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`.

1 files changed, 19 insertions, 13 deletions

diff --git a/fluid/io/Project_Reader.h b/fluid/io/Project_Reader.h
index 20928d25f..b25b04ead 100644
--- a/fluid/io/Project_Reader.h
+++ b/fluid/io/Project_Reader.h
@@ -1,7 +1,7 @@
 //
-// Fluid file routines for the Fast Light Tool Kit (FLTK).
+// Fluid Project File Reader header 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
@@ -17,35 +17,41 @@
 #ifndef FLUID_IO_PROJECT_READER_H
 #define FLUID_IO_PROJECT_READER_H
 
-#include "nodes/Fl_Type.h"
+#include "nodes/Node.h"
 
 #include <FL/fl_attr.h>
 
 #include <stdio.h>
 
 
-class Fl_Type;
+class Node;
 
 namespace fld {
+
+class Project;
+
 namespace io {
 
 extern int fdesign_flip;
 
-int read_file(const char *, int merge, Strategy strategy=Strategy::FROM_FILE_AS_LAST_CHILD);
+int read_file(Project &proj, const char *, int merge, Strategy strategy=Strategy::FROM_FILE_AS_LAST_CHILD);
 
 class Project_Reader
 {
 protected:
+  /// Link Project_Reader class to the project.
+  Project &proj_;
+
   /// Project input file
-  FILE *fin;
+  FILE *fin = nullptr;
   /// Number of most recently read line
-  int lineno;
+  int lineno = 0;
   /// Pointer to the file path and name (not copied!)
-  const char *fname;
+  const char *fname = nullptr;
   /// Expanding buffer to store the most recently read word
-  char *buffer;
+  char *buffer = nullptr;
   /// Exact size of the expanding buffer in bytes
-  int buflen;
+  int buflen = 0;
 
   void expand_buffer(int length);
 
@@ -53,16 +59,16 @@ protected:
 
 public:
   /// Holds the file version number after reading the "version" tag
-  double read_version;
+  double read_version = 0.0;
 
 public:
-  Project_Reader();
+  Project_Reader(Project &proj);
   ~Project_Reader();
   int open_read(const char *s);
   int close_read();
   const char *filename_name();
   int read_quoted();
-  Fl_Type *read_children(Fl_Type *p, int merge, Strategy strategy, char skip_options=0);
+  Node *read_children(Node *p, int merge, Strategy strategy, char skip_options=0);
   int read_project(const char *, int merge, Strategy strategy=Strategy::FROM_FILE_AS_LAST_CHILD);
   void read_error(const char *format, ...);
   const char *read_word(int wantbrace = 0);