drivers/staging/speakup/selection.c

   1 #include <linux/slab.h> /* for kmalloc */
   2 #include <linux/consolemap.h>
   3 #include <linux/interrupt.h>
   4 #include <linux/sched.h>
   5 #include <linux/selection.h>
   6
   7 #include "speakup.h"
   8
   9 /* ------ cut and paste ----- */
  10 /* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
  11 #define ishardspace(c)      ((c) == ' ')
  12
  13 unsigned short xs, ys, xe, ye; /* our region points */
  14
  15 /* Variables for selection control. */
  16 /* must not be disallocated */
  17 struct vc_data *spk_sel_cons;
  18 /* cleared by clear_selection */
  19 static int sel_start = -1;
  20 static int sel_end;
  21 static int sel_buffer_lth;
  22 static char *sel_buffer;
  23
  24 static unsigned char sel_pos(int n)
  25 {
  26         return inverse_translate(spk_sel_cons,
  27                 screen_glyph(spk_sel_cons, n), 0);
  28 }
  29
  30 void speakup_clear_selection(void)
  31 {
  32         sel_start = -1;
  33 }
  34
  35 /* does screen address p correspond to character at LH/RH edge of screen? */
  36 static int atedge(const int p, int size_row)
  37 {
  38         return !(p % size_row) || !((p + 2) % size_row);
  39 }
  40
  41 /* constrain v such that v <= u */
  42 static unsigned short limit(const unsigned short v, const unsigned short u)
  43 {
  44         return (v > u) ? u : v;
  45 }
  46
  47 int speakup_set_selection(struct tty_struct *tty)
  48 {
  49         int new_sel_start, new_sel_end;
  50         char *bp, *obp;
  51         int i, ps, pe;
  52         struct vc_data *vc = vc_cons[fg_console].d;
  53
  54         xs = limit(xs, vc->vc_cols - 1);
  55         ys = limit(ys, vc->vc_rows - 1);
  56         xe = limit(xe, vc->vc_cols - 1);
  57         ye = limit(ye, vc->vc_rows - 1);
  58         ps = ys * vc->vc_size_row + (xs << 1);
  59         pe = ye * vc->vc_size_row + (xe << 1);
  60
  61         if (ps > pe) {
  62                 /* make sel_start <= sel_end */
  63                 int tmp = ps;
  64                 ps = pe;
  65                 pe = tmp;
  66         }
  67
  68         if (spk_sel_cons != vc_cons[fg_console].d) {
  69                 speakup_clear_selection();
  70                 spk_sel_cons = vc_cons[fg_console].d;
  71                 dev_warn(tty->dev,
  72                         "Selection: mark console not the same as cut\n");
  73                 return -EINVAL;
  74         }
  75
  76         new_sel_start = ps;
  77         new_sel_end = pe;
  78
  79         /* select to end of line if on trailing space */
  80         if (new_sel_end > new_sel_start &&
  81             !atedge(new_sel_end, vc->vc_size_row) &&
  82             ishardspace(sel_pos(new_sel_end))) {
  83                 for (pe = new_sel_end + 2; ; pe += 2)
  84                         if (!ishardspace(sel_pos(pe)) ||
  85                             atedge(pe, vc->vc_size_row))
  86                                 break;
  87                 if (ishardspace(sel_pos(pe)))
  88                         new_sel_end = pe;
  89         }
  90         if ((new_sel_start == sel_start) && (new_sel_end == sel_end))
  91                 return 0; /* no action required */
  92
  93         sel_start = new_sel_start;
  94         sel_end = new_sel_end;
  95         /* Allocate a new buffer before freeing the old one ... */
  96         bp = kmalloc((sel_end-sel_start)/2+1, GFP_ATOMIC);
  97         if (!bp) {
  98                 dev_warn(tty->dev, "selection: kmalloc() failed\n");
  99                 speakup_clear_selection();
 100                 return -ENOMEM;
 101         }
 102         kfree(sel_buffer);
 103         sel_buffer = bp;
 104
 105         obp = bp;
 106         for (i = sel_start; i <= sel_end; i += 2) {
 107                 *bp = sel_pos(i);
 108                 if (!ishardspace(*bp++))
 109                         obp = bp;
 110                 if (!((i + 2) % vc->vc_size_row)) {
 111                         /* strip trailing blanks from line and add newline,
 112                            unless non-space at end of line. */
 113                         if (obp != bp) {
 114                                 bp = obp;
 115                                 *bp++ = '\r';
 116                         }
 117                         obp = bp;
 118                 }
 119         }
 120         sel_buffer_lth = bp - sel_buffer;
 121         return 0;
 122 }
 123
 124 /* TODO: move to some helper thread, probably.  That'd fix having to check for
 125  * in_atomic().  */
 126 int speakup_paste_selection(struct tty_struct *tty)
 127 {
 128         struct vc_data *vc = (struct vc_data *) tty->driver_data;
 129         int pasted = 0, count;
 130         DECLARE_WAITQUEUE(wait, current);
 131         add_wait_queue(&vc->paste_wait, &wait);
 132         while (sel_buffer && sel_buffer_lth > pasted) {
 133                 set_current_state(TASK_INTERRUPTIBLE);
 134                 if (test_bit(TTY_THROTTLED, &tty->flags)) {
 135                         if (in_atomic())
 136                                 /* if we are in an interrupt handler, abort */
 137                                 break;
 138                         schedule();
 139                         continue;
 140                 }
 141                 count = sel_buffer_lth - pasted;
 142                 count = min_t(int, count, tty->receive_room);
 143                 tty->ldisc->ops->receive_buf(tty, sel_buffer + pasted,
 144                         NULL, count);
 145                 pasted += count;
 146         }
 147         remove_wait_queue(&vc->paste_wait, &wait);
 148         current->state = TASK_RUNNING;
 149         return 0;
 150 }
 151