+bool Panel::navigate(Navigation nav)
+{
+ if(Container::navigate(nav))
+ return true;
+
+ if(nav==NAV_UP || nav==NAV_DOWN || nav==NAV_LEFT || nav==NAV_RIGHT)
+ {
+ int x = geom.w/2;
+ int y = geom.h/2;
+ if(input_focus)
+ {
+ const Geometry &fgeom = input_focus->get_geometry();
+ x = fgeom.x+fgeom.w/2;
+ y = fgeom.y+fgeom.h/2;
+ }
+ else if(nav==NAV_UP)
+ y = 0;
+ else if(nav==NAV_DOWN)
+ y = geom.h;
+ else if(nav==NAV_RIGHT)
+ x = 0;
+ else if(nav==NAV_LEFT)
+ x = geom.w;
+
+ Widget *sibling = 0;
+ int best_score = 0;
+ for(list<Child *>::const_iterator i=children.begin(); i!=children.end(); ++i)
+ {
+ if((*i)->widget==input_focus || !(*i)->widget->is_focusable())
+ continue;
+
+ const Geometry &cgeom = (*i)->widget->get_geometry();
+ int dx = cgeom.x+cgeom.w/2-x;
+ int dy = cgeom.y+cgeom.h/2-y;
+
+ int score = -1;
+ if(nav==NAV_UP && dy>0)
+ score = dy+abs(dx)*4;
+ else if(nav==NAV_DOWN && dy<0)
+ score = -dy+abs(dx)*4;
+ else if(nav==NAV_RIGHT && dx>0)
+ score = dx+abs(dy)*4;
+ else if(nav==NAV_LEFT && dx<0)
+ score = -dx+abs(dy)*4;
+
+ if(score>0 && (!sibling || score<best_score))
+ {
+ sibling = (*i)->widget;
+ best_score = score;
+ }
+ }
+
+ if(sibling)
+ {
+ set_input_focus(sibling);
+ if(Panel *panel = dynamic_cast<Panel *>(sibling))
+ panel->navigate(nav);
+ return true;
+ }
+ }
+
+ return false;
+}
+
+void Panel::on_geometry_change()
+{
+ if(layout)
+ layout->update();
+}
+
+void Panel::on_child_added(Widget &wdg)
+{
+ if(layout)
+ {
+ layout->add_widget(wdg);
+ signal_autosize_changed.emit();
+ }
+}
+
+void Panel::on_child_removed(Widget &wdg)
+{
+ if(layout)
+ {
+ layout->remove_widget(wdg);
+ signal_autosize_changed.emit();
+ }
+}
+
+
+Panel::Loader::Loader(Panel &p, map<string, Widget *> &m):
+ DataFile::DerivedObjectLoader<Panel, Widget::Loader>(p),
+ wdg_map(m),
+ last_widget(0)
+{
+ add("button", &Loader::child<Button>);
+ add("column", &Loader::arrangement<Column>);
+ add("constraint",&Loader::constraint);
+ add("draghandle",&Loader::child<DragHandle>);
+ add("dropdown", &Loader::child<Dropdown>);
+ add("entry", &Loader::child<Entry>);
+ add("expand", &Loader::expand);
+ add("ghost", &Loader::ghost);
+ add("gravity", &Loader::gravity);
+ add("grid", &Loader::grid);
+ add("hslider", &Loader::child<HSlider>);
+ add("image", &Loader::child<Image>);
+ add("indicator", &Loader::child<Indicator>);
+ add("label", &Loader::child<Label>);
+ add("layout", &Loader::layout);
+ add("list", &Loader::child<List>);
+ add("panel", &Loader::panel);
+ add("row", &Loader::arrangement<Row>);
+ add("stack", &Loader::arrangement<Stack>);
+ add("toggle", &Loader::child<Toggle>);
+ add("vslider", &Loader::child<VSlider>);
+}
+
+Layout &Panel::Loader::get_layout()