text: /*
    Simple DirectMedia Layer
    Copyright (C) 1997-2022 Sam Lantinga <slouken@libsdl.org>
  
    This software is provided 'as-is', without any express or implied
    warranty.  In no event will the authors be held liable for any damages
    arising from the use of this software.
  
    Permission is granted to anyone to use this software for any purpose,
    including commercial applications, and to alter it and redistribute it
    freely, subject to the following restrictions:
  
    1. The origin of this software must not be misrepresented; you must not
       claim that you wrote the original software. If you use this software
       in a product, an acknowledgment in the product documentation would be
       appreciated but is not required.
    2. Altered source versions must be plainly marked as such, and must not be
       misrepresented as being the original software.
    3. This notice may not be removed or altered from any source distribution.
  */
  #include "../SDL_internal.h"
  
  /* General event handling code for SDL */
  
  #include "SDL.h"
  #include "SDL_events.h"
  #include "SDL_thread.h"
  #include "SDL_events_c.h"
  #include "../SDL_hints_c.h"
  #include "../timer/SDL_timer_c.h"
  #if !SDL_JOYSTICK_DISABLED
  #include "../joystick/SDL_joystick_c.h"
  #endif
  #include "../video/SDL_sysvideo.h"
  #include "SDL_syswm.h"
  
  #undef SDL_PRIs64
  #ifdef __WIN32__
  #define SDL_PRIs64  "I64d"
  #else
  #define SDL_PRIs64  "lld"
  #endif
  
  /* An arbitrary limit so we don't have unbounded growth */
  #define SDL_MAX_QUEUED_EVENTS   65535
  
  /* Determines how often we wake to call SDL_PumpEvents() in SDL_WaitEventTimeout_Device() */
  #define PERIODIC_POLL_INTERVAL_MS 3000
  
  typedef struct SDL_EventWatcher {
      SDL_EventFilter callback;
      void *userdata;
      SDL_bool removed;
  } SDL_EventWatcher;
  
  static SDL_mutex *SDL_event_watchers_lock;
  static SDL_EventWatcher SDL_EventOK;
  static SDL_EventWatcher *SDL_event_watchers = NULL;
  static int SDL_event_watchers_count = 0;
  static SDL_bool SDL_event_watchers_dispatching = SDL_FALSE;
  static SDL_bool SDL_event_watchers_removed = SDL_FALSE;
  
  typedef struct {
      Uint32 bits[8];
  } SDL_DisabledEventBlock;
  
  static SDL_DisabledEventBlock *SDL_disabled_events[256];
  static Uint32 SDL_userevents = SDL_USEREVENT;
  
  /* Private data -- event queue */
  typedef struct _SDL_EventEntry
  {
      SDL_Event event;
      SDL_SysWMmsg msg;
      struct _SDL_EventEntry *prev;
      struct _SDL_EventEntry *next;
  } SDL_EventEntry;
  
  typedef struct _SDL_SysWMEntry
  {
      SDL_SysWMmsg msg;
      struct _SDL_SysWMEntry *next;
  } SDL_SysWMEntry;
  
  static struct
  {
      SDL_mutex *lock;
      SDL_atomic_t active;
      SDL_atomic_t count;
      int max_events_seen;
      SDL_EventEntry *head;
      SDL_EventEntry *tail;
      SDL_EventEntry *free;
      SDL_SysWMEntry *wmmsg_used;
      SDL_SysWMEntry *wmmsg_free;
  } SDL_EventQ = { NULL, { 1 }, { 0 }, 0, NULL, NULL, NULL, NULL, NULL };
  
  
  #if !SDL_JOYSTICK_DISABLED
  
  static SDL_bool SDL_update_joysticks = SDL_TRUE;
  
  static void
  SDL_CalculateShouldUpdateJoysticks()
  {
      if (SDL_GetHintBoolean(SDL_HINT_AUTO_UPDATE_JOYSTICKS, SDL_TRUE) &&
          (!SDL_disabled_events[SDL_JOYAXISMOTION >> 8] || SDL_JoystickEventState(SDL_QUERY))) {
          SDL_update_joysticks = SDL_TRUE;
      } else {
          SDL_update_joysticks = SDL_FALSE;
      }
  }
  
  static void SDLCALL
  SDL_AutoUpdateJoysticksChanged(void *userdata, const char *name, const char *oldValue, const char *hint)
  {
      SDL_CalculateShouldUpdateJoysticks();
  }
  
  #endif /* !SDL_JOYSTICK_DISABLED */
  
  
  #if !SDL_SENSOR_DISABLED
  
  static SDL_bool SDL_update_sensors = SDL_TRUE;
  
  static void
  SDL_CalculateShouldUpdateSensors()
  {
      if (SDL_GetHintBoolean(SDL_HINT_AUTO_UPDATE_SENSORS, SDL_TRUE) &&
          !SDL_disabled_events[SDL_SENSORUPDATE >> 8]) {
          SDL_update_sensors = SDL_TRUE;
      } else {
          SDL_update_sensors = SDL_FALSE;
      }
  }
  
  static void SDLCALL
  SDL_AutoUpdateSensorsChanged(void *userdata, const char *name, const char *oldValue, const char *hint)
  {
      SDL_CalculateShouldUpdateSensors();
  }
  
  #endif /* !SDL_SENSOR_DISABLED */
  
  static void SDLCALL
  SDL_PollSentinelChanged(void *userdata, const char *name, const char *oldValue, const char *hint)
  {
      SDL_EventState(SDL_POLLSENTINEL, SDL_GetStringBoolean(hint, SDL_TRUE) ? SDL_ENABLE : SDL_DISABLE);
  }
  
  /* 0 (default) means no logging, 1 means logging, 2 means logging with mouse and finger motion */
  static int SDL_DoEventLogging = 0;
  
  static void SDLCALL
  SDL_EventLoggingChanged(void *userdata, const char *name, const char *oldValue, const char *hint)
  {
      SDL_DoEventLogging = (hint && *hint) ? SDL_clamp(SDL_atoi(hint), 0, 2) : 0;
  }
  
  static void
  SDL_LogEvent(const SDL_Event *event)
  {
      char name[32];
      char details[128];
  
      /* sensor/mouse/finger motion are spammy, ignore these if they aren't demanded. */
      if ( (SDL_DoEventLogging < 2) &&
              ( (event->type == SDL_MOUSEMOTION) ||
                (event->type == SDL_FINGERMOTION) ||
                (event->type == SDL_CONTROLLERTOUCHPADMOTION) ||
                (event->type == SDL_CONTROLLERSENSORUPDATE) ||
                (event->type == SDL_SENSORUPDATE) ) ) {
          return;
      }
  
      /* this is to make SDL_snprintf() calls cleaner. */
      #define uint unsigned int
  
      name[0] = '\0';
      details[0] = '\0';
  
      /* !!! FIXME: This code is kinda ugly, sorry. */
  
      if ((event->type >= SDL_USEREVENT) && (event->type <= SDL_LASTEVENT)) {
          char plusstr[16];
          SDL_strlcpy(name, "SDL_USEREVENT", sizeof (name));
          if (event->type > SDL_USEREVENT) {
              SDL_snprintf(plusstr, sizeof (plusstr), "+%u", ((uint) event->type) - SDL_USEREVENT);
          } else {
              plusstr[0] = '\0';
          }
          SDL_snprintf(details, sizeof (details), "%s (timestamp=%u windowid=%u code=%d data1=%p data2=%p)",
                  plusstr, (uint) event->user.timestamp, (uint) event->user.windowID,
                  (int) event->user.code, event->user.data1, event->user.data2);
      }
  
      switch (event->type) {
          #define SDL_EVENT_CASE(x) case x: SDL_strlcpy(name, #x, sizeof (name));
          SDL_EVENT_CASE(SDL_FIRSTEVENT) SDL_strlcpy(details, " (THIS IS PROBABLY A BUG!)", sizeof (details)); break;
          SDL_EVENT_CASE(SDL_QUIT) SDL_snprintf(details, sizeof (details), " (timestamp=%u)", (uint) event->quit.timestamp); break;
          SDL_EVENT_CASE(SDL_APP_TERMINATING) break;
          SDL_EVENT_CASE(SDL_APP_LOWMEMORY) break;
          SDL_EVENT_CASE(SDL_APP_WILLENTERBACKGROUND) break;
          SDL_EVENT_CASE(SDL_APP_DIDENTERBACKGROUND) break;
          SDL_EVENT_CASE(SDL_APP_WILLENTERFOREGROUND) break;
          SDL_EVENT_CASE(SDL_APP_DIDENTERFOREGROUND) break;
          SDL_EVENT_CASE(SDL_KEYMAPCHANGED) break;
          SDL_EVENT_CASE(SDL_CLIPBOARDUPDATE) break;
          SDL_EVENT_CASE(SDL_RENDER_TARGETS_RESET) break;
          SDL_EVENT_CASE(SDL_RENDER_DEVICE_RESET) break;
  
          SDL_EVENT_CASE(SDL_WINDOWEVENT) {
              char name2[64];
              switch(event->window.event) {
                  case SDL_WINDOWEVENT_NONE: SDL_strlcpy(name2, "SDL_WINDOWEVENT_NONE (THIS IS PROBABLY A BUG!)", sizeof (name2)); break;
                  #define SDL_WINDOWEVENT_CASE(x) case x: SDL_strlcpy(name2, #x, sizeof (name2)); break
                  SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_SHOWN);
                  SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_HIDDEN);
                  SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_EXPOSED);
                  SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_MOVED);
                  SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_RESIZED);
                  SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_SIZE_CHANGED);
                  SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_MINIMIZED);
                  SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_MAXIMIZED);
                  SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_RESTORED);
                  SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_ENTER);
                  SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_LEAVE);
                  SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_FOCUS_GAINED);
                  SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_FOCUS_LOST);
                  SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_CLOSE);
                  SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_TAKE_FOCUS);
                  SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_HIT_TEST);
                  #undef SDL_WINDOWEVENT_CASE
                  default: SDL_strlcpy(name2, "UNKNOWN (bug? fixme?)", sizeof (name2)); break;
              }
              SDL_snprintf(details, sizeof (details), " (timestamp=%u windowid=%u event=%s data1=%d data2=%d)",
                          (uint) event->window.timestamp, (uint) event->window.windowID, name2, (int) event->window.data1, (int) event->window.data2);
              break;
          }
  
          SDL_EVENT_CASE(SDL_SYSWMEVENT)
              /* !!! FIXME: we don't delve further at the moment. */
              SDL_snprintf(details, sizeof (details), " (timestamp=%u)", (uint) event->syswm.timestamp);
              break;
  
          #define PRINT_KEY_EVENT(event) \
              SDL_snprintf(details, sizeof (details), " (timestamp=%u windowid=%u state=%s repeat=%s scancode=%u keycode=%u mod=%u)", \
                  (uint) event->key.timestamp, (uint) event->key.windowID, \
                  event->key.state == SDL_PRESSED ? "pressed" : "released", \
                  event->key.repeat ? "true" : "false", \
                  (uint) event->key.keysym.scancode, \
                  (uint) event->key.keysym.sym, \
                  (uint) event->key.keysym.mod)
          SDL_EVENT_CASE(SDL_KEYDOWN) PRINT_KEY_EVENT(event); break;
          SDL_EVENT_CASE(SDL_KEYUP) PRINT_KEY_EVENT(event); break;
          #undef PRINT_KEY_EVENT
  
          SDL_EVENT_CASE(SDL_TEXTEDITING)
              SDL_snprintf(details, sizeof (details), " (timestamp=%u windowid=%u text='%s' start=%d length=%d)",
                  (uint) event->edit.timestamp, (uint) event->edit.windowID,
                  event->edit.text, (int) event->edit.start, (int) event->edit.length);
              break;
  
          SDL_EVENT_CASE(SDL_TEXTINPUT)
              SDL_snprintf(details, sizeof (details), " (timestamp=%u windowid=%u text='%s')", (uint) event->text.timestamp, (uint) event->text.windowID, event->text.text);
              break;
  
  
          SDL_EVENT_CASE(SDL_MOUSEMOTION)
              SDL_snprintf(details, sizeof (details), " (timestamp=%u windowid=%u which=%u state=%u x=%d y=%d xrel=%d yrel=%d)",
                      (uint) event->motion.timestamp, (uint) event->motion.windowID,
                      (uint) event->motion.which, (uint) event->motion.state,
                      (int) event->motion.x, (int) event->motion.y,
                      (int) event->motion.xrel, (int) event->motion.yrel);
              break;
  
          #define PRINT_MBUTTON_EVENT(event) \
              SDL_snprintf(details, sizeof (details), " (timestamp=%u windowid=%u which=%u button=%u state=%s clicks=%u x=%d y=%d)", \
                      (uint) event->button.timestamp, (uint) event->button.windowID, \
                      (uint) event->button.which, (uint) event->button.button, \
                      event->button.state == SDL_PRESSED ? "pressed" : "released", \
                      (uint) event->button.clicks, (int) event->button.x, (int) event->button.y)
          SDL_EVENT_CASE(SDL_MOUSEBUTTONDOWN) PRINT_MBUTTON_EVENT(event); break;
          SDL_EVENT_CASE(SDL_MOUSEBUTTONUP) PRINT_MBUTTON_EVENT(event); break;
          #undef PRINT_MBUTTON_EVENT
  
  
          SDL_EVENT_CASE(SDL_MOUSEWHEEL)
              SDL_snprintf(details, sizeof (details), " (timestamp=%u windowid=%u which=%u x=%d y=%d preciseX=%f preciseY=%f direction=%s)",
                      (uint) event->wheel.timestamp, (uint) event->wheel.windowID,
                      (uint) event->wheel.which, (int) event->wheel.x, (int) event->wheel.y,
                      event->wheel.preciseX, event->wheel.preciseY,
                      event->wheel.direction == SDL_MOUSEWHEEL_NORMAL ? "normal" : "flipped");
              break;
  
          SDL_EVENT_CASE(SDL_JOYAXISMOTION)
              SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d axis=%u value=%d)",
                  (uint) event->jaxis.timestamp, (int) event->jaxis.which,
                  (uint) event->jaxis.axis, (int) event->jaxis.value);
              break;
  
          SDL_EVENT_CASE(SDL_JOYBALLMOTION)
              SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d ball=%u xrel=%d yrel=%d)",
                  (uint) event->jball.timestamp, (int) event->jball.which,
                  (uint) event->jball.ball, (int) event->jball.xrel, (int) event->jball.yrel);
              break;
  
          SDL_EVENT_CASE(SDL_JOYHATMOTION)
              SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d hat=%u value=%u)",
                  (uint) event->jhat.timestamp, (int) event->jhat.which,
                  (uint) event->jhat.hat, (uint) event->jhat.value);
              break;
  
          #define PRINT_JBUTTON_EVENT(event) \
              SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d button=%u state=%s)", \
                  (uint) event->jbutton.timestamp, (int) event->jbutton.which, \
                  (uint) event->jbutton.button, event->jbutton.state == SDL_PRESSED ? "pressed" : "released")
          SDL_EVENT_CASE(SDL_JOYBUTTONDOWN) PRINT_JBUTTON_EVENT(event); break;
          SDL_EVENT_CASE(SDL_JOYBUTTONUP) PRINT_JBUTTON_EVENT(event); break;
          #undef PRINT_JBUTTON_EVENT
  
          #define PRINT_JOYDEV_EVENT(event) SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d)", (uint) event->jdevice.timestamp, (int) event->jdevice.which)
          SDL_EVENT_CASE(SDL_JOYDEVICEADDED) PRINT_JOYDEV_EVENT(event); break;
          SDL_EVENT_CASE(SDL_JOYDEVICEREMOVED) PRINT_JOYDEV_EVENT(event); break;
          #undef PRINT_JOYDEV_EVENT
  
          SDL_EVENT_CASE(SDL_CONTROLLERAXISMOTION)
              SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d axis=%u value=%d)",
                  (uint) event->caxis.timestamp, (int) event->caxis.which,
                  (uint) event->caxis.axis, (int) event->caxis.value);
              break;
  
          #define PRINT_CBUTTON_EVENT(event) \
              SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d button=%u state=%s)", \
                  (uint) event->cbutton.timestamp, (int) event->cbutton.which, \
                  (uint) event->cbutton.button, event->cbutton.state == SDL_PRESSED ? "pressed" : "released")
          SDL_EVENT_CASE(SDL_CONTROLLERBUTTONDOWN) PRINT_CBUTTON_EVENT(event); break;
          SDL_EVENT_CASE(SDL_CONTROLLERBUTTONUP) PRINT_CBUTTON_EVENT(event); break;
          #undef PRINT_CBUTTON_EVENT
  
          #define PRINT_CONTROLLERDEV_EVENT(event) SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d)", (uint) event->cdevice.timestamp, (int) event->cdevice.which)
          SDL_EVENT_CASE(SDL_CONTROLLERDEVICEADDED) PRINT_CONTROLLERDEV_EVENT(event); break;
          SDL_EVENT_CASE(SDL_CONTROLLERDEVICEREMOVED) PRINT_CONTROLLERDEV_EVENT(event); break;
          SDL_EVENT_CASE(SDL_CONTROLLERDEVICEREMAPPED) PRINT_CONTROLLERDEV_EVENT(event); break;
          #undef PRINT_CONTROLLERDEV_EVENT
  
          #define PRINT_CTOUCHPAD_EVENT(event) \
              SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d touchpad=%d finger=%d x=%f y=%f pressure=%f)", \
                  (uint) event->ctouchpad.timestamp, (int) event->ctouchpad.which, \
                  (int) event->ctouchpad.touchpad, (int) event->ctouchpad.finger, \
                  event->ctouchpad.x, event->ctouchpad.y, event->ctouchpad.pressure)
          SDL_EVENT_CASE(SDL_CONTROLLERTOUCHPADDOWN) PRINT_CTOUCHPAD_EVENT(event); break;
          SDL_EVENT_CASE(SDL_CONTROLLERTOUCHPADUP) PRINT_CTOUCHPAD_EVENT(event); break;
          SDL_EVENT_CASE(SDL_CONTROLLERTOUCHPADMOTION) PRINT_CTOUCHPAD_EVENT(event); break;
          #undef PRINT_CTOUCHPAD_EVENT
  
         SDL_EVENT_CASE(SDL_CONTROLLERSENSORUPDATE)
              SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d sensor=%d data[0]=%f data[1]=%f data[2]=%f)", \
                  (uint) event->csensor.timestamp, (int) event->csensor.which, (int) event->csensor.sensor, \
                  event->csensor.data[0], event->csensor.data[1], event->csensor.data[2]);
              break;
  
          #define PRINT_FINGER_EVENT(event) \
              SDL_snprintf(details, sizeof (details), " (timestamp=%u touchid=%"SDL_PRIs64" fingerid=%"SDL_PRIs64" x=%f y=%f dx=%f dy=%f pressure=%f)", \
                  (uint) event->tfinger.timestamp, (long long)event->tfinger.touchId, \
                  (long long)event->tfinger.fingerId, event->tfinger.x, event->tfinger.y, \
                  event->tfinger.dx, event->tfinger.dy, event->tfinger.pressure)
          SDL_EVENT_CASE(SDL_FINGERDOWN) PRINT_FINGER_EVENT(event); break;
          SDL_EVENT_CASE(SDL_FINGERUP) PRINT_FINGER_EVENT(event); break;
          SDL_EVENT_CASE(SDL_FINGERMOTION) PRINT_FINGER_EVENT(event); break;
          #undef PRINT_FINGER_EVENT
  
          #define PRINT_DOLLAR_EVENT(event) \
              SDL_snprintf(details, sizeof (details), " (timestamp=%u touchid=%"SDL_PRIs64" gestureid=%"SDL_PRIs64" numfingers=%u error=%f x=%f y=%f)", \
                  (uint) event->dgesture.timestamp, (long long)event->dgesture.touchId, \
                  (long long)event->dgesture.gestureId, (uint) event->dgesture.numFingers, \
                  event->dgesture.error, event->dgesture.x, event->dgesture.y);
          SDL_EVENT_CASE(SDL_DOLLARGESTURE) PRINT_DOLLAR_EVENT(event); break;
          SDL_EVENT_CASE(SDL_DOLLARRECORD) PRINT_DOLLAR_EVENT(event); break;
          #undef PRINT_DOLLAR_EVENT
  
          SDL_EVENT_CASE(SDL_MULTIGESTURE)
              SDL_snprintf(details, sizeof (details), " (timestamp=%u touchid=%"SDL_PRIs64" dtheta=%f ddist=%f x=%f y=%f numfingers=%u)",
                  (uint) event->mgesture.timestamp, (long long)event->mgesture.touchId,
                  event->mgesture.dTheta, event->mgesture.dDist,
                  event->mgesture.x, event->mgesture.y, (uint) event->mgesture.numFingers);
              break;
  
          #define PRINT_DROP_EVENT(event) SDL_snprintf(details, sizeof (details), " (file='%s' timestamp=%u windowid=%u)", event->drop.file, (uint) event->drop.timestamp, (uint) event->drop.windowID)
          SDL_EVENT_CASE(SDL_DROPFILE) PRINT_DROP_EVENT(event); break;
          SDL_EVENT_CASE(SDL_DROPTEXT) PRINT_DROP_EVENT(event); break;
          SDL_EVENT_CASE(SDL_DROPBEGIN) PRINT_DROP_EVENT(event); break;
          SDL_EVENT_CASE(SDL_DROPCOMPLETE) PRINT_DROP_EVENT(event); break;
          #undef PRINT_DROP_EVENT
  
          #define PRINT_AUDIODEV_EVENT(event) SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%u iscapture=%s)", (uint) event->adevice.timestamp, (uint) event->adevice.which, event->adevice.iscapture ? "true" : "false");
          SDL_EVENT_CASE(SDL_AUDIODEVICEADDED) PRINT_AUDIODEV_EVENT(event); break;
          SDL_EVENT_CASE(SDL_AUDIODEVICEREMOVED) PRINT_AUDIODEV_EVENT(event); break;
          #undef PRINT_AUDIODEV_EVENT
  
          SDL_EVENT_CASE(SDL_SENSORUPDATE)
              SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d data[0]=%f data[1]=%f data[2]=%f data[3]=%f data[4]=%f data[5]=%f)", \
                  (uint) event->sensor.timestamp, (int) event->sensor.which, \
                  event->sensor.data[0], event->sensor.data[1], event->sensor.data[2], \
                  event->sensor.data[3], event->sensor.data[4], event->sensor.data[5]);
              break;
  
          #undef SDL_EVENT_CASE
  
          case SDL_POLLSENTINEL:
              /* No logging necessary for this one */
              break;
  
          default:
              if (!name[0]) {
                  SDL_strlcpy(name, "UNKNOWN", sizeof (name));
                  SDL_snprintf(details, sizeof (details), " #%u! (Bug? FIXME?)", (uint) event->type);
              }
              break;
      }
  
      if (name[0]) {
          SDL_Log("SDL EVENT: %s%s", name, details);
      }
  
      #undef uint
  }
  
  
  
  /* Public functions */
  
  void
  SDL_StopEventLoop(void)
  {
      const char *report = SDL_GetHint("SDL_EVENT_QUEUE_STATISTICS");
      int i;
      SDL_EventEntry *entry;
      SDL_SysWMEntry *wmmsg;
  
      if (SDL_EventQ.lock) {
          SDL_LockMutex(SDL_EventQ.lock);
      }
  
      SDL_AtomicSet(&SDL_EventQ.active, 0);
  
      if (report && SDL_atoi(report)) {
          SDL_Log("SDL EVENT QUEUE: Maximum events in-flight: %d\n",
                  SDL_EventQ.max_events_seen);
      }
  
      /* Clean out EventQ */
      for (entry = SDL_EventQ.head; entry; ) {
          SDL_EventEntry *next = entry->next;
          SDL_free(entry);
          entry = next;
      }
      for (entry = SDL_EventQ.free; entry; ) {
          SDL_EventEntry *next = entry->next;
          SDL_free(entry);
          entry = next;
      }
      for (wmmsg = SDL_EventQ.wmmsg_used; wmmsg; ) {
          SDL_SysWMEntry *next = wmmsg->next;
          SDL_free(wmmsg);
          wmmsg = next;
      }
      for (wmmsg = SDL_EventQ.wmmsg_free; wmmsg; ) {
          SDL_SysWMEntry *next = wmmsg->next;
          SDL_free(wmmsg);
          wmmsg = next;
      }
  
      SDL_AtomicSet(&SDL_EventQ.count, 0);
      SDL_EventQ.max_events_seen = 0;
      SDL_EventQ.head = NULL;
      SDL_EventQ.tail = NULL;
      SDL_EventQ.free = NULL;
      SDL_EventQ.wmmsg_used = NULL;
      SDL_EventQ.wmmsg_free = NULL;
  
      /* Clear disabled event state */
      for (i = 0; i < SDL_arraysize(SDL_disabled_events); ++i) {
          SDL_free(SDL_disabled_events[i]);
          SDL_disabled_events[i] = NULL;
      }
  
      if (SDL_event_watchers_lock) {
          SDL_DestroyMutex(SDL_event_watchers_lock);
          SDL_event_watchers_lock = NULL;
      }
      if (SDL_event_watchers) {
          SDL_free(SDL_event_watchers);
          SDL_event_watchers = NULL;
          SDL_event_watchers_count = 0;
      }
      SDL_zero(SDL_EventOK);
  
      if (SDL_EventQ.lock) {
          SDL_UnlockMutex(SDL_EventQ.lock);
          SDL_DestroyMutex(SDL_EventQ.lock);
          SDL_EventQ.lock = NULL;
      }
  }
  
  /* This function (and associated calls) may be called more than once */
  int
  SDL_StartEventLoop(void)
  {
      /* We'll leave the event queue alone, since we might have gotten
         some important events at launch (like SDL_DROPFILE)
  
         FIXME: Does this introduce any other bugs with events at startup?
       */
  
      /* Create the lock and set ourselves active */
  #if !SDL_THREADS_DISABLED
      if (!SDL_EventQ.lock) {
          SDL_EventQ.lock = SDL_CreateMutex();
          if (SDL_EventQ.lock == NULL) {
              return -1;
          }
      }
  
      if (!SDL_event_watchers_lock) {
          SDL_event_watchers_lock = SDL_CreateMutex();
          if (SDL_event_watchers_lock == NULL) {
              return -1;
          }
      }
  #endif /* !SDL_THREADS_DISABLED */
  
      /* Process most event types */
      SDL_EventState(SDL_TEXTINPUT, SDL_DISABLE);
      SDL_EventState(SDL_TEXTEDITING, SDL_DISABLE);
      SDL_EventState(SDL_SYSWMEVENT, SDL_DISABLE);
  #if 0 /* Leave these events enabled so apps can respond to items being dragged onto them at startup */
      SDL_EventState(SDL_DROPFILE, SDL_DISABLE);
      SDL_EventState(SDL_DROPTEXT, SDL_DISABLE);
  #endif
  
      SDL_AtomicSet(&SDL_EventQ.active, 1);
  
      return 0;
  }
  
  
  /* Add an event to the event queue -- called with the queue locked */
  static int
  SDL_AddEvent(SDL_Event * event)
  {
      SDL_EventEntry *entry;
      const int initial_count = SDL_AtomicGet(&SDL_EventQ.count);
      int final_count;
  
      if (initial_count >= SDL_MAX_QUEUED_EVENTS) {
          SDL_SetError("Event queue is full (%d events)", initial_count);
          return 0;
      }
  
      if (SDL_EventQ.free == NULL) {
          entry = (SDL_EventEntry *)SDL_malloc(sizeof(*entry));
          if (!entry) {
              return 0;
          }
      } else {
          entry = SDL_EventQ.free;
          SDL_EventQ.free = entry->next;
      }
  
      if (SDL_DoEventLogging) {
          SDL_LogEvent(event);
      }
  
      entry->event = *event;
      if (event->type == SDL_SYSWMEVENT) {
          entry->msg = *event->syswm.msg;
          entry->event.syswm.msg = &entry->msg;
      }
  
      if (SDL_EventQ.tail) {
          SDL_EventQ.tail->next = entry;
          entry->prev = SDL_EventQ.tail;
          SDL_EventQ.tail = entry;
          entry->next = NULL;
      } else {
          SDL_assert(!SDL_EventQ.head);
          SDL_EventQ.head = entry;
          SDL_EventQ.tail = entry;
          entry->prev = NULL;
          entry->next = NULL;
      }
  
      final_count = SDL_AtomicAdd(&SDL_EventQ.count, 1) + 1;
      if (final_count > SDL_EventQ.max_events_seen) {
          SDL_EventQ.max_events_seen = final_count;
      }
  
      return 1;
  }
  
  /* Remove an event from the queue -- called with the queue locked */
  static void
  SDL_CutEvent(SDL_EventEntry *entry)
  {
      if (entry->prev) {
          entry->prev->next = entry->next;
      }
      if (entry->next) {
          entry->next->prev = entry->prev;
      }
  
      if (entry == SDL_EventQ.head) {
          SDL_assert(entry->prev == NULL);
          SDL_EventQ.head = entry->next;
      }
      if (entry == SDL_EventQ.tail) {
          SDL_assert(entry->next == NULL);
          SDL_EventQ.tail = entry->prev;
      }
  
      entry->next = SDL_EventQ.free;
      SDL_EventQ.free = entry;
      SDL_assert(SDL_AtomicGet(&SDL_EventQ.count) > 0);
      SDL_AtomicAdd(&SDL_EventQ.count, -1);
  }
  
  static int
  SDL_SendWakeupEvent()
  {
      SDL_VideoDevice *_this = SDL_GetVideoDevice();
      if (!_this || !_this->SendWakeupEvent) {
          return 0;
      }
      if (!_this->wakeup_lock || SDL_LockMutex(_this->wakeup_lock) == 0) {
          if (_this->wakeup_window) {
              _this->SendWakeupEvent(_this, _this->wakeup_window);
  
              /* No more wakeup events needed until we enter a new wait */
              _this->wakeup_window = NULL;
          }
          if (_this->wakeup_lock) {
              SDL_UnlockMutex(_this->wakeup_lock);
          }
      }
      return 0;
  }
  
  /* Lock the event queue, take a peep at it, and unlock it */
  int
  SDL_PeepEvents(SDL_Event * events, int numevents, SDL_eventaction action,
                 Uint32 minType, Uint32 maxType)
  {
      int i, used;
  
      /* Don't look after we've quit */
      if (!SDL_AtomicGet(&SDL_EventQ.active)) {
          /* We get a few spurious events at shutdown, so don't warn then */
          if (action != SDL_ADDEVENT) {
              SDL_SetError("The event system has been shut down");
          }
          return (-1);
      }
      /* Lock the event queue */
      used = 0;
      if (!SDL_EventQ.lock || SDL_LockMutex(SDL_EventQ.lock) == 0) {
          if (action == SDL_ADDEVENT) {
              for (i = 0; i < numevents; ++i) {
                  used += SDL_AddEvent(&events[i]);
              }
          } else {
              SDL_EventEntry *entry, *next;
              SDL_SysWMEntry *wmmsg, *wmmsg_next;
              Uint32 type;
  
              if (action == SDL_GETEVENT) {
                  /* Clean out any used wmmsg data
                     FIXME: Do we want to retain the data for some period of time?
                   */
                  for (wmmsg = SDL_EventQ.wmmsg_used; wmmsg; wmmsg = wmmsg_next) {
                      wmmsg_next = wmmsg->next;
                      wmmsg->next = SDL_EventQ.wmmsg_free;
                      SDL_EventQ.wmmsg_free = wmmsg;
                  }
                  SDL_EventQ.wmmsg_used = NULL;
              }
  
              for (entry = SDL_EventQ.head; entry && (!events || used < numevents); entry = next) {
                  next = entry->next;
                  type = entry->event.type;
                  if (minType <= type && type <= maxType) {
                      if (events) {
                          events[used] = entry->event;
                          if (entry->event.type == SDL_SYSWMEVENT) {
                              /* We need to copy the wmmsg somewhere safe.
                                 For now we'll guarantee it's valid at least until
                                 the next call to SDL_PeepEvents()
                               */
                              if (SDL_EventQ.wmmsg_free) {
                                  wmmsg = SDL_EventQ.wmmsg_free;
                                  SDL_EventQ.wmmsg_free = wmmsg->next;
                              } else {
                                  wmmsg = (SDL_SysWMEntry *)SDL_malloc(sizeof(*wmmsg));
                              }
                              wmmsg->msg = *entry->event.syswm.msg;
                              wmmsg->next = SDL_EventQ.wmmsg_used;
                              SDL_EventQ.wmmsg_used = wmmsg;
                              events[used].syswm.msg = &wmmsg->msg;
                          }
  
                          if (action == SDL_GETEVENT) {
                              SDL_CutEvent(entry);
                          }
                      }
                      ++used;
                  }
              }
          }
          if (SDL_EventQ.lock) {
              SDL_UnlockMutex(SDL_EventQ.lock);
          }
      } else {
          return SDL_SetError("Couldn't lock event queue");
      }
  
      if (used > 0 && action == SDL_ADDEVENT) {
          SDL_SendWakeupEvent();
      }
  
      return (used);
  }
  
  SDL_bool
  SDL_HasEvent(Uint32 type)
  {
      return (SDL_PeepEvents(NULL, 0, SDL_PEEKEVENT, type, type) > 0);
  }
  
  SDL_bool
  SDL_HasEvents(Uint32 minType, Uint32 maxType)
  {
      return (SDL_PeepEvents(NULL, 0, SDL_PEEKEVENT, minType, maxType) > 0);
  }
  
  void
  SDL_FlushEvent(Uint32 type)
  {
      SDL_FlushEvents(type, type);
  }
  
  void
  SDL_FlushEvents(Uint32 minType, Uint32 maxType)
  {
      /* !!! FIXME: we need to manually SDL_free() the strings in TEXTINPUT and
         drag'n'drop events if we're flushing them without passing them to the
         app, but I don't know if this is the right place to do that. */
  
      /* Don't look after we've quit */
      if (!SDL_AtomicGet(&SDL_EventQ.active)) {
          return;
      }
  
      /* Make sure the events are current */
  #if 0
      /* Actually, we can't do this since we might be flushing while processing
         a resize event, and calling this might trigger further resize events.
      */
      SDL_PumpEvents();
  #endif
  
      /* Lock the event queue */
      if (!SDL_EventQ.lock || SDL_LockMutex(SDL_EventQ.lock) == 0) {
          SDL_EventEntry *entry, *next;
          Uint32 type;
          for (entry = SDL_EventQ.head; entry; entry = next) {
              next = entry->next;
              type = entry->event.type;
              if (minType <= type && type <= maxType) {
                  SDL_CutEvent(entry);
              }
          }
          if (SDL_EventQ.lock) {
              SDL_UnlockMutex(SDL_EventQ.lock);
          }
      }
  }
  
  /* Run the system dependent event loops */
  void
  SDL_PumpEvents(void)
  {
      SDL_VideoDevice *_this = SDL_GetVideoDevice();
  
      /* Release any keys held down from last frame */
      SDL_ReleaseAutoReleaseKeys();
  
      /* Get events from the video subsystem */
      if (_this) {
          _this->PumpEvents(_this);
      }
  
  #if !SDL_JOYSTICK_DISABLED
      /* Check for joystick state change */
      if (SDL_update_joysticks) {
          SDL_JoystickUpdate();
      }
  #endif
  
  #if !SDL_SENSOR_DISABLED
      /* Check for sensor state change */
      if (SDL_update_sensors) {
          SDL_SensorUpdate();
      }
  #endif
  
      SDL_SendPendingSignalEvents();  /* in case we had a signal handler fire, etc. */
  }
  
  /* Public functions */
  
  int
  SDL_PollEvent(SDL_Event * event)
  {
      return SDL_WaitEventTimeout(event, 0);
  }
  
  static SDL_bool
  SDL_events_need_periodic_poll() {
      SDL_bool need_periodic_poll = SDL_FALSE;
  
  #if !SDL_JOYSTICK_DISABLED
      need_periodic_poll =
          SDL_WasInit(SDL_INIT_JOYSTICK) &&
          (!SDL_disabled_events[SDL_JOYAXISMOTION >> 8] || SDL_JoystickEventState(SDL_QUERY));
  #endif
  
  #if !SDL_SENSOR_DISABLED
      need_periodic_poll = need_periodic_poll ||
          (SDL_WasInit(SDL_INIT_SENSOR) && !SDL_disabled_events[SDL_SENSORUPDATE >> 8]);
  #endif
  
      return need_periodic_poll;
  }
  
  static int
  SDL_WaitEventTimeout_Device(_THIS, SDL_Window *wakeup_window, SDL_Event * event, Uint32 start, int timeout)
  {
      int loop_timeout = timeout;
      SDL_bool need_periodic_poll = SDL_events_need_periodic_poll();
  
      for (;;) {
          /* Pump events on entry and each time we wake to ensure:
             a) All pending events are batch processed after waking up from a wait
             b) Waiting can be completely skipped if events are already available to be pumped
             c) Periodic processing that takes place in some platform PumpEvents() functions happens
             d) Signals received in WaitEventTimeout() are turned into SDL events
          */
          SDL_PumpEvents();
  
          if (!_this->wakeup_lock || SDL_LockMutex(_this->wakeup_lock) == 0) {
              int status = SDL_PeepEvents(event, 1, SDL_GETEVENT, SDL_FIRSTEVENT, SDL_LASTEVENT);
              /* If status == 0 we are going to block so wakeup will be needed. */
              if (status == 0) {
                  _this->wakeup_window = wakeup_window;
              } else {
                  _this->wakeup_window = NULL;
              }
              if (_this->wakeup_lock) {
                  SDL_UnlockMutex(_this->wakeup_lock);
              }
              if (status < 0) {
                  /* Got an error: return */
                  break;
              }
              if (status > 0) {
                  /* There is an event, we can return. */
                  return 1;
              }
              /* No events found in the queue, call WaitEventTimeout to wait for an event. */
              if (timeout > 0) {
                  Uint32 elapsed = SDL_GetTicks() - start;
                  if (elapsed >= (Uint32)timeout) {
                      /* Set wakeup_window to NULL without holding the lock. */
                      _this->wakeup_window = NULL;
                      return 0;
                  }
                  loop_timeout = (int)((Uint32)timeout - elapsed);
              }
              if (need_periodic_poll) {
                  if (loop_timeout >= 0) {
                      loop_timeout = SDL_min(loop_timeout, PERIODIC_POLL_INTERVAL_MS);
                  } else {
                      loop_timeout = PERIODIC_POLL_INTERVAL_MS;
                  }
              }
              status = _this->WaitEventTimeout(_this, loop_timeout);
              /* Set wakeup_window to NULL without holding the lock. */
              _this->wakeup_window = NULL;
              if (status <= 0) {
                  /* There is either an error or the timeout is elapsed: return */
                  return status;
              }
              /* An event was found and pumped into the SDL events queue. Continue the loop
                to let SDL_PeepEvents pick it up .*/
          }
      }
      return 0;
  }
  
  static SDL_bool
  SDL_events_need_polling() {
      SDL_bool need_polling = SDL_FALSE;
  
  #if !SDL_JOYSTICK_DISABLED
      need_polling =
          SDL_WasInit(SDL_INIT_JOYSTICK) &&
          (!SDL_disabled_events[SDL_JOYAXISMOTION >> 8] || SDL_JoystickEventState(SDL_QUERY)) &&
          (SDL_NumJoysticks() > 0);
  #endif
  
  #if !SDL_SENSOR_DISABLED
      need_polling = need_polling ||
          (SDL_WasInit(SDL_INIT_SENSOR) && !SDL_disabled_events[SDL_SENSORUPDATE >> 8] && (SDL_NumSensors() > 0));
  #endif
  
      return need_polling;
  }
  
  static SDL_Window *
  SDL_find_active_window(SDL_VideoDevice * _this)
  {
      SDL_Window *window;
      for (window = _this->windows; window; window = window->next) {
          if (!window->is_destroying) {
              return window;
          }
      }
      return NULL;
  }
  
  int
  SDL_WaitEvent(SDL_Event * event)
  {
      return SDL_WaitEventTimeout(event, -1);
  }
  
  int
  SDL_WaitEventTimeout(SDL_Event * event, int timeout)
  {
      SDL_VideoDevice *_this = SDL_GetVideoDevice();
      SDL_Window *wakeup_window;
      Uint32 start = 0;
      Uint32 expiration = 0;
  
      /* First check for existing events */
      switch (SDL_PeepEvents(event, 1, SDL_GETEVENT, SDL_FIRSTEVENT, SDL_LASTEVENT)) {
      case -1:
          return 0;
      case 0:
          break;
      default:
          /* Check whether we have reached the end of the poll cycle, and no more events are left */
          if (timeout == 0 && event && event->type == SDL_POLLSENTINEL) {
              return (SDL_PeepEvents(event, 1, SDL_GETEVENT, SDL_FIRSTEVENT, SDL_LASTEVENT) == 1);
          }
          /* Has existing events */
          return 1;
      }
  
      if (timeout > 0) {
          start = SDL_GetTicks();
          expiration = start + timeout;
      }
  
      if (timeout != 0 && _this && _this->WaitEventTimeout && _this->SendWakeupEvent && !SDL_events_need_polling()) {
          /* Look if a shown window is available to send the wakeup event. */
          wakeup_window = SDL_find_active_window(_this);
          if (wakeup_window) {
              int status = SDL_WaitEventTimeout_Device(_this, wakeup_window, event, start, timeout);
  
              /* There may be implementation-defined conditions where the backend cannot
                 reliably wait for the next event. If that happens, fall back to polling. */
              if (status >= 0) {
                  return status;
              }
          }
      }
  
      for (;;) {
          SDL_PumpEvents();
          switch (SDL_PeepEvents(event, 1, SDL_GETEVENT, SDL_FIRSTEVENT, SDL_LASTEVENT)) {
          case -1:
              return 0;
          case 0:
              if (timeout == 0) {
                  /* Polling and no events, just return */
                  return 0;
              }
              if (timeout > 0 && SDL_TICKS_PASSED(SDL_GetTicks(), expiration)) {
                  /* Timeout expired and no events */
                  return 0;
              }
              SDL_Delay(1);
              break;
          default:
              if (timeout == 0 && SDL_GetEventState(SDL_POLLSENTINEL) == SDL_ENABLE) {
                  /* We are at the start of a poll cycle with at least one new event.
                     Add a sentinel event to mark the end of the cycle. */
                  SDL_Event sentinel;
                  sentinel.type = SDL_POLLSENTINEL;
                  SDL_PushEvent(&sentinel);
              }
              /* Has events */
              return 1;
          }
      }
  }
  
  int
  SDL_PushEvent(SDL_Event * event)
  {
      event->common.timestamp = SDL_GetTicks();
  
      if (SDL_EventOK.callback || SDL_event_watchers_count > 0) {
          if (!SDL_event_watchers_lock || SDL_LockMutex(SDL_event_watchers_lock) == 0) {
              if (SDL_EventOK.callback && !SDL_EventOK.callback(SDL_EventOK.userdata, event)) {
                  if (SDL_event_watchers_lock) {
                      SDL_UnlockMutex(SDL_event_watchers_lock);
                  }
                  return 0;
              }
  
              if (SDL_event_watchers_count > 0) {
                  /* Make sure we only dispatch the current watcher list */
                  int i, event_watchers_count = SDL_event_watchers_count;
  
                  SDL_event_watchers_dispatching = SDL_TRUE;
                  for (i = 0; i < event_watchers_count; ++i) {
                      if (!SDL_event_watchers[i].removed) {
                          SDL_event_watchers[i].callback(SDL_event_watchers[i].userdata, event);
                      }
                  }
                  SDL_event_watchers_dispatching = SDL_FALSE;
  
                  if (SDL_event_watchers_removed) {
                      for (i = SDL_event_watchers_count; i--; ) {
                          if (SDL_event_watchers[i].removed) {
                              --SDL_event_watchers_count;
                              if (i < SDL_event_watchers_count) {
                                  SDL_memmove(&SDL_event_watchers[i], &SDL_event_watchers[i+1], (SDL_event_watchers_count - i) * sizeof(SDL_event_watchers[i]));
                              }
                          }
                      }
                      SDL_event_watchers_removed = SDL_FALSE;
                  }
              }
  
              if (SDL_event_watchers_lock) {
                  SDL_UnlockMutex(SDL_event_watchers_lock);
              }
          }
      }
  
      if (SDL_PeepEvents(event, 1, SDL_ADDEVENT, 0, 0) <= 0) {
          return -1;
      }
  
      SDL_GestureProcessEvent(event);
  
      return 1;
  }
  
  void
  SDL_SetEventFilter(SDL_EventFilter filter, void *userdata)
  {
      if (!SDL_event_watchers_lock || SDL_LockMutex(SDL_event_watchers_lock) == 0) {
          /* Set filter and discard pending events */
          SDL_EventOK.callback = filter;
          SDL_EventOK.userdata = userdata;
          SDL_FlushEvents(SDL_FIRSTEVENT, SDL_LASTEVENT);
  
          if (SDL_event_watchers_lock) {
              SDL_UnlockMutex(SDL_event_watchers_lock);
          }
      }
  }
  
  SDL_bool
  SDL_GetEventFilter(SDL_EventFilter * filter, void **userdata)
  {
      SDL_EventWatcher event_ok;
  
      if (!SDL_event_watchers_lock || SDL_LockMutex(SDL_event_watchers_lock) == 0) {
          event_ok = SDL_EventOK;
  
          if (SDL_event_watchers_lock) {
              SDL_UnlockMutex(SDL_event_watchers_lock);
          }
      } else {
          SDL_zero(event_ok);
      }
  
      if (filter) {
          *filter = event_ok.callback;
      }
      if (userdata) {
          *userdata = event_ok.userdata;
      }
      return event_ok.callback ? SDL_TRUE : SDL_FALSE;
  }
  
  void
  SDL_AddEventWatch(SDL_EventFilter filter, void *userdata)
  {
      if (!SDL_event_watchers_lock || SDL_LockMutex(SDL_event_watchers_lock) == 0) {
          SDL_EventWatcher *event_watchers;
  
          event_watchers = SDL_realloc(SDL_event_watchers, (SDL_event_watchers_count + 1) * sizeof(*event_watchers));
          if (event_watchers) {
              SDL_EventWatcher *watcher;
  
              SDL_event_watchers = event_watchers;
              watcher = &SDL_event_watchers[SDL_event_watchers_count];
              watcher->callback = filter;
              watcher->userdata = userdata;
              watcher->removed = SDL_FALSE;
              ++SDL_event_watchers_count;
          }
  
          if (SDL_event_watchers_lock) {
              SDL_UnlockMutex(SDL_event_watchers_lock);
          }
      }
  }
  
  void
  SDL_DelEventWatch(SDL_EventFilter filter, void *userdata)
  {
      if (!SDL_event_watchers_lock || SDL_LockMutex(SDL_event_watchers_lock) == 0) {
          int i;
  
          for (i = 0; i < SDL_event_watchers_count; ++i) {
              if (SDL_event_watchers[i].callback == filter && SDL_event_watchers[i].userdata == userdata) {
                  if (SDL_event_watchers_dispatching) {
                      SDL_event_watchers[i].removed = SDL_TRUE;
                      SDL_event_watchers_removed = SDL_TRUE;
                  } else {
                      --SDL_event_watchers_count;
                      if (i < SDL_event_watchers_count) {
                          SDL_memmove(&SDL_event_watchers[i], &SDL_event_watchers[i+1], (SDL_event_watchers_count - i) * sizeof(SDL_event_watchers[i]));
                      }
                  }
                  break;
              }
          }
  
          if (SDL_event_watchers_lock) {
              SDL_UnlockMutex(SDL_event_watchers_lock);
          }
      }
  }
  
  void
  SDL_FilterEvents(SDL_EventFilter filter, void *userdata)
  {
      if (!SDL_EventQ.lock || SDL_LockMutex(SDL_EventQ.lock) == 0) {
          SDL_EventEntry *entry, *next;
          for (entry = SDL_EventQ.head; entry; entry = next) {
              next = entry->next;
              if (!filter(userdata, &entry->event)) {
                  SDL_CutEvent(entry);
              }
          }
          if (SDL_EventQ.lock) {
              SDL_UnlockMutex(SDL_EventQ.lock);
          }
      }
  }
  
  Uint8
  SDL_EventState(Uint32 type, int state)
  {
      const SDL_bool isdnd = ((state == SDL_DISABLE) || (state == SDL_ENABLE)) &&
                             ((type == SDL_DROPFILE) || (type == SDL_DROPTEXT));
      Uint8 current_state;
      Uint8 hi = ((type >> 8) & 0xff);
      Uint8 lo = (type & 0xff);
  
      if (SDL_disabled_events[hi] &&
          (SDL_disabled_events[hi]->bits[lo/32] & (1 << (lo&31)))) {
          current_state = SDL_DISABLE;
      } else {
          current_state = SDL_ENABLE;
      }
  
      if (state != current_state)
      {
          switch (state) {
          case SDL_DISABLE:
              /* Disable this event type and discard pending events */
              if (!SDL_disabled_events[hi]) {
                  SDL_disabled_events[hi] = (SDL_DisabledEventBlock*) SDL_calloc(1, sizeof(SDL_DisabledEventBlock));
                  if (!SDL_disabled_events[hi]) {
                      /* Out of memory, nothing we can do... */
                      break;
                  }
              }
              SDL_disabled_events[hi]->bits[lo/32] |= (1 << (lo&31));
              SDL_FlushEvent(type);
              break;
          case SDL_ENABLE:
              SDL_disabled_events[hi]->bits[lo/32] &= ~(1 << (lo&31));
              break;
          default:
              /* Querying state... */
              break;
          }
  
  #if !SDL_JOYSTICK_DISABLED
          if (state == SDL_DISABLE || state == SDL_ENABLE) {
              SDL_CalculateShouldUpdateJoysticks();
          }
  #endif
  #if !SDL_SENSOR_DISABLED
          if (state == SDL_DISABLE || state == SDL_ENABLE) {
              SDL_CalculateShouldUpdateSensors();
          }
  #endif
      }
  
      /* turn off drag'n'drop support if we've disabled the events.
         This might change some UI details at the OS level. */
      if (isdnd) {
          SDL_ToggleDragAndDropSupport();
      }
  
      return current_state;
  }
  
  Uint32
  SDL_RegisterEvents(int numevents)
  {
      Uint32 event_base;
  
      if ((numevents > 0) && (SDL_userevents+numevents <= SDL_LASTEVENT)) {
          event_base = SDL_userevents;
          SDL_userevents += numevents;
      } else {
          event_base = (Uint32)-1;
      }
      return event_base;
  }
  
  int
  SDL_SendAppEvent(SDL_EventType eventType)
  {
      int posted;
  
      posted = 0;
      if (SDL_GetEventState(eventType) == SDL_ENABLE) {
          SDL_Event event;
          event.type = eventType;
          posted = (SDL_PushEvent(&event) > 0);
      }
      return (posted);
  }
  
  int
  SDL_SendSysWMEvent(SDL_SysWMmsg * message)
  {
      int posted;
  
      posted = 0;
      if (SDL_GetEventState(SDL_SYSWMEVENT) == SDL_ENABLE) {
          SDL_Event event;
          SDL_memset(&event, 0, sizeof(event));
          event.type = SDL_SYSWMEVENT;
          event.syswm.msg = message;
          posted = (SDL_PushEvent(&event) > 0);
      }
      /* Update internal event state */
      return (posted);
  }
  
  int
  SDL_SendKeymapChangedEvent(void)
  {
      return SDL_SendAppEvent(SDL_KEYMAPCHANGED);
  }
  
  int
  SDL_SendLocaleChangedEvent(void)
  {
      return SDL_SendAppEvent(SDL_LOCALECHANGED);
  }
  
  int
  SDL_EventsInit(void)
  {
  #if !SDL_JOYSTICK_DISABLED
      SDL_AddHintCallback(SDL_HINT_AUTO_UPDATE_JOYSTICKS, SDL_AutoUpdateJoysticksChanged, NULL);
  #endif
  #if !SDL_SENSOR_DISABLED
      SDL_AddHintCallback(SDL_HINT_AUTO_UPDATE_SENSORS, SDL_AutoUpdateSensorsChanged, NULL);
  #endif
      SDL_AddHintCallback(SDL_HINT_EVENT_LOGGING, SDL_EventLoggingChanged, NULL);
      SDL_AddHintCallback(SDL_HINT_POLL_SENTINEL, SDL_PollSentinelChanged, NULL);
      if (SDL_StartEventLoop() < 0) {
          SDL_DelHintCallback(SDL_HINT_EVENT_LOGGING, SDL_EventLoggingChanged, NULL);
          return -1;
      }
  
      SDL_QuitInit();
  
      return 0;
  }
  
  void
  SDL_EventsQuit(void)
  {
      SDL_QuitQuit();
      SDL_StopEventLoop();
      SDL_DelHintCallback(SDL_HINT_POLL_SENTINEL, SDL_PollSentinelChanged, NULL);
      SDL_DelHintCallback(SDL_HINT_EVENT_LOGGING, SDL_EventLoggingChanged, NULL);
  #if !SDL_JOYSTICK_DISABLED
      SDL_DelHintCallback(SDL_HINT_AUTO_UPDATE_JOYSTICKS, SDL_AutoUpdateJoysticksChanged, NULL);
  #endif
  #if !SDL_SENSOR_DISABLED
      SDL_DelHintCallback(SDL_HINT_AUTO_UPDATE_SENSORS, SDL_AutoUpdateSensorsChanged, NULL);
  #endif
  }
  
  /* vi: set ts=4 sw=4 expandtab: */
  