(function(root) {
'use strict';
/**
* Helper for binding user key input to actions.
* @class Input
* @constructor
* @param {Function} onKeyAction - Function called when a key bound to an action is pressed (function(action){}).
* @param {Object} bindings - An object of key val pairs mapping an action to an array of keys that trigger it. Input.Keys is used to convert input key string names to key codes.
* @param bindings.action1 {Array} Input keys mapped to action1. ['A', 'B', ...]
* @param bindings.action2 {Array} Input keys mapped to action2. ['X', 'Y', ...]
* @param bindings....
* @example
//bindings param example:
{
up: ['UP_ARROW'],
down: ['DOWN_ARROW'],
left: ['LEFT_ARROW'],
right: ['RIGHT_ARROW'],
}
*/
var Input = function Input(onKeyAction, bindings) {
this.bindings = {};
if (onKeyAction !== void 0) {
this.onKeyAction = onKeyAction;
}
if (bindings !== void 0) {
this.addBindings(bindings);
}
this.startListening();
};
Input.prototype = {
constructor: Input,
/**
* An object of key val pairs mapping keyCode to action
* @property bindings
* @type Object
*/
bindings: null,
/**
* Function called when a key bound to an action is pressed (function(action){}).
* @property onKeyAction
* @type Function
*/
onKeyAction: null,
/**
* Bind a user action to a key input
* @method bindAction
* @param {String} action - The action to bind the key to.
* @param {String} keyName - The keyname to bind the action to. @see Input.Keys
*/
bindAction: function(action, keyName) {
var keyCode = Input.Keys[keyName];
this.bindings[keyCode] = action;
},
/**
* Converts a user input key code to an action bound to that key or false if none is bound.
* @method getActionFromKeyCode
* @param {String} keyCode - The key code to retrieve an action bound to.
* @return String|bool The action bound to the keyCode or false.
*/
getActionFromKeyCode: function(keyCode) {
if (keyCode in this.bindings) {
return this.bindings[keyCode];
}
return false;
},
/**
* Loads multiple action key bindings
* @method addBindings
* @param {Object} bindings - An object of key val pairs mapping an action to an array of keys that trigger it. Input.Keys is used to convert input key string names to key codes.
* @param bindings.action1 {Array} Input keys mapped to action1. ['A', 'B', ...]
* @param bindings.action2 {Array} Input keys mapped to action2. ['X', 'Y', ...]
* @param bindings....
* @example
//bindings param example:
{
up: ['UP_ARROW'],
down: ['DOWN_ARROW'],
left: ['LEFT_ARROW'],
right: ['RIGHT_ARROW'],
}
*/
addBindings: function(bindings) {
for (var action in bindings) {
var keys = bindings[action];
for (var i = 0; i < keys.length; i++) {
var key = keys[i];
this.bindAction(action, key);
}
}
},
/**
* Event handler for document.addEventListener('keydown', this). Triggered when a key is pressed.
* If an action is bound to the key pressed, false is returned to cancel the default browser behavior of the keypress.
* If an action is not bound to the key pressed, true is returned allowing the default browser behavior of the keypress to function.
* @method handleEvent
* @param {Object} event - The onkeydown event.
* @return bool
*/
handleEvent: function(event) {
// ignore if modifer keys pressed
if(event.ctrlKey || event.shiftKey || event.altKey || event.metaKey){
return true;
}
var keyCode = event.keyCode;
var action = this.getActionFromKeyCode(keyCode);
// if no action bound to this keycode resolve the keydown event normally
if (action === false) {
return true;
}
// call onKeyAction callback with the action matched
this.onKeyAction(action);
// cancel default browser keypress behavior
event.preventDefault();
return false;
},
/**
* Binds event listener for document keydown event.
* @method startListening
*/
startListening: function(){
document.addEventListener('keydown', this);
},
/**
* Unbinds document keydown event listener
* @method stopListening
*/
stopListening: function(){
document.removeEventListener('keydown', this);
}
};
/**
* @static
* @property Keys
* @type {Object}
*/
Input.Keys = {
'BACKSPACE': 8,
'TAB': 9,
'ENTER': 13,
'PAUSE': 19,
'CAPS': 20,
'ESC': 27,
'SPACE': 32,
'PAGE_UP': 33,
'PAGE_DOWN': 34,
'END': 35,
'HOME': 36,
'LEFT_ARROW': 37,
'UP_ARROW': 38,
'RIGHT_ARROW': 39,
'DOWN_ARROW': 40,
'INSERT': 45,
'DELETE': 46,
'0': 48,
'1': 49,
'2': 50,
'3': 51,
'4': 52,
'5': 53,
'6': 54,
'7': 55,
'8': 56,
'9': 57,
'A': 65,
'B': 66,
'C': 67,
'D': 68,
'E': 69,
'F': 70,
'G': 71,
'H': 72,
'I': 73,
'J': 74,
'K': 75,
'L': 76,
'M': 77,
'N': 78,
'O': 79,
'P': 80,
'Q': 81,
'R': 82,
'S': 83,
'T': 84,
'U': 85,
'V': 86,
'W': 87,
'X': 88,
'Y': 89,
'Z': 90,
'NUMPAD_0': 96,
'NUMPAD_1': 97,
'NUMPAD_2': 98,
'NUMPAD_3': 99,
'NUMPAD_4': 100,
'NUMPAD_5': 101,
'NUMPAD_6': 102,
'NUMPAD_7': 103,
'NUMPAD_8': 104,
'NUMPAD_9': 105,
'MULTIPLY': 106,
'ADD': 107,
'SUBSTRACT': 109,
'DECIMAL': 110,
'DIVIDE': 111,
'F1': 112,
'F2': 113,
'F3': 114,
'F4': 115,
'F5': 116,
'F6': 117,
'F7': 118,
'F8': 119,
'F9': 120,
'F10': 121,
'F11': 122,
'F12': 123,
'SHIFT': 16,
'CTRL': 17,
'ALT': 18,
'PLUS': 187,
'COMMA': 188,
'MINUS': 189,
'PERIOD': 190,
'BACK_TICK': 192,
'LEFT_BRACKET': 219,
'RIGHT_BRACKET': 221
};
root.RL.Input = Input;
}(this));
