GTK 4.12 deprecates gdk_wayland_toplevel_unexport_handle() in favor
of the new gdk_wayland_toplevel_drop_exported_handle(). We are not
bound by API stability, so we can just expose the additional argument
that the replacement requires instead of tracking the handle
internally.
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2778>
With the previous preparations in place, it is time to take the plunge.
As both the app and the portal use the same small library for handling
external windows, port everything at once to avoid the hassle of building
and installing two versions of the library.
With the portal using GTK4 now, all extensions must port their preference
widgets as well.
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1495>
In order to support OpenExtensionPrefs()'s parentWindow parameter,
we will need the ability to make a window transient to an external
window identified by a string handle.
This takes the corresponding code from xdg-desktop-portal-gtk and
brings it into an introspectable form, likewise the counterpart in
libportal to export a string handle for a GtkWindow.
https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1087
