2 * Copyright 2010-2011 Calxeda, Inc.
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License as published by the Free
6 * Software Foundation; either version 2 of the License, or (at your option)
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 * You should have received a copy of the GNU General Public License along with
15 * this program. If not, see <http://www.gnu.org/licenses/>.
21 #include <linux/list.h>
26 * Internally, each item in a menu is represented by a struct menu_item.
28 * These items will be alloc'd and initialized by menu_item_add and destroyed
29 * by menu_item_destroy, and the consumer of the interface never sees that
30 * this struct is used at all.
35 struct list_head list;
39 * The menu is composed of a list of items along with settings and callbacks
40 * provided by the user. An incomplete definition of this struct is available
41 * in menu.h, but the full definition is here to prevent consumers from
42 * relying on its contents.
45 struct menu_item *default_item;
49 void (*item_data_print)(void *);
50 struct list_head items;
54 * An iterator function for menu items. callback will be called for each item
55 * in m, with m, a pointer to the item, and extra being passed to callback. If
56 * callback returns a value other than NULL, iteration stops and the value
57 * return by callback is returned from menu_items_iter. This allows it to be
58 * used for search type operations. It is also safe for callback to remove the
59 * item from the list of items.
61 static inline void *menu_items_iter(struct menu *m,
62 void *(*callback)(struct menu *, struct menu_item *, void *),
65 struct list_head *pos, *n;
66 struct menu_item *item;
69 list_for_each_safe(pos, n, &m->items) {
70 item = list_entry(pos, struct menu_item, list);
72 ret = callback(m, item, extra);
82 * Print a menu_item. If the consumer provided an item_data_print function
83 * when creating the menu, call it with a pointer to the item's private data.
84 * Otherwise, print the key of the item.
86 static inline void *menu_item_print(struct menu *m,
87 struct menu_item *item,
90 if (!m->item_data_print)
91 printf("%s\n", item->key);
93 m->item_data_print(item->data);
99 * Free the memory used by a menu item. This includes the memory used by its
102 static inline void *menu_item_destroy(struct menu *m,
103 struct menu_item *item,
115 * Display a menu so the user can make a choice of an item. First display its
116 * title, if any, and then each item in the menu.
118 static inline void menu_display(struct menu *m)
121 printf("%s:\n", m->title);
123 menu_items_iter(m, menu_item_print, NULL);
127 * Check if an item's key matches a provided string, pointed to by extra. If
128 * extra is NULL, an item with a NULL key will match. Otherwise, the item's
129 * key has to match according to strcmp.
131 * This is called via menu_items_iter, so it returns a pointer to the item if
132 * the key matches, and returns NULL otherwise.
134 static inline void *menu_item_key_match(struct menu *m,
135 struct menu_item *item, void *extra)
137 char *item_key = extra;
139 if (!item_key || !item->key) {
140 if (item_key == item->key)
146 if (strcmp(item->key, item_key) == 0)
153 * Find the first item with a key matching item_key, if any exists.
155 static inline struct menu_item *menu_item_by_key(struct menu *m,
158 return menu_items_iter(m, menu_item_key_match, item_key);
162 * Wait for the user to hit a key according to the timeout set for the menu.
163 * Returns 1 if the user hit a key, or 0 if the timeout expired.
165 static inline int menu_interrupted(struct menu *m)
170 if (abortboot(m->timeout/10))
177 * Checks whether or not the default menu item should be used without
178 * prompting for a user choice. If the menu is set to always prompt, or the
179 * user hits a key during the timeout period, return 0. Otherwise, return 1 to
180 * indicate we should use the default menu item.
182 static inline int menu_use_default(struct menu *m)
184 return !m->prompt && !menu_interrupted(m);
188 * Set *choice to point to the default item's data, if any default item was
189 * set, and returns 1. If no default item was set, returns -ENOENT.
191 static inline int menu_default_choice(struct menu *m, void **choice)
193 if (m->default_item) {
194 *choice = m->default_item->data;
202 * Displays the menu and asks the user to choose an item. *choice will point
203 * to the private data of the item the user chooses. The user makes a choice
204 * by inputting a string matching the key of an item. Invalid choices will
205 * cause the user to be prompted again, repeatedly, until the user makes a
206 * valid choice. The user can exit the menu without making a choice via ^c.
208 * Returns 1 if the user made a choice, or -EINTR if they bail via ^c.
210 static inline int menu_interactive_choice(struct menu *m, void **choice)
212 char cbuf[CONFIG_SYS_CBSIZE];
213 struct menu_item *choice_item = NULL;
216 while (!choice_item) {
221 readret = readline_into_buffer("Enter choice: ", cbuf);
224 choice_item = menu_item_by_key(m, cbuf);
227 printf("%s not found\n", cbuf);
234 *choice = choice_item->data;
240 * menu_default_set() - Sets the default choice for the menu. This is safe to
241 * call more than once on a menu.
243 * m - Points to a menu created by menu_create().
245 * item_key - Points to a string that, when compared using strcmp, matches the
246 * key for an existing item in the menu.
248 * Returns 1 if successful, -EINVAL if m is NULL, or -ENOENT if no item with a
249 * key matching item_key is found.
251 int menu_default_set(struct menu *m, char *item_key)
253 struct menu_item *item;
258 item = menu_item_by_key(m, item_key);
263 m->default_item = item;
269 * menu_get_choice() - Returns the user's selected menu entry, or the default
270 * if the menu is set to not prompt or the timeout expires. This is safe to
271 * call more than once.
273 * m - Points to a menu created by menu_create().
275 * choice - Points to a location that will store a pointer to the selected
276 * menu item. If no item is selected or there is an error, no value will be
277 * written at the location it points to.
279 * Returns 1 if successful, -EINVAL if m or choice is NULL, -ENOENT if no
280 * default has been set and the menu is set to not prompt or the timeout
281 * expires, or -EINTR if the user exits the menu via ^c.
283 int menu_get_choice(struct menu *m, void **choice)
288 if (menu_use_default(m))
289 return menu_default_choice(m, choice);
291 return menu_interactive_choice(m, choice);
295 * menu_item_add() - Adds or replaces a menu item. Note that this replaces the
296 * data of an item if it already exists, but doesn't change the order of the
299 * m - Points to a menu created by menu_create().
301 * item_key - Points to a string that will uniquely identify the item. The
302 * string will be copied to internal storage, and is safe to discard after
303 * passing to menu_item_add.
305 * item_data - An opaque pointer associated with an item. It is never
306 * dereferenced internally, but will be passed to the item_data_print, and
307 * will be returned from menu_get_choice if the menu item is selected.
309 * Returns 1 if successful, -EINVAL if m is NULL, or -ENOMEM if there is
310 * insufficient memory to add the menu item.
312 int menu_item_add(struct menu *m, char *item_key, void *item_data)
314 struct menu_item *item;
319 item = menu_item_by_key(m, item_key);
322 item->data = item_data;
326 item = malloc(sizeof *item);
330 item->key = strdup(item_key);
337 item->data = item_data;
339 list_add_tail(&item->list, &m->items);
345 * menu_create() - Creates a menu handle with default settings
347 * title - If not NULL, points to a string that will be displayed before the
348 * list of menu items. It will be copied to internal storage, and is safe to
349 * discard after passing to menu_create().
351 * timeout - A delay in seconds to wait for user input. If 0, timeout is
352 * disabled, and the default choice will be returned unless prompt is 1.
354 * prompt - If 0, don't ask for user input unless there is an interrupted
355 * timeout. If 1, the user will be prompted for input regardless of the value
358 * item_data_print - If not NULL, will be called for each item when the menu
359 * is displayed, with the pointer to the item's data passed as the argument.
360 * If NULL, each item's key will be printed instead. Since an item's key is
361 * what must be entered to select an item, the item_data_print function should
362 * make it obvious what the key for each entry is.
364 * Returns a pointer to the menu if successful, or NULL if there is
365 * insufficient memory available to create the menu.
367 struct menu *menu_create(char *title, int timeout, int prompt,
368 void (*item_data_print)(void *))
372 m = malloc(sizeof *m);
377 m->default_item = NULL;
379 m->timeout = timeout;
380 m->item_data_print = item_data_print;
383 m->title = strdup(title);
392 INIT_LIST_HEAD(&m->items);
398 * menu_destroy() - frees the memory used by a menu and its items.
400 * m - Points to a menu created by menu_create().
402 * Returns 1 if successful, or -EINVAL if m is NULL.
404 int menu_destroy(struct menu *m)
409 menu_items_iter(m, menu_item_destroy, NULL);