/*

 *  textbox.c -- implements the text box

 *

 *  ORIGINAL AUTHOR: Savio Lam (lam836@cs.cuhk.hk)

 *  MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap (roadcap@cfw.com)

 *

 *  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);

static int hscroll;

static int begin_reached, end_reached, page_length;

static const char *buf;

static const char *page;

/*

 * refresh window content

 */

static void refresh_text_box(WINDOW *dialog, WINDOW *box, int boxh, int boxw,

							  int cur_y, int cur_x)

{

	print_page(box, boxh, boxw);

	print_position(dialog);

	wmove(dialog, cur_y, cur_x);	/* Restore cursor position */

	wrefresh(dialog);

}

/*

 * Display text from a file in a dialog box.

 */

int dialog_textbox(const char *title, const char *tbuf,

		   int initial_height, int initial_width)

{

	int i, x, y, cur_x, cur_y, key = 0;

	int height, width, boxh, boxw;

	int passed_end;

	WINDOW *dialog, *box;

	begin_reached = 1;

	end_reached = 0;

	page_length = 0;

	hscroll = 0;

	buf = tbuf;

	page = buf;	/* page is pointer to start of page to be displayed */

do_resize:

	getmaxyx(stdscr, height, width);

	if (height < 8 || width < 8)

		return -ERRDISPLAYTOOSMALL;

	if (initial_height != 0)

		height = initial_height;

	else

		if (height > 4)

			height -= 4;

		else

			height = 0;

	if (initial_width != 0)

		width = initial_width;

	else

		if (width > 5)

			width -= 5;

		else

			width = 0;

	/* 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 box region, used for scrolling text */

	boxh = height - 4;

	boxw = width - 2;

	box = subwin(dialog, boxh, boxw, y + 1, x + 1);

	wattrset(box, dlg.dialog.atr);

	wbkgdset(box, dlg.dialog.atr & A_COLOR);

	keypad(box, TRUE);

	/* register the new window, along with its borders */

	draw_box(dialog, 0, 0, height, width,

		 dlg.dialog.atr, dlg.border.atr);

	wattrset(dialog, dlg.border.atr);

	mvwaddch(dialog, height - 3, 0, ACS_LTEE);

	for (i = 0; i < width - 2; i++)

		waddch(dialog, ACS_HLINE);

	wattrset(dialog, dlg.dialog.atr);

	wbkgdset(dialog, dlg.dialog.atr & A_COLOR);

	waddch(dialog, ACS_RTEE);

	print_title(dialog, title, width);

	print_button(dialog, gettext(" 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(box, boxh, boxw, dlg.dialog.atr);

	refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x);

	while ((key != KEY_ESC) && (key != '\n')) {

		key = wgetch(dialog);

		switch (key) {

		case 'E':	/* Exit */

		case 'e':

		case 'X':

		case 'x':

			delwin(box);

			delwin(dialog);

			return 0;

		case 'g':	/* First page */

		case KEY_HOME:

			if (!begin_reached) {

				begin_reached = 1;

				page = buf;

				refresh_text_box(dialog, box, boxh, boxw,

						 cur_y, cur_x);

			}

			break;

		case 'G':	/* Last page */

		case KEY_END:

			end_reached = 1;

			/* point to last char in buf */

			page = buf + strlen(buf);

			back_lines(boxh);

			refresh_text_box(dialog, box, boxh, boxw,

					 cur_y, cur_x);

			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(box, TRUE);

				wscrl(box, -1);	/* Scroll box region down one line */

				scrollok(box, FALSE);

				page_length = 0;

				passed_end = 0;

				for (i = 0; i < boxh; i++) {

					if (!i) {

						/* print first line of page */

						print_line(box, 0, boxw);

						wnoutrefresh(box);

					} 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);

				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 + boxh);

			refresh_text_box(dialog, box, boxh, boxw,

					 cur_y, cur_x);

			break;

		case 'J':	/* Next line */

		case 'j':

		case KEY_DOWN:

			if (!end_reached) {

				begin_reached = 0;

				scrollok(box, TRUE);

				scroll(box);	/* Scroll box region up one line */

				scrollok(box, FALSE);

				print_line(box, boxh - 1, boxw);

				wnoutrefresh(box);

				print_position(dialog);

				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;

			refresh_text_box(dialog, box, boxh, boxw,

					 cur_y, cur_x);

			break;

		case '0':	/* Beginning of line */

		case 'H':	/* Scroll left */

		case 'h':

		case KEY_LEFT:

			if (hscroll <= 0)

				break;

			if (key == '0')

				hscroll = 0;

			else

				hscroll--;

			/* Reprint current page to scroll horizontally */

			back_lines(page_length);

			refresh_text_box(dialog, box, boxh, boxw,

					 cur_y, cur_x);

			break;

		case 'L':	/* Scroll right */

		case 'l':

		case KEY_RIGHT:

			if (hscroll >= MAX_LEN)

				break;

			hscroll++;

			/* Reprint current page to scroll horizontally */

			back_lines(page_length);

			refresh_text_box(dialog, box, boxh, boxw,

					 cur_y, cur_x);

			break;

		case KEY_ESC:

			key = on_key_esc(dialog);

			break;

		case KEY_RESIZE:

			back_lines(height);

			delwin(box);

			delwin(dialog);

			on_key_resize();

			goto do_resize;

		}

	}

	delwin(box);

	delwin(dialog);

	return key;		/* ESC pressed */

}

/*

 * Go back 'n' lines in text. Called by dialog_textbox().

 * 'page' will be updated to point to the desired line in 'buf'.

 */

static void back_lines(int n)

{

	int i;

	begin_reached = 0;

	/* Go back 'n' lines */

	for (i = 0; i < n; i++) {

		if (*page == '\0') {

			if (end_reached) {

				end_reached = 0;

				continue;

			}

		}

		if (page == buf) {

			begin_reached = 1;

			return;

		}

		page--;

		do {

			if (page == buf) {

				begin_reached = 1;

				return;

			}

			page--;

		} while (*page != '\n');

		page++;

	}

}

/*

 * Print a new page of text. Called by dialog_textbox().

 */

static void print_page(WINDOW * win, int height, int width)

{

	int i, passed_end = 0;

	page_length = 0;

	for (i = 0; i < height; i++) {

		print_line(win, i, width);

		if (!passed_end)

			page_length++;

		if (end_reached && !passed_end)

			passed_end = 1;

	}

	wnoutrefresh(win);

}

/*

 * Print a new line of text. Called by dialog_textbox() and print_page().

 */

static void print_line(WINDOW * win, int row, int width)

{

	int y, x;

	char *line;

	line = get_line();

	line += MIN(strlen(line), hscroll);	/* Scroll horizontally */

	wmove(win, row, 0);	/* move cursor to correct line */

	waddch(win, ' ');

	waddnstr(win, line, MIN(strlen(line), width - 2));

	getyx(win, y, x);

	/* Clear 'residue' of previous line */

#if OLD_NCURSES

	{

		int i;

		for (i = 0; i < width - x; i++)

			waddch(win, ' ');

	}

#else

	wclrtoeol(win);

#endif

}

/*

 * Return current line of text. Called by dialog_textbox() and print_line().

 * 'page' should point to start of current line before calling, and will be

 * updated to point to start of next line.

 */

static char *get_line(void)

{

	int i = 0;

	static char line[MAX_LEN + 1];

	end_reached = 0;

	while (*page != '\n') {

		if (*page == '\0') {

			if (!end_reached) {

				end_reached = 1;

				break;

			}

		} else if (i < MAX_LEN)

			line[i++] = *(page++);

		else {

			/* Truncate lines longer than MAX_LEN characters */

			if (i == MAX_LEN)

				line[i++] = '\0';

			page++;

		}

	}

	if (i <= MAX_LEN)

		line[i] = '\0';

	if (!end_reached)

		page++;		/* move pass '\n' */

	return line;

}

/*

 * Print current position

 */

static void print_position(WINDOW * win)

{

	int percent;

	wattrset(win, dlg.position_indicator.atr);

	wbkgdset(win, dlg.position_indicator.atr & A_COLOR);

	percent = (page - buf) * 100 / strlen(buf);

	wmove(win, getmaxy(win) - 3, getmaxx(win) - 9);

	wprintw(win, "(%3d%%)", percent);

}