+int
+menu_driver(Menu* menu, MenuAction action)
+{
+
+ switch (action) {
+ case MENU_UP:
+ menu->selected_item = menu->selected_item-1 >= 0 ? menu->selected_item-1 : 0;
+ break;
+
+ case MENU_DOWN:
+ menu->selected_item = menu->selected_item+1 <= menu->menu_length-1 ? menu->selected_item+1 : menu->menu_length-1;
+ break;
+
+ case MENU_TOP:
+ menu->selected_item = 0;
+ break;
+
+ case MENU_BOTTOM:
+ menu->selected_item = menu->menu_length-1;
+ break;
+
+ case MENU_MOVE_UP:
+ if (menu->selected_item <= 0) break;
+ swap_item(menu, menu->selected_item, menu->selected_item-1);
+ menu->selected_item -= 1;
+ break;
+
+ case MENU_MOVE_DOWN:
+ if (menu->selected_item >= menu->menu_length-1) break;
+ swap_item(menu, menu->selected_item, menu->selected_item+1);
+ menu->selected_item += 1;
+ break;
+
+ case MENU_DELETE:
+ delete_item(menu, menu->selected_item);
+ break;
+
+ case MENU_APPEND:
+ insert_item(menu, create_blank_menuitem(), menu->menu_length);
+ render_menu(menu); // refresh after inserting
+ menu_insert_mode(menu, menu->selected_item);
+ break;
+
+ case MENU_INSERT_ABOVE:
+ insert_item(menu, create_blank_menuitem(), menu->selected_item);
+ render_menu(menu);
+ menu_insert_mode(menu, menu->selected_item);
+ break;
+
+ case MENU_INSERT_BELOW:
+ insert_item(menu, create_blank_menuitem(), menu->selected_item+1);
+ render_menu(menu);
+ menu_insert_mode(menu, menu->selected_item); // inserted item is cur now
+ break;
+
+ case MENU_EDIT:
+ menu_insert_mode(menu, menu->selected_item);
+ break;
+
+ default: // This is here for debug, disable later
+ fprintf(stderr, "Invalid menu action");
+ }
+
+ return 0;
+}
+
+int
+render_menu(Menu* menu)
+{
+ wclear(menu->menu_win);
+
+ /* calculate scroll */
+ int visible;
+
+ visible = items_visible(menu, menu->scroll_offset);
+
+ if (menu->selected_item >= menu->scroll_offset+visible) {
+ menu->scroll_offset = clamp(
+ menu->selected_item-items_visible_rev(menu, menu->selected_item)+1,
+ 0,
+ floorzero(menu->menu_length-1)
+ );
+
+ } else if (menu->selected_item < menu->scroll_offset) {
+ menu->scroll_offset = clamp(
+ menu->selected_item,
+ 0,
+ floorzero(menu->menu_length-1)
+ );
+ }
+
+ /* render menu items */
+ int curline = 0;
+ for (int i = menu->scroll_offset; i < menu->menu_length; i++) {
+ menu->render_item(menu, i, curline);
+ curline += menu->item_height(menu->menu_items[i]);
+ }
+
+ wrefresh(menu->menu_win);
+
+ return 0;
+}
+
+void
+default_render_item(Menu* menu, int item_index, int start_y)
+{
+ MenuItem* curitem;
+ int hlcolor;
+
+ curitem = menu->menu_items[item_index];
+
+ /* color selected item */
+ hlcolor = COLOR_PAIR((item_index == menu->selected_item && menu->focused == true) ? TS_SELECTED : TS_NONSELECTED);
+ wattron(menu->menu_win, hlcolor);
+ mvwprintw(menu->menu_win, start_y, 0, curitem->title);
+ wattroff(menu->menu_win, hlcolor);
+}
+
+
+int
+default_item_height(MenuItem* menuitem)
+{
+ return 1; // maybe account for line wrap by default
+}
+
+int
+items_visible(Menu* menu, int offset)
+{
+ int maxheight;
+ int maxwidth; // unused
+
+ getmaxyx(menu->menu_win, maxheight, maxwidth);
+
+ int vis = 0;
+ int lines = 0;
+ for (int i = offset ; i < menu->menu_length; i++) {
+
+ lines += menu->item_height(menu->menu_items[i]);
+ if (lines > maxheight) break;
+ vis += 1;
+
+ }
+
+ return vis;
+}
+
+int
+items_visible_rev(Menu* menu, int offset)
+{
+ int maxheight;
+ int maxwidth; // unused
+
+ getmaxyx(menu->menu_win, maxheight, maxwidth);
+
+ int vis = 0;
+ int lines = 0;
+ for (int i = offset; i > 0; i--) {
+
+ lines += menu->item_height(menu->menu_items[i]);
+ if (lines > maxheight) break;
+ vis +=1;
+
+ }
+
+ return vis;
+}
+