/*

File: utilities.js

Abstract: Some handy JavaScript utilities.

Version: 1.1

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may be used to endorse or promote products derived from the Apple

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*/

Function.prototype.bind = function(thisObject)

{

    var func = this;

    var args = Array.prototype.slice.call(arguments, 1);

    return function() { return func.apply(thisObject, args.concat(Array.prototype.slice.call(arguments, 0))); };

}

/**

 *  Indicates whether an object is undefined.

 */

function objectIsUndefined(object) {

  return (object === undefined);

}

/**

 *  Indicates whether an object is a Function.

 */

function objectIsFunction(object) {

  return (typeof object == 'function');

}

/**

 *  Indicates whether an object implements a given method, useful to check if a delegate

 *  object implements a given delegate method.

 */

function objectHasMethod(object, methodNameAsString) {

  return (  object !== null &&

            !this.objectIsUndefined(object[methodNameAsString]) &&

            this.objectIsFunction(object[methodNameAsString])

         );

}

/* ==================== Animation Keyframe helpers ==================== */

function findKeyframes(keyframesName)

{

  for (var i = 0; i < document.styleSheets.length; ++i) {

    var curSheet = document.styleSheets[i];

    for (var j = 0; j < curSheet.cssRules.length; ++j) {

      var curRule = curSheet.cssRules[j];

      if (curRule.type == window.CSSRule.WEBKIT_KEYFRAMES_RULE && curRule.name == keyframesName)

        return curRule;

    }

  }

  return null;

}

function createKeyframes(name, keyframes)

{

  // FIXME: Maybe create our own sheet just for these rules so we can remove them all when done.

  var curSheet = document.styleSheets[0];

  curSheet.insertRule('@-webkit-keyframes ' + name + ' { ' + keyframes + ' }', curSheet.rules.length);

}

/* ==================== Element Extensions ==================== */

Element.prototype.removeAllChildren = function ()

{

  while (this.firstChild) {

    this.removeChild(this.firstChild);

  }

};

/**

 *  Indicates whether the element has a given class name within its class attribute.

 */

Element.prototype.hasClassName = function (className) {

  return new RegExp('(?:^|\\s+)' + className + '(?:\\s+|$)').test(this.className);

};

/**

 *  Adds the given class name to the element's class attribute if it's not already there.

 */

Element.prototype.addClassName = function (className) {

  if (!this.hasClassName(className)) {

    this.className = [this.className, className].join(' ').replace(/^\s*|\s*$/g, "");

  }

};

/**

 *  Removes the given class name from the element's class attribute if it's there.

 */

Element.prototype.removeClassName = function (className) {

  if (this.hasClassName(className)) {

    var curClasses = this.className;

    this.className = curClasses.replace(new RegExp('(?:^|\\s+)' + className + '(?:\\s+|$)', 'g'), ' ').replace(/^\s*|\s*$/g, "");

  }

};