editbox.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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

FILE_LICENCE ( GPL2_OR_LATER );

#include <string.h>
#include <assert.h>
#include <gpxe/editbox.h>

/** @file
 *
 * Editable text box widget
 *
 */

#define EDITBOX_MIN_CHARS 3

/**
 * Initialise text box widget
 *
 * @v box               Editable text box widget
 * @v buf               Text buffer
 * @v len               Size of text buffer
 * @v win               Containing window
 * @v row               Row
 * @v col               Starting column
 * @v width             Width
 * @v flags             Flags
 */
void init_editbox ( struct edit_box *box, char *buf, size_t len,
                    WINDOW *win, unsigned int row, unsigned int col,
                    unsigned int width, unsigned int flags ) {
        memset ( box, 0, sizeof ( *box ) );
        box->string.buf = buf;
        box->string.len = len;
        box->string.cursor = strlen ( buf );
        box->win = ( win ? win : stdscr );
        box->row = row;
        box->col = col;
        box->width = width;
        box->flags = flags;
}

/**
 * Draw text box widget
 *
 * @v box               Editable text box widget
 *
 */
void draw_editbox ( struct edit_box *box ) {
        size_t width = box->width;
        char buf[ width + 1 ];
        signed int cursor_offset, underflow, overflow, first;
        size_t len;

        /* Adjust starting offset so that cursor remains within box */
        cursor_offset = ( box->string.cursor - box->first );
        underflow = ( EDITBOX_MIN_CHARS - cursor_offset );
        overflow = ( cursor_offset - ( width - 1 ) );
        first = box->first;
        if ( underflow > 0 ) {
                first -= underflow;
                if ( first < 0 )
                        first = 0;
        } else if ( overflow > 0 ) {
                first += overflow;
        }
        box->first = first;
        cursor_offset = ( box->string.cursor - first );

        /* Construct underscore-padded string portion */
        memset ( buf, '_', width );
        buf[width] = '\0';
        len = ( strlen ( box->string.buf ) - first );
        if ( len > width )
                len = width;
        if ( box->flags & EDITBOX_STARS ) {
                memset ( buf, '*', len );
        } else {
                memcpy ( buf, ( box->string.buf + first ), len );
        }

        /* Print box content and move cursor */
        if ( ! box->win )
                box->win = stdscr;
        mvwprintw ( box->win, box->row, box->col, "%s", buf );
        wmove ( box->win, box->row, ( box->col + cursor_offset ) );
}