1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright 2010-2011 Calxeda, Inc.
10 #include <linux/list.h>
15 * Internally, each item in a menu is represented by a struct menu_item.
17 * These items will be alloc'd and initialized by menu_item_add and destroyed
18 * by menu_item_destroy, and the consumer of the interface never sees that
19 * this struct is used at all.
24 struct list_head list
;
28 * The menu is composed of a list of items along with settings and callbacks
29 * provided by the user. An incomplete definition of this struct is available
30 * in menu.h, but the full definition is here to prevent consumers from
31 * relying on its contents.
34 struct menu_item
*default_item
;
38 void (*item_data_print
)(void *);
39 char *(*item_choice
)(void *);
40 void *item_choice_data
;
41 struct list_head items
;
45 * An iterator function for menu items. callback will be called for each item
46 * in m, with m, a pointer to the item, and extra being passed to callback. If
47 * callback returns a value other than NULL, iteration stops and the value
48 * return by callback is returned from menu_items_iter. This allows it to be
49 * used for search type operations. It is also safe for callback to remove the
50 * item from the list of items.
52 static inline void *menu_items_iter(struct menu
*m
,
53 void *(*callback
)(struct menu
*, struct menu_item
*, void *),
56 struct list_head
*pos
, *n
;
57 struct menu_item
*item
;
60 list_for_each_safe(pos
, n
, &m
->items
) {
61 item
= list_entry(pos
, struct menu_item
, list
);
63 ret
= callback(m
, item
, extra
);
73 * Print a menu_item. If the consumer provided an item_data_print function
74 * when creating the menu, call it with a pointer to the item's private data.
75 * Otherwise, print the key of the item.
77 static inline void *menu_item_print(struct menu
*m
,
78 struct menu_item
*item
,
81 if (!m
->item_data_print
) {
85 m
->item_data_print(item
->data
);
92 * Free the memory used by a menu item. This includes the memory used by its
95 static inline void *menu_item_destroy(struct menu
*m
,
96 struct menu_item
*item
,
107 __weak
void menu_display_statusline(struct menu
*m
)
112 * Display a menu so the user can make a choice of an item. First display its
113 * title, if any, and then each item in the menu.
115 static inline void menu_display(struct menu
*m
)
121 menu_display_statusline(m
);
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 * Set *choice to point to the default item's data, if any default item was
163 * set, and returns 1. If no default item was set, returns -ENOENT.
165 int menu_default_choice(struct menu
*m
, void **choice
)
167 if (m
->default_item
) {
168 *choice
= m
->default_item
->data
;
176 * Displays the menu and asks the user to choose an item. *choice will point
177 * to the private data of the item the user chooses. The user makes a choice
178 * by inputting a string matching the key of an item. Invalid choices will
179 * cause the user to be prompted again, repeatedly, until the user makes a
180 * valid choice. The user can exit the menu without making a choice via ^c.
182 * Returns 1 if the user made a choice, or -EINTR if they bail via ^c.
184 static inline int menu_interactive_choice(struct menu
*m
, void **choice
)
186 char cbuf
[CONFIG_SYS_CBSIZE
];
187 struct menu_item
*choice_item
= NULL
;
190 while (!choice_item
) {
195 if (!m
->item_choice
) {
196 readret
= cli_readline_into_buffer("Enter choice: ",
200 choice_item
= menu_item_by_key(m
, cbuf
);
202 printf("%s not found\n", cbuf
);
203 } else if (readret
== -1) {
204 printf("<INTERRUPT>\n");
207 return menu_default_choice(m
, choice
);
210 char *key
= m
->item_choice(m
->item_choice_data
);
213 choice_item
= menu_item_by_key(m
, key
);
220 *choice
= choice_item
->data
;
226 * menu_default_set() - Sets the default choice for the menu. This is safe to
227 * call more than once on a menu.
229 * m - Points to a menu created by menu_create().
231 * item_key - Points to a string that, when compared using strcmp, matches the
232 * key for an existing item in the menu.
234 * Returns 1 if successful, -EINVAL if m is NULL, or -ENOENT if no item with a
235 * key matching item_key is found.
237 int menu_default_set(struct menu
*m
, char *item_key
)
239 struct menu_item
*item
;
244 item
= menu_item_by_key(m
, item_key
);
249 m
->default_item
= item
;
255 * menu_get_choice() - Returns the user's selected menu entry, or the default
256 * if the menu is set to not prompt or the timeout expires. This is safe to
257 * call more than once.
259 * m - Points to a menu created by menu_create().
261 * choice - Points to a location that will store a pointer to the selected
262 * menu item. If no item is selected or there is an error, no value will be
263 * written at the location it points to.
265 * Returns 1 if successful, -EINVAL if m or choice is NULL, -ENOENT if no
266 * default has been set and the menu is set to not prompt or the timeout
267 * expires, or -EINTR if the user exits the menu via ^c.
269 int menu_get_choice(struct menu
*m
, void **choice
)
275 return menu_default_choice(m
, choice
);
277 return menu_interactive_choice(m
, choice
);
281 * menu_item_add() - Adds or replaces a menu item. Note that this replaces the
282 * data of an item if it already exists, but doesn't change the order of the
285 * m - Points to a menu created by menu_create().
287 * item_key - Points to a string that will uniquely identify the item. The
288 * string will be copied to internal storage, and is safe to discard after
289 * passing to menu_item_add.
291 * item_data - An opaque pointer associated with an item. It is never
292 * dereferenced internally, but will be passed to the item_data_print, and
293 * will be returned from menu_get_choice if the menu item is selected.
295 * Returns 1 if successful, -EINVAL if m is NULL, or -ENOMEM if there is
296 * insufficient memory to add the menu item.
298 int menu_item_add(struct menu
*m
, char *item_key
, void *item_data
)
300 struct menu_item
*item
;
305 item
= menu_item_by_key(m
, item_key
);
308 item
->data
= item_data
;
312 item
= malloc(sizeof *item
);
316 item
->key
= strdup(item_key
);
323 item
->data
= item_data
;
325 list_add_tail(&item
->list
, &m
->items
);
331 * menu_create() - Creates a menu handle with default settings
333 * title - If not NULL, points to a string that will be displayed before the
334 * list of menu items. It will be copied to internal storage, and is safe to
335 * discard after passing to menu_create().
337 * timeout - A delay in seconds to wait for user input. If 0, timeout is
338 * disabled, and the default choice will be returned unless prompt is 1.
340 * prompt - If 0, don't ask for user input unless there is an interrupted
341 * timeout. If 1, the user will be prompted for input regardless of the value
344 * item_data_print - If not NULL, will be called for each item when the menu
345 * is displayed, with the pointer to the item's data passed as the argument.
346 * If NULL, each item's key will be printed instead. Since an item's key is
347 * what must be entered to select an item, the item_data_print function should
348 * make it obvious what the key for each entry is.
350 * item_choice - If not NULL, will be called when asking the user to choose an
351 * item. Returns a key string corresponding to the chosen item or NULL if
352 * no item has been selected.
354 * item_choice_data - Will be passed as the argument to the item_choice function
356 * Returns a pointer to the menu if successful, or NULL if there is
357 * insufficient memory available to create the menu.
359 struct menu
*menu_create(char *title
, int timeout
, int prompt
,
360 void (*item_data_print
)(void *),
361 char *(*item_choice
)(void *),
362 void *item_choice_data
)
366 m
= malloc(sizeof *m
);
371 m
->default_item
= NULL
;
373 m
->timeout
= timeout
;
374 m
->item_data_print
= item_data_print
;
375 m
->item_choice
= item_choice
;
376 m
->item_choice_data
= item_choice_data
;
379 m
->title
= strdup(title
);
388 INIT_LIST_HEAD(&m
->items
);
394 * menu_destroy() - frees the memory used by a menu and its items.
396 * m - Points to a menu created by menu_create().
398 * Returns 1 if successful, or -EINVAL if m is NULL.
400 int menu_destroy(struct menu
*m
)
405 menu_items_iter(m
, menu_item_destroy
, NULL
);