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, 143 insertions, 0 deletions

diff --git a/fluid/app/templates.cxx b/fluid/app/templates.cxx
new file mode 100644
index 000000000..802357ed2
--- /dev/null
+++ b/fluid/app/templates.cxx
@@ -0,0 +1,143 @@
+//
+// Fluid Project Templates 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/templates.h"
+
+#include "Fluid.h"
+#include "io/Project_Writer.h"
+#include "nodes/factory.h"
+#include "nodes/Tree.h"
+#include "nodes/Window_Node.h"
+#include "panels/template_panel.h"
+
+#include <FL/filename.H>
+#include <FL/fl_ask.H>
+#include <FL/Fl_PNG_Image.H>
+#include "../src/flstring.h"
+
+using namespace fld;
+using namespace fld::app;
+
+/**
+ Save a design template.
+ \todo We should document the concept of templates.
+ */
+void fld::app::save_template() {
+  // Setup the template panel...
+  if (!template_panel) make_template_panel();
+
+  template_clear();
+  template_browser->add("New Template");
+  template_load();
+
+  template_name->show();
+  template_name->value("");
+
+  template_instance->hide();
+
+  template_delete->show();
+  template_delete->deactivate();
+
+  template_submit->label("Save");
+  template_submit->deactivate();
+
+  template_panel->label("Save Template");
+
+  // Show the panel and wait for the user to do something...
+  template_panel->show();
+  while (template_panel->shown()) Fl::wait();
+
+  // Get the template name, return if it is empty...
+  const char *c = template_name->value();
+  if (!c || !*c) return;
+
+  // Convert template name to filename_with_underscores
+  char savename[FL_PATH_MAX], *saveptr;
+  strlcpy(savename, c, sizeof(savename));
+  for (saveptr = savename; *saveptr; saveptr ++) {
+    if (isspace(*saveptr)) *saveptr = '_';
+  }
+
+  // Find the templates directory...
+  char filename[FL_PATH_MAX];
+  Fluid.preferences.getUserdataPath(filename, sizeof(filename));
+
+  strlcat(filename, "templates", sizeof(filename));
+  if (fl_access(filename, 0)) fl_make_path(filename);
+
+  strlcat(filename, "/", sizeof(filename));
+  strlcat(filename, savename, sizeof(filename));
+
+  char *ext = filename + strlen(filename);
+  if (ext >= (filename + sizeof(filename) - 5)) {
+    fl_alert("The template name \"%s\" is too long!", c);
+    return;
+  }
+
+  // Save the .fl file...
+  strcpy(ext, ".fl");
+
+  if (!fl_access(filename, 0)) {
+    if (fl_choice("The template \"%s\" already exists.\n"
+                  "Do you want to replace it?", "Cancel",
+                  "Replace", nullptr, c) == 0) return;
+  }
+
+  if (!fld::io::write_file(Fluid.proj, filename)) {
+    fl_alert("Error writing %s: %s", filename, strerror(errno));
+    return;
+  }
+
+#if defined(HAVE_LIBPNG) && defined(HAVE_LIBZ)
+  // Get the screenshot, if any...
+  Node *t;
+
+  for (t = Fluid.proj.tree.first; t; t = t->next) {
+    // Find the first window...
+    if (t->is_a(Type::Window)) break;
+  }
+
+  if (!t) return;
+
+  // Grab a screenshot...
+  Window_Node *wt = (Window_Node *)t;
+  uchar *pixels;
+  int w, h;
+
+  if ((pixels = wt->read_image(w, h)) == nullptr) return;
+
+  // Save to a PNG file...
+  strcpy(ext, ".png");
+
+  errno = 0;
+  if (fl_write_png(filename, pixels, w, h, 3) != 0) {
+    delete[] pixels;
+    fl_alert("Error writing %s: %s", filename, strerror(errno));
+    return;
+  }
+
+#  if 0 // The original PPM output code...
+  strcpy(ext, ".ppm");
+  fp = fl_fopen(filename, "wb");
+  fprintf(fp, "P6\n%d %d 255\n", w, h);
+  fwrite(pixels, w * h, 3, fp);
+  fclose(fp);
+#  endif // 0
+
+  delete[] pixels;
+#endif // HAVE_LIBPNG && HAVE_LIBZ
+}
+