Fluid: improve filechooser and paths (#1475)

* some refactoring still needed

fluid/CMakeLists.txt

@@ -119,6 +119,7 @@ set(CPPFILES
   app/shell_command.cxx
   app/templates.cxx
   io/Code_Writer.cxx
+  io/file_chooser.cxx
   io/Project_Writer.cxx
   io/Project_Reader.cxx
   io/String_Writer.cxx
@@ -175,6 +176,7 @@ set(HEADERFILES
   app/shell_command.h
   app/templates.h
   io/Code_Writer.h
+  io/file_chooser.h
   io/Project_Writer.h
   io/Project_Reader.h
   io/String_Writer.h

fluid/Fluid.cxx

@@ -23,6 +23,7 @@
 #include "proj/undo.h"
 #include "io/Project_Reader.h"
 #include "io/Project_Writer.h"
+#include "io/file_chooser.h"
 #include "io/Code_Writer.h"
 #include "nodes/Node.h"
 #include "nodes/Function_Node.h"
@@ -502,7 +503,12 @@ bool Application::open_project_file(const std::string &filename_arg) {
   // ask for a filename if none was given
   std::string new_filename = filename_arg;
   if (new_filename.empty()) {
-    new_filename = open_project_filechooser("Open Project File");
+    new_filename = fluid::io::load_project_filechooser(
+      "Open Project File",
+      history.latest_project_path(),
+      launch_path(),
+      "FLUID Project Files\t*.f[ld]\n"
+    );
     if (new_filename.empty()) {
       return false;
     }
@@ -533,7 +539,12 @@ bool Application::merge_project_file(const std::string &filename_arg) {
   // ask for a filename if none was given
   std::string new_filename = filename_arg;
   if (new_filename.empty()) {
-    new_filename = open_project_filechooser(title);
+    new_filename = fluid::io::load_project_filechooser(
+      title,
+      history.latest_project_path(),
+      launch_path(),
+      "FLUID Project Files\t*.f[ld]\n"
+    );
     if (new_filename.empty()) {
       return false;
     }
@@ -566,6 +577,7 @@ bool Application::merge_project_file(const std::string &filename_arg) {
     proj.set_modflag(0, 0);
     proj.undo.clear();
   }
+  proj.update_settings_dialog();
   if (oldfilename) free((void *)oldfilename);
   return true;
 }
@@ -1207,32 +1219,6 @@ void Application::make_main_window() {
   }
 }
 
-
-/**
- Open a native file chooser to allow choosing a project file for reading.
-
- Path and filename are preset with the current project filename, if there
- is one.
-
- \param title a text describing the action after selecting a file (load, merge, ...)
- \return the file path and name, or an empty string if the operation was canceled
- */
-std::string Application::open_project_filechooser(const std::string &title) {
-  Fl_Native_File_Chooser dialog;
-  dialog.title(title.c_str());
-  dialog.type(Fl_Native_File_Chooser::BROWSE_FILE);
-  dialog.filter("FLUID Files\t*.f[ld]\n");
-  if (proj.proj_filename) {
-    std::string current_project_file = proj.proj_filename;
-    dialog.directory(fl_filename_path_str(current_project_file).c_str());
-    dialog.preset_file(fl_filename_name_str(current_project_file).c_str());
-  }
-  if (dialog.show() != 0)
-    return std::string();
-  return std::string(dialog.filename());
-}
-
-
 /**
  Give the user the opportunity to save a project before clearing it.
 

fluid/Fluid.h

@@ -193,8 +193,6 @@ public: // Methods
 
   // Build the main app window and create a few other dialogs.
   void make_main_window();
-  // Open a native file chooser to allow choosing a project file for reading.
-  std::string open_project_filechooser(const std::string &title);
   // Give the user the opportunity to save a project before clearing it.
   bool confirm_project_clear();
   // Ensure that text widgets in the widget panel propagates apply current changes.

fluid/app/history.cxx

@@ -48,6 +48,7 @@ void History::load() {
       else Fluid.history_item[i].flags = 0;
     } else break;
   }
+  Fluid.preferences.get("latest_project_path", latest_project_path_, "");
 
   for (; i < 10; i ++) {
     if (i) Fluid.history_item[i-1].flags |= FL_MENU_DIVIDER;
@@ -79,6 +80,12 @@ void History::update(std::string project_file) {
     if (!strcmp(absolute.c_str(), abspath[i])) break;
 #endif // _WIN32 || __APPLE__
 
+  std::string path = fl_filename_path_str(absolute);
+  if (path != latest_project_path_) {
+    latest_project_path_ = path;
+    Fluid.preferences.set("latest_project_path", latest_project_path_);
+  }
+
   // Does the first entry match?
   if (i == 0)
     return;

fluid/app/history.h

@@ -24,7 +24,11 @@
 namespace fluid {
 namespace app {
 
-class History {
+class History
+{
+private:
+  std::string latest_project_path_ { };
+
 public:
   /// Stores the absolute filename of the last 10 project files, saved in app preferences.
   char abspath[10][FL_PATH_MAX] { };
@@ -36,6 +40,8 @@ public:
   void load();
   // Add a new file to the project history using absolute paths.
   void update(std::string project_file);
+  // Return the path to the last opened project file, or an empty string if none.
+  std::string latest_project_path() const { return latest_project_path_; }
 };
 
 } // namespace app

fluid/io/file_chooser.cxx

@@ -0,0 +1,198 @@
+//
+// Fluid C++ File Chooser code for the Fast Light Tool Kit (FLTK).
+//
+// Copyright 2026 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 "io/file_chooser.h"
+
+#include "Fluid.h"
+
+#include <FL/Fl_Native_File_Chooser.H>
+#include <FL/filename.H>
+
+
+static constexpr int load_type = Fl_Native_File_Chooser::BROWSE_FILE;
+static constexpr int save_type = Fl_Native_File_Chooser::BROWSE_SAVE_FILE;
+static constexpr int load_options = Fl_Native_File_Chooser::PREVIEW;
+#ifdef __APPLE__
+static constexpr int save_options = Fl_Native_File_Chooser::NEW_FOLDER|Fl_Native_File_Chooser::SAVEAS_CONFIRM;
+#else
+static constexpr int save_options = Fl_Native_File_Chooser::NEW_FOLDER|Fl_Native_File_Chooser::SAVEAS_CONFIRM;
+#endif
+
+static void set_paths(
+  Fl_Native_File_Chooser& fnfc,
+  const std::string& preset_path,
+  const std::string& fallback_path,
+  std::string& preset_directory,
+  std::string& preset_filename)
+{
+  std::string preset;
+
+  if (!preset_path.empty()) {
+    preset = fl_filename_absolute_str(preset_path);
+    preset_directory = fl_filename_path_str(preset);
+    preset_filename = fl_filename_name_str(preset);
+  } else {
+    if (!fallback_path.empty()) {
+      preset = fl_filename_absolute_str(fallback_path);
+    } else {
+      preset = fl_filename_absolute_str(Fluid.launch_path());
+    }
+    preset_directory = preset;
+    preset_filename.clear();
+  }
+  fnfc.directory(preset_directory.c_str());
+  fnfc.preset_file(preset_filename.c_str());
+}
+
+/**
+ Lets the user choose a project file to open.
+ \param title the dialog window's title
+ \param preset_path the path and name to a file that should be preselected in the dialog, or an empty string to use the fallback path
+ \param fallback_path the path to use if no preset path is provided
+ \param filter the file filter to apply in the dialog
+ \return the absolute path to the chosen file, or an empty string if the operation was canceled
+ */
+std::string fluid::io::load_project_filechooser(
+  const std::string& title,
+  const std::string& preset_path,
+  const std::string& fallback_path,
+  const std::string& filter)
+{
+  std::string preset_directory;
+  std::string preset_filename;
+
+  Fl_Native_File_Chooser fnfc;
+  fnfc.type(load_type);
+  fnfc.options(load_options);
+  fnfc.title(title.c_str());
+  fnfc.filter(filter.c_str());
+  set_paths(fnfc, preset_path, fallback_path, preset_directory, preset_filename);
+
+  switch (fnfc.show()) {
+    case -1: // Error
+      fl_alert("Can't open project:\n%s", fnfc.errmsg());
+      return "";
+    case 1: // Cancelled
+      return "";
+    default: // Success
+      return fl_filename_absolute_str(fnfc.filename());
+  }
+}
+
+/**
+ Lets the user choose a data file to inline into the code.
+ \param title the dialog window's title
+ \param preset_path the path and name to a file that should be preselected in the dialog, or an empty string to use the fallback path
+ \param fallback_path the path to use if no preset path is provided
+ \param filter the file filter to apply in the dialog
+ \return the relative path to the chosen file, or an empty string if the operation was canceled
+ */
+std::string fluid::io::load_inline_data_filechooser(
+  const std::string& title,
+  const std::string& preset_path,
+  const std::string& fallback_path,
+  const std::string& filter)
+{
+  std::string preset_directory;
+  std::string preset_filename;
+
+  Fl_Native_File_Chooser fnfc;
+  fnfc.type(load_type);
+  fnfc.options(load_options);
+  fnfc.title(title.c_str());
+  fnfc.filter(filter.c_str());
+  set_paths(fnfc, preset_path, fallback_path, preset_directory, preset_filename);
+
+  switch (fnfc.show()) {
+    case -1: // Error
+      fl_alert("Can't open data file:\n%s", fnfc.errmsg());
+      return "";
+    case 1: // Cancelled
+      return "";
+    default: // Success
+      return fl_filename_relative_str(fnfc.filename());
+  }
+}
+
+/**
+ Lets the user choose a comment file to load.
+ \param title the dialog window's title
+ \param preset_path not useful here, we never save the path to the comment file, just import it immediately
+ \param fallback_path the path to use if no preset path is provided
+ \param filter the file filter to apply in the dialog
+ \return the absolute path to the chosen file, or an empty string if the operation was canceled
+ */
+std::string fluid::io::load_comment_filechooser(
+  const std::string& title,
+  const std::string& preset_path,
+  const std::string& fallback_path,
+  const std::string& filter)
+{
+  std::string preset_directory;
+  std::string preset_filename;
+
+  Fl_Native_File_Chooser fnfc;
+  fnfc.type(load_type);
+  fnfc.options(load_options);
+  fnfc.title(title.c_str());
+  fnfc.filter(filter.c_str());
+  set_paths(fnfc, preset_path, fallback_path, preset_directory, preset_filename);
+
+  switch (fnfc.show()) {
+    case -1: // Error
+      fl_alert("Can't open comment file:\n%s", fnfc.errmsg());
+      return "";
+    case 1: // Cancelled
+      return "";
+    default: // Success
+      return fl_filename_absolute_str(fnfc.filename());
+  }
+}
+
+/**
+ Lets the user choose an image file to load.
+ \param title the dialog window's title
+ \param preset_path the path and name to a file that should be preselected in the dialog, or an empty string to use the fallback path
+ \param fallback_path the path to use if no preset path is provided
+ \param filter the file filter to apply in the dialog
+ \return the relative path to the chosen file, or an empty string if the operation was canceled
+ */
+std::string fluid::io::load_image_filechooser(
+  const std::string& title,
+  const std::string& preset_path,
+  const std::string& fallback_path,
+  const std::string& filter)
+{
+  std::string preset_directory;
+  std::string preset_filename;
+
+  Fl_Native_File_Chooser fnfc;
+  fnfc.type(load_type);
+  fnfc.options(load_options);
+  fnfc.title(title.c_str());
+  fnfc.filter(filter.c_str());
+  set_paths(fnfc, preset_path, fallback_path, preset_directory, preset_filename);
+
+  switch (fnfc.show()) {
+    case -1: // Error
+      fl_alert("Can't open image file:\n%s", fnfc.errmsg());
+      return "";
+    case 1: // Cancelled
+      return "";
+    default: // Success
+      return fl_filename_relative_str(fnfc.filename());
+  }
+}

fluid/io/file_chooser.h

@@ -0,0 +1,65 @@
+//
+// Fluid C++ File Chooser header for the Fast Light Tool Kit (FLTK).
+//
+// Copyright 2026 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
+//
+
+#ifndef FLUID_IO_FILE_CHOOSER_H
+#define FLUID_IO_FILE_CHOOSER_H
+
+#include <string>
+
+namespace fluid {
+
+namespace io {
+
+// ✔︎ Load Inline Data
+// ✔︎ Pick a comment
+// ✔︎ ui_find_image (the offender here, I guess)
+
+// Application::save_project_file
+// ✔︎ Application::open_project_filechooser
+// Fd_Shell_Command_List::export_selected
+// Fd_Shell_Command_List::import_from_file
+// Load Layout Settings
+// Save Layout Settings
+
+extern std::string load_project_filechooser(
+  const std::string& title,
+  const std::string& preset_path,
+  const std::string& fallback_path,
+  const std::string& filter);
+
+extern std::string load_inline_data_filechooser(
+  const std::string& title,
+  const std::string& preset_path,
+  const std::string& fallback_path,
+  const std::string& filter);
+
+extern std::string load_comment_filechooser(
+  const std::string& title,
+  const std::string& preset_path,
+  const std::string& fallback_path,
+  const std::string& filter);
+
+extern std::string load_image_filechooser(
+  const std::string& title,
+  const std::string& preset_path,
+  const std::string& fallback_path,
+  const std::string& filter);
+
+} // namespace io
+
+} // namespace fluid
+
+#endif // FLUID_IO_FILE_CHOOSER_H

fluid/panels/widget_panel.cxx

@@ -23,6 +23,7 @@
 #include "proj/undo.h"
 #include "nodes/Window_Node.h"
 #include "nodes/Grid_Node.h"
+#include "io/file_chooser.h"
 #include "nodes/Menu_Node.h"
 #include "nodes/Function_Node.h"
 #include <FL/Fl_Spinner.H>
@@ -53,7 +54,7 @@ extern int haderror;
  Allow widget navigation on text fields with Tab.
 */
 static int use_tab_navigation(int, Fl_Text_Editor*) {
-//fl ▼ ------------------------ code --~--=--=-~=-==~~=-~=-~- ▼ fl//
+//fl ▼ ------------------------ code ---~=~=-----=-=~-~=~--~- ▼ fl//
   return 0;
 //fl ▲ ----------~~-~=---~-------------~-=--~~-=~=-~~--~-~=-- ▲ fl//
 }
@@ -2651,19 +2652,25 @@ static void cb_wp_data_filename(Fl_Input* o, void* v) {
 static void cb_fileopen(Fl_Button*, void* v) {
 //fl ▼ ---------------------- callback ~--=-~~~=~~--~=-=~-=~- ▼ fl//
   if (v != LOAD) {
+
     Fluid.proj.enter_project_dir();
-    const char *fn = fl_file_chooser("Load Inline Data",
-      nullptr, wp_data_filename->value(), 1);
+    std::string fn = fluid::io::load_inline_data_filechooser(
+      "Load Inline Data",
+      wp_data_filename->value(),
+      Fluid.proj.projectfile_path(),
+      ""
+    );
     Fluid.proj.leave_project_dir();
-    if (fn) {
-      if (strcmp(fn, wp_data_filename->value())) {
+    
+    if (!fn.empty()) {
+      if (strcmp(fn.c_str(), wp_data_filename->value())) {
         Fluid.proj.set_modflag(1);
-        wp_data_filename->value(fn);
+        wp_data_filename->value(fn.c_str());
         wp_data_filename->do_callback();
       }
     }
   }
-//fl ▲ ----------=~~---~~=~~=----------~--~-~=~=-~=--~=-~~=-- ▲ fl//
+//fl ▲ ----------=~~---~~=~~=----------~-~=--~-=~~~~--~~~=--- ▲ fl//
 }
 
 static void cb_Comment(Fl_Text_Editor* o, void* v) {
@@ -2814,17 +2821,22 @@ static void cb_comment_load_2(Fl_Button*, void* v) {
 //fl ▼ ---------------------- callback ~~~~~=~-=~~-=-=-~=-=~= ▼ fl//
   // load a comment from disk
   if (v != LOAD) {
-    fl_file_chooser_ok_label("Load");
-    const char *fname = fl_file_chooser("Pick a comment", nullptr, nullptr);
-    fl_file_chooser_ok_label(nullptr);
-    if (fname) {
-      if (comment_tabs_name->buffer()->loadfile(fname)) {
-        fl_alert("Error loading file\n%s", fname);
+     Fluid.proj.enter_project_dir();
+    std::string fname = fluid::io::load_comment_filechooser(
+      "Load Comment From File",
+      "",
+      Fluid.proj.projectfile_path(),
+      ""
+    );
+    Fluid.proj.leave_project_dir();
+     if (!fname.empty()) {
+      if (comment_tabs_name->buffer()->loadfile(fname.c_str())) {
+        fl_alert("Error loading file\n%s", fname.c_str());
       }
       comment_tabs_name->do_callback();
     }
   }
-//fl ▲ ----------=~--=--=~=~=----------~~-~~----=--~~-~~~=~=- ▲ fl//
+//fl ▲ ----------=~--=--=~=~=----------~~=--~--~=-=-=-=--=--~ ▲ fl//
 }
 
 static void cb_output(Fl_Check_Button* o, void* v) {

fluid/panels/widget_panel.fl

@@ -57,6 +57,9 @@ decl {\#include "nodes/Window_Node.h"} {uid b4c3 private global
 decl {\#include "nodes/Grid_Node.h"} {uid 867b private global
 }
 
+decl {\#include "io/file_chooser.h"} {uid 867e private global
+}
+
 decl {\#include "nodes/Menu_Node.h"} {uid 2b16 private global
 }
 
@@ -546,7 +549,7 @@ Function {make_widget_panel()} {uid 9310
             xywh {95 40 309 20} labelfont 1 labelsize 11 align 4
           } {
             Fl_Input wp_gui_label {uid 5f88
-              callback label_cb
+              callback label_cb selected
               tooltip {The label text for the widget.
 Use Ctrl-J for newlines.} xywh {95 40 190 20} labelfont 1 labelsize 11 when 15 textsize 11 resizable
             }
@@ -2636,7 +2639,7 @@ if (v == LOAD) {
       }
       Fl_Tabs data_tabs {uid 3ae5
         callback {if (current_node && current_node->is_a(Type::Data))
-  propagate_load((Fl_Group *)o,v);} open
+  propagate_load((Fl_Group *)o,v);}
         xywh {10 10 400 350} selection_color 12 labelsize 11 labelcolor 255 hide
       } {
         Fl_Group data_tabs_data {uid b260
@@ -2818,14 +2821,20 @@ update_current(o, v,
             Fl_Button {} {uid a0fe
               label {@fileopen}
               callback {if (v != LOAD) {
+
   Fluid.proj.enter_project_dir();
-  const char *fn = fl_file_chooser("Load Inline Data",
-    nullptr, wp_data_filename->value(), 1);
+  std::string fn = fluid::io::load_inline_data_filechooser(
+    "Load Inline Data",
+    wp_data_filename->value(),
+    Fluid.proj.projectfile_path(),
+    ""
+  );
   Fluid.proj.leave_project_dir();
-  if (fn) {
-    if (strcmp(fn, wp_data_filename->value())) {
+  
+  if (!fn.empty()) {
+    if (strcmp(fn.c_str(), wp_data_filename->value())) {
       Fluid.proj.set_modflag(1);
-      wp_data_filename->value(fn);
+      wp_data_filename->value(fn.c_str());
       wp_data_filename->do_callback();
     }
   }
@@ -2983,12 +2992,17 @@ if (v == LOAD) {
               label {Import...}
               callback {// load a comment from disk
 if (v != LOAD) {
-  fl_file_chooser_ok_label("Load");
-  const char *fname = fl_file_chooser("Pick a comment", nullptr, nullptr);
-  fl_file_chooser_ok_label(nullptr);
-  if (fname) {
-    if (comment_tabs_name->buffer()->loadfile(fname)) {
-      fl_alert("Error loading file\\n%s", fname);
+   Fluid.proj.enter_project_dir();
+  std::string fname = fluid::io::load_comment_filechooser(
+    "Load Comment From File",
+    "",
+    Fluid.proj.projectfile_path(),
+    ""
+  );
+  Fluid.proj.leave_project_dir();
+   if (!fname.empty()) {
+    if (comment_tabs_name->buffer()->loadfile(fname.c_str())) {
+      fl_alert("Error loading file\\n%s", fname.c_str());
     }
     comment_tabs_name->do_callback();
   }

fluid/proj/Image_Asset.cxx

@@ -17,6 +17,8 @@
 #include "proj/Image_Asset.h"
 
 #include "Fluid.h"
+#include "Project.h"
+#include "io/file_chooser.h"
 #include "io/Project_Reader.h"
 #include "io/Project_Writer.h"
 #include "io/Code_Writer.h"
@@ -451,16 +453,18 @@ Image_Asset::~Image_Asset() {
  */
 std::shared_ptr<Image_Asset> ui_find_image(const char *oldname) {
   Fluid.proj.enter_project_dir();
-  fl_file_chooser_ok_label("Use Image");
-  const char *name = fl_file_chooser("Image?",
-            "Image Files (*.{bm,bmp,gif,jpg,pbm,pgm,png,ppm,xbm,xpm,svg"
+
+  std::string name = fluid::io::load_image_filechooser(
+    "Image?",
+    oldname ? oldname : "",
+    Fluid.proj.projectfile_path(),
+    "Image Files\t*.{bm,bmp,gif,jpg,pbm,pgm,png,ppm,xbm,xpm,svg"
 #ifdef HAVE_LIBZ
                         ",svgz"
 #endif
-                                     "})",
-            oldname,1);
-  fl_file_chooser_ok_label(nullptr);
-  std::shared_ptr<Image_Asset> ret = (name && *name) ? Fluid.proj.image_assets.find_or_create(name) : nullptr;
+                                     "}"
+  );
+  std::shared_ptr<Image_Asset> ret = (!name.empty()) ? Fluid.proj.image_assets.find_or_create(name) : nullptr;
   Fluid.proj.leave_project_dir();
   return ret;
 }