keygrabber.c

   1 /*
   2  * keygrabber.c - key grabbing
   3  *
   4  * Copyright © 2008 Julien Danjou <julien@danjou.info>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  */
  21
  22 #include <unistd.h>
  23
  24 #include "structs.h"
  25 #include "keygrabber.h"
  26 #include "key.h"
  27 #include "common/xutil.h"
  28
  29 /** Grab the keyboard.
  30  * \return True if keyboard was grabbed.
  31  */
  32 static bool
  33 keygrabber_grab(void)
  34 {
  35     int i;
  36     xcb_grab_keyboard_reply_t *xgb;
  37
  38     for(i = 1000; i; i--)
  39     {
  40         if((xgb = xcb_grab_keyboard_reply(globalconf.connection,
  41                                           xcb_grab_keyboard(globalconf.connection, true,
  42                                                             xutil_screen_get(globalconf.connection,
  43                                                                                globalconf.default_screen)->root,
  44                                                             XCB_CURRENT_TIME, XCB_GRAB_MODE_ASYNC,
  45                                                             XCB_GRAB_MODE_ASYNC),
  46                                           NULL)))
  47         {
  48             p_delete(&xgb);
  49             return true;
  50         }
  51         usleep(1000);
  52     }
  53     return false;
  54 }
  55
  56 /** Handle keypress event.
  57  * \param L Lua stack to push the key pressed.
  58  * \param e Received XKeyEvent.
  59  * \return True if a key was succesfully get, false otherwise.
  60  */
  61 bool
  62 keygrabber_handlekpress(lua_State *L, xcb_key_press_event_t *e)
  63 {
  64     /* transfer event (keycode + modifiers) to keysym */
  65     xcb_keysym_t ksym = key_getkeysym(e->detail, e->state);
  66
  67     /* convert keysym to string */
  68     char buf[MAX(MB_LEN_MAX, 32)];
  69     if(!key_press_lookup_string(ksym, buf, countof(buf)))
  70         return false;
  71
  72     luaA_pushmodifiers(L, e->state);
  73
  74     lua_pushstring(L, buf);
  75
  76     switch(e->response_type)
  77     {
  78       case XCB_KEY_PRESS:
  79         lua_pushliteral(L, "press");
  80         break;
  81       case XCB_KEY_RELEASE:
  82         lua_pushliteral(L, "release");
  83         break;
  84     }
  85
  86     return true;
  87 }
  88
  89 /** Grab keyboard and read pressed keys, calling callback function at each key
  90  * pressed. The callback function must return a boolean value: true to
  91  * continue grabbing, false to stop.
  92  * The function is called with 3 arguments:
  93  * a table containing modifiers keys, a string with the key pressed and a
  94  * string with eithe "press" or "release" to indicate the event type.
  95  *
  96  * \param L The Lua VM state.
  97  * \return The number of elements pushed on stack.
  98  *
  99  * \luastack
 100  *
 101  * \lparam A callback function as described above.
 102  */
 103 static int
 104 luaA_keygrabber_run(lua_State *L)
 105 {
 106     if(globalconf.keygrabber != LUA_REFNIL)
 107         luaL_error(L, "keygrabber already running");
 108
 109     luaA_registerfct(L, 1, &globalconf.keygrabber);
 110
 111     if(!keygrabber_grab())
 112     {
 113         luaA_unregister(L, &globalconf.keygrabber);
 114         luaL_error(L, "unable to grab keyboard");
 115     }
 116
 117     return 0;
 118 }
 119
 120 /** Stop grabbing the keyboard.
 121  * \param L The Lua VM state.
 122  * \return The number of elements pushed on stack.
 123  */
 124 int
 125 luaA_keygrabber_stop(lua_State *L)
 126 {
 127     xcb_ungrab_keyboard(globalconf.connection, XCB_CURRENT_TIME);
 128     luaA_unregister(L, &globalconf.keygrabber);
 129     return 0;
 130 }
 131
 132 const struct luaL_reg awesome_keygrabber_lib[] =
 133 {
 134     { "run", luaA_keygrabber_run },
 135     { "stop", luaA_keygrabber_stop },
 136     { NULL, NULL }
 137 };