+Container::Child &Container::add_child(Widget &wdg)
+{
+ wdg.set_parent(this);
+ children.push_back(make_unique<Child>(*this, &wdg));
+ if(wdg.get_animation_interval())
+ check_animation_interval();
+ children_rebuild_needed = true;
+ signal_rebuild_needed.emit();
+ on_child_added(wdg);
+ return *children.back();
+}
+