diff options
| -rw-r--r-- | common/Makefile | 1 | ||||
| -rw-r--r-- | common/menu.c | 393 | ||||
| -rw-r--r-- | doc/README.menu | 119 | ||||
| -rw-r--r-- | include/menu.h | 30 |
4 files changed, 543 insertions, 0 deletions
diff --git a/common/Makefile b/common/Makefile index fdc4206853..8e8dad4c91 100644 --- a/common/Makefile +++ b/common/Makefile @@ -177,6 +177,7 @@ COBJS-$(CONFIG_CMD_KGDB) += kgdb.o kgdb_stubs.o COBJS-$(CONFIG_KALLSYMS) += kallsyms.o COBJS-$(CONFIG_LCD) += lcd.o COBJS-$(CONFIG_LYNXKDI) += lynxkdi.o +COBJS-$(CONFIG_MENU) += menu.o COBJS-$(CONFIG_MODEM_SUPPORT) += modem.o COBJS-$(CONFIG_UPDATE_TFTP) += update.o COBJS-$(CONFIG_USB_KEYBOARD) += usb_kbd.o diff --git a/common/menu.c b/common/menu.c new file mode 100644 index 0000000000..56439374f7 --- /dev/null +++ b/common/menu.c @@ -0,0 +1,393 @@ +/* + * Copyright 2010-2011 Calxeda, Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <common.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; + char *title; + int prompt; + void (*item_data_print)(void *); + 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) + printf("%s\n", item->key); + 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; +} + +/* + * 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) + printf("%s:\n", m->title); + + 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); +} + +/* + * Checks whether or not the default menu item should be used without + * prompting for a user choice. If the menu is set to always prompt, return + * 0. Otherwise, return 1 to indicate we should use the default menu item. + */ +static inline int menu_use_default(struct menu *m) +{ + return !m->prompt; +} + +/* + * 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. + */ +static inline 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); + + readret = readline_into_buffer("Enter choice: ", cbuf); + + if (readret >= 0) { + choice_item = menu_item_by_key(m, cbuf); + + if (!choice_item) + printf("%s not found\n", cbuf); + } else { + printf("^C\n"); + return -EINTR; + } + } + + *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. 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 -EINTR if the + * user exits the menu via ^c. + */ +int menu_get_choice(struct menu *m, void **choice) +{ + if (!m || !choice) + return -EINVAL; + + if (menu_use_default(m)) + 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(). + * + * prompt - If 0, don't ask for user input. + * + * 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. + * + * 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 prompt, + void (*item_data_print)(void *)) +{ + struct menu *m; + + m = malloc(sizeof *m); + + if (!m) + return NULL; + + m->default_item = NULL; + m->prompt = prompt; + m->item_data_print = item_data_print; + + 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; +} diff --git a/doc/README.menu b/doc/README.menu new file mode 100644 index 0000000000..f55eb801b9 --- /dev/null +++ b/doc/README.menu @@ -0,0 +1,119 @@ +/* + * Copyright 2010-2011 Calxeda, Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ + +U-boot provides a set of interfaces for creating and using simple, text +based menus. Menus are displayed as lists of labeled entries on the +console, and an entry can be selected by entering its label. + +To use the menu code, enable CONFIG_MENU, and include "menu.h" where +the interfaces should be available. + +Menus are composed of items. Each item has a key used to identify it in +the menu, and an opaque pointer to data controlled by the consumer. + +Interfaces +---------- +#include "menu.h" + +/* + * Consumers of the menu interfaces will use a struct menu * as the + * handle for a menu. struct menu is only fully defined in menu.c, + * preventing consumers of the menu interfaces from accessing its + * contents directly. + */ +struct menu; + +/* + * NOTE: See comments in common/menu.c for more detailed documentation on + * these interfaces. + */ + +/* + * menu_create() - Creates a menu handle with default settings + */ +struct menu *menu_create(char *title, int prompt, + void (*item_data_print)(void *)); + +/* + * menu_item_add() - Adds or replaces a menu item + */ +int menu_item_add(struct menu *m, char *item_key, void *item_data); + +/* + * menu_default_set() - Sets the default choice for the menu + */ +int menu_default_set(struct menu *m, char *item_key); + +/* + * menu_get_choice() - Returns the user's selected menu entry, or the + * default if the menu is set to not prompt. + */ +int menu_get_choice(struct menu *m, void **choice); + +/* + * menu_destroy() - frees the memory used by a menu and its items. + */ +int menu_destroy(struct menu *m); + + +Example Code +------------ +This example creates a menu that always prompts, and allows the user +to pick from a list of tools. The item key and data are the same. + +#include "menu.h" + +char *tools[] = { + "Hammer", + "Screwdriver", + "Nail gun", + NULL +}; + +char *pick_a_tool(void) +{ + struct menu *m; + int i; + char *tool = NULL; + + m = menu_create("Tools", 1, NULL); + + for(i = 0; tools[i]; i++) { + if (menu_item_add(m, tools[i], tools[i]) != 1) { + printf("failed to add item!"); + menu_destroy(m); + return NULL; + } + } + + if (menu_get_choice(m, (void **)&tool) != 1) + printf("Problem picking tool!\n"); + + menu_destroy(m); + + return tool; +} + +void caller(void) +{ + char *tool = pick_a_tool(); + + if (tool) { + printf("picked a tool: %s\n", tool); + use_tool(tool); + } +} diff --git a/include/menu.h b/include/menu.h new file mode 100644 index 0000000000..d47e1a029c --- /dev/null +++ b/include/menu.h @@ -0,0 +1,30 @@ +/* + * Copyright 2010-2011 Calxeda, Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#ifndef __MENU_H__ +#define __MENU_H__ + +struct menu; + +struct menu *menu_create(char *title, int prompt, + void (*item_data_print)(void *)); +int menu_default_set(struct menu *m, char *item_key); +int menu_get_choice(struct menu *m, void **choice); +int menu_item_add(struct menu *m, char *item_key, void *item_data); +int menu_destroy(struct menu *m); + +#endif /* __MENU_H__ */ |