engine/key_handler.js

   1 /*
   2  * key_handler.js
   3  *
   4  * Copyright 2020 Elias Fleckenstein <eliasfleckenstein@web.de>
   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
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  19  * MA 02110-1301, USA.
  20  *
  21  *
  22  */
  23
  24 dragonblocks.KeyHandler = class
  25 {
  26         constructor()
  27         {
  28                 this.locked = {};
  29                 this.upHandlers = {};
  30                 this.downHandlers = {};
  31
  32                 let self = this;
  33
  34                 addEventListener("keydown", event => {
  35                         self.handle(event);
  36                 });
  37
  38                 addEventListener("keyup", event => {
  39                         self.handle(event);
  40                 });
  41
  42                 addEventListener("wheel", event => {
  43                         self.handle(event);
  44                 });
  45         }
  46
  47         lock(key)
  48         {
  49                 this.locked[key] = true;
  50         }
  51
  52         lockAll()
  53         {
  54                 for(let key in this.upHandlers)
  55                         this.lock(key);
  56
  57                 for(let key in this.downHandlers)
  58                         this.lock(key);
  59         }
  60
  61         unlock(key)
  62         {
  63                 dragonblocks.keyHandler.locked[key] = false;
  64         }
  65
  66         unlockAll()
  67         {
  68                 for (let key in this.locked)
  69                         this.unlock(key);
  70         }
  71
  72         down(key, func)
  73         {
  74                 this.downHandlers[key] = func;
  75                 this.lock(key);
  76         }
  77
  78         up(key, func)
  79         {
  80                 this.upHandlers[key] = func;
  81                 this.lock(key);
  82         }
  83
  84         handle(event)
  85         {
  86                 switch (event.type) {
  87                         case "keydown":
  88                         case "keypress":
  89                                 if (this.locked[event.key])
  90                                         return;
  91
  92                                 if (this.downHandlers[event.key]) {
  93                                         event.preventDefault();
  94                                         (this.downHandlers[event.key])();
  95                                 }
  96                                 break;
  97
  98                         case "keyup":
  99                                 if (this.locked[event.key])
 100                                         return;
 101
 102                                 if (this.upHandlers[event.key]){
 103                                         event.preventDefault();
 104                                         (this.upHandlers[event.key])();
 105                                 }
 106                                 break;
 107
 108                         case "wheel":
 109                                 if (this.locked["scroll"])
 110                                         return;
 111
 112                                 if (event.deltaY > 0 && this.downHandlers["scroll"]) {
 113                                         event.preventDefault();
 114                                         (this.downHandlers["scroll"])();
 115                                 } else if (this.upHandlers["scroll"]) {
 116                                         event.preventDefault();
 117                                         (this.upHandlers["scroll"])();
 118                                 }
 119                                 break;
 120                 }
 121         }
 122 };
 123
 124 dragonblocks.keyHandler = new dragonblocks.KeyHandler();
 125
 126 dragonblocks.registerOnStarted(_ => {
 127         dragonblocks.keyHandler.unlockAll();
 128 });