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Jason Hobbsb69bf522011-08-23 11:06:49 +00001/*
2 * Copyright 2010-2011 Calxeda, Inc.
3 *
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)
7 * any later version.
8 *
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
12 * more details.
13 *
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/>.
16 */
17
18#include <common.h>
19#include <malloc.h>
20#include <errno.h>
21#include <linux/list.h>
22
23#include "menu.h"
24
25/*
26 * Internally, each item in a menu is represented by a struct menu_item.
27 *
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.
31 */
32struct menu_item {
33 char *key;
34 void *data;
35 struct list_head list;
36};
37
38/*
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.
43 */
44struct menu {
45 struct menu_item *default_item;
Jason Hobbsb41bc5a2011-08-23 11:06:50 +000046 int timeout;
Jason Hobbsb69bf522011-08-23 11:06:49 +000047 char *title;
48 int prompt;
49 void (*item_data_print)(void *);
50 struct list_head items;
51};
52
53/*
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.
60 */
61static inline void *menu_items_iter(struct menu *m,
62 void *(*callback)(struct menu *, struct menu_item *, void *),
63 void *extra)
64{
65 struct list_head *pos, *n;
66 struct menu_item *item;
67 void *ret;
68
69 list_for_each_safe(pos, n, &m->items) {
70 item = list_entry(pos, struct menu_item, list);
71
72 ret = callback(m, item, extra);
73
74 if (ret)
75 return ret;
76 }
77
78 return NULL;
79}
80
81/*
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.
85 */
86static inline void *menu_item_print(struct menu *m,
87 struct menu_item *item,
88 void *extra)
89{
90 if (!m->item_data_print)
91 printf("%s\n", item->key);
92 else
93 m->item_data_print(item->data);
94
95 return NULL;
96}
97
98/*
99 * Free the memory used by a menu item. This includes the memory used by its
100 * key.
101 */
102static inline void *menu_item_destroy(struct menu *m,
103 struct menu_item *item,
104 void *extra)
105{
106 if (item->key)
107 free(item->key);
108
109 free(item);
110
111 return NULL;
112}
113
114/*
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.
117 */
118static inline void menu_display(struct menu *m)
119{
120 if (m->title)
121 printf("%s:\n", m->title);
122
123 menu_items_iter(m, menu_item_print, NULL);
124}
125
126/*
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.
130 *
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.
133 */
134static inline void *menu_item_key_match(struct menu *m,
135 struct menu_item *item, void *extra)
136{
137 char *item_key = extra;
138
139 if (!item_key || !item->key) {
140 if (item_key == item->key)
141 return item;
142
143 return NULL;
144 }
145
146 if (strcmp(item->key, item_key) == 0)
147 return item;
148
149 return NULL;
150}
151
152/*
153 * Find the first item with a key matching item_key, if any exists.
154 */
155static inline struct menu_item *menu_item_by_key(struct menu *m,
156 char *item_key)
157{
158 return menu_items_iter(m, menu_item_key_match, item_key);
159}
160
161/*
Jason Hobbsb41bc5a2011-08-23 11:06:50 +0000162 * 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.
164 */
165static inline int menu_interrupted(struct menu *m)
166{
167 if (!m->timeout)
168 return 0;
169
170 if (abortboot(m->timeout/10))
171 return 1;
172
173 return 0;
174}
175
176/*
Jason Hobbsb69bf522011-08-23 11:06:49 +0000177 * Checks whether or not the default menu item should be used without
Jason Hobbsb41bc5a2011-08-23 11:06:50 +0000178 * 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.
Jason Hobbsb69bf522011-08-23 11:06:49 +0000181 */
182static inline int menu_use_default(struct menu *m)
183{
Jason Hobbsb41bc5a2011-08-23 11:06:50 +0000184 return !m->prompt && !menu_interrupted(m);
Jason Hobbsb69bf522011-08-23 11:06:49 +0000185}
186
187/*
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.
190 */
191static inline int menu_default_choice(struct menu *m, void **choice)
192{
193 if (m->default_item) {
194 *choice = m->default_item->data;
195 return 1;
196 }
197
198 return -ENOENT;
199}
200
201/*
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.
207 *
208 * Returns 1 if the user made a choice, or -EINTR if they bail via ^c.
209 */
210static inline int menu_interactive_choice(struct menu *m, void **choice)
211{
212 char cbuf[CONFIG_SYS_CBSIZE];
213 struct menu_item *choice_item = NULL;
214 int readret;
215
216 while (!choice_item) {
217 cbuf[0] = '\0';
218
219 menu_display(m);
220
221 readret = readline_into_buffer("Enter choice: ", cbuf);
222
223 if (readret >= 0) {
224 choice_item = menu_item_by_key(m, cbuf);
225
226 if (!choice_item)
227 printf("%s not found\n", cbuf);
228 } else {
229 printf("^C\n");
230 return -EINTR;
231 }
232 }
233
234 *choice = choice_item->data;
235
236 return 1;
237}
238
239/*
240 * menu_default_set() - Sets the default choice for the menu. This is safe to
241 * call more than once on a menu.
242 *
243 * m - Points to a menu created by menu_create().
244 *
245 * item_key - Points to a string that, when compared using strcmp, matches the
246 * key for an existing item in the menu.
247 *
248 * Returns 1 if successful, -EINVAL if m is NULL, or -ENOENT if no item with a
249 * key matching item_key is found.
250 */
251int menu_default_set(struct menu *m, char *item_key)
252{
253 struct menu_item *item;
254
255 if (!m)
256 return -EINVAL;
257
258 item = menu_item_by_key(m, item_key);
259
260 if (!item)
261 return -ENOENT;
262
263 m->default_item = item;
264
265 return 1;
266}
267
268/*
269 * menu_get_choice() - Returns the user's selected menu entry, or the default
Jason Hobbsb41bc5a2011-08-23 11:06:50 +0000270 * if the menu is set to not prompt or the timeout expires. This is safe to
271 * call more than once.
Jason Hobbsb69bf522011-08-23 11:06:49 +0000272 *
273 * m - Points to a menu created by menu_create().
274 *
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.
278 *
279 * Returns 1 if successful, -EINVAL if m or choice is NULL, -ENOENT if no
Jason Hobbsb41bc5a2011-08-23 11:06:50 +0000280 * 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.
Jason Hobbsb69bf522011-08-23 11:06:49 +0000282 */
283int menu_get_choice(struct menu *m, void **choice)
284{
285 if (!m || !choice)
286 return -EINVAL;
287
288 if (menu_use_default(m))
289 return menu_default_choice(m, choice);
290
291 return menu_interactive_choice(m, choice);
292}
293
294/*
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
297 * item.
298 *
299 * m - Points to a menu created by menu_create().
300 *
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.
304 *
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.
308 *
309 * Returns 1 if successful, -EINVAL if m is NULL, or -ENOMEM if there is
310 * insufficient memory to add the menu item.
311 */
312int menu_item_add(struct menu *m, char *item_key, void *item_data)
313{
314 struct menu_item *item;
315
316 if (!m)
317 return -EINVAL;
318
319 item = menu_item_by_key(m, item_key);
320
321 if (item) {
322 item->data = item_data;
323 return 1;
324 }
325
326 item = malloc(sizeof *item);
327 if (!item)
328 return -ENOMEM;
329
330 item->key = strdup(item_key);
331
332 if (!item->key) {
333 free(item);
334 return -ENOMEM;
335 }
336
337 item->data = item_data;
338
339 list_add_tail(&item->list, &m->items);
340
341 return 1;
342}
343
344/*
345 * menu_create() - Creates a menu handle with default settings
346 *
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().
350 *
Jason Hobbsb41bc5a2011-08-23 11:06:50 +0000351 * 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.
353 *
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
356 * of timeout.
Jason Hobbsb69bf522011-08-23 11:06:49 +0000357 *
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.
363 *
364 * Returns a pointer to the menu if successful, or NULL if there is
365 * insufficient memory available to create the menu.
366 */
Jason Hobbsb41bc5a2011-08-23 11:06:50 +0000367struct menu *menu_create(char *title, int timeout, int prompt,
Jason Hobbsb69bf522011-08-23 11:06:49 +0000368 void (*item_data_print)(void *))
369{
370 struct menu *m;
371
372 m = malloc(sizeof *m);
373
374 if (!m)
375 return NULL;
376
377 m->default_item = NULL;
378 m->prompt = prompt;
Jason Hobbsb41bc5a2011-08-23 11:06:50 +0000379 m->timeout = timeout;
Jason Hobbsb69bf522011-08-23 11:06:49 +0000380 m->item_data_print = item_data_print;
381
382 if (title) {
383 m->title = strdup(title);
384 if (!m->title) {
385 free(m);
386 return NULL;
387 }
388 } else
389 m->title = NULL;
390
391
392 INIT_LIST_HEAD(&m->items);
393
394 return m;
395}
396
397/*
398 * menu_destroy() - frees the memory used by a menu and its items.
399 *
400 * m - Points to a menu created by menu_create().
401 *
402 * Returns 1 if successful, or -EINVAL if m is NULL.
403 */
404int menu_destroy(struct menu *m)
405{
406 if (!m)
407 return -EINVAL;
408
409 menu_items_iter(m, menu_item_destroy, NULL);
410
411 if (m->title)
412 free(m->title);
413
414 free(m);
415
416 return 1;
417}