wmix/mmkeys.c

   1 /* WMix -- a mixer using the OSS mixer API.
   2  * Copyright (C) 2014 Christophe CURIS for the WindowMaker Team
   3  *
   4  * This program 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  * This program 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
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18 /*
  19  * mmkeys.c: functions related to grabbing the Multimedia Keys on keyboard
  20  */
  21
  22 #include <stdio.h>
  23 #include <string.h>
  24
  25 #include <X11/Xlib.h>
  26 #include <X11/Xproto.h>
  27 #include <X11/keysym.h>
  28 #include <X11/XF86keysym.h>
  29
  30 #include "include/common.h"
  31 #include "include/config.h"
  32 #include "include/mmkeys.h"
  33
  34
  35 /* The global configuration */
  36 struct multimedia_keys mmkeys;
  37
  38 /* The list of keys we're interrested in */
  39 static const struct {
  40         KeySym  symbol;
  41         KeyCode *store;
  42         const char *name;
  43 } key_list[] = {
  44         { XF86XK_AudioRaiseVolume, &mmkeys.raise_volume, "AudioRaiseVolume" },
  45         { XF86XK_AudioLowerVolume, &mmkeys.lower_volume, "AudioLowerVolume" },
  46         { XF86XK_AudioMute,        &mmkeys.mute,         "AudioMute"        }
  47 };
  48
  49 /* The modifiers that should not have impact on the key grabbed */
  50 static const struct {
  51         KeySym symbol;
  52         const char *name;
  53 } modifier_symbol[] = {
  54         { XK_Caps_Lock, "CapsLock" },
  55         { XK_Num_Lock,  "NumLock"  }
  56 };
  57
  58 typedef struct {
  59         int count;
  60         unsigned int list[1 << lengthof(modifier_symbol)];
  61 } modifier_masks;
  62
  63 /* The structure to track grab installation for errors */
  64 static struct mmkey_track {
  65         XErrorHandler previous_handler;
  66         struct {
  67                 const char *key_name;
  68                 unsigned long serial[1 << lengthof(modifier_symbol)];
  69                 Bool displayed;
  70         } request[lengthof(key_list)];
  71 } *track_install = NULL;
  72
  73 /* Local functions */
  74 static void mmkey_build_modifier_list(Display *display, modifier_masks *result);
  75 static int  mmkey_catch_grab_error(Display *display, XErrorEvent *event);
  76
  77
  78 /*
  79  * Grab the multimedia keys on the X server
  80  *
  81  * That basically means that whenever these keys are pressed
  82  * the events will be sent to us instead of the application
  83  * that has current focus.
  84  */
  85 void mmkey_install(Display *display)
  86 {
  87         modifier_masks mod_masks;
  88         struct mmkey_track install_info;
  89         Window root_window;
  90         int i, j;
  91
  92         mmkey_build_modifier_list(display, &mod_masks);
  93
  94         root_window = DefaultRootWindow(display);
  95
  96         memset(&install_info, 0, sizeof(install_info));
  97         install_info.previous_handler = XSetErrorHandler(mmkey_catch_grab_error);
  98         track_install = &install_info;
  99         for (i = 0; i < lengthof(key_list); i++) {
 100                 KeyCode key;
 101
 102                 key = XKeysymToKeycode(display, key_list[i].symbol);
 103                 *(key_list[i].store) = key;
 104
 105                 if (key == None)
 106                         continue;
 107
 108                 install_info.request[i].key_name = key_list[i].name;
 109                 install_info.request[i].displayed = False;
 110                 for (j = 0; j < mod_masks.count; j++) {
 111                         install_info.request[i].serial[j] = NextRequest(display);
 112                         XGrabKey(display, key, mod_masks.list[j], root_window,
 113                                  False, GrabModeAsync, GrabModeAsync);
 114                 }
 115                 if (config.verbose)
 116                         printf("Found multimedia key: %s\n", key_list[i].name);
 117         }
 118
 119         /* The grab may fail, so make sure it is reported now */
 120         XSync(display, False);
 121         XSetErrorHandler(install_info.previous_handler);
 122         track_install = NULL;
 123 }
 124
 125 /*
 126  * Build the list of bit-masks for all the modifiers we want to not have impact on our grab
 127  */
 128 static void mmkey_build_modifier_list(Display *display, modifier_masks *result)
 129 {
 130         XModifierKeymap *mods;
 131         KeyCode mod_code[lengthof(modifier_symbol)];
 132         unsigned int mod_mask[lengthof(modifier_symbol)];
 133         char buffer[256];
 134         int nb_modifiers;
 135         int i, j, k;
 136
 137         /* Get the bitmask associated with the modifiers */
 138         for (i = 0; i < lengthof(modifier_symbol); i++) {
 139                 mod_code[i] = XKeysymToKeycode(display, modifier_symbol[i].symbol);
 140                 mod_mask[i] = 0L;
 141         }
 142
 143         mods = XGetModifierMapping(display);
 144         for (i = 0; i < 8; i++) {
 145                 for (j = 0; j < mods->max_keypermod; j++) {
 146                         KeyCode key_mod;
 147
 148                         key_mod = mods->modifiermap[i * mods->max_keypermod + j];
 149                         for (k = 0; k < lengthof(mod_code); k++) {
 150                                 if ((mod_code[k] != None) && (key_mod == mod_code[k]))
 151                                         mod_mask[k] |= 1 << i;
 152                         }
 153                 }
 154         }
 155         XFreeModifiermap(mods);
 156
 157         /* Count the number of modifiers found (and display the list to the user) */
 158         if (config.verbose)
 159                 strcpy(buffer, "Found key modifiers: ");
 160
 161         nb_modifiers = 0;
 162         for (i = 0; i < lengthof(modifier_symbol); i++) {
 163                 if (mod_mask[i] != 0) {
 164                         if (config.verbose) {
 165                                 if (nb_modifiers > 0)
 166                                         strcat(buffer, ", ");
 167                                 strcat(buffer, modifier_symbol[i].name);
 168                         }
 169                         nb_modifiers++;
 170                 }
 171         }
 172         if (config.verbose) {
 173                 if (nb_modifiers == 0)
 174                         strcat(buffer, "None");
 175                 puts(buffer);
 176         }
 177
 178         /* Build the list of possible combinations of modifiers */
 179         result->count = 1 << nb_modifiers;
 180         for (i = 0; i < lengthof(result->list); i++)
 181                 result->list[i] = 0L;
 182         k = 1;
 183         for (i = 0; i < lengthof(mod_mask); i++) {
 184                 if (mod_mask[i] != 0) {
 185                         for (j = 1; j < result->count; j++)
 186                                 if (j & k)
 187                                         result->list[j] |= mod_mask[i];
 188
 189                         k <<= 1;
 190                 }
 191         }
 192 }
 193
 194 /*
 195  * Callback when X11 reports an error
 196  *
 197  * We only track errors from XGrabKey and display them to user, instead of
 198  * letting the default error handler exit
 199  */
 200 static int mmkey_catch_grab_error(Display *display, XErrorEvent *event)
 201 {
 202         int i, j;
 203
 204         if ((event->error_code == BadAccess) && (event->request_code == X_GrabKey)) {
 205                 for (i = 0; i < lengthof(track_install->request); i++) {
 206                         for (j = 0; j < lengthof(track_install->request[i].serial); j++) {
 207                                 if (track_install->request[i].serial[j] == 0L)
 208                                         break;
 209                                 if (event->serial == track_install->request[i].serial[j]) {
 210                                         if (!track_install->request[i].displayed) {
 211                                                 fprintf(stderr, "wmix:warning: could not grab key %s, is another application using it?\n",
 212                                                         track_install->request[i].key_name);
 213                                                 track_install->request[i].displayed = True;
 214                                         }
 215                                         return 0;
 216                                 }
 217                         }
 218                 }
 219         }
 220
 221         /* That's not an XGrabKey known issue, let the default handler manage this */
 222         return track_install->previous_handler(display, event);
 223 }