textbox.c

busybox-1.2.0的源码包

/*
 *  textbox.c -- implements the text box
 *
 *  ORIGINAL AUTHOR: Savio Lam ([e-mail])
 *  MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap ([e-mail])
 *
 *  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 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.
 */

#include "dialog.h"

static void back_lines (int n);
static void print_page (WINDOW * win, int height, int width);
static void print_line (WINDOW * win, int row, int width);
static char *get_line (void);
static void print_position (WINDOW * win, int height, int width);

static int hscroll, fd, file_size, bytes_read;
static int begin_reached = 1, end_reached, page_length;
static char *buf, *page;

/*
 * Display text from a file in a dialog box.
 */
int
dialog_textbox (const char *title, const char *file, int height, int width)
{
    int i, x, y, cur_x, cur_y, fpos, key = 0;
    int passed_end;
    char search_term[MAX_LEN + 1];
    WINDOW *dialog, *text;

    search_term[0] = '\0';	/* no search term entered yet */

    /* Open input file for reading */
    if ((fd = open (file, O_RDONLY)) == -1) {
	endwin ();
	fprintf (stderr,
		 "\nCan't open input file in dialog_textbox().\n");
	exit (-1);
    }
    /* Get file size. Actually, 'file_size' is the real file size - 1,
       since it's only the last byte offset from the beginning */
    if ((file_size = lseek (fd, 0, SEEK_END)) == -1) {
	endwin ();
	fprintf (stderr, "\nError getting file size in dialog_textbox().\n");
	exit (-1);
    }
    /* Restore file pointer to beginning of file after getting file size */
    if (lseek (fd, 0, SEEK_SET) == -1) {
	endwin ();
	fprintf (stderr, "\nError moving file pointer in dialog_textbox().\n");
	exit (-1);
    }
    /* Allocate space for read buffer */
    if ((buf = malloc (BUF_SIZE + 1)) == NULL) {
	endwin ();
	fprintf (stderr, "\nCan't allocate memory in dialog_textbox().\n");
	exit (-1);
    }
    if ((bytes_read = read (fd, buf, BUF_SIZE)) == -1) {
	endwin ();
	fprintf (stderr, "\nError reading file in dialog_textbox().\n");
	exit (-1);
    }
    buf[bytes_read] = '\0';	/* mark end of valid data */
    page = buf;			/* page is pointer to start of page to be displayed */

    /* center dialog box on screen */
    x = (COLS - width) / 2;
    y = (LINES - height) / 2;


    draw_shadow (stdscr, y, x, height, width);

    dialog = newwin (height, width, y, x);
    keypad (dialog, TRUE);

    /* Create window for text region, used for scrolling text */
    text = subwin (dialog, height - 4, width - 2, y + 1, x + 1);
    wattrset (text, dialog_attr);
    wbkgdset (text, dialog_attr & A_COLOR);

    keypad (text, TRUE);

    /* register the new window, along with its borders */
    draw_box (dialog, 0, 0, height, width, dialog_attr, border_attr);

    wattrset (dialog, border_attr);
    mvwaddch (dialog, height-3, 0, ACS_LTEE);
    for (i = 0; i < width - 2; i++)
	waddch (dialog, ACS_HLINE);
    wattrset (dialog, dialog_attr);
    wbkgdset (dialog, dialog_attr & A_COLOR);
    waddch (dialog, ACS_RTEE);

    if (title != NULL && strlen(title) >= width-2 ) {
	/* truncate long title -- mec */
	char * title2 = malloc(width-2+1);
	memcpy( title2, title, width-2 );
	title2[width-2] = '\0';
	title = title2;
    }

    if (title != NULL) {
	wattrset (dialog, title_attr);
	mvwaddch (dialog, 0, (width - strlen(title))/2 - 1, ' ');
	waddstr (dialog, (char *)title);
	waddch (dialog, ' ');
    }
    print_button (dialog, " Exit ", height - 2, width / 2 - 4, TRUE);
    wnoutrefresh (dialog);
    getyx (dialog, cur_y, cur_x);	/* Save cursor position */

    /* Print first page of text */
    attr_clear (text, height - 4, width - 2, dialog_attr);
    print_page (text, height - 4, width - 2);
    print_position (dialog, height, width);
    wmove (dialog, cur_y, cur_x);	/* Restore cursor position */
    wrefresh (dialog);

    while ((key != ESC) && (key != '\n')) {
	key = wgetch (dialog);
	switch (key) {
	case 'E':		/* Exit */
	case 'e':
	case 'X':
	case 'x':
	    delwin (dialog);
	    free (buf);
	    close (fd);
	    return 0;
	case 'g':		/* First page */
	case KEY_HOME:
	    if (!begin_reached) {
		begin_reached = 1;
		/* First page not in buffer? */
		if ((fpos = lseek (fd, 0, SEEK_CUR)) == -1) {
		    endwin ();
		    fprintf (stderr,
		      "\nError moving file pointer in dialog_textbox().\n");
		    exit (-1);
		}
		if (fpos > bytes_read) {	/* Yes, we have to read it in */
		    if (lseek (fd, 0, SEEK_SET) == -1) {
			endwin ();
			fprintf (stderr, "\nError moving file pointer in "
				 "dialog_textbox().\n");
			exit (-1);
		    }
		    if ((bytes_read = read (fd, buf, BUF_SIZE)) == -1) {
			endwin ();
			fprintf (stderr,
			     "\nError reading file in dialog_textbox().\n");
			exit (-1);
		    }
		    buf[bytes_read] = '\0';
		}
		page = buf;
		print_page (text, height - 4, width - 2);
		print_position (dialog, height, width);
		wmove (dialog, cur_y, cur_x);	/* Restore cursor position */
		wrefresh (dialog);
	    }
	    break;
	case 'G':		/* Last page */
	case KEY_END:

	    end_reached = 1;
	    /* Last page not in buffer? */
	    if ((fpos = lseek (fd, 0, SEEK_CUR)) == -1) {
		endwin ();
		fprintf (stderr,
		      "\nError moving file pointer in dialog_textbox().\n");
		exit (-1);
	    }
	    if (fpos < file_size) {	/* Yes, we have to read it in */
		if (lseek (fd, -BUF_SIZE, SEEK_END) == -1) {
		    endwin ();
		    fprintf (stderr,
		      "\nError moving file pointer in dialog_textbox().\n");
		    exit (-1);
		}
		if ((bytes_read = read (fd, buf, BUF_SIZE)) == -1) {
		    endwin ();
		    fprintf (stderr,
			     "\nError reading file in dialog_textbox().\n");
		    exit (-1);
		}
		buf[bytes_read] = '\0';
	    }
	    page = buf + bytes_read;
	    back_lines (height - 4);
	    print_page (text, height - 4, width - 2);
	    print_position (dialog, height, width);
	    wmove (dialog, cur_y, cur_x);	/* Restore cursor position */
	    wrefresh (dialog);
	    break;
	case 'K':		/* Previous line */
	case 'k':
	case KEY_UP:
	    if (!begin_reached) {
		back_lines (page_length + 1);

		/* We don't call print_page() here but use scrolling to ensure
		   faster screen update. However, 'end_reached' and
		   'page_length' should still be updated, and 'page' should
		   point to start of next page. This is done by calling
		   get_line() in the following 'for' loop. */
		scrollok (text, TRUE);
		wscrl (text, -1);	/* Scroll text region down one line */
		scrollok (text, FALSE);
		page_length = 0;
		passed_end = 0;
		for (i = 0; i < height - 4; i++) {
		    if (!i) {
			/* print first line of page */
			print_line (text, 0, width - 2);
			wnoutrefresh (text);
		    } else
			/* Called to update 'end_reached' and 'page' */
			get_line ();
		    if (!passed_end)
			page_length++;
		    if (end_reached && !passed_end)
			passed_end = 1;
		}

		print_position (dialog, height, width);
		wmove (dialog, cur_y, cur_x);	/* Restore cursor position */
		wrefresh (dialog);
	    }
	    break;
	case 'B':		/* Previous page */
	case 'b':
	case KEY_PPAGE:
	    if (begin_reached)
		break;
	    back_lines (page_length + height - 4);
	    print_page (text, height - 4, width - 2);
	    print_position (dialog, height, width);
	    wmove (dialog, cur_y, cur_x);
	    wrefresh (dialog);
	    break;
	case 'J':		/* Next line */
	case 'j':
	case KEY_DOWN:
	    if (!end_reached) {
		begin_reached = 0;
		scrollok (text, TRUE);
		scroll (text);	/* Scroll text region up one line */
		scrollok (text, FALSE);
		print_line (text, height - 5, width - 2);
		wnoutrefresh (text);
		print_position (dialog, height, width);
		wmove (dialog, cur_y, cur_x);	/* Restore cursor position */
		wrefresh (dialog);
	    }
	    break;
	case KEY_NPAGE:		/* Next page */
	case ' ':
	    if (end_reached)
		break;

	    begin_reached = 0;
	    print_page (text, height - 4, width - 2);
	    print_position (dialog, height, width);