2 * Copyright 2010-2011 Calxeda, Inc.
4 * SPDX-License-Identifier: GPL-2.0+
11 #include <linux/list.h>
16 * Internally, each item in a menu is represented by a struct menu_item.
18 * These items will be alloc'd and initialized by menu_item_add and destroyed
19 * by menu_item_destroy, and the consumer of the interface never sees that
20 * this struct is used at all.
25 struct list_head list;
29 * The menu is composed of a list of items along with settings and callbacks
30 * provided by the user. An incomplete definition of this struct is available
31 * in menu.h, but the full definition is here to prevent consumers from
32 * relying on its contents.
35 struct menu_item *default_item;
39 void (*item_data_print)(void *);
40 char *(*item_choice)(void *);
41 void *item_choice_data;
42 struct list_head items;
46 * An iterator function for menu items. callback will be called for each item
47 * in m, with m, a pointer to the item, and extra being passed to callback. If
48 * callback returns a value other than NULL, iteration stops and the value
49 * return by callback is returned from menu_items_iter. This allows it to be
50 * used for search type operations. It is also safe for callback to remove the
51 * item from the list of items.
53 static inline void *menu_items_iter(struct menu *m,
54 void *(*callback)(struct menu *, struct menu_item *, void *),
57 struct list_head *pos, *n;
58 struct menu_item *item;
61 list_for_each_safe(pos, n, &m->items) {
62 item = list_entry(pos, struct menu_item, list);
64 ret = callback(m, item, extra);
74 * Print a menu_item. If the consumer provided an item_data_print function
75 * when creating the menu, call it with a pointer to the item's private data.
76 * Otherwise, print the key of the item.
78 static inline void *menu_item_print(struct menu *m,
79 struct menu_item *item,
82 if (!m->item_data_print) {
86 m->item_data_print(item->data);
93 * Free the memory used by a menu item. This includes the memory used by its
96 static inline void *menu_item_destroy(struct menu *m,
97 struct menu_item *item,
108 __weak void menu_display_statusline(struct menu *m)
113 * Display a menu so the user can make a choice of an item. First display its
114 * title, if any, and then each item in the menu.
116 static inline void menu_display(struct menu *m)
122 menu_display_statusline(m);
124 menu_items_iter(m, menu_item_print, NULL);
128 * Check if an item's key matches a provided string, pointed to by extra. If
129 * extra is NULL, an item with a NULL key will match. Otherwise, the item's
130 * key has to match according to strcmp.
132 * This is called via menu_items_iter, so it returns a pointer to the item if
133 * the key matches, and returns NULL otherwise.
135 static inline void *menu_item_key_match(struct menu *m,
136 struct menu_item *item, void *extra)
138 char *item_key = extra;
140 if (!item_key || !item->key) {
141 if (item_key == item->key)
147 if (strcmp(item->key, item_key) == 0)
154 * Find the first item with a key matching item_key, if any exists.
156 static inline struct menu_item *menu_item_by_key(struct menu *m,
159 return menu_items_iter(m, menu_item_key_match, item_key);
163 * Set *choice to point to the default item's data, if any default item was
164 * set, and returns 1. If no default item was set, returns -ENOENT.
166 int menu_default_choice(struct menu *m, void **choice)
168 if (m->default_item) {
169 *choice = m->default_item->data;
177 * Displays the menu and asks the user to choose an item. *choice will point
178 * to the private data of the item the user chooses. The user makes a choice
179 * by inputting a string matching the key of an item. Invalid choices will
180 * cause the user to be prompted again, repeatedly, until the user makes a
181 * valid choice. The user can exit the menu without making a choice via ^c.
183 * Returns 1 if the user made a choice, or -EINTR if they bail via ^c.
185 static inline int menu_interactive_choice(struct menu *m, void **choice)
187 char cbuf[CONFIG_SYS_CBSIZE];
188 struct menu_item *choice_item = NULL;
191 while (!choice_item) {
196 if (!m->item_choice) {
197 readret = cli_readline_into_buffer("Enter choice: ",
202 choice_item = menu_item_by_key(m, cbuf);
204 printf("%s not found\n", cbuf);
205 } else if (readret == -1) {
206 printf("<INTERRUPT>\n");
209 return menu_default_choice(m, choice);
212 char *key = m->item_choice(m->item_choice_data);
215 choice_item = menu_item_by_key(m, key);
222 *choice = choice_item->data;
228 * menu_default_set() - Sets the default choice for the menu. This is safe to
229 * call more than once on a menu.
231 * m - Points to a menu created by menu_create().
233 * item_key - Points to a string that, when compared using strcmp, matches the
234 * key for an existing item in the menu.
236 * Returns 1 if successful, -EINVAL if m is NULL, or -ENOENT if no item with a
237 * key matching item_key is found.
239 int menu_default_set(struct menu *m, char *item_key)
241 struct menu_item *item;
246 item = menu_item_by_key(m, item_key);
251 m->default_item = item;
257 * menu_get_choice() - Returns the user's selected menu entry, or the default
258 * if the menu is set to not prompt or the timeout expires. This is safe to
259 * call more than once.
261 * m - Points to a menu created by menu_create().
263 * choice - Points to a location that will store a pointer to the selected
264 * menu item. If no item is selected or there is an error, no value will be
265 * written at the location it points to.
267 * Returns 1 if successful, -EINVAL if m or choice is NULL, -ENOENT if no
268 * default has been set and the menu is set to not prompt or the timeout
269 * expires, or -EINTR if the user exits the menu via ^c.
271 int menu_get_choice(struct menu *m, void **choice)
277 return menu_default_choice(m, choice);
279 return menu_interactive_choice(m, choice);
283 * menu_item_add() - Adds or replaces a menu item. Note that this replaces the
284 * data of an item if it already exists, but doesn't change the order of the
287 * m - Points to a menu created by menu_create().
289 * item_key - Points to a string that will uniquely identify the item. The
290 * string will be copied to internal storage, and is safe to discard after
291 * passing to menu_item_add.
293 * item_data - An opaque pointer associated with an item. It is never
294 * dereferenced internally, but will be passed to the item_data_print, and
295 * will be returned from menu_get_choice if the menu item is selected.
297 * Returns 1 if successful, -EINVAL if m is NULL, or -ENOMEM if there is
298 * insufficient memory to add the menu item.
300 int menu_item_add(struct menu *m, char *item_key, void *item_data)
302 struct menu_item *item;
307 item = menu_item_by_key(m, item_key);
310 item->data = item_data;
314 item = malloc(sizeof *item);
318 item->key = strdup(item_key);
325 item->data = item_data;
327 list_add_tail(&item->list, &m->items);
333 * menu_create() - Creates a menu handle with default settings
335 * title - If not NULL, points to a string that will be displayed before the
336 * list of menu items. It will be copied to internal storage, and is safe to
337 * discard after passing to menu_create().
339 * timeout - A delay in seconds to wait for user input. If 0, timeout is
340 * disabled, and the default choice will be returned unless prompt is 1.
342 * prompt - If 0, don't ask for user input unless there is an interrupted
343 * timeout. If 1, the user will be prompted for input regardless of the value
346 * item_data_print - If not NULL, will be called for each item when the menu
347 * is displayed, with the pointer to the item's data passed as the argument.
348 * If NULL, each item's key will be printed instead. Since an item's key is
349 * what must be entered to select an item, the item_data_print function should
350 * make it obvious what the key for each entry is.
352 * item_choice - If not NULL, will be called when asking the user to choose an
353 * item. Returns a key string corresponding to the chosen item or NULL if
354 * no item has been selected.
356 * item_choice_data - Will be passed as the argument to the item_choice function
358 * Returns a pointer to the menu if successful, or NULL if there is
359 * insufficient memory available to create the menu.
361 struct menu *menu_create(char *title, int timeout, int prompt,
362 void (*item_data_print)(void *),
363 char *(*item_choice)(void *),
364 void *item_choice_data)
368 m = malloc(sizeof *m);
373 m->default_item = NULL;
375 m->timeout = timeout;
376 m->item_data_print = item_data_print;
377 m->item_choice = item_choice;
378 m->item_choice_data = item_choice_data;
381 m->title = strdup(title);
390 INIT_LIST_HEAD(&m->items);
396 * menu_destroy() - frees the memory used by a menu and its items.
398 * m - Points to a menu created by menu_create().
400 * Returns 1 if successful, or -EINVAL if m is NULL.
402 int menu_destroy(struct menu *m)
407 menu_items_iter(m, menu_item_destroy, NULL);