source/lib/input.cpp

   1 /* Copyright (C) 2021 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 #include "precompiled.h"
  28 #include "input.h"
  29
  30 #include "lib/external_libraries/libsdl.h"
  31
  32 #include <list>
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35
  36 const size_t MAX_HANDLERS = 10;
  37 static InHandler handler_stack[MAX_HANDLERS];
  38 static size_t handler_stack_top = 0;
  39
  40 static std::list<SDL_Event_> priority_events;
  41
  42 void in_add_handler(InHandler handler)
  43 {
  44         ENSURE(handler);
  45
  46         if(handler_stack_top >= MAX_HANDLERS)
  47                 WARN_IF_ERR(ERR::LIMIT);
  48
  49         handler_stack[handler_stack_top++] = handler;
  50 }
  51
  52 void in_reset_handlers()
  53 {
  54         handler_stack_top = 0;
  55 }
  56
  57 // send ev to each handler until one returns IN_HANDLED
  58 void in_dispatch_event(const SDL_Event_* ev)
  59 {
  60         for(int i = (int)handler_stack_top-1; i >= 0; i--)
  61         {
  62                 ENSURE(handler_stack[i] && ev);
  63                 InReaction ret = handler_stack[i](ev);
  64                 // .. done, return
  65                 if(ret == IN_HANDLED)
  66                         return;
  67                 // .. next handler
  68                 else if(ret == IN_PASS)
  69                         continue;
  70                 // .. invalid return value
  71                 else
  72                         DEBUG_WARN_ERR(ERR::LOGIC);     // invalid handler return value
  73         }
  74 }
  75
  76 void in_push_priority_event(const SDL_Event_* event)
  77 {
  78         priority_events.push_back(*event);
  79 }
  80
  81 int in_poll_priority_event(SDL_Event_* event)
  82 {
  83         if (priority_events.empty())
  84                 return 0;
  85
  86         *event = priority_events.front();
  87         priority_events.pop_front();
  88         return 1;
  89 }
  90
  91 int in_poll_event(SDL_Event_* event)
  92 {
  93         return in_poll_priority_event(event) ? 1 : SDL_PollEvent(&event->ev);
  94 }