/*
 * Copyright (C) 2002-2007 The Warp Rogue Team
 * Part of the Warp Rogue Project
 *
 * This software is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License.
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY.
 *
 * See the license.txt file for more details.
 */

/*
 * Module Name: Ui
 * Description: -
 */

/*
 * Menus
 */

#define Uses_Util
#include "mheader.h"

#include "ui.h"



static int		menu_max_item_length(MENU *);



/*
 * creates a menu
 */
MENU * menu_create(LIST *items)
{
	MENU *menu;

	menu = checked_malloc(sizeof *menu);

	menu->items = items;

	menu->entered_command = CM_NIL;

	menu->first_visible = menu->last_visible = menu->highlighted = 0;

	menu->last = menu->items->n_nodes - 1;

	return menu;
}



/*
 * frees a menu
 */
void menu_free(MENU *menu)
{

	list_free(menu->items);

	free(menu);
}



/*
 * free a menu and uses the passed destructor to free its items
 */
void menu_free_with(MENU *menu, void (*destructor)(void *))
{

	list_free_with(menu->items, destructor);

	free(menu);
}



/*
 * sets the appearance of a menu
 */
void menu_set_appearance(MENU *menu, SCREEN_AREA *menu_area)
{
	int visible_rows;

	if (menu_area->bottom == MENU_AUTO) {
		
		menu_area->bottom = menu_area->top + menu->last;
	}

	if (menu_area->right == MENU_AUTO) {
		
		menu_area->right = menu_area->left + 
			menu_max_item_length(menu) - 1;
	}

	if (menu->first_visible > 0) {
		
		return;
	}

	visible_rows = menu_area->bottom - menu_area->top + 1;

	if (menu->highlighted >= visible_rows) {
		
		menu->first_visible = menu->highlighted;
		menu->last_visible  = menu->highlighted + visible_rows - 1;
		
		if (menu->last_visible > menu->last) {
			
			menu->last_visible = menu->last;
		}

	} else {
		
		menu->first_visible = 0;
		menu->last_visible = visible_rows - 1;
		
		if (menu->last_visible > menu->last) {
			
			menu->last_visible = menu->last;
		}
	}

}



/*
 * "executes" a menu (i.e. displays it on screen and lets the user select an item)
 */
COMMAND menu_execute(MENU *menu, SCREEN_AREA *menu_area)
{

	do {

		render_menu(menu, menu_area);
		update_screen();

		menu->entered_command = command_bar_get_command();

		if (menu->entered_command == CM_DOWN) {

			if (menu->highlighted < menu->last) {

				if (menu->highlighted == menu->last_visible) {
					menu->first_visible += 1;
					menu->last_visible += 1;
				}

				menu->highlighted += 1;

			}

		} else if (menu->entered_command == CM_UP) {

			if (menu->highlighted > 0) {

				if (menu->highlighted == menu->first_visible) {
					menu->first_visible -= 1;
					menu->last_visible -= 1;
				}

				menu->highlighted -= 1;
			}

		}


	} while (menu->entered_command == CM_DOWN || 
		menu->entered_command == CM_UP);

	return menu->entered_command;
}



/*
 * returns the length of the longest menu item (in characters)
 */
static int menu_max_item_length(MENU *menu)
{
	LIST_NODE *node;
	int item_length;
	int max_length;

	for (node = menu->items->head, max_length = 0;
		node != NULL;
		node = node->next) {

		item_length = strlen((const char *)node->data);
		if (item_length > max_length) max_length = item_length;

	}

	return max_length;
}