Gtk3: GtkImage prevents user from shrinking the window - gtk

Question

Gtk3 in C: I am trying to create a window that loads a picture from a png/jpeg file. I want the user to be able to resize the window and automatically scale the picture to fit the window.
So here is what I do:
app = gtk_application_new("foo", G_APPLICATION_FLAGS_NONE);
g_signal_connect(app, "activate", G_CALLBACK(activate), NULL);
status = g_application_run(G_APPLICATION(app), argc, argv);
then the activate method does:
GtkWidget *window;
window = gtk_application_window_new(app);
gtk_window_set_title(GTK_WINDOW(window), "foo");
gtk_window_set_default_size(GTK_WINDOW(window), 600, 600);
GError *err = NULL;
// Note: original and image are global variables, because I can't
// get user_data for callbacks working. Will sort this out later.
original = gdk_pixbuf_new_from_file("myfile.png", &err);
if (err != NULL) {
fatalf(scope, "Unable to read file: %s\n", err->message);
exit(1);
}
image = gtk_image_new();
gtk_container_add(GTK_CONTAINER(window), image);
gtk_widget_show_all(window);
g_signal_connect(G_OBJECT(window), "configure-event", G_CALLBACK(resize_picture), NULL);
and the resize_picture:
gint w, h;
gtk_window_get_size(window, &w, &h);
GdkPixbuf *resized = gdk_pixbuf_scale_simple(original, w, h, GDK_INTERP_BILINEAR);
gtk_image_set_from_pixbuf(image, resized);
Now the problem is that the GtkImage appears to impose the minimum size on the window. I can enlarge the window, which scales up the picture, but I cannot shrink it. Is there some property I can set on GtkWindow or GtkImage to allow me to do that? Or do I need to use something else than GtkImage?

Answer 1

The solution is to switch to GTK4 and use GtkPicture instead of GtkImage.
GtkPicture has can_shrink property, which solves this problem.