1/*
2 *  textbox.c -- implements the text box
3 *
4 *  ORIGINAL AUTHOR: Savio Lam (lam836@cs.cuhk.hk)
5 *  MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap (roadcap@cfw.com)
6 *
7 *  This program is free software; you can redistribute it and/or
8 *  modify it under the terms of the GNU General Public License
9 *  as published by the Free Software Foundation; either version 2
10 *  of the License, or (at your option) any later version.
11 *
12 *  This program is distributed in the hope that it will be useful,
13 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
14 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 *  GNU General Public License for more details.
16 *
17 *  You should have received a copy of the GNU General Public License
18 *  along with this program; if not, write to the Free Software
19 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22#include "dialog.h"
23
24static void back_lines(int n);
25static void print_page(WINDOW * win, int height, int width);
26static void print_line(WINDOW * win, int row, int width);
27static char *get_line(void);
28static void print_position(WINDOW * win);
29
30static int hscroll;
31static int begin_reached, end_reached, page_length;
32static const char *buf;
33static const char *page;
34
35/*
36 * refresh window content
37 */
38static void refresh_text_box(WINDOW *dialog, WINDOW *box, int boxh, int boxw,
39							  int cur_y, int cur_x)
40{
41	print_page(box, boxh, boxw);
42	print_position(dialog);
43	wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
44	wrefresh(dialog);
45}
46
47
48/*
49 * Display text from a file in a dialog box.
50 */
51int dialog_textbox(const char *title, const char *tbuf,
52		   int initial_height, int initial_width)
53{
54	int i, x, y, cur_x, cur_y, key = 0;
55	int height, width, boxh, boxw;
56	int passed_end;
57	WINDOW *dialog, *box;
58
59	begin_reached = 1;
60	end_reached = 0;
61	page_length = 0;
62	hscroll = 0;
63	buf = tbuf;
64	page = buf;	/* page is pointer to start of page to be displayed */
65
66do_resize:
67	getmaxyx(stdscr, height, width);
68	if (height < 8 || width < 8)
69		return -ERRDISPLAYTOOSMALL;
70	if (initial_height != 0)
71		height = initial_height;
72	else
73		if (height > 4)
74			height -= 4;
75		else
76			height = 0;
77	if (initial_width != 0)
78		width = initial_width;
79	else
80		if (width > 5)
81			width -= 5;
82		else
83			width = 0;
84
85	/* center dialog box on screen */
86	x = (COLS - width) / 2;
87	y = (LINES - height) / 2;
88
89	draw_shadow(stdscr, y, x, height, width);
90
91	dialog = newwin(height, width, y, x);
92	keypad(dialog, TRUE);
93
94	/* Create window for box region, used for scrolling text */
95	boxh = height - 4;
96	boxw = width - 2;
97	box = subwin(dialog, boxh, boxw, y + 1, x + 1);
98	wattrset(box, dlg.dialog.atr);
99	wbkgdset(box, dlg.dialog.atr & A_COLOR);
100
101	keypad(box, TRUE);
102
103	/* register the new window, along with its borders */
104	draw_box(dialog, 0, 0, height, width,
105		 dlg.dialog.atr, dlg.border.atr);
106
107	wattrset(dialog, dlg.border.atr);
108	mvwaddch(dialog, height - 3, 0, ACS_LTEE);
109	for (i = 0; i < width - 2; i++)
110		waddch(dialog, ACS_HLINE);
111	wattrset(dialog, dlg.dialog.atr);
112	wbkgdset(dialog, dlg.dialog.atr & A_COLOR);
113	waddch(dialog, ACS_RTEE);
114
115	print_title(dialog, title, width);
116
117	print_button(dialog, " Exit ", height - 2, width / 2 - 4, TRUE);
118	wnoutrefresh(dialog);
119	getyx(dialog, cur_y, cur_x);	/* Save cursor position */
120
121	/* Print first page of text */
122	attr_clear(box, boxh, boxw, dlg.dialog.atr);
123	refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x);
124
125	while ((key != KEY_ESC) && (key != '\n')) {
126		key = wgetch(dialog);
127		switch (key) {
128		case 'E':	/* Exit */
129		case 'e':
130		case 'X':
131		case 'x':
132			delwin(box);
133			delwin(dialog);
134			return 0;
135		case 'g':	/* First page */
136		case KEY_HOME:
137			if (!begin_reached) {
138				begin_reached = 1;
139				page = buf;
140				refresh_text_box(dialog, box, boxh, boxw,
141						 cur_y, cur_x);
142			}
143			break;
144		case 'G':	/* Last page */
145		case KEY_END:
146
147			end_reached = 1;
148			/* point to last char in buf */
149			page = buf + strlen(buf);
150			back_lines(boxh);
151			refresh_text_box(dialog, box, boxh, boxw,
152					 cur_y, cur_x);
153			break;
154		case 'K':	/* Previous line */
155		case 'k':
156		case KEY_UP:
157			if (!begin_reached) {
158				back_lines(page_length + 1);
159
160				/* We don't call print_page() here but use
161				 * scrolling to ensure faster screen update.
162				 * However, 'end_reached' and 'page_length'
163				 * should still be updated, and 'page' should
164				 * point to start of next page. This is done
165				 * by calling get_line() in the following
166				 * 'for' loop. */
167				scrollok(box, TRUE);
168				wscrl(box, -1);	/* Scroll box region down one line */
169				scrollok(box, FALSE);
170				page_length = 0;
171				passed_end = 0;
172				for (i = 0; i < boxh; i++) {
173					if (!i) {
174						/* print first line of page */
175						print_line(box, 0, boxw);
176						wnoutrefresh(box);
177					} else
178						/* Called to update 'end_reached' and 'page' */
179						get_line();
180					if (!passed_end)
181						page_length++;
182					if (end_reached && !passed_end)
183						passed_end = 1;
184				}
185
186				print_position(dialog);
187				wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
188				wrefresh(dialog);
189			}
190			break;
191		case 'B':	/* Previous page */
192		case 'b':
193		case KEY_PPAGE:
194			if (begin_reached)
195				break;
196			back_lines(page_length + boxh);
197			refresh_text_box(dialog, box, boxh, boxw,
198					 cur_y, cur_x);
199			break;
200		case 'J':	/* Next line */
201		case 'j':
202		case KEY_DOWN:
203			if (!end_reached) {
204				begin_reached = 0;
205				scrollok(box, TRUE);
206				scroll(box);	/* Scroll box region up one line */
207				scrollok(box, FALSE);
208				print_line(box, boxh - 1, boxw);
209				wnoutrefresh(box);
210				print_position(dialog);
211				wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
212				wrefresh(dialog);
213			}
214			break;
215		case KEY_NPAGE:	/* Next page */
216		case ' ':
217			if (end_reached)
218				break;
219
220			begin_reached = 0;
221			refresh_text_box(dialog, box, boxh, boxw,
222					 cur_y, cur_x);
223			break;
224		case '0':	/* Beginning of line */
225		case 'H':	/* Scroll left */
226		case 'h':
227		case KEY_LEFT:
228			if (hscroll <= 0)
229				break;
230
231			if (key == '0')
232				hscroll = 0;
233			else
234				hscroll--;
235			/* Reprint current page to scroll horizontally */
236			back_lines(page_length);
237			refresh_text_box(dialog, box, boxh, boxw,
238					 cur_y, cur_x);
239			break;
240		case 'L':	/* Scroll right */
241		case 'l':
242		case KEY_RIGHT:
243			if (hscroll >= MAX_LEN)
244				break;
245			hscroll++;
246			/* Reprint current page to scroll horizontally */
247			back_lines(page_length);
248			refresh_text_box(dialog, box, boxh, boxw,
249					 cur_y, cur_x);
250			break;
251		case KEY_ESC:
252			key = on_key_esc(dialog);
253			break;
254		case KEY_RESIZE:
255			back_lines(height);
256			delwin(box);
257			delwin(dialog);
258			on_key_resize();
259			goto do_resize;
260		}
261	}
262	delwin(box);
263	delwin(dialog);
264	return key;		/* ESC pressed */
265}
266
267/*
268 * Go back 'n' lines in text. Called by dialog_textbox().
269 * 'page' will be updated to point to the desired line in 'buf'.
270 */
271static void back_lines(int n)
272{
273	int i;
274
275	begin_reached = 0;
276	/* Go back 'n' lines */
277	for (i = 0; i < n; i++) {
278		if (*page == '\0') {
279			if (end_reached) {
280				end_reached = 0;
281				continue;
282			}
283		}
284		if (page == buf) {
285			begin_reached = 1;
286			return;
287		}
288		page--;
289		do {
290			if (page == buf) {
291				begin_reached = 1;
292				return;
293			}
294			page--;
295		} while (*page != '\n');
296		page++;
297	}
298}
299
300/*
301 * Print a new page of text. Called by dialog_textbox().
302 */
303static void print_page(WINDOW * win, int height, int width)
304{
305	int i, passed_end = 0;
306
307	page_length = 0;
308	for (i = 0; i < height; i++) {
309		print_line(win, i, width);
310		if (!passed_end)
311			page_length++;
312		if (end_reached && !passed_end)
313			passed_end = 1;
314	}
315	wnoutrefresh(win);
316}
317
318/*
319 * Print a new line of text. Called by dialog_textbox() and print_page().
320 */
321static void print_line(WINDOW * win, int row, int width)
322{
323	int y, x;
324	char *line;
325
326	line = get_line();
327	line += MIN(strlen(line), hscroll);	/* Scroll horizontally */
328	wmove(win, row, 0);	/* move cursor to correct line */
329	waddch(win, ' ');
330	waddnstr(win, line, MIN(strlen(line), width - 2));
331
332	getyx(win, y, x);
333	/* Clear 'residue' of previous line */
334#if OLD_NCURSES
335	{
336		int i;
337		for (i = 0; i < width - x; i++)
338			waddch(win, ' ');
339	}
340#else
341	wclrtoeol(win);
342#endif
343}
344
345/*
346 * Return current line of text. Called by dialog_textbox() and print_line().
347 * 'page' should point to start of current line before calling, and will be
348 * updated to point to start of next line.
349 */
350static char *get_line(void)
351{
352	int i = 0;
353	static char line[MAX_LEN + 1];
354
355	end_reached = 0;
356	while (*page != '\n') {
357		if (*page == '\0') {
358			if (!end_reached) {
359				end_reached = 1;
360				break;
361			}
362		} else if (i < MAX_LEN)
363			line[i++] = *(page++);
364		else {
365			/* Truncate lines longer than MAX_LEN characters */
366			if (i == MAX_LEN)
367				line[i++] = '\0';
368			page++;
369		}
370	}
371	if (i <= MAX_LEN)
372		line[i] = '\0';
373	if (!end_reached)
374		page++;		/* move pass '\n' */
375
376	return line;
377}
378
379/*
380 * Print current position
381 */
382static void print_position(WINDOW * win)
383{
384	int percent;
385
386	wattrset(win, dlg.position_indicator.atr);
387	wbkgdset(win, dlg.position_indicator.atr & A_COLOR);
388	percent = (page - buf) * 100 / strlen(buf);
389	wmove(win, getmaxy(win) - 3, getmaxx(win) - 9);
390	wprintw(win, "(%3d%%)", percent);
391}
392