Number sequence handler for Mousetrap

mousetrap.numbers.js

/**
 * Mousetrap numbers plugin -- add support for 'number' and 'numbers' keywords
 *
 * Usage:
 *
 *   Mousetrap.bind('number', callback)  - handle any single number
 *
 *   Mousetrap.bind('numbers', callback) - handle a sequence of 1+ numbers
 *
 *   // pre sequence
 *   Mousetrap.bind('a b numbers', callback) - handle a sequence of 'a b' followed by any numbers
 *
 *   // post sequence
 *   Mousetrap.bind('numbers a b', callback) - handle a sequence of numbers followed by 'a b'
 *
 * callback receives (event, combo, numbers).
 *
 * Note: the array form of bind() is NOT supported for numbers, ie,
 *   Mousetrap.bind(['numbers'], callback) - NO!
 *
 * To use multiple number sequences -- instantiate new Mousetraps (as of v1.5):
 *
 *   (new Mousetrap()).bind('numbers g', gotoPage)
 *   (new Mousetrap()).bind('numbers f', gotoForm)
 *
 *
 * Created by github.com/moos on 4/4/15.
 * 
 * MIT License
 */

!(function(Mousetrap) {

  var NUMBERS = '0,1,2,3,4,5,6,7,8,9';
  var SEQ_TIMEOUT = 1000;

  var origBind = Mousetrap.prototype.bind;
  Mousetrap.prototype.bind = function(keys, callback, action) {

    // don't handle arrays
    if (keys instanceof Array) {
      return origBind.apply(this, arguments);
    }

    var key = keys,
      combo = key;

    // special key
    if (key === 'number') {
      this._bindMultiple.call(this, NUMBERS.split(','), callback, action);
      return this;
    }

    // numbers sequence!
    if (/numbers/.test(key)) {

      // remove numbers
      key = key.replace(/\s*numbers\s*/,'');

      // make sure multiple spaces in a row become a single space
      key = key.replace(/\s+/g, ' ');

      var trapNumbers = new TrapNumbers(callback, combo, !key);

      // bind post/pre sequence if any
      if (key) this._bindMultiple.call(this, [key], bind(trapNumbers.onSeqComplete, trapNumbers), action);

      // bind numbers
      this.bind('number', bind(trapNumbers.onNumber, trapNumbers), action);

      return this;
    }

    // normal case
    return origBind.apply(this, arguments);
  };


  var bind = function(fn, context){
    return function() {
      fn.apply(context, arguments);
    };
  };

  function TrapNumbers(callback, combo, seqOK){
    this.numbers = [];
    this.combo = combo;
    this.keyTimer = null;
    this.callback = callback;
    this.executeOnLast = /numbers$/.test(combo);
    this.seqOK = seqOK;
  }

  TrapNumbers.prototype = {
    onNumber: function(e, key) {
      this.numbers.push(key);
      this.keyPing();
      this.lastEvent = e;
    },

    keyPing: function(){
      var self = this;
      if (this.keyTimer) {
        clearTimeout(this.keyTimer);
      }

      // clear the numbers after a while
      this.keyTimer = setTimeout(function(){
        if (self.executeOnLast) self.execute();
        self.reset();
      }, SEQ_TIMEOUT);
    },

    reset: function(){
      this.numbers = [];
      this.seqOK = false;
    },

    execute: function(){
      if (this.seqOK && this.numbers.length) {
        this.callback( this.lastEvent, this.combo, this.getNumber());
        this.reset();
        return true;
      }
      return false;
    },

    getNumber: function(){
      return Number(this.numbers.join(''));
    },

    /**
     * sequence complete handler - seq. can be either before or after numbers.
     */
    onSeqComplete: function() {
      this.seqOK = true;
      if (!this.executeOnLast && this.execute()) return;

      // must be before -- remember seq OK and ping timer
      // also: reset any previously entered numbers
      this.reset();
      this.seqOK = true;
      this.keyPing();
    }
  };

}) (Mousetrap);