mp_fifo.c

   1 /*
   2  * This file is part of MPlayer.
   3  *
   4  * MPlayer is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * MPlayer is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #include <stdlib.h>
  20 #include <assert.h>
  21 #include <stdbool.h>
  22 #include "osdep/timer.h"
  23 #include "input/input.h"
  24 #include "input/keycodes.h"
  25 #include "mp_fifo.h"
  26 #include "talloc.h"
  27 #include "options.h"
  28
  29
  30 struct mp_fifo {
  31     struct MPOpts *opts;
  32     int *data;
  33     int readpos;
  34     int size;
  35     int num_entries;
  36     int max_up;
  37     int num_up;
  38     int last_key_down;
  39     unsigned last_down_time;
  40 };
  41
  42 struct mp_fifo *mp_fifo_create(struct MPOpts *opts)
  43 {
  44     struct mp_fifo *fifo = talloc_zero(NULL, struct mp_fifo);
  45     fifo->opts = opts;
  46     /* Typical mouse wheel use will generate a sequence repeating 3 events:
  47      * down, doubleclick, up, down, doubleclick, up, ...
  48      * Normally only one of those event types triggers a command,
  49      * so allow opts->key_fifo_size such repeats.
  50      */
  51     fifo->max_up = opts->key_fifo_size;
  52     fifo->size = opts->key_fifo_size * 3;
  53     fifo->data = talloc_array_ptrtype(fifo, fifo->data, fifo->size);
  54     return fifo;
  55 }
  56
  57 static bool is_up(int code)
  58 {
  59     return code > 0 && !(code & MP_KEY_DOWN)
  60         && !(code >= MOUSE_BTN0_DBL && code < MOUSE_BTN_DBL_END);
  61 }
  62
  63 static int fifo_peek(struct mp_fifo *fifo, int offset)
  64 {
  65     return fifo->data[(fifo->readpos + offset) % fifo->size];
  66 }
  67
  68 static int fifo_read(struct mp_fifo *fifo)
  69 {
  70     int code = fifo_peek(fifo, 0);
  71     fifo->readpos += 1;
  72     fifo->readpos %= fifo->size;
  73     fifo->num_entries--;
  74     fifo->num_up -= is_up(code);
  75     assert(fifo->num_entries >= 0);
  76     assert(fifo->num_up >= 0);
  77     return code;
  78 }
  79
  80 static void fifo_write(struct mp_fifo *fifo, int code)
  81 {
  82     fifo->data[(fifo->readpos + fifo->num_entries) % fifo->size] = code;
  83     fifo->num_entries++;
  84     fifo->num_up += is_up(code);
  85     assert(fifo->num_entries <= fifo->size);
  86     assert(fifo->num_up <= fifo->max_up);
  87 }
  88
  89 static void mplayer_put_key_internal(struct mp_fifo *fifo, int code)
  90 {
  91     // Clear key-down state if we're forced to drop entries
  92     if (fifo->num_entries >= fifo->size - 1
  93         || fifo->num_up >= fifo->max_up) {
  94         if (fifo_peek(fifo, fifo->num_entries - 1) != MP_INPUT_RELEASE_ALL)
  95             fifo_write(fifo, MP_INPUT_RELEASE_ALL);
  96     } else
  97         fifo_write(fifo, code);
  98 }
  99
 100 int mplayer_get_key(void *ctx, int fd)
 101 {
 102     struct mp_fifo *fifo = ctx;
 103     if (!fifo->num_entries)
 104         return MP_INPUT_NOTHING;
 105     return fifo_read(fifo);
 106 }
 107
 108 static void put_double(struct mp_fifo *fifo, int code)
 109 {
 110   if (code >= MOUSE_BTN0 && code < MOUSE_BTN_END)
 111       mplayer_put_key_internal(fifo, code - MOUSE_BTN0 + MOUSE_BTN0_DBL);
 112 }
 113
 114 void mplayer_put_key(struct mp_fifo *fifo, int code)
 115 {
 116     unsigned now = GetTimerMS();
 117     int doubleclick_time = fifo->opts->doubleclick_time;
 118     // ignore system-doubleclick if we generate these events ourselves
 119     if (doubleclick_time
 120         && (code & ~MP_KEY_DOWN) >= MOUSE_BTN0_DBL
 121         && (code & ~MP_KEY_DOWN) < MOUSE_BTN_DBL_END)
 122         return;
 123     mplayer_put_key_internal(fifo, code);
 124     if (code & MP_KEY_DOWN) {
 125         code &= ~MP_KEY_DOWN;
 126         if (fifo->last_key_down == code
 127             && now - fifo->last_down_time < doubleclick_time)
 128             put_double(fifo, code);
 129         fifo->last_key_down = code;
 130         fifo->last_down_time = now;
 131     }
 132 }