source/lib/input.h

   1 /* Copyright (C) 2017 Wildfire Games.
   2  *
   3  * Permission is hereby granted, free of charge, to any person obtaining
   4  * a copy of this software and associated documentation files (the
   5  * "Software"), to deal in the Software without restriction, including
   6  * without limitation the rights to use, copy, modify, merge, publish,
   7  * distribute, sublicense, and/or sell copies of the Software, and to
   8  * permit persons to whom the Software is furnished to do so, subject to
   9  * the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included
  12  * in all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  15  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  16  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  17  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
  18  * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  19  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  20  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  21  */
  22
  23 /*
  24  * SDL input redirector; dispatches to multiple handlers.
  25  */
  26
  27 #ifndef INCLUDED_INPUT
  28 #define INCLUDED_INPUT
  29
  30
  31 #include "lib/external_libraries/libsdl_fwd.h"
  32
  33 // input handler return values.
  34 enum InReaction
  35 {
  36         // (the handlers' return values are checked and these
  37         // 'strange' values might bring errors to light)
  38
  39         // pass the event to the next handler in the chain
  40         IN_PASS = 4,
  41
  42         // we've handled it; no other handlers will receive this event.
  43         IN_HANDLED = 2
  44 };
  45
  46 typedef InReaction (*InHandler)(const SDL_Event_*);
  47
  48 // register an input handler, which will receive all subsequent events first.
  49 // events are passed to other handlers if handler returns IN_PASS.
  50 extern void in_add_handler(InHandler handler);
  51
  52 // remove all registered input handlers
  53 extern void in_reset_handlers();
  54
  55 // send event to each handler (newest first) until one returns true
  56 extern void in_dispatch_event(const SDL_Event_* event);
  57
  58 // push an event onto the back of a high-priority queue - the new event will
  59 // be returned by in_poll_event before any standard SDL events
  60 extern void in_push_priority_event(const SDL_Event_* event);
  61
  62 // reads events that were pushed by in_push_priority_event
  63 // returns 1 if an event was read, 0 otherwise.
  64 extern int in_poll_priority_event(SDL_Event_* event);
  65
  66 // reads events that were pushed by in_push_priority_event, or, if there are
  67 // no high-priority events) reads from the SDL event queue with SDL_PollEvent.
  68 // returns 1 if an event was read, 0 otherwise.
  69 extern int in_poll_event(SDL_Event_* event);
  70
  71 #endif  // #ifndef INCLUDED_INPUT