+ if(items.empty())
+ max_scroll = 0;
+ else
+ max_scroll = last_to_first_row(rows.size()-1);
+
+ if(first_row>max_scroll)
+ first_row = max_scroll;
+
+ slider.set_range(0, max_scroll);
+ slider.set_page_size(rows.size()-max_scroll);
+ slider.set_value(max_scroll-first_row);
+}
+
+void List::scroll_to_focus()
+{
+ if(focus_index==INVALID_INDEX || items[focus_index]->is_visible())
+ return;
+
+ size_t focus_row = item_index_to_row(focus_index);
+ if(focus_row<first_row)
+ slider.set_value(max_scroll-focus_row);
+ else
+ slider.set_value(max_scroll-last_to_first_row(focus_row));
+}
+
+void List::slider_value_changed(double value)
+{
+ if(max_scroll>0 && !ignore_slider_change)
+ {
+ first_row = max_scroll-static_cast<size_t>(value);
+ mark_rebuild();
+ }
+}
+
+void List::adjust_index(size_t &index, size_t pos, ptrdiff_t change)
+{
+ if(index==INVALID_INDEX)
+ return;
+ else if(index>pos)
+ index += change;
+ else if(index==pos)
+ index = (change>0 ? index+change : INVALID_INDEX);
+}
+
+
+List::DataObserver::DataObserver(List &l):
+ list(l)
+{
+ list.data->signal_item_added.connect(sigc::mem_fun(this, &DataObserver::item_added));
+ list.data->signal_item_removed.connect(sigc::mem_fun(this, &DataObserver::item_removed));
+ list.data->signal_cleared.connect(sigc::mem_fun(this, &DataObserver::cleared));
+ list.data->signal_refresh_item.connect(sigc::mem_fun(this, &DataObserver::refresh_item));