Is there currently any support for file chooser functionality?

[dixego]

I'm trying to create a very simple application that requires loading, showing and saving images.
While browsing the code in gintro/gtk.nim, I've noticed most (all?) of the GtkFileChooser interface functions are missing. Most importantly, there doesn't seem to be any way to retrieve a filename from a file chooser dialog (I did actually manage to create one, FileChooserNative). Am I missing something or is this just not implemented yet? Any help on how I would go about creating these bindings myself (since GtkFileChooser is not a "class" but an "interface")?

[StefanSalewski]

Thanks for reporting.

So we have to investigate why it is missing -- it is not missing intentional. Unfortunately I have not much free time available currently.

Do you have some GTK experience? Can you provide some working test code in C, Python, Ruby or any other language? That would help. Note that we also have oldgtk3 and legacy gtk2 nimble packages. And other GUI libs like nimx, libui and more, which may be better suited for you when you have no gtk experience and want to create only small trivial applications.

[StefanSalewski]

Seems to be not a bug of generator script:

/usr/share/gir-1.0/Gtk-3.0.gir

      <constructor name="new"
                   c:identifier="gtk_file_chooser_dialog_new"
                   version="2.4"
                   introspectable="0">

So gtk_file_chooser_dialog_new() function is not introspectable, so skipped by generator. I guess this is due to variable number of arguments. We have to add code for this manually. I hope the native filechooser will work for you for now.

[dixego]

I don't have much Gtk experience, but I do have a working example doing more or less what I want to do in C, using the GtkFileChooserNative

#include <gtk/gtk.h>

static void on_open_image(GtkButton *button, gpointer user_data) {
  GtkWidget *image = GTK_WIDGET(user_data);
  GtkWidget *toplevel = gtk_widget_get_toplevel(image);
  GtkFileFilter *filter = gtk_file_filter_new();
  GtkFileChooserNative *dialog = gtk_file_chooser_native_new("Open Image", 
                                                 GTK_WINDOW(toplevel),
                                                 GTK_FILE_CHOOSER_ACTION_OPEN,
                                                 "OK", 
                                                 "Cancel");
  gtk_file_filter_add_pixbuf_formats(filter);
  gtk_file_chooser_add_filter(GTK_FILE_CHOOSER(dialog), filter);

  switch(gtk_native_dialog_run(GTK_NATIVE_DIALOG(dialog))) {
    case GTK_RESPONSE_ACCEPT:
      {
        gchar *filename = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(dialog));
        gtk_image_set_from_file(GTK_IMAGE(image), filename);
        break;
      }
    default:
      break;
  }

  g_object_unref(dialog);
}

static GtkWidget *create_window() {
  GtkWidget *window;
  GtkWidget *button;
  GtkWidget *image;
  GtkWidget *menu_bar;
  GtkWidget *box;

  window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
  gtk_window_set_title(GTK_WINDOW(window), "image-viewer");
  box = gtk_box_new(GTK_ORIENTATION_VERTICAL, 5);
  button = gtk_button_new_with_label("Open Image");
  menu_bar = gtk_menu_bar_new();
  image = gtk_image_new();

  gtk_box_pack_start(GTK_BOX(box), image, TRUE, TRUE, 0);
  gtk_box_pack_start(GTK_BOX(box), button, FALSE, FALSE, 0);
  gtk_box_pack_start(GTK_BOX(box), menu_bar, TRUE, TRUE, 0);

  gtk_container_add(GTK_CONTAINER(window), box);

  g_signal_connect(button, "clicked", G_CALLBACK(on_open_image), image);
  g_signal_connect(window, "destroy", G_CALLBACK(gtk_main_quit), NULL);
  return window;
}

int main(int argc, char **argv) {
  gtk_init(&argc, &argv);
  GtkWidget *window = create_window();
  gtk_widget_show_all(window);
  gtk_main();
  return 0;
}

The main problem with porting this to nim currently is that none of the gtk_file_chooser functions appear to be bound in gtk.nim, including the only one I need to get this example working, gtk_file_chooser_get_filename

Here's my nim code as it is right now:

import gintro/[gtk, glib, gobject, gio]

proc bye(b: Button) =
  mainQuit()
  echo "exiting.."

proc onOpenImage(button: Button, image: Image) =
  var 
    toplevel = image.getToplevel()
    chooserDialog = newFileChooserNative("Open Image", cast[Window](toplevel), FileChooserAction.open, "Accept", "Cancel")
    button = newFileChooserButtonWithDialog(cast[Dialog](chooserDialog))
  case cast[ResponseType](chooserDialog.run())
  of ResponseType.accept:
    ##let filename = gtk_file_chooser_get_filename(cast[gtk.FileChooserWidget](chooserDialog))
  else:
    discard;
  chooserDialog.destroy()

proc createWindow(): Window =
  result = newWindow()
  result.title = "image viewer"
  var box = newBox(Orientation.vertical, 5)
  var image = newImage()
  var button = newButton("Open image")
  box.packStart(image, expand = true, fill = true, padding = 0)
  box.packStart(button, expand = false, fill = false, padding = 0)
  result.add(box)
  button.connect("clicked", onOpenImage, image)
  button.connect("destroy", bye)

proc mainProc() =
  var 
    argc: int = 0
    argv: cstringArray = nil
  init(argc, argv)
  let window = createWindow()
  window.showAll()
  main()

mainProc()

Seeing as how GtkFileChooser is a GObject interface, how could I write bindings to its functions by hand? Is it even possible without breaking the rest of the bindings?

[StefanSalewski]

Thanks for C example code.

I think we have only to provide newFileChooserDialog() proc manually -- will try to code and ship it tonight.

[StefanSalewski]

But you are right, functions with C names like gtk_file_chooser_get_filename() are currently missing too. They should have been generated automatically, we have to investigate why not.

[StefanSalewski]

Fixed.

After

nimble uninstall gintro
nimble install gintro
# should install v0.4.3

try this:

import gintro/[gtk, gobject]

proc bye(b: Button) =
  mainQuit()
  echo "exiting.."

proc onOpenImage(button: Button, image: Image) = 
  let toplevel = image.getToplevel()
  let dialog = newFileChooserDialog("Open File", Window(toplevel), FileChooserAction.open)
  discard dialog.addButton("OK", ResponseType.accept.ord)
  discard dialog.addButton("Cancel", ResponseType.cancel.ord)
  case dialog.run
  of ResponseType.accept.ord:
    let filename = dialog.getFilename
    echo "Selected: ", $filename
  else:
    discard
  dialog.destroy()

proc createWindow(): Window =
  result = newWindow()
  result.title = "image viewer"
  var box = newBox(Orientation.vertical, 5)
  var image = newImage()
  var button = newButton("Open image")
  box.packStart(image, expand = true, fill = true, padding = 0)
  box.packStart(button, expand = false, fill = false, padding = 0)
  result.add(box)
  button.connect("clicked", onOpenImage, image)
  button.connect("destroy", bye)

proc mainProc() =
  #var 
  #  argc: int = 0
  #  argv: cstringArray = nil
  #init(argc, argv)
  gtk.init()
  let window = createWindow()
  window.showAll()
  main()

mainProc()

[dixego]

It works! Thank you very much