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/device.h> /* for dev_warn */
   6 #include <linux/selection.h>
   7
   8 #include "speakup.h"
   9
  10 /* ------ cut and paste ----- */
  11 /* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
  12 #define ishardspace(c)      ((c) == ' ')
  13
  14 unsigned short xs, ys, xe, ye; /* our region points */
  15
  16 /* Variables for selection control. */
  17 /* must not be disallocated */
  18 struct vc_data *spk_sel_cons;
  19 /* cleared by clear_selection */
  20 static int sel_start = -1;
  21 static int sel_end;
  22 static int sel_buffer_lth;
  23 static char *sel_buffer;
  24
  25 static unsigned char sel_pos(int n)
  26 {
  27         return inverse_translate(spk_sel_cons,
  28                 screen_glyph(spk_sel_cons, n), 0);
  29 }
  30
  31 void speakup_clear_selection(void)
  32 {
  33         sel_start = -1;
  34 }
  35
  36 /* does screen address p correspond to character at LH/RH edge of screen? */
  37 static int atedge(const int p, int size_row)
  38 {
  39         return !(p % size_row) || !((p + 2) % size_row);
  40 }
  41
  42 /* constrain v such that v <= u */
  43 static unsigned short limit(const unsigned short v, const unsigned short u)
  44 {
  45         return (v > u) ? u : v;
  46 }
  47
  48 int speakup_set_selection(struct tty_struct *tty)
  49 {
  50         int new_sel_start, new_sel_end;
  51         char *bp, *obp;
  52         int i, ps, pe;
  53         struct vc_data *vc = vc_cons[fg_console].d;
  54
  55         xs = limit(xs, vc->vc_cols - 1);
  56         ys = limit(ys, vc->vc_rows - 1);
  57         xe = limit(xe, vc->vc_cols - 1);
  58         ye = limit(ye, vc->vc_rows - 1);
  59         ps = ys * vc->vc_size_row + (xs << 1);
  60         pe = ye * vc->vc_size_row + (xe << 1);
  61
  62         if (ps > pe) {
  63                 /* make sel_start <= sel_end */
  64                 int tmp = ps;
  65                 ps = pe;
  66                 pe = tmp;
  67         }
  68
  69         if (spk_sel_cons != vc_cons[fg_console].d) {
  70                 speakup_clear_selection();
  71                 spk_sel_cons = vc_cons[fg_console].d;
  72                 dev_warn(tty->dev,
  73                         "Selection: mark console not the same as cut\n");
  74                 return -EINVAL;
  75         }
  76
  77         new_sel_start = ps;
  78         new_sel_end = pe;
  79
  80         /* select to end of line if on trailing space */
  81         if (new_sel_end > new_sel_start &&
  82             !atedge(new_sel_end, vc->vc_size_row) &&
  83             ishardspace(sel_pos(new_sel_end))) {
  84                 for (pe = new_sel_end + 2; ; pe += 2)
  85                         if (!ishardspace(sel_pos(pe)) ||
  86                             atedge(pe, vc->vc_size_row))
  87                                 break;
  88                 if (ishardspace(sel_pos(pe)))
  89                         new_sel_end = pe;
  90         }
  91         if ((new_sel_start == sel_start) && (new_sel_end == sel_end))
  92                 return 0; /* no action required */
  93
  94         sel_start = new_sel_start;
  95         sel_end = new_sel_end;
  96         /* Allocate a new buffer before freeing the old one ... */
  97         bp = kmalloc((sel_end-sel_start)/2+1, GFP_ATOMIC);
  98         if (!bp) {
  99                 dev_warn(tty->dev, "selection: kmalloc() failed\n");
 100                 speakup_clear_selection();
 101                 return -ENOMEM;
 102         }
 103         kfree(sel_buffer);
 104         sel_buffer = bp;
 105
 106         obp = bp;
 107         for (i = sel_start; i <= sel_end; i += 2) {
 108                 *bp = sel_pos(i);
 109                 if (!ishardspace(*bp++))
 110                         obp = bp;
 111                 if (!((i + 2) % vc->vc_size_row)) {
 112                         /* strip trailing blanks from line and add newline,
 113                            unless non-space at end of line. */
 114                         if (obp != bp) {
 115                                 bp = obp;
 116                                 *bp++ = '\r';
 117                         }
 118                         obp = bp;
 119                 }
 120         }
 121         sel_buffer_lth = bp - sel_buffer;
 122         return 0;
 123 }
 124
 125 /* TODO: move to some helper thread, probably.  That'd fix having to check for
 126  * in_atomic().  */
 127 int speakup_paste_selection(struct tty_struct *tty)
 128 {
 129         struct vc_data *vc = (struct vc_data *) tty->driver_data;
 130         int pasted = 0, count;
 131         DECLARE_WAITQUEUE(wait, current);
 132         add_wait_queue(&vc->paste_wait, &wait);
 133         while (sel_buffer && sel_buffer_lth > pasted) {
 134                 set_current_state(TASK_INTERRUPTIBLE);
 135                 if (test_bit(TTY_THROTTLED, &tty->flags)) {
 136                         if (in_atomic())
 137                                 /* if we are in an interrupt handler, abort */
 138                                 break;
 139                         schedule();
 140                         continue;
 141                 }
 142                 count = sel_buffer_lth - pasted;
 143                 count = min_t(int, count, tty->receive_room);
 144                 tty->ldisc->ops->receive_buf(tty, sel_buffer + pasted,
 145                         NULL, count);
 146                 pasted += count;
 147         }
 148         remove_wait_queue(&vc->paste_wait, &wait);
 149         current->state = TASK_RUNNING;
 150         return 0;
 151 }
 152