I have a large widget that I would like to fit into a small place and make it scrollable.
For this, I have an example code as follows. It creates a Gtk::Window with default size 100×100, it has a Gtk::Box that contains a Gtk::Viewport and a Gtk::Scrollbar. The Gtk::Viewport widget contains a “large” widget with size 200×200. Unfortunately, the window grows to 200×200.

Is there a way to handle Gtk::Window resize event? We don’t have an event controller for it, nor we can override Gtk::Widget::size_allocate function because it’s not virtual.

I have a window that extends Gtk::Window. I would like to go fullscreen on the second monitor using fullscreen_on_monitor(const Glib::RefPtr< Gdk::Monitor > &monitor). How do I get the second monitor?