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, 115 insertions, 0 deletions

diff --git a/fluid/app/history.cxx b/fluid/app/history.cxx
new file mode 100644
index 000000000..7eadb5469
--- /dev/null
+++ b/fluid/app/history.cxx
@@ -0,0 +1,115 @@
+//
+// Fluid Project File History code for the Fast Light Tool Kit (FLTK).
+//
+// 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
+// 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 "app/history.h"
+
+#include "Fluid.h"
+
+#include "../src/flstring.h"
+
+using namespace fld;
+using namespace fld::app;
+
+
+/**
+ Load file history from preferences.
+
+ This loads the absolute filepaths of the last 10 used design files.
+ It also computes and stores the relative filepaths for display in
+ the main menu.
+ */
+void History::load() {
+  int   i;              // Looping var
+  int   max_files;
+
+  Fluid.preferences.get("recent_files", max_files, 5);
+  if (max_files > 10) max_files = 10;
+
+  for (i = 0; i < max_files; i ++) {
+    Fluid.preferences.get( Fl_Preferences::Name("file%d", i), abspath[i], "", sizeof(abspath[i]));
+    if (abspath[i][0]) {
+      // Make a shortened version of the filename for the menu...
+      std::string fn = fl_filename_shortened(abspath[i], 48);
+      strncpy(relpath[i], fn.c_str(), sizeof(relpath[i]) - 1);
+      if (i == 9) Fluid.history_item[i].flags = FL_MENU_DIVIDER;
+      else Fluid.history_item[i].flags = 0;
+    } else break;
+  }
+
+  for (; i < 10; i ++) {
+    if (i) Fluid.history_item[i-1].flags |= FL_MENU_DIVIDER;
+    Fluid.history_item[i].hide();
+  }
+}
+
+/**
+ Update file history from preferences.
+
+ Add this new filepath to the history and update the main menu.
+ Writes the new file history to the app preferences.
+
+ \param[in] project_file path and filename of .fl project file, will be
+    converted into an absolute file path based on the current working directory.
+ */
+void History::update(std::string project_file) {
+  int   i;              // Looping var
+  int   max_files;
+
+  Fluid.preferences.get("recent_files", max_files, 5);
+  if (max_files > 10) max_files = 10;
+
+  std::string absolute = fld::fix_separators(fl_filename_absolute_str(project_file));
+  for (i = 0; i < max_files; i ++)
+#if defined(_WIN32) || defined(__APPLE__)
+    if (!strcasecmp(absolute.c_str(), abspath[i])) break;
+#else
+    if (!strcmp(absolute.c_str(), abspath[i])) break;
+#endif // _WIN32 || __APPLE__
+
+  // Does the first entry match?
+  if (i == 0)
+    return;
+
+  // Was there no match?
+  if (i >= max_files)
+    i = max_files - 1;
+
+  // Move the other filenames down in the list...
+  memmove(abspath + 1, abspath, i * sizeof(abspath[0]));
+  memmove(relpath + 1, relpath, i * sizeof(relpath[0]));
+
+  // Put the new file at the top...
+  strlcpy(abspath[0], absolute.c_str(), sizeof(abspath[0]));
+  std::string fn = fl_filename_shortened(absolute, 48);
+  strncpy(relpath[0], fn.c_str(), sizeof(relpath[0]) - 1);
+
+  // Update the menu items as needed...
+  for (i = 0; i < max_files; i ++) {
+    Fluid.preferences.set( Fl_Preferences::Name("file%d", i), abspath[i]);
+    if (abspath[i][0]) {
+      if (i == 9) Fluid.history_item[i].flags = FL_MENU_DIVIDER;
+      else Fluid.history_item[i].flags = 0;
+    } else break;
+  }
+
+  for (; i < 10; i ++) {
+    Fluid.preferences.set( Fl_Preferences::Name("file%d", i), "");
+    if (i) Fluid.history_item[i-1].flags |= FL_MENU_DIVIDER;
+    Fluid.history_item[i].hide();
+  }
+  Fluid.preferences.flush();
+}
+