views: Redraw the agenda view when week-start-day changes

Updates the visible rows after the selected date shifts within the week.
The agenda view displays all events starting from the selected day and
up until the last day of the same week.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-calendar/-/merge_requests/822>

src/gui/views/gcal-agenda-view.c

@@ -299,6 +299,15 @@ gcal_agenda_view_get_previous_date (GcalView *view)
   return g_date_time_add_weeks (self->date, -1);
 }
 
+static void
+gcal_agenda_view_first_weekday_changed (GcalView *view)
+{
+  GcalAgendaView *self = GCAL_AGENDA_VIEW (view);
+
+  gtk_list_view_scroll_to (self->list_view, 0, GTK_LIST_SCROLL_FOCUS, NULL);
+  gcal_timeline_subscriber_range_changed (GCAL_TIMELINE_SUBSCRIBER (view));
+}
+
 static void
 gcal_view_interface_init (GcalViewInterface *iface)
 {
@@ -308,6 +317,7 @@ gcal_view_interface_init (GcalViewInterface *iface)
   iface->clear_marks = gcal_agenda_view_clear_marks;
   iface->get_next_date = gcal_agenda_view_get_next_date;
   iface->get_previous_date = gcal_agenda_view_get_previous_date;
+  iface->first_weekday_changed = gcal_agenda_view_first_weekday_changed;
 }