File: /usr/src/linux/drivers/char/selection.c
1 /*
2 * linux/drivers/char/selection.c
3 *
4 * This module exports the functions:
5 *
6 * 'int set_selection(const unsigned long arg)'
7 * 'void clear_selection(void)'
8 * 'int paste_selection(struct tty_struct *tty)'
9 * 'int sel_loadlut(const unsigned long arg)'
10 *
11 * Now that /dev/vcs exists, most of this can disappear again.
12 */
13
14 #include <linux/module.h>
15 #include <linux/tty.h>
16 #include <linux/sched.h>
17 #include <linux/mm.h>
18 #include <linux/slab.h>
19 #include <linux/types.h>
20
21 #include <asm/uaccess.h>
22
23 #include <linux/vt_kern.h>
24 #include <linux/consolemap.h>
25 #include <linux/console_struct.h>
26 #include <linux/selection.h>
27
28 #ifndef MIN
29 #define MIN(a,b) ((a) < (b) ? (a) : (b))
30 #endif
31
32 /* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
33 #define isspace(c) ((c) == ' ')
34
35 extern void poke_blanked_console(void);
36
37 /* Variables for selection control. */
38 /* Use a dynamic buffer, instead of static (Dec 1994) */
39 int sel_cons; /* must not be disallocated */
40 static volatile int sel_start = -1; /* cleared by clear_selection */
41 static int sel_end;
42 static int sel_buffer_lth;
43 static char *sel_buffer;
44
45 /* clear_selection, highlight and highlight_pointer can be called
46 from interrupt (via scrollback/front) */
47
48 /* set reverse video on characters s-e of console with selection. */
49 inline static void
50 highlight(const int s, const int e) {
51 invert_screen(sel_cons, s, e-s+2, 1);
52 }
53
54 /* use complementary color to show the pointer */
55 inline static void
56 highlight_pointer(const int where) {
57 complement_pos(sel_cons, where);
58 }
59
60 static unsigned char
61 sel_pos(int n)
62 {
63 return inverse_translate(vc_cons[sel_cons].d, screen_glyph(sel_cons, n));
64 }
65
66 /* remove the current selection highlight, if any,
67 from the console holding the selection. */
68 void
69 clear_selection(void) {
70 highlight_pointer(-1); /* hide the pointer */
71 if (sel_start != -1) {
72 highlight(sel_start, sel_end);
73 sel_start = -1;
74 }
75 }
76
77 /*
78 * User settable table: what characters are to be considered alphabetic?
79 * 256 bits
80 */
81 static u32 inwordLut[8]={
82 0x00000000, /* control chars */
83 0x03FF0000, /* digits */
84 0x87FFFFFE, /* uppercase and '_' */
85 0x07FFFFFE, /* lowercase */
86 0x00000000,
87 0x00000000,
88 0xFF7FFFFF, /* latin-1 accented letters, not multiplication sign */
89 0xFF7FFFFF /* latin-1 accented letters, not division sign */
90 };
91
92 static inline int inword(const unsigned char c) {
93 return ( inwordLut[c>>5] >> (c & 0x1F) ) & 1;
94 }
95
96 /* set inwordLut contents. Invoked by ioctl(). */
97 int sel_loadlut(const unsigned long arg)
98 {
99 return copy_from_user(inwordLut, (u32 *)(arg+4), 32) ? -EFAULT : 0;
100 }
101
102 /* does screen address p correspond to character at LH/RH edge of screen? */
103 static inline int atedge(const int p, int size_row)
104 {
105 return (!(p % size_row) || !((p + 2) % size_row));
106 }
107
108 /* constrain v such that v <= u */
109 static inline unsigned short limit(const unsigned short v, const unsigned short u)
110 {
111 return (v > u) ? u : v;
112 }
113
114 /* set the current selection. Invoked by ioctl() or by kernel code. */
115 int set_selection(const unsigned long arg, struct tty_struct *tty, int user)
116 {
117 int sel_mode, new_sel_start, new_sel_end, spc;
118 char *bp, *obp;
119 int i, ps, pe;
120 unsigned int currcons = fg_console;
121
122 unblank_screen();
123 poke_blanked_console();
124
125 { unsigned short *args, xs, ys, xe, ye;
126
127 args = (unsigned short *)(arg + 1);
128 if (user) {
129 if (verify_area(VERIFY_READ, args, sizeof(short) * 5))
130 return -EFAULT;
131 __get_user(xs, args++);
132 __get_user(ys, args++);
133 __get_user(xe, args++);
134 __get_user(ye, args++);
135 __get_user(sel_mode, args);
136 } else {
137 xs = *(args++); /* set selection from kernel */
138 ys = *(args++);
139 xe = *(args++);
140 ye = *(args++);
141 sel_mode = *args;
142 }
143 xs--; ys--; xe--; ye--;
144 xs = limit(xs, video_num_columns - 1);
145 ys = limit(ys, video_num_lines - 1);
146 xe = limit(xe, video_num_columns - 1);
147 ye = limit(ye, video_num_lines - 1);
148 ps = ys * video_size_row + (xs << 1);
149 pe = ye * video_size_row + (xe << 1);
150
151 if (sel_mode == 4) {
152 /* useful for screendump without selection highlights */
153 clear_selection();
154 return 0;
155 }
156
157 if (mouse_reporting() && (sel_mode & 16)) {
158 mouse_report(tty, sel_mode & 15, xs, ys);
159 return 0;
160 }
161 }
162
163 if (ps > pe) /* make sel_start <= sel_end */
164 {
165 int tmp = ps;
166 ps = pe;
167 pe = tmp;
168 }
169
170 if (sel_cons != fg_console) {
171 clear_selection();
172 sel_cons = fg_console;
173 }
174
175 switch (sel_mode)
176 {
177 case 0: /* character-by-character selection */
178 new_sel_start = ps;
179 new_sel_end = pe;
180 break;
181 case 1: /* word-by-word selection */
182 spc = isspace(sel_pos(ps));
183 for (new_sel_start = ps; ; ps -= 2)
184 {
185 if ((spc && !isspace(sel_pos(ps))) ||
186 (!spc && !inword(sel_pos(ps))))
187 break;
188 new_sel_start = ps;
189 if (!(ps % video_size_row))
190 break;
191 }
192 spc = isspace(sel_pos(pe));
193 for (new_sel_end = pe; ; pe += 2)
194 {
195 if ((spc && !isspace(sel_pos(pe))) ||
196 (!spc && !inword(sel_pos(pe))))
197 break;
198 new_sel_end = pe;
199 if (!((pe + 2) % video_size_row))
200 break;
201 }
202 break;
203 case 2: /* line-by-line selection */
204 new_sel_start = ps - ps % video_size_row;
205 new_sel_end = pe + video_size_row
206 - pe % video_size_row - 2;
207 break;
208 case 3:
209 highlight_pointer(pe);
210 return 0;
211 default:
212 return -EINVAL;
213 }
214
215 /* remove the pointer */
216 highlight_pointer(-1);
217
218 /* select to end of line if on trailing space */
219 if (new_sel_end > new_sel_start &&
220 !atedge(new_sel_end, video_size_row) &&
221 isspace(sel_pos(new_sel_end))) {
222 for (pe = new_sel_end + 2; ; pe += 2)
223 if (!isspace(sel_pos(pe)) ||
224 atedge(pe, video_size_row))
225 break;
226 if (isspace(sel_pos(pe)))
227 new_sel_end = pe;
228 }
229 if (sel_start == -1) /* no current selection */
230 highlight(new_sel_start, new_sel_end);
231 else if (new_sel_start == sel_start)
232 {
233 if (new_sel_end == sel_end) /* no action required */
234 return 0;
235 else if (new_sel_end > sel_end) /* extend to right */
236 highlight(sel_end + 2, new_sel_end);
237 else /* contract from right */
238 highlight(new_sel_end + 2, sel_end);
239 }
240 else if (new_sel_end == sel_end)
241 {
242 if (new_sel_start < sel_start) /* extend to left */
243 highlight(new_sel_start, sel_start - 2);
244 else /* contract from left */
245 highlight(sel_start, new_sel_start - 2);
246 }
247 else /* some other case; start selection from scratch */
248 {
249 clear_selection();
250 highlight(new_sel_start, new_sel_end);
251 }
252 sel_start = new_sel_start;
253 sel_end = new_sel_end;
254
255 /* Allocate a new buffer before freeing the old one ... */
256 bp = kmalloc((sel_end-sel_start)/2+1, GFP_KERNEL);
257 if (!bp) {
258 printk(KERN_WARNING "selection: kmalloc() failed\n");
259 clear_selection();
260 return -ENOMEM;
261 }
262 if (sel_buffer)
263 kfree(sel_buffer);
264 sel_buffer = bp;
265
266 obp = bp;
267 for (i = sel_start; i <= sel_end; i += 2) {
268 *bp = sel_pos(i);
269 if (!isspace(*bp++))
270 obp = bp;
271 if (! ((i + 2) % video_size_row)) {
272 /* strip trailing blanks from line and add newline,
273 unless non-space at end of line. */
274 if (obp != bp) {
275 bp = obp;
276 *bp++ = '\r';
277 }
278 obp = bp;
279 }
280 }
281 sel_buffer_lth = bp - sel_buffer;
282 return 0;
283 }
284
285 /* Insert the contents of the selection buffer into the
286 * queue of the tty associated with the current console.
287 * Invoked by ioctl().
288 */
289 int paste_selection(struct tty_struct *tty)
290 {
291 struct vt_struct *vt = (struct vt_struct *) tty->driver_data;
292 int pasted = 0, count;
293 DECLARE_WAITQUEUE(wait, current);
294
295 poke_blanked_console();
296 add_wait_queue(&vt->paste_wait, &wait);
297 while (sel_buffer && sel_buffer_lth > pasted) {
298 set_current_state(TASK_INTERRUPTIBLE);
299 if (test_bit(TTY_THROTTLED, &tty->flags)) {
300 schedule();
301 continue;
302 }
303 count = sel_buffer_lth - pasted;
304 count = MIN(count, tty->ldisc.receive_room(tty));
305 tty->ldisc.receive_buf(tty, sel_buffer + pasted, 0, count);
306 pasted += count;
307 }
308 remove_wait_queue(&vt->paste_wait, &wait);
309 current->state = TASK_RUNNING;
310 return 0;
311 }
312
313 EXPORT_SYMBOL(set_selection);
314 EXPORT_SYMBOL(paste_selection);
315