/* * Copyright 2010-2011 Calxeda, Inc. * * SPDX-License-Identifier: GPL-2.0+ */ #include <common.h> #include <cli.h> #include <malloc.h> #include <errno.h> #include <linux/list.h> #include "menu.h" /* * Internally, each item in a menu is represented by a struct menu_item. * * These items will be alloc'd and initialized by menu_item_add and destroyed * by menu_item_destroy, and the consumer of the interface never sees that * this struct is used at all. */ struct menu_item { char *key; void *data; struct list_head list; }; /* * The menu is composed of a list of items along with settings and callbacks * provided by the user. An incomplete definition of this struct is available * in menu.h, but the full definition is here to prevent consumers from * relying on its contents. */ struct menu { struct menu_item *default_item; int timeout; char *title; int prompt; void (*item_data_print)(void *); char *(*item_choice)(void *); void *item_choice_data; struct list_head items; }; /* * An iterator function for menu items. callback will be called for each item * in m, with m, a pointer to the item, and extra being passed to callback. If * callback returns a value other than NULL, iteration stops and the value * return by callback is returned from menu_items_iter. This allows it to be * used for search type operations. It is also safe for callback to remove the * item from the list of items. */ static inline void *menu_items_iter(struct menu *m, void *(*callback)(struct menu *, struct menu_item *, void *), void *extra) { struct list_head *pos, *n; struct menu_item *item; void *ret; list_for_each_safe(pos, n, &m->items) { item = list_entry(pos, struct menu_item, list); ret = callback(m, item, extra); if (ret) return ret; } return NULL; } /* * Print a menu_item. If the consumer provided an item_data_print function * when creating the menu, call it with a pointer to the item's private data. * Otherwise, print the key of the item. */ static inline void *menu_item_print(struct menu *m, struct menu_item *item, void *extra) { if (!m->item_data_print) { puts(item->key); putc('\n'); } else { m->item_data_print(item->data); } return NULL; } /* * Free the memory used by a menu item. This includes the memory used by its * key. */ static inline void *menu_item_destroy(struct menu *m, struct menu_item *item, void *extra) { if (item->key) free(item->key); free(item); return NULL; } __weak void menu_display_statusline(struct menu *m) { } /* * Display a menu so the user can make a choice of an item. First display its * title, if any, and then each item in the menu. */ static inline void menu_display(struct menu *m) { if (m->title) { puts(m->title); putc('\n'); } menu_display_statusline(m); menu_items_iter(m, menu_item_print, NULL); } /* * Check if an item's key matches a provided string, pointed to by extra. If * extra is NULL, an item with a NULL key will match. Otherwise, the item's * key has to match according to strcmp. * * This is called via menu_items_iter, so it returns a pointer to the item if * the key matches, and returns NULL otherwise. */ static inline void *menu_item_key_match(struct menu *m, struct menu_item *item, void *extra) { char *item_key = extra; if (!item_key || !item->key) { if (item_key == item->key) return item; return NULL; } if (strcmp(item->key, item_key) == 0) return item; return NULL; } /* * Find the first item with a key matching item_key, if any exists. */ static inline struct menu_item *menu_item_by_key(struct menu *m, char *item_key) { return menu_items_iter(m, menu_item_key_match, item_key); } /* * Set *choice to point to the default item's data, if any default item was * set, and returns 1. If no default item was set, returns -ENOENT. */ int menu_default_choice(struct menu *m, void **choice) { if (m->default_item) { *choice = m->default_item->data; return 1; } return -ENOENT; } /* * Displays the menu and asks the user to choose an item. *choice will point * to the private data of the item the user chooses. The user makes a choice * by inputting a string matching the key of an item. Invalid choices will * cause the user to be prompted again, repeatedly, until the user makes a * valid choice. The user can exit the menu without making a choice via ^c. * * Returns 1 if the user made a choice, or -EINTR if they bail via ^c. */ static inline int menu_interactive_choice(struct menu *m, void **choice) { char cbuf[CONFIG_SYS_CBSIZE]; struct menu_item *choice_item = NULL; int readret; while (!choice_item) { cbuf[0] = '\0'; menu_display(m); if (!m->item_choice) { readret = cli_readline_into_buffer("Enter choice: ", cbuf, m->timeout / 10); if (readret >= 0) { choice_item = menu_item_by_key(m, cbuf); if (!choice_item) printf("%s not found\n", cbuf); } else { return menu_default_choice(m, choice); } } else { char *key = m->item_choice(m->item_choice_data); if (key) choice_item = menu_item_by_key(m, key); } if (!choice_item) m->timeout = 0; } *choice = choice_item->data; return 1; } /* * menu_default_set() - Sets the default choice for the menu. This is safe to * call more than once on a menu. * * m - Points to a menu created by menu_create(). * * item_key - Points to a string that, when compared using strcmp, matches the * key for an existing item in the menu. * * Returns 1 if successful, -EINVAL if m is NULL, or -ENOENT if no item with a * key matching item_key is found. */ int menu_default_set(struct menu *m, char *item_key) { struct menu_item *item; if (!m) return -EINVAL; item = menu_item_by_key(m, item_key); if (!item) return -ENOENT; m->default_item = item; return 1; } /* * menu_get_choice() - Returns the user's selected menu entry, or the default * if the menu is set to not prompt or the timeout expires. This is safe to * call more than once. * * m - Points to a menu created by menu_create(). * * choice - Points to a location that will store a pointer to the selected * menu item. If no item is selected or there is an error, no value will be * written at the location it points to. * * Returns 1 if successful, -EINVAL if m or choice is NULL, -ENOENT if no * default has been set and the menu is set to not prompt or the timeout * expires, or -EINTR if the user exits the menu via ^c. */ int menu_get_choice(struct menu *m, void **choice) { if (!m || !choice) return -EINVAL; if (!m->prompt) return menu_default_choice(m, choice); return menu_interactive_choice(m, choice); } /* * menu_item_add() - Adds or replaces a menu item. Note that this replaces the * data of an item if it already exists, but doesn't change the order of the * item. * * m - Points to a menu created by menu_create(). * * item_key - Points to a string that will uniquely identify the item. The * string will be copied to internal storage, and is safe to discard after * passing to menu_item_add. * * item_data - An opaque pointer associated with an item. It is never * dereferenced internally, but will be passed to the item_data_print, and * will be returned from menu_get_choice if the menu item is selected. * * Returns 1 if successful, -EINVAL if m is NULL, or -ENOMEM if there is * insufficient memory to add the menu item. */ int menu_item_add(struct menu *m, char *item_key, void *item_data) { struct menu_item *item; if (!m) return -EINVAL; item = menu_item_by_key(m, item_key); if (item) { item->data = item_data; return 1; } item = malloc(sizeof *item); if (!item) return -ENOMEM; item->key = strdup(item_key); if (!item->key) { free(item); return -ENOMEM; } item->data = item_data; list_add_tail(&item->list, &m->items); return 1; } /* * menu_create() - Creates a menu handle with default settings * * title - If not NULL, points to a string that will be displayed before the * list of menu items. It will be copied to internal storage, and is safe to * discard after passing to menu_create(). * * timeout - A delay in seconds to wait for user input. If 0, timeout is * disabled, and the default choice will be returned unless prompt is 1. * * prompt - If 0, don't ask for user input unless there is an interrupted * timeout. If 1, the user will be prompted for input regardless of the value * of timeout. * * item_data_print - If not NULL, will be called for each item when the menu * is displayed, with the pointer to the item's data passed as the argument. * If NULL, each item's key will be printed instead. Since an item's key is * what must be entered to select an item, the item_data_print function should * make it obvious what the key for each entry is. * * item_choice - If not NULL, will be called when asking the user to choose an * item. Returns a key string corresponding to the choosen item or NULL if * no item has been selected. * * item_choice_data - Will be passed as the argument to the item_choice function * * Returns a pointer to the menu if successful, or NULL if there is * insufficient memory available to create the menu. */ struct menu *menu_create(char *title, int timeout, int prompt, void (*item_data_print)(void *), char *(*item_choice)(void *), void *item_choice_data) { struct menu *m; m = malloc(sizeof *m); if (!m) return NULL; m->default_item = NULL; m->prompt = prompt; m->timeout = timeout; m->item_data_print = item_data_print; m->item_choice = item_choice; m->item_choice_data = item_choice_data; if (title) { m->title = strdup(title); if (!m->title) { free(m); return NULL; } } else m->title = NULL; INIT_LIST_HEAD(&m->items); return m; } /* * menu_destroy() - frees the memory used by a menu and its items. * * m - Points to a menu created by menu_create(). * * Returns 1 if successful, or -EINVAL if m is NULL. */ int menu_destroy(struct menu *m) { if (!m) return -EINVAL; menu_items_iter(m, menu_item_destroy, NULL); if (m->title) free(m->title); free(m); return 1; }