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, 335 insertions, 0 deletions

diff --git a/fluid/Project.cxx b/fluid/Project.cxx
new file mode 100644
index 000000000..9eb555299
--- /dev/null
+++ b/fluid/Project.cxx
@@ -0,0 +1,335 @@
+//
+// Fluid Project 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 "Project.h"
+
+#include "io/String_Writer.h"
+#include "nodes/Node.h"
+#include "panels/settings_panel.h"
+#include "panels/codeview_panel.h"
+
+using namespace fld;
+
+// ---- project settings
+
+/**
+ Initialize a new project.
+ */
+Project::Project() {
+}
+
+/**
+ Clear all project resources.
+ Not implemented.
+ */
+Project::~Project() {
+}
+
+/**
+ Reset all project setting to create a new empty project.
+ */
+void Project::reset() {
+  ::delete_all();
+  i18n_type = fld::I18n_Type::NONE;
+
+  i18n_gnu_include = "<libintl.h>";
+  i18n_gnu_conditional = "";
+  i18n_gnu_function = "gettext";
+  i18n_gnu_static_function = "gettext_noop";
+
+  i18n_pos_include = "<nl_types.h>";
+  i18n_pos_conditional = "";
+  i18n_pos_file = "";
+  i18n_pos_set = "1";
+
+  include_H_from_C = 1;
+  use_FL_COMMAND = 0;
+  utf8_in_src = 0;
+  avoid_early_includes = 0;
+  header_file_set = 0;
+  code_file_set = 0;
+  header_file_name = ".h";
+  code_file_name = ".cxx";
+  write_mergeback_data = 0;
+}
+
+/**
+ Tell the project and i18n tab of the settings dialog to refresh themselves.
+ */
+void Project::update_settings_dialog() {
+  if (settings_window) {
+    w_settings_project_tab->do_callback(w_settings_project_tab, LOAD);
+    w_settings_i18n_tab->do_callback(w_settings_i18n_tab, LOAD);
+  }
+}
+
+/**
+ Get the absolute path of the project file, for example `/Users/matt/dev/`.
+ \return the path ending in '/'
+ */
+std::string Project::projectfile_path() const {
+  return end_with_slash(fl_filename_absolute_str(fl_filename_path_str(proj_filename), Fluid.launch_path()));
+}
+
+/**
+ Get the project file name including extension, for example `test.fl`.
+ \return the file name without path
+ */
+std::string Project::projectfile_name() const {
+  return fl_filename_name(proj_filename);
+}
+
+/**
+ Get the absolute path of the generated C++ code file, for example `/Users/matt/dev/src/`.
+ \return the path ending in '/'
+ */
+std::string Project::codefile_path() const {
+  std::string path = fl_filename_path_str(code_file_name);
+  if (Fluid.batch_mode)
+    return end_with_slash(fl_filename_absolute_str(path, Fluid.launch_path()));
+  else
+    return end_with_slash(fl_filename_absolute_str(path, projectfile_path()));
+}
+
+/**
+ Get the generated C++ code file name including extension, for example `test.cxx`.
+ \return the file name without path
+ */
+std::string Project::codefile_name() const {
+  std::string name = fl_filename_name_str(code_file_name);
+  if (name.empty()) {
+    return fl_filename_setext_str(fl_filename_name(proj_filename), ".cxx");
+  } else if (name[0] == '.') {
+    return fl_filename_setext_str(fl_filename_name(proj_filename), code_file_name);
+  } else {
+    return name;
+  }
+}
+
+/**
+ Get the absolute path of the generated C++ header file, for example `/Users/matt/dev/src/`.
+ \return the path ending in '/'
+ */
+std::string Project::headerfile_path() const {
+  std::string path = fl_filename_path_str(header_file_name);
+  if (Fluid.batch_mode)
+    return end_with_slash(fl_filename_absolute_str(path, Fluid.launch_path()));
+  else
+    return end_with_slash(fl_filename_absolute_str(path, projectfile_path()));
+}
+
+/**
+ Get the generated C++ header file name including extension, for example `test.cxx`.
+ \return the file name without path
+ */
+std::string Project::headerfile_name() const {
+  std::string name = fl_filename_name_str(header_file_name);
+  if (name.empty()) {
+    return fl_filename_setext_str(fl_filename_name_str(proj_filename), ".h");
+  } else if (name[0] == '.') {
+    return fl_filename_setext_str(fl_filename_name_str(proj_filename), header_file_name);
+  } else {
+    return name;
+  }
+}
+
+/**
+ Get the absolute path of the generated i18n strings file, for example `/Users/matt/dev/`.
+ Although it may be more useful to put the text file into the same directory
+ with the source and header file, historically, the text is always saved with
+ the project file in interactive mode, and in the FLUID launch directory in
+ batch mode.
+ \return the path ending in '/'
+ */
+std::string Project::stringsfile_path() const {
+  if (Fluid.batch_mode)
+    return Fluid.launch_path();
+  else
+    return projectfile_path();
+}
+
+/**
+ Get the generated i18n text file name including extension, for example `test.po`.
+ \return the file name without path
+ */
+std::string Project::stringsfile_name() const {
+  switch (i18n_type) {
+    default: return fl_filename_setext_str(fl_filename_name(proj_filename), ".txt");
+    case fld::I18n_Type::GNU: return fl_filename_setext_str(fl_filename_name(proj_filename), ".po");
+    case fld::I18n_Type::POSIX: return fl_filename_setext_str(fl_filename_name(proj_filename), ".msg");
+  }
+}
+
+/**
+ Get the name of the project file without the filename extension.
+ \return the file name without path or extension
+ */
+std::string Project::basename() const {
+  return fl_filename_setext_str(fl_filename_name(proj_filename), "");
+}
+
+
+/**
+ Change the current working directory to the .fl project directory.
+
+ Every call to enter_project_dir() must have a corresponding leave_project_dir()
+ call. Enter and leave calls can be nested.
+
+ The first call to enter_project_dir() remembers the original directory, usually
+ the launch directory of the application. Nested calls will increment a nesting
+ counter. When the nesting counter is back to 0, leave_project_dir() will return
+ to the original directory.
+
+ The global variable 'filename' must be set to the current project file with
+ absolute or relative path information.
+
+ \see leave_project_dir(), pwd, in_project_dir
+ */
+void Project::enter_project_dir() {
+  if (in_project_dir<0) {
+    fprintf(stderr, "** Fluid internal error: enter_project_dir() calls unmatched\n");
+    return;
+  }
+  in_project_dir++;
+  // check if we are already in the project dir and do nothing if so
+  if (in_project_dir>1) return;
+  // check if there is an active project, and do nothing if there is none
+  if (!proj_filename || !*proj_filename) {
+    fprintf(stderr, "** Fluid internal error: enter_project_dir() no filename set\n");
+    return;
+  }
+  // store the current working directory for later
+  app_work_dir = fl_getcwd_str();
+  // set the current directory to the path of our .fl file
+  std::string project_path = fl_filename_path_str(fl_filename_absolute_str(proj_filename));
+  if (fl_chdir(project_path.c_str()) == -1) {
+    fprintf(stderr, "** Fluid internal error: enter_project_dir() can't chdir to %s: %s\n",
+            project_path.c_str(), strerror(errno));
+    return;
+  }
+  //fprintf(stderr, "chdir from %s to %s\n", app_work_dir.c_str(), fl_getcwd().c_str());
+}
+
+/**
+ Change the current working directory to the previous directory.
+ \see enter_project_dir(), pwd, in_project_dir
+ */
+void Project::leave_project_dir() {
+  if (in_project_dir == 0) {
+    fprintf(stderr, "** Fluid internal error: leave_project_dir() calls unmatched\n");
+    return;
+  }
+  in_project_dir--;
+  // still nested, stay in the project directory
+  if (in_project_dir > 0) return;
+  // no longer nested, return to the original, usually the application working directory
+  if (fl_chdir(app_work_dir.c_str()) < 0) {
+    fprintf(stderr, "** Fluid internal error: leave_project_dir() can't chdir back to %s : %s\n",
+            app_work_dir.c_str(), strerror(errno));
+  }
+}
+
+/**
+ Set the filename of the current .fl design.
+ \param[in] c the new absolute filename and path
+ */
+void Project::set_filename(const char *c) {
+  if (proj_filename) free((void *)proj_filename);
+  proj_filename = c ? fl_strdup(c) : nullptr;
+
+  if (proj_filename && !Fluid.batch_mode)
+    Fluid.history.update(proj_filename);
+
+  set_modflag(modflag);
+}
+
+/**
+ Write the strings that are used in i18n.
+ */
+void Project::write_strings() {
+  Fluid.flush_text_widgets();
+  if (!proj_filename) {
+    Fluid.save_project_file(nullptr);
+    if (!proj_filename) return;
+  }
+  std::string filename = stringsfile_path() + stringsfile_name();
+  int x = fld::io::write_strings(*this, filename);
+  if (Fluid.batch_mode) {
+    if (x) {
+      fprintf(stderr, "%s : %s\n", filename.c_str(), strerror(errno));
+      exit(1);
+    }
+  } else {
+    if (x) {
+      fl_message("Can't write %s: %s", filename.c_str(), strerror(errno));
+    } else if (completion_button->value()) {
+      fl_message("Wrote %s", stringsfile_name().c_str());
+    }
+  }
+}
+
+
+/**
+ Set the "modified" flag and update the title of the main window.
+
+ The first argument sets the modification state of the current design against
+ the corresponding .fl design file. Any change to the widget tree will mark
+ the design 'modified'. Saving the design will mark it clean.
+
+ The second argument is optional and set the modification state of the current
+ design against the source code and header file. Any change to the tree,
+ including saving the tree, will mark the code 'outdated'. Generating source
+ code and header files will clear this flag until the next modification.
+
+ \param[in] mf 0 to clear the modflag, 1 to mark the design "modified", -1 to
+ ignore this parameter
+ \param[in] mfc default -1 to let \c mf control \c modflag_c, 0 to mark the
+ code files current, 1 to mark it out of date. -2 to ignore changes to mf.
+ */
+void Project::set_modflag(int mf, int mfc) {
+  const char *code_ext = nullptr;
+  char new_title[FL_PATH_MAX];
+
+  // Update the modflag_c to the worst possible condition. We could be a bit
+  // more graceful and compare modification times of the files, but C++ has
+  // no API for that until C++17.
+  if (mf!=-1) {
+    modflag = mf;
+    if (mfc==-1 && mf==1)
+      mfc = mf;
+  }
+  if (mfc>=0) {
+    modflag_c = mfc;
+  }
+
+  if (Fluid.main_window) {
+    std::string basename;
+    if (!proj_filename) basename = "Untitled.fl";
+    else basename = fl_filename_name_str(std::string(proj_filename));
+    code_ext = fl_filename_ext(code_file_name.c_str());
+    char mod_star = modflag ? '*' : ' ';
+    char mod_c_star = modflag_c ? '*' : ' ';
+    snprintf(new_title, sizeof(new_title), "%s%c  %s%c",
+             basename.c_str(), mod_star, code_ext, mod_c_star);
+    const char *old_title = Fluid.main_window->label();
+    // only update the title if it actually changed
+    if (!old_title || strcmp(old_title, new_title))
+      Fluid.main_window->copy_label(new_title);
+  }
+  // if the UI was modified in any way, update the Code View panel
+  if (codeview_panel && codeview_panel->visible() && cv_autorefresh->value())
+    codeview_defer_update();
+}