Root/scripts/kconfig/lxdialog/textbox.c

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, 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            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

Archive Download this file



interactive