keycharm.js

"use strict";
/**
 * Created by Alex on 11/6/2014.
 */

// https://github.com/umdjs/umd/blob/master/returnExports.js#L40-L60
// if the module has no dependencies, the above pattern can be simplified to
(function (root, factory) {
  if (typeof define === 'function' && define.amd) {
    // AMD. Register as an anonymous module.
    define([], factory);
  } else if (typeof exports === 'object') {
    // Node. Does not work with strict CommonJS, but
    // only CommonJS-like environments that support module.exports,
    // like Node.
    module.exports = factory();
  } else {
    // Browser globals (root is window)
    root.keycharm = factory();
  }
}(this, function () {

  function keycharm(options) {
    var preventDefault = options && options.preventDefault || false;

    var container = options && options.container || window;

    var _exportFunctions = {};
    var _bound = {keydown:{}, keyup:{}};
    var _keys = {};
    var i;

    // a - z
    for (i = 97; i <= 122; i++) {_keys[String.fromCharCode(i)] = {code:65 + (i - 97), shift: false};}
    // A - Z
    for (i = 65; i <= 90; i++) {_keys[String.fromCharCode(i)] = {code:i, shift: true};}
    // 0 - 9
    for (i = 0;  i <= 9;   i++) {_keys['' + i] = {code:48 + i, shift: false};}
    // F1 - F12
    for (i = 1;  i <= 12;   i++) {_keys['F' + i] = {code:111 + i, shift: false};}
    // num0 - num9
    for (i = 0;  i <= 9;   i++) {_keys['num' + i] = {code:96 + i, shift: false};}

    // numpad misc
    _keys['num*'] = {code:106, shift: false};
    _keys['num+'] = {code:107, shift: false};
    _keys['num-'] = {code:109, shift: false};
    _keys['num/'] = {code:111, shift: false};
    _keys['num.'] = {code:110, shift: false};
    // arrows
    _keys['left']  = {code:37, shift: false};
    _keys['up']    = {code:38, shift: false};
    _keys['right'] = {code:39, shift: false};
    _keys['down']  = {code:40, shift: false};
    // extra keys
    _keys['space'] = {code:32, shift: false};
    _keys['enter'] = {code:13, shift: false};
    _keys['shift'] = {code:16, shift: undefined};
    _keys['esc']   = {code:27, shift: false};
    _keys['backspace'] = {code:8, shift: false};
    _keys['tab']       = {code:9, shift: false};
    _keys['ctrl']      = {code:17, shift: false};
    _keys['alt']       = {code:18, shift: false};
    _keys['delete']    = {code:46, shift: false};
    _keys['pageup']    = {code:33, shift: false};
    _keys['pagedown']  = {code:34, shift: false};
    // symbols
    _keys['=']     = {code:187, shift: false};
    _keys['-']     = {code:189, shift: false};
    _keys[']']     = {code:221, shift: false};
    _keys['[']     = {code:219, shift: false};



    var down = function(event) {handleEvent(event,'keydown');};
    var up = function(event) {handleEvent(event,'keyup');};

    // handle the actualy bound key with the event
    var handleEvent = function(event,type) {
      if (_bound[type][event.keyCode] !== undefined) {
        var bound = _bound[type][event.keyCode];
        for (var i = 0; i < bound.length; i++) {
          if (bound[i].shift === undefined) {
            bound[i].fn(event);
          }
          else if (bound[i].shift == true && event.shiftKey == true) {
            bound[i].fn(event);
          }
          else if (bound[i].shift == false && event.shiftKey == false) {
            bound[i].fn(event);
          }
        }

        if (preventDefault == true) {
          event.preventDefault();
        }
      }
    };

    // bind a key to a callback
    _exportFunctions.bind = function(key, callback, type) {
      if (type === undefined) {
        type = 'keydown';
      }
      if (_keys[key] === undefined) {
        throw new Error("unsupported key: " + key);
      }
      if (_bound[type][_keys[key].code] === undefined) {
        _bound[type][_keys[key].code] = [];
      }
      _bound[type][_keys[key].code].push({fn:callback, shift:_keys[key].shift});
    };


    // bind all keys to a call back (demo purposes)
    _exportFunctions.bindAll = function(callback, type) {
      if (type === undefined) {
        type = 'keydown';
      }
      for (var key in _keys) {
        if (_keys.hasOwnProperty(key)) {
          _exportFunctions.bind(key,callback,type);
        }
      }
    };

    // get the key label from an event
    _exportFunctions.getKey = function(event) {
      for (var key in _keys) {
        if (_keys.hasOwnProperty(key)) {
          if (event.shiftKey == true && _keys[key].shift == true && event.keyCode == _keys[key].code) {
            return key;
          }
          else if (event.shiftKey == false && _keys[key].shift == false && event.keyCode == _keys[key].code) {
            return key;
          }
          else if (event.keyCode == _keys[key].code && key == 'shift') {
            return key;
          }
        }
      }
      return "unknown key, currently not supported";
    };

    // unbind either a specific callback from a key or all of them (by leaving callback undefined)
    _exportFunctions.unbind = function(key, callback, type) {
      if (type === undefined) {
        type = 'keydown';
      }
      if (_keys[key] === undefined) {
        throw new Error("unsupported key: " + key);
      }
      if (callback !== undefined) {
        var newBindings = [];
        var bound = _bound[type][_keys[key].code];
        if (bound !== undefined) {
          for (var i = 0; i < bound.length; i++) {
            if (!(bound[i].fn == callback && bound[i].shift == _keys[key].shift)) {
              newBindings.push(_bound[type][_keys[key].code][i]);
            }
          }
        }
        _bound[type][_keys[key].code] = newBindings;
      }
      else {
        _bound[type][_keys[key].code] = [];
      }
    };

    // reset all bound variables.
    _exportFunctions.reset = function() {
      _bound = {keydown:{}, keyup:{}};
    };

    // unbind all listeners and reset all variables.
    _exportFunctions.destroy = function() {
      _bound = {keydown:{}, keyup:{}};
      container.removeEventListener('keydown', down, true);
      container.removeEventListener('keyup', up, true);
    };

    // create listeners.
    container.addEventListener('keydown',down,true);
    container.addEventListener('keyup',up,true);

    // return the public functions.
    return _exportFunctions;
  }

  return keycharm;
}));