xref: /linux/scripts/kconfig/lxdialog/textbox.c (revision 95e9fd10f06cb5642028b6b851e32b8c8afb4571)
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 
24 static void back_lines(int n);
25 static void print_page(WINDOW * win, int height, int width);
26 static void print_line(WINDOW * win, int row, int width);
27 static char *get_line(void);
28 static void print_position(WINDOW * win);
29 
30 static int hscroll;
31 static int begin_reached, end_reached, page_length;
32 static const char *buf;
33 static const char *page;
34 
35 /*
36  * refresh window content
37  */
38 static 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  */
51 int 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 
66 do_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, gettext(" 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 		case 'q':
133 			delwin(box);
134 			delwin(dialog);
135 			return 0;
136 		case 'g':	/* First page */
137 		case KEY_HOME:
138 			if (!begin_reached) {
139 				begin_reached = 1;
140 				page = buf;
141 				refresh_text_box(dialog, box, boxh, boxw,
142 						 cur_y, cur_x);
143 			}
144 			break;
145 		case 'G':	/* Last page */
146 		case KEY_END:
147 
148 			end_reached = 1;
149 			/* point to last char in buf */
150 			page = buf + strlen(buf);
151 			back_lines(boxh);
152 			refresh_text_box(dialog, box, boxh, boxw,
153 					 cur_y, cur_x);
154 			break;
155 		case 'K':	/* Previous line */
156 		case 'k':
157 		case KEY_UP:
158 			if (!begin_reached) {
159 				back_lines(page_length + 1);
160 
161 				/* We don't call print_page() here but use
162 				 * scrolling to ensure faster screen update.
163 				 * However, 'end_reached' and 'page_length'
164 				 * should still be updated, and 'page' should
165 				 * point to start of next page. This is done
166 				 * by calling get_line() in the following
167 				 * 'for' loop. */
168 				scrollok(box, TRUE);
169 				wscrl(box, -1);	/* Scroll box region down one line */
170 				scrollok(box, FALSE);
171 				page_length = 0;
172 				passed_end = 0;
173 				for (i = 0; i < boxh; i++) {
174 					if (!i) {
175 						/* print first line of page */
176 						print_line(box, 0, boxw);
177 						wnoutrefresh(box);
178 					} else
179 						/* Called to update 'end_reached' and 'page' */
180 						get_line();
181 					if (!passed_end)
182 						page_length++;
183 					if (end_reached && !passed_end)
184 						passed_end = 1;
185 				}
186 
187 				print_position(dialog);
188 				wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
189 				wrefresh(dialog);
190 			}
191 			break;
192 		case 'B':	/* Previous page */
193 		case 'b':
194 		case 'u':
195 		case KEY_PPAGE:
196 			if (begin_reached)
197 				break;
198 			back_lines(page_length + boxh);
199 			refresh_text_box(dialog, box, boxh, boxw,
200 					 cur_y, cur_x);
201 			break;
202 		case 'J':	/* Next line */
203 		case 'j':
204 		case KEY_DOWN:
205 			if (!end_reached) {
206 				begin_reached = 0;
207 				scrollok(box, TRUE);
208 				scroll(box);	/* Scroll box region up one line */
209 				scrollok(box, FALSE);
210 				print_line(box, boxh - 1, boxw);
211 				wnoutrefresh(box);
212 				print_position(dialog);
213 				wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
214 				wrefresh(dialog);
215 			}
216 			break;
217 		case KEY_NPAGE:	/* Next page */
218 		case ' ':
219 		case 'd':
220 			if (end_reached)
221 				break;
222 
223 			begin_reached = 0;
224 			refresh_text_box(dialog, box, boxh, boxw,
225 					 cur_y, cur_x);
226 			break;
227 		case '0':	/* Beginning of line */
228 		case 'H':	/* Scroll left */
229 		case 'h':
230 		case KEY_LEFT:
231 			if (hscroll <= 0)
232 				break;
233 
234 			if (key == '0')
235 				hscroll = 0;
236 			else
237 				hscroll--;
238 			/* Reprint current page to scroll horizontally */
239 			back_lines(page_length);
240 			refresh_text_box(dialog, box, boxh, boxw,
241 					 cur_y, cur_x);
242 			break;
243 		case 'L':	/* Scroll right */
244 		case 'l':
245 		case KEY_RIGHT:
246 			if (hscroll >= MAX_LEN)
247 				break;
248 			hscroll++;
249 			/* Reprint current page to scroll horizontally */
250 			back_lines(page_length);
251 			refresh_text_box(dialog, box, boxh, boxw,
252 					 cur_y, cur_x);
253 			break;
254 		case KEY_ESC:
255 			key = on_key_esc(dialog);
256 			break;
257 		case KEY_RESIZE:
258 			back_lines(height);
259 			delwin(box);
260 			delwin(dialog);
261 			on_key_resize();
262 			goto do_resize;
263 		}
264 	}
265 	delwin(box);
266 	delwin(dialog);
267 	return key;		/* ESC pressed */
268 }
269 
270 /*
271  * Go back 'n' lines in text. Called by dialog_textbox().
272  * 'page' will be updated to point to the desired line in 'buf'.
273  */
274 static void back_lines(int n)
275 {
276 	int i;
277 
278 	begin_reached = 0;
279 	/* Go back 'n' lines */
280 	for (i = 0; i < n; i++) {
281 		if (*page == '\0') {
282 			if (end_reached) {
283 				end_reached = 0;
284 				continue;
285 			}
286 		}
287 		if (page == buf) {
288 			begin_reached = 1;
289 			return;
290 		}
291 		page--;
292 		do {
293 			if (page == buf) {
294 				begin_reached = 1;
295 				return;
296 			}
297 			page--;
298 		} while (*page != '\n');
299 		page++;
300 	}
301 }
302 
303 /*
304  * Print a new page of text. Called by dialog_textbox().
305  */
306 static void print_page(WINDOW * win, int height, int width)
307 {
308 	int i, passed_end = 0;
309 
310 	page_length = 0;
311 	for (i = 0; i < height; i++) {
312 		print_line(win, i, width);
313 		if (!passed_end)
314 			page_length++;
315 		if (end_reached && !passed_end)
316 			passed_end = 1;
317 	}
318 	wnoutrefresh(win);
319 }
320 
321 /*
322  * Print a new line of text. Called by dialog_textbox() and print_page().
323  */
324 static void print_line(WINDOW * win, int row, int width)
325 {
326 	char *line;
327 
328 	line = get_line();
329 	line += MIN(strlen(line), hscroll);	/* Scroll horizontally */
330 	wmove(win, row, 0);	/* move cursor to correct line */
331 	waddch(win, ' ');
332 	waddnstr(win, line, MIN(strlen(line), width - 2));
333 
334 	/* Clear 'residue' of previous line */
335 #if OLD_NCURSES
336 	{
337 		int x = getcurx(win);
338 		int i;
339 		for (i = 0; i < width - x; i++)
340 			waddch(win, ' ');
341 	}
342 #else
343 	wclrtoeol(win);
344 #endif
345 }
346 
347 /*
348  * Return current line of text. Called by dialog_textbox() and print_line().
349  * 'page' should point to start of current line before calling, and will be
350  * updated to point to start of next line.
351  */
352 static char *get_line(void)
353 {
354 	int i = 0;
355 	static char line[MAX_LEN + 1];
356 
357 	end_reached = 0;
358 	while (*page != '\n') {
359 		if (*page == '\0') {
360 			if (!end_reached) {
361 				end_reached = 1;
362 				break;
363 			}
364 		} else if (i < MAX_LEN)
365 			line[i++] = *(page++);
366 		else {
367 			/* Truncate lines longer than MAX_LEN characters */
368 			if (i == MAX_LEN)
369 				line[i++] = '\0';
370 			page++;
371 		}
372 	}
373 	if (i <= MAX_LEN)
374 		line[i] = '\0';
375 	if (!end_reached)
376 		page++;		/* move pass '\n' */
377 
378 	return line;
379 }
380 
381 /*
382  * Print current position
383  */
384 static void print_position(WINDOW * win)
385 {
386 	int percent;
387 
388 	wattrset(win, dlg.position_indicator.atr);
389 	wbkgdset(win, dlg.position_indicator.atr & A_COLOR);
390 	percent = (page - buf) * 100 / strlen(buf);
391 	wmove(win, getmaxy(win) - 3, getmaxx(win) - 9);
392 	wprintw(win, "(%3d%%)", percent);
393 }
394