settings_ui.c

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/*
 * Copyright (C) 2006 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 );

#include <stdio.h>
#include <stdarg.h>
#include <unistd.h>
#include <string.h>
#include <curses.h>
#include <ipxe/console.h>
#include <ipxe/settings.h>
#include <ipxe/editbox.h>
#include <ipxe/keys.h>
#include <ipxe/ansicol.h>
#include <ipxe/jumpscroll.h>
#include <ipxe/settings_ui.h>
#include <config/branding.h>

/** @file
 *
 * Option configuration console
 *
 */

/* Screen layout */
#define TITLE_ROW               1U
#define SETTINGS_LIST_ROW       3U
#define SETTINGS_LIST_COL       1U
#define SETTINGS_LIST_ROWS      ( LINES - 6U - SETTINGS_LIST_ROW )
#define INFO_ROW                ( LINES - 5U )
#define ALERT_ROW               ( LINES - 2U )
#define INSTRUCTION_ROW         ( LINES - 2U )
#define INSTRUCTION_PAD "     "

/** Layout of text within a setting row */
#define SETTING_ROW_TEXT( cols ) struct {                               \
        char start[0];                                                  \
        char pad1[1];                                                   \
        union {                                                         \
                char settings[ cols - 1 - 1 - 1 - 1 ];                  \
                struct {                                                \
                        char name[15];                                  \
                        char pad2[1];                                   \
                        char value[ cols - 1 - 15 - 1 - 1 - 1 - 1 ];    \
                } setting;                                              \
        } u;                                                            \
        char pad3[1];                                                   \
        char nul;                                                       \
} __attribute__ (( packed ))

/** A settings user interface row */
struct settings_ui_row {
        /** Target configuration settings block
         *
         * Valid only for rows that lead to new settings blocks.
         */
        struct settings *settings;
        /** Configuration setting origin
         *
         * Valid only for rows that represent individual settings.
         */
        struct settings *origin;
        /** Configuration setting
         *
         * Valid only for rows that represent individual settings.
         */
        struct setting setting;
        /** Screen row */
        unsigned int row;
        /** Edit box widget used for editing setting */
        struct edit_box editbox;
        /** Editing in progress flag */
        int editing;
        /** Buffer for setting's value */
        char value[256]; /* enough size for a DHCP string */
};

/** A settings user interface */
struct settings_ui {
        /** Settings block */
        struct settings *settings;
        /** Jump scroller */
        struct jump_scroller scroll;
        /** Current row */
        struct settings_ui_row row;
};

/**
 * Select a setting
 *
 * @v ui                Settings user interface
 * @v index             Index of setting row
 * @ret count           Number of setting rows
 */
static unsigned int select_setting_row ( struct settings_ui *ui,
                                         unsigned int index ) {
        SETTING_ROW_TEXT ( COLS ) *text;
        struct settings *settings;
        struct setting *setting;
        struct setting *previous = NULL;
        unsigned int count = 0;

        /* Initialise structure */
        memset ( &ui->row, 0, sizeof ( ui->row ) );
        ui->row.row = ( SETTINGS_LIST_ROW + index - ui->scroll.first );

        /* Include parent settings block, if applicable */
        if ( ui->settings->parent && ( count++ == index ) ) {
                ui->row.settings = ui->settings->parent;
                snprintf ( ui->row.value, sizeof ( ui->row.value ),
                           "../" );
        }

        /* Include any child settings blocks, if applicable */
        list_for_each_entry ( settings, &ui->settings->children, siblings ) {
                if ( count++ == index ) {
                        ui->row.settings = settings;
                        snprintf ( ui->row.value, sizeof ( ui->row.value ),
                                   "%s/", settings->name );
                }
        }

        /* Include any applicable settings */
        for_each_table_entry ( setting, SETTINGS ) {

                /* Skip inapplicable settings */
                if ( ! setting_applies ( ui->settings, setting ) )
                        continue;

                /* Skip duplicate settings */
                if ( previous && ( setting_cmp ( setting, previous ) == 0 ) )
                        continue;
                previous = setting;

                /* Read current setting value and origin */
                if ( count++ == index ) {
                        fetchf_setting ( ui->settings, setting, &ui->row.origin,
                                         &ui->row.setting, ui->row.value,
                                         sizeof ( ui->row.value ) );
                }
        }

        /* Initialise edit box */
        init_editbox ( &ui->row.editbox, ui->row.value,
                       sizeof ( ui->row.value ), NULL, ui->row.row,
                       ( SETTINGS_LIST_COL +
                         offsetof ( typeof ( *text ), u.setting.value ) ),
                       sizeof ( text->u.setting.value ), 0 );

        return count;
}

/**
 * Copy string without NUL termination
 *
 * @v dest              Destination
 * @v src               Source
 * @v len               Maximum length of destination
 * @ret len             Length of (unterminated) string
 */
static size_t string_copy ( char *dest, const char *src, size_t len ) {
        size_t src_len;

        src_len = strlen ( src );
        if ( len > src_len )
                len = src_len;
        memcpy ( dest, src, len );
        return len;
}

/**
 * Draw setting row
 *
 * @v ui                Settings UI
 */
static void draw_setting_row ( struct settings_ui *ui ) {
        SETTING_ROW_TEXT ( COLS ) text;
        unsigned int curs_offset;
        char *value;

        /* Fill row with spaces */
        memset ( &text, ' ', sizeof ( text ) );
        text.nul = '\0';

        /* Construct row content */
        if ( ui->row.settings ) {

                /* Construct space-padded name */
                curs_offset = ( offsetof ( typeof ( text ), u.settings ) +
                                string_copy ( text.u.settings,
                                              ui->row.value,
                                              sizeof ( text.u.settings ) ) );

        } else {

                /* Construct dot-padded name */
                memset ( text.u.setting.name, '.',
                         sizeof ( text.u.setting.name ) );
                string_copy ( text.u.setting.name, ui->row.setting.name,
                              sizeof ( text.u.setting.name ) );

                /* Construct space-padded value */
                value = ui->row.value;
                if ( ! *value )
                        value = "<not specified>";
                curs_offset = ( offsetof ( typeof ( text ), u.setting.value ) +
                                string_copy ( text.u.setting.value, value,
                                              sizeof ( text.u.setting.value )));
        }

        /* Print row */
        if ( ( ui->row.origin == ui->settings ) || ( ui->row.settings != NULL ))
                attron ( A_BOLD );
        mvprintw ( ui->row.row, SETTINGS_LIST_COL, "%s", text.start );
        attroff ( A_BOLD );
        move ( ui->row.row, ( SETTINGS_LIST_COL + curs_offset ) );
}

/**
 * Edit setting ui
 *
 * @v ui                Settings UI
 * @v key               Key pressed by user
 * @ret key             Key returned to application, or zero
 */
static int edit_setting ( struct settings_ui *ui, int key ) {
        assert ( ui->row.setting.name != NULL );
        ui->row.editing = 1;
        return edit_editbox ( &ui->row.editbox, key );
}

/**
 * Save setting ui value back to configuration settings
 *
 * @v ui                Settings UI
 */
static int save_setting ( struct settings_ui *ui ) {
        assert ( ui->row.setting.name != NULL );
        return storef_setting ( ui->settings, &ui->row.setting, ui->row.value );
}

/**
 * Print message centred on specified row
 *
 * @v row               Row
 * @v fmt               printf() format string
 * @v args              printf() argument list
 */
static void vmsg ( unsigned int row, const char *fmt, va_list args ) {
        char buf[COLS];
        size_t len;

        len = vsnprintf ( buf, sizeof ( buf ), fmt, args );
        mvprintw ( row, ( ( COLS - len ) / 2 ), "%s", buf );
}

/**
 * Print message centred on specified row
 *
 * @v row               Row
 * @v fmt               printf() format string
 * @v ..                printf() arguments
 */
static void msg ( unsigned int row, const char *fmt, ... ) {
        va_list args;

        va_start ( args, fmt );
        vmsg ( row, fmt, args );
        va_end ( args );
}

/**
 * Clear message on specified row
 *
 * @v row               Row
 */
static void clearmsg ( unsigned int row ) {
        move ( row, 0 );
        clrtoeol();
}

/**
 * Print alert message
 *
 * @v fmt               printf() format string
 * @v args              printf() argument list
 */
static void valert ( const char *fmt, va_list args ) {
        clearmsg ( ALERT_ROW );
        color_set ( CPAIR_ALERT, NULL );
        vmsg ( ALERT_ROW, fmt, args );
        sleep ( 2 );
        color_set ( CPAIR_NORMAL, NULL );
        clearmsg ( ALERT_ROW );
}

/**
 * Print alert message
 *
 * @v fmt               printf() format string
 * @v ...               printf() arguments
 */
static void alert ( const char *fmt, ... ) {
        va_list args;

        va_start ( args, fmt );
        valert ( fmt, args );
        va_end ( args );
}

/**
 * Draw title row
 *
 * @v ui                Settings UI
 */
static void draw_title_row ( struct settings_ui *ui ) {
        const char *name;

        clearmsg ( TITLE_ROW );
        name = settings_name ( ui->settings );
        attron ( A_BOLD );
        msg ( TITLE_ROW, PRODUCT_SHORT_NAME " configuration settings%s%s",
              ( name[0] ? " - " : "" ), name );
        attroff ( A_BOLD );
}

/**
 * Draw information row
 *
 * @v ui                Settings UI
 */
static void draw_info_row ( struct settings_ui *ui ) {
        char buf[32];

        /* Draw nothing unless this row represents a setting */
        clearmsg ( INFO_ROW );
        clearmsg ( INFO_ROW + 1 );
        if ( ! ui->row.setting.name )
                return;

        /* Determine a suitable setting name */
        setting_name ( ( ui->row.origin ?
                         ui->row.origin : ui->settings ),
                       &ui->row.setting, buf, sizeof ( buf ) );

        /* Draw row */
        attron ( A_BOLD );
        msg ( INFO_ROW, "%s - %s", buf, ui->row.setting.description );
        attroff ( A_BOLD );
        color_set ( CPAIR_URL, NULL );
        msg ( ( INFO_ROW + 1 ), PRODUCT_SETTING_URI, ui->row.setting.name );
        color_set ( CPAIR_NORMAL, NULL );
}

/**
 * Draw instruction row
 *
 * @v ui                Settings UI
 */
static void draw_instruction_row ( struct settings_ui *ui ) {

        clearmsg ( INSTRUCTION_ROW );
        if ( ui->row.editing ) {
                msg ( INSTRUCTION_ROW,
                      "Enter - accept changes" INSTRUCTION_PAD
                      "Ctrl-C - discard changes" );
        } else {
                msg ( INSTRUCTION_ROW,
                      "%sCtrl-X - exit configuration utility",
                      ( ( ui->row.origin == ui->settings ) ?
                        "Ctrl-D - delete setting" INSTRUCTION_PAD : "" ) );
        }
}

/**
 * Draw the current block of setting rows
 *
 * @v ui                Settings UI
 */
static void draw_setting_rows ( struct settings_ui *ui ) {
        unsigned int i;

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

        /* Draw visible settings. */
        for ( i = 0 ; i < SETTINGS_LIST_ROWS ; i++ ) {
                if ( ( ui->scroll.first + i ) < ui->scroll.count ) {
                        select_setting_row ( ui, ( ui->scroll.first + i ) );
                        draw_setting_row ( ui );
                } else {
                        clearmsg ( SETTINGS_LIST_ROW + i );
                }
        }
}

/**
 * Select settings block
 *
 * @v ui                Settings UI
 * @v settings          Settings block
 */
static void select_settings ( struct settings_ui *ui,
                              struct settings *settings ) {

        ui->settings = settings_target ( settings );
        ui->scroll.count = select_setting_row ( ui, 0 );
        ui->scroll.rows = SETTINGS_LIST_ROWS;
        ui->scroll.current = 0;
        ui->scroll.first = 0;
        draw_title_row ( ui );
        draw_setting_rows ( ui );
        select_setting_row ( ui, 0 );
}

static int main_loop ( struct settings *settings ) {
        struct settings_ui ui;
        unsigned int previous;
        int redraw = 1;
        int move;
        int key;
        int rc;

        /* Print initial screen content */
        color_set ( CPAIR_NORMAL, NULL );
        memset ( &ui, 0, sizeof ( ui ) );
        select_settings ( &ui, settings );

        while ( 1 ) {

                /* Redraw rows if necessary */
                if ( redraw ) {
                        draw_info_row ( &ui );
                        draw_instruction_row ( &ui );
                        color_set ( ( ui.row.editing ?
                                      CPAIR_EDIT : CPAIR_SELECT ), NULL );
                        draw_setting_row ( &ui );
                        color_set ( CPAIR_NORMAL, NULL );
                        curs_set ( ui.row.editing );
                        redraw = 0;
                }

                /* Edit setting, if we are currently editing */
                if ( ui.row.editing ) {

                        /* Sanity check */
                        assert ( ui.row.setting.name != NULL );

                        /* Redraw edit box */
                        color_set ( CPAIR_EDIT, NULL );
                        draw_editbox ( &ui.row.editbox );
                        color_set ( CPAIR_NORMAL, NULL );

                        /* Process keypress */
                        key = edit_setting ( &ui, getkey ( 0 ) );
                        switch ( key ) {
                        case CR:
                        case LF:
                                if ( ( rc = save_setting ( &ui ) ) != 0 )
                                        alert ( " %s ", strerror ( rc ) );
                                /* Fall through */
                        case CTRL_C:
                                select_setting_row ( &ui, ui.scroll.current );
                                redraw = 1;
                                break;
                        default:
                                /* Do nothing */
                                break;
                        }

                        continue;
                }

                /* Otherwise, navigate through settings */
                key = getkey ( 0 );
                move = jump_scroll_key ( &ui.scroll, key );
                if ( move ) {
                        previous = ui.scroll.current;
                        jump_scroll_move ( &ui.scroll, move );
                        if ( ui.scroll.current != previous ) {
                                draw_setting_row ( &ui );
                                redraw = 1;
                                if ( jump_scroll ( &ui.scroll ) )
                                        draw_setting_rows ( &ui );
                                select_setting_row ( &ui, ui.scroll.current );
                        }
                        continue;
                }

                /* Handle non-navigation keys */
                switch ( key ) {
                case CTRL_D:
                        if ( ! ui.row.setting.name )
                                break;
                        if ( ( rc = delete_setting ( ui.settings,
                                                     &ui.row.setting ) ) != 0 ){
                                alert ( " %s ", strerror ( rc ) );
                        }
                        select_setting_row ( &ui, ui.scroll.current );
                        redraw = 1;
                        break;
                case CTRL_X:
                        return 0;
                case CR:
                case LF:
                        if ( ui.row.settings ) {
                                select_settings ( &ui, ui.row.settings );
                                redraw = 1;
                        }
                        /* Fall through */
                default:
                        if ( ui.row.setting.name ) {
                                edit_setting ( &ui, key );
                                redraw = 1;
                        }
                        break;
                }
        }
}

int settings_ui ( struct settings *settings ) {
        int rc;

        initscr();
        start_color();
        color_set ( CPAIR_NORMAL, NULL );
        curs_set ( 0 );
        erase();
        
        rc = main_loop ( settings );

        endwin();

        return rc;
}