menu_ui.c

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/*
 * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
 *
 * 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 any later version.
 *
 * This program is distributed in the hope that 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 * You can also choose to distribute this program under the terms of
 * the Unmodified Binary Distribution Licence (as given in the file
 * COPYING.UBDL), provided that you have satisfied its requirements.
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

/** @file
 *
 * Menu interface
 *
 */

#include <string.h>
#include <errno.h>
#include <curses.h>
#include <ipxe/keys.h>
#include <ipxe/timer.h>
#include <ipxe/console.h>
#include <ipxe/ansicol.h>
#include <ipxe/jumpscroll.h>
#include <ipxe/dynui.h>

/* Screen layout */
#define TITLE_ROW       1U
#define MENU_ROW        3U
#define MENU_COL        1U
#define MENU_ROWS       ( LINES - 2U - MENU_ROW )
#define MENU_COLS       ( COLS - 2U )
#define MENU_PAD        2U

/** A menu user interface */
struct menu_ui {
        /** Dynamic user interface */
        struct dynamic_ui *dynui;
        /** Jump scroller */
        struct jump_scroller scroll;
        /** Timeout (0=indefinite) */
        unsigned long timeout;
};

/**
 * Draw a numbered menu item
 *
 * @v ui                Menu user interface
 * @v index             Index
 */
static void draw_menu_item ( struct menu_ui *ui, unsigned int index ) {
        struct dynamic_item *item;
        unsigned int row_offset;
        char buf[ MENU_COLS + 1 /* NUL */ ];
        char timeout_buf[6]; /* "(xxx)" + NUL */
        size_t timeout_len;
        size_t max_len;
        size_t len;

        /* Move to start of row */
        row_offset = ( index - ui->scroll.first );
        move ( ( MENU_ROW + row_offset ), MENU_COL );

        /* Get menu item */
        item = dynui_item ( ui->dynui, index );
        if ( item ) {

                /* Draw separators in a different colour */
                if ( ! item->name )
                        color_set ( CPAIR_SEPARATOR, NULL );

                /* Highlight if this is the selected item */
                if ( index == ui->scroll.current ) {
                        color_set ( CPAIR_SELECT, NULL );
                        attron ( A_BOLD );
                }

                /* Construct row */
                memset ( buf, ' ', ( sizeof ( buf ) - 1 ) );
                buf[ sizeof ( buf ) -1 ] = '\0';
                len = strlen ( item->text );
                max_len = ( sizeof ( buf ) - 1 /* NUL */ - ( 2 * MENU_PAD ) );
                if ( len > max_len )
                        len = max_len;
                memcpy ( ( buf + MENU_PAD ), item->text, len );

                /* Add timeout if applicable */
                timeout_len =
                        snprintf ( timeout_buf, sizeof ( timeout_buf ), "(%ld)",
                                   ( ( ui->timeout + TICKS_PER_SEC - 1 ) /
                                     TICKS_PER_SEC ) );
                if ( ( index == ui->scroll.current ) && ( ui->timeout != 0 ) ) {
                        memcpy ( ( buf + MENU_COLS - MENU_PAD - timeout_len ),
                                 timeout_buf, timeout_len );
                }

                /* Print row */
                printw ( "%s", buf );

                /* Reset attributes */
                color_set ( CPAIR_NORMAL, NULL );
                attroff ( A_BOLD );

        } else {
                /* Clear row if there is no corresponding menu item */
                clrtoeol();
        }

        /* Move cursor back to start of row */
        move ( ( MENU_ROW + row_offset ), MENU_COL );
}

/**
 * Draw the current block of menu items
 *
 * @v ui                Menu user interface
 */
static void draw_menu_items ( struct menu_ui *ui ) {
        unsigned int i;

        /* Draw ellipses before and/or after the list as necessary */
        color_set ( CPAIR_SEPARATOR, NULL );
        mvaddstr ( ( MENU_ROW - 1 ), ( MENU_COL + MENU_PAD ),
                   ( jump_scroll_is_first ( &ui->scroll ) ? "   " : "..." ) );
        mvaddstr ( ( MENU_ROW + MENU_ROWS ), ( MENU_COL + MENU_PAD ),
                   ( jump_scroll_is_last ( &ui->scroll ) ? "   " : "..." ) );
        color_set ( CPAIR_NORMAL, NULL );

        /* Draw visible items */
        for ( i = 0 ; i < MENU_ROWS ; i++ )
                draw_menu_item ( ui, ( ui->scroll.first + i ) );
}

/**
 * Menu main loop
 *
 * @v ui                Menu user interface
 * @ret selected        Selected item
 * @ret rc              Return status code
 */
static int menu_loop ( struct menu_ui *ui, struct dynamic_item **selected ) {
        struct dynamic_item *item;
        unsigned long timeout;
        unsigned int previous;
        unsigned int move;
        int key;
        int chosen = 0;
        int rc = 0;

        do {
                /* Record current selection */
                previous = ui->scroll.current;

                /* Calculate timeout as remainder of current second */
                timeout = ( ui->timeout % TICKS_PER_SEC );
                if ( ( timeout == 0 ) && ( ui->timeout != 0 ) )
                        timeout = TICKS_PER_SEC;
                ui->timeout -= timeout;

                /* Get key */
                move = SCROLL_NONE;
                key = getkey ( timeout );
                if ( key < 0 ) {
                        /* Choose default if we finally time out */
                        if ( ui->timeout == 0 )
                                chosen = 1;
                } else {
                        /* Cancel any timeout */
                        ui->timeout = 0;

                        /* Handle scroll keys */
                        move = jump_scroll_key ( &ui->scroll, key );

                        /* Handle other keys */
                        switch ( key ) {
                        case ESC:
                        case CTRL_C:
                                rc = -ECANCELED;
                                break;
                        case CR:
                        case LF:
                                chosen = 1;
                                break;
                        default:
                                item = dynui_shortcut ( ui->dynui, key );
                                if ( item ) {
                                        ui->scroll.current = item->index;
                                        if ( item->name ) {
                                                chosen = 1;
                                        } else {
                                                move = SCROLL_DOWN;
                                        }
                                }
                                break;
                        }
                }

                /* Move selection, if applicable */
                while ( move ) {
                        move = jump_scroll_move ( &ui->scroll, move );
                        item = dynui_item ( ui->dynui, ui->scroll.current );
                        if ( item->name )
                                break;
                }

                /* Redraw selection if necessary */
                if ( ( ui->scroll.current != previous ) || ( timeout != 0 ) ) {
                        draw_menu_item ( ui, previous );
                        if ( jump_scroll ( &ui->scroll ) )
                                draw_menu_items ( ui );
                        draw_menu_item ( ui, ui->scroll.current );
                }

                /* Record selection */
                item = dynui_item ( ui->dynui, ui->scroll.current );
                assert ( item != NULL );
                assert ( item->name != NULL );
                *selected = item;

        } while ( ( rc == 0 ) && ! chosen );

        return rc;
}

/**
 * Show menu
 *
 * @v dynui             Dynamic user interface
 * @v timeout           Timeout period, in ticks (0=indefinite)
 * @ret selected        Selected item
 * @ret rc              Return status code
 */
int show_menu ( struct dynamic_ui *dynui, unsigned long timeout,
                const char *select, struct dynamic_item **selected ) {
        struct dynamic_item *item;
        struct menu_ui ui;
        char buf[ MENU_COLS + 1 /* NUL */ ];
        int named_count = 0;
        int rc;

        /* Initialise UI */
        memset ( &ui, 0, sizeof ( ui ) );
        ui.dynui = dynui;
        ui.scroll.rows = MENU_ROWS;
        ui.timeout = timeout;
        list_for_each_entry ( item, &dynui->items, list ) {
                if ( item->name ) {
                        if ( ! named_count )
                                ui.scroll.current = ui.scroll.count;
                        named_count++;
                        if ( select ) {
                                if ( strcmp ( select, item->name ) == 0 )
                                        ui.scroll.current = ui.scroll.count;
                        } else {
                                if ( item->flags & DYNUI_DEFAULT )
                                        ui.scroll.current = ui.scroll.count;
                        }
                }
                ui.scroll.count++;
        }
        if ( ! named_count ) {
                /* Menus with no named items cannot be selected from,
                 * and will seriously confuse the navigation logic.
                 * Refuse to display any such menus.
                 */
                return -ENOENT;
        }

        /* Initialise screen */
        initscr();
        start_color();
        color_set ( CPAIR_NORMAL, NULL );
        curs_set ( 0 );
        erase();

        /* Draw initial content */
        attron ( A_BOLD );
        snprintf ( buf, sizeof ( buf ), "%s", ui.dynui->title );
        mvprintw ( TITLE_ROW, ( ( COLS - strlen ( buf ) ) / 2 ), "%s", buf );
        attroff ( A_BOLD );
        jump_scroll ( &ui.scroll );
        draw_menu_items ( &ui );
        draw_menu_item ( &ui, ui.scroll.current );

        /* Enter main loop */
        rc = menu_loop ( &ui, selected );
        assert ( *selected );

        /* Clear screen */
        endwin();

        return rc;
}