1 /*
2  *  textbox.c -- implements the text box
3  *
4  *  ORIGINAL AUTHOR: Savio Lam ([email protected])
5  *  MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap ([email protected])
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, int height, int width);
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  * Display text from a file in a dialog box.
37  */
38 int dialog_textbox(const char *title, const char *tbuf, int height, int width)
39 {
40 	int i, x, y, cur_x, cur_y, key = 0;
41 	int texth, textw;
42 	int passed_end;
43 	WINDOW *dialog, *text;
44 
45 	begin_reached = 1;
46 	end_reached = 0;
47 	page_length = 0;
48 	hscroll = 0;
49 	buf = tbuf;
50 	page = buf;	/* page is pointer to start of page to be displayed */
51 
52 	/* center dialog box on screen */
53 	x = (COLS - width) / 2;
54 	y = (LINES - height) / 2;
55 
56 	draw_shadow(stdscr, y, x, height, width);
57 
58 	dialog = newwin(height, width, y, x);
59 	keypad(dialog, TRUE);
60 
61 	/* Create window for text region, used for scrolling text */
62 	texth = height - 4;
63 	textw = width - 2;
64 	text = subwin(dialog, texth, textw, y + 1, x + 1);
65 	wattrset(text, dlg.dialog.atr);
66 	wbkgdset(text, dlg.dialog.atr & A_COLOR);
67 
68 	keypad(text, TRUE);
69 
70 	/* register the new window, along with its borders */
71 	draw_box(dialog, 0, 0, height, width,
72 		 dlg.dialog.atr, dlg.border.atr);
73 
74 	wattrset(dialog, dlg.border.atr);
75 	mvwaddch(dialog, height - 3, 0, ACS_LTEE);
76 	for (i = 0; i < width - 2; i++)
77 		waddch(dialog, ACS_HLINE);
78 	wattrset(dialog, dlg.dialog.atr);
79 	wbkgdset(dialog, dlg.dialog.atr & A_COLOR);
80 	waddch(dialog, ACS_RTEE);
81 
82 	print_title(dialog, title, width);
83 
84 	print_button(dialog, " Exit ", height - 2, width / 2 - 4, TRUE);
85 	wnoutrefresh(dialog);
86 	getyx(dialog, cur_y, cur_x);	/* Save cursor position */
87 
88 	/* Print first page of text */
89 	attr_clear(text, texth, textw, dlg.dialog.atr);
90 	print_page(text, texth, textw);
91 	print_position(dialog, height, width);
92 	wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
93 	wrefresh(dialog);
94 
95 	while ((key != ESC) && (key != '\n')) {
96 		key = wgetch(dialog);
97 		switch (key) {
98 		case 'E':	/* Exit */
99 		case 'e':
100 		case 'X':
101 		case 'x':
102 			delwin(text);
103 			delwin(dialog);
104 			return 0;
105 		case 'g':	/* First page */
106 		case KEY_HOME:
107 			if (!begin_reached) {
108 				begin_reached = 1;
109 				page = buf;
110 				print_page(text, texth, textw);
111 				print_position(dialog, height, width);
112 				wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
113 				wrefresh(dialog);
114 			}
115 			break;
116 		case 'G':	/* Last page */
117 		case KEY_END:
118 
119 			end_reached = 1;
120 			/* point to last char in buf */
121 			page = buf + strlen(buf);
122 			back_lines(texth);
123 			print_page(text, texth, textw);
124 			print_position(dialog, height, width);
125 			wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
126 			wrefresh(dialog);
127 			break;
128 		case 'K':	/* Previous line */
129 		case 'k':
130 		case KEY_UP:
131 			if (!begin_reached) {
132 				back_lines(page_length + 1);
133 
134 				/* We don't call print_page() here but use
135 				 * scrolling to ensure faster screen update.
136 				 * However, 'end_reached' and 'page_length'
137 				 * should still be updated, and 'page' should
138 				 * point to start of next page. This is done
139 				 * by calling get_line() in the following
140 				 * 'for' loop. */
141 				scrollok(text, TRUE);
142 				wscrl(text, -1);	/* Scroll text region down one line */
143 				scrollok(text, FALSE);
144 				page_length = 0;
145 				passed_end = 0;
146 				for (i = 0; i < texth; i++) {
147 					if (!i) {
148 						/* print first line of page */
149 						print_line(text, 0, textw);
150 						wnoutrefresh(text);
151 					} else
152 						/* Called to update 'end_reached' and 'page' */
153 						get_line();
154 					if (!passed_end)
155 						page_length++;
156 					if (end_reached && !passed_end)
157 						passed_end = 1;
158 				}
159 
160 				print_position(dialog, height, width);
161 				wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
162 				wrefresh(dialog);
163 			}
164 			break;
165 		case 'B':	/* Previous page */
166 		case 'b':
167 		case KEY_PPAGE:
168 			if (begin_reached)
169 				break;
170 			back_lines(page_length + texth);
171 			print_page(text, texth, textw);
172 			print_position(dialog, height, width);
173 			wmove(dialog, cur_y, cur_x);
174 			wrefresh(dialog);
175 			break;
176 		case 'J':	/* Next line */
177 		case 'j':
178 		case KEY_DOWN:
179 			if (!end_reached) {
180 				begin_reached = 0;
181 				scrollok(text, TRUE);
182 				scroll(text);	/* Scroll text region up one line */
183 				scrollok(text, FALSE);
184 				print_line(text, texth - 1, textw);
185 				wnoutrefresh(text);
186 				print_position(dialog, height, width);
187 				wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
188 				wrefresh(dialog);
189 			}
190 			break;
191 		case KEY_NPAGE:	/* Next page */
192 		case ' ':
193 			if (end_reached)
194 				break;
195 
196 			begin_reached = 0;
197 			print_page(text, texth, textw);
198 			print_position(dialog, height, width);
199 			wmove(dialog, cur_y, cur_x);
200 			wrefresh(dialog);
201 			break;
202 		case '0':	/* Beginning of line */
203 		case 'H':	/* Scroll left */
204 		case 'h':
205 		case KEY_LEFT:
206 			if (hscroll <= 0)
207 				break;
208 
209 			if (key == '0')
210 				hscroll = 0;
211 			else
212 				hscroll--;
213 			/* Reprint current page to scroll horizontally */
214 			back_lines(page_length);
215 			print_page(text, texth, textw);
216 			wmove(dialog, cur_y, cur_x);
217 			wrefresh(dialog);
218 			break;
219 		case 'L':	/* Scroll right */
220 		case 'l':
221 		case KEY_RIGHT:
222 			if (hscroll >= MAX_LEN)
223 				break;
224 			hscroll++;
225 			/* Reprint current page to scroll horizontally */
226 			back_lines(page_length);
227 			print_page(text, texth, textw);
228 			wmove(dialog, cur_y, cur_x);
229 			wrefresh(dialog);
230 			break;
231 		case ESC:
232 			break;
233 		}
234 	}
235 	delwin(text);
236 	delwin(dialog);
237 	return 255;		/* ESC pressed */
238 }
239 
240 /*
241  * Go back 'n' lines in text. Called by dialog_textbox().
242  * 'page' will be updated to point to the desired line in 'buf'.
243  */
244 static void back_lines(int n)
245 {
246 	int i;
247 
248 	begin_reached = 0;
249 	/* Go back 'n' lines */
250 	for (i = 0; i < n; i++) {
251 		if (*page == '\0') {
252 			if (end_reached) {
253 				end_reached = 0;
254 				continue;
255 			}
256 		}
257 		if (page == buf) {
258 			begin_reached = 1;
259 			return;
260 		}
261 		page--;
262 		do {
263 			if (page == buf) {
264 				begin_reached = 1;
265 				return;
266 			}
267 			page--;
268 		} while (*page != '\n');
269 		page++;
270 	}
271 }
272 
273 /*
274  * Print a new page of text. Called by dialog_textbox().
275  */
276 static void print_page(WINDOW * win, int height, int width)
277 {
278 	int i, passed_end = 0;
279 
280 	page_length = 0;
281 	for (i = 0; i < height; i++) {
282 		print_line(win, i, width);
283 		if (!passed_end)
284 			page_length++;
285 		if (end_reached && !passed_end)
286 			passed_end = 1;
287 	}
288 	wnoutrefresh(win);
289 }
290 
291 /*
292  * Print a new line of text. Called by dialog_textbox() and print_page().
293  */
294 static void print_line(WINDOW * win, int row, int width)
295 {
296 	int y, x;
297 	char *line;
298 
299 	line = get_line();
300 	line += MIN(strlen(line), hscroll);	/* Scroll horizontally */
301 	wmove(win, row, 0);	/* move cursor to correct line */
302 	waddch(win, ' ');
303 	waddnstr(win, line, MIN(strlen(line), width - 2));
304 
305 	getyx(win, y, x);
306 	/* Clear 'residue' of previous line */
307 #if OLD_NCURSES
308 	{
309 		int i;
310 		for (i = 0; i < width - x; i++)
311 			waddch(win, ' ');
312 	}
313 #else
314 	wclrtoeol(win);
315 #endif
316 }
317 
318 /*
319  * Return current line of text. Called by dialog_textbox() and print_line().
320  * 'page' should point to start of current line before calling, and will be
321  * updated to point to start of next line.
322  */
323 static char *get_line(void)
324 {
325 	int i = 0;
326 	static char line[MAX_LEN + 1];
327 
328 	end_reached = 0;
329 	while (*page != '\n') {
330 		if (*page == '\0') {
331 			if (!end_reached) {
332 				end_reached = 1;
333 				break;
334 			}
335 		} else if (i < MAX_LEN)
336 			line[i++] = *(page++);
337 		else {
338 			/* Truncate lines longer than MAX_LEN characters */
339 			if (i == MAX_LEN)
340 				line[i++] = '\0';
341 			page++;
342 		}
343 	}
344 	if (i <= MAX_LEN)
345 		line[i] = '\0';
346 	if (!end_reached)
347 		page++;		/* move pass '\n' */
348 
349 	return line;
350 }
351 
352 /*
353  * Print current position
354  */
355 static void print_position(WINDOW * win, int height, int width)
356 {
357 	int percent;
358 
359 	wattrset(win, dlg.position_indicator.atr);
360 	wbkgdset(win, dlg.position_indicator.atr & A_COLOR);
361 	percent = (page - buf) * 100 / strlen(buf);
362 	wmove(win, height - 3, width - 9);
363 	wprintw(win, "(%3d%%)", percent);
364 }
365