/*!
* jQuery UI Touch Punch 0.2.1
*
* Copyright 2011, Dave Furfero
* Dual licensed under the MIT or GPL Version 2 licenses.
*
* Depends:
* jquery.ui.widget.js
* jquery.ui.mouse.js
*/
(function ($) {

  // Detect touch support
  $.support.touch = 'ontouchend' in document;

  // Ignore browsers without touch support
  if (!$.support.touch) {
    return;
  }

  var mouseProto = $.ui.mouse.prototype,
      _mouseInit = mouseProto._mouseInit,
      touchHandled;

  /**
* Simulate a mouse event based on a corresponding touch event
* @param {Object} event A touch event
* @param {String} simulatedType The corresponding mouse event
*/
  function simulateMouseEvent (event, simulatedType) {

    // Ignore multi-touch events
    if (event.originalEvent.touches.length > 1) {
      return;
    }

    event.preventDefault();

    var touch = event.originalEvent.changedTouches[0],
        simulatedEvent = document.createEvent('MouseEvents');
    
    // Initialize the simulated mouse event using the touch event's coordinates
    simulatedEvent.initMouseEvent(
      simulatedType, // type
      true, // bubbles
      true, // cancelable
      window, // view
      1, // detail
      touch.screenX, // screenX
      touch.screenY, // screenY
      touch.clientX, // clientX
      touch.clientY, // clientY
      false, // ctrlKey
      false, // altKey
      false, // shiftKey
      false, // metaKey
      0, // button
      null // relatedTarget
    );

    // Dispatch the simulated event to the target element
    event.target.dispatchEvent(simulatedEvent);
  }

  /**
* Handle the jQuery UI widget's touchstart events
* @param {Object} event The widget element's touchstart event
*/
  mouseProto._touchStart = function (event) {

    var self = this;

    // Ignore the event if another widget is already being handled
    if (touchHandled || !self._mouseCapture(event)) {
      return;
    }

    // Set the flag to prevent other widgets from inheriting the touch event
    touchHandled = true;

    // Track movement to determine if interaction was a click
    self._touchMoved = false;

    // Simulate the mouseover event
    simulateMouseEvent(event, 'mouseover');

    // Simulate the mousemove event
    simulateMouseEvent(event, 'mousemove');

    // Simulate the mousedown event
    simulateMouseEvent(event, 'mousedown');
  };

  /**
* Handle the jQuery UI widget's touchmove events
* @param {Object} event The document's touchmove event
*/
  mouseProto._touchMove = function (event) {

    // Ignore event if not handled
    if (!touchHandled) {
      return;
    }

    // Interaction was not a click
    this._touchMoved = true;

    // Simulate the mousemove event
    simulateMouseEvent(event, 'mousemove');
  };

  /**
* Handle the jQuery UI widget's touchend events
* @param {Object} event The document's touchend event
*/
  mouseProto._touchEnd = function (event) {

    // Ignore event if not handled
    if (!touchHandled) {
      return;
    }

    // Simulate the mouseup event
    simulateMouseEvent(event, 'mouseup');

    // Simulate the mouseout event
    simulateMouseEvent(event, 'mouseout');

    // If the touch interaction did not move, it should trigger a click
    if (!this._touchMoved) {

      // Simulate the click event
      simulateMouseEvent(event, 'click');
    }

    // Unset the flag to allow other widgets to inherit the touch event
    touchHandled = false;
  };

  /**
* A duck punch of the $.ui.mouse _mouseInit method to support touch events.
* This method extends the widget with bound touch event handlers that
* translate touch events to mouse events and pass them to the widget's
* original mouse event handling methods.
*/
  mouseProto._mouseInit = function () {
    
    var self = this;

    // Delegate the touch handlers to the widget's element
    self.element
      .bind('touchstart', $.proxy(self, '_touchStart'))
      .bind('touchmove', $.proxy(self, '_touchMove'))
      .bind('touchend', $.proxy(self, '_touchEnd'));

    // Call the original $.ui.mouse init method
    _mouseInit.call(self);
  };

})(jQuery);