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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  */
refresh_text_box(WINDOW * dialog,WINDOW * box,int boxh,int boxw,int cur_y,int cur_x)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  */
dialog_textbox(const char * title,const char * tbuf,int initial_height,int initial_width)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, " 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  */
back_lines(int n)271 static 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  */
print_page(WINDOW * win,int height,int width)303 static 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  */
print_line(WINDOW * win,int row,int width)321 static 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  */
get_line(void)350 static 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  */
print_position(WINDOW * win)382 static 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