/*

  *  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);

 }