Disable "scroll" event propagation on a widget that receives the "scroll" event in GTK4.

gistfile1.txt

/* Disable scroll on a widget by adding a capture phase event handler and
 * connecting a no-op callback to the "scroll" event.
 */
static GtkWidget *
disable_scroll( GtkWidget *w )
{
        GtkEventController *ec;

        ec = gtk_event_controller_scroll_new(
                        GTK_EVENT_CONTROLLER_SCROLL_VERTICAL );

        gtk_event_controller_set_propagation_phase( ec, GTK_PHASE_CAPTURE );
        g_signal_connect( ec, "scroll", G_CALLBACK( disable_scroll_cb ), w );
        gtk_widget_add_controller( w, ec );

        return w;
}