid/rsrcs/pixmaps.h
index 628bcd199..a09362f3d 100644
--- a/fluid/rsrcs/pixmaps.h
+++ b/fluid/rsrcs/pixmaps.h
@@ -1,7 +1,7 @@
 //
-// Fluid Image management for the Fast Light Tool Kit (FLTK).
+// Fluid GUI Image header for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2021 by Bill Spitzak and others.
+// Copyright 1998-2025 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