Baidu space popup Result Analysis page 1/3

The pop-up window and drag-and-drop effect of Baidu space looks quite good. Currently, many well-known websites use this technology. Next we will put my down JS Code I analyzed some of them, but there are still many things that I don't understand. I didn't write comments. Please help me explain them. I am a beginner. Please give me some advice on anything wrong.
Let's declare one piece. This code is only used for learning. The technology copyright belongs to Baidu.
It is mainly a file called: Popup. JS, as follows:
/**//*********************************** * *********** Popup. JS *************************************** ***********/
// Add a push method for the array Array
// Add an object to the end of the array
If (! Array. Prototype. Push)
{
Array. Prototype. Push = function ()
{
VaR startlength = This. length;
For (VAR I = 0; I <arguments. length; I ++)
{
This [startlength + I] = arguments [I];
}
Return this. length;
}
};

// Process G Function Parameters
Function g ()
{
// Define an array to save Parameters
VaR elements = new array ();
// Cyclically analyze the parameters in G
For (VAR I = 0; I <arguments. length; I ++)
{
VaR element = arguments [I];

// If the parameter type is string, the object with this parameter as ID is obtained.
If (typeof element = 'string ')
{
Element = Document. getelementbyid (element );
}
// If the parameter length is 1
If (arguments. Length = 1)
{
Return element;
}
// Add the object to the end of the array
Elements. Push (element );
};
Return elements;
};

Function. Prototype. Bind = function (object)
{
VaR _ method = this;
Return function ()
{
_ Method. Apply (object, arguments );
};
};

// Bind events
Function. Prototype. bindaseventlistener = function (object)
{
VaR _ method = this;
Return function (event) {__ method. Call (object, event | window. Event );};
};

Object. Extend = function (destination, source)
{
For (property in source)
{
Destination [property] = source [property];
};
Return destination;
};

If (! Window. Event)
{
VaR event = new object ();
};

Object. Extend (
Event,

{
Observers: false,
Element: function (Event)
{
Return event.tar GET | event. srcelement;
},

Isleftclick: function (Event)
{
Return (event. Which) & (event. Which = 1) | (event. Button) & (event. Button = 1 )));
},

Pointerx: function (Event)
{
Return event. pagex | (event.clientx((document.doc umentelement. scrollleft | document. Body. scrollleft ));
},

Pointery: function (Event)
{
Return event. Pagey | (event.clienty((document.doc umentelement. scrolltop | document. Body. scrolltop ));
},

Stop: function (Event)
{
If (event. preventdefault)
{
Event. preventdefault ();
Event. stoppropagation ();
}
Else
{
Event. returnvalue = false;
Event. cancelbubble = true;
};
},

Findelement: function (event, tagname)
{
VaR element = event. element (event );
While (element. parentnode &&(! Element. tagname | (element. tagname. touppercase ()! = Tagname. touppercase ())))
Element = element. parentnode;
Return element;
},

_ Observeandcache: function (element, name, observer, usecapture)
{
If (! This. Observers)
This. Observers = [];
If (element. addeventlistener)
{
This. Observers. Push ([element, name, observer, usecapture]);
Element. addeventlistener (name, observer, usecapture );
}
Else if (element. attachevent)
{
This. Observers. Push ([element, name, observer, usecapture]);
Element. attachevent ('on' + name, observer );
};
},

Unloadcache: function ()
{
If (! Event. Observers)
Return;
For (VAR I = 0; I <event. Observers. length; I ++)
{
Event. stopobserving. Apply (this, event. Observers [I]);
Event. Observers [I] [0] = NULL;
};
Event. Observers = false;
},

Observe: function (element, name, observer, usecapture)
{
VaR element = g (element );
Usecapture = usecapture | false;
If (name = 'keypress' & (navigator. appversion. Match (/Konqueror | safari | khtml/) | element. attachevent ))
Name = 'keylow ';
This. _ observeandcache (element, name, observer, usecapture );
},

Stopobserving: function (element, name, observer, usecapture)
{
VaR element = g (element );
Usecapture = usecapture | false;
If (name = 'keypress' & (navigator. appversion. Match (/Konqueror | safari | khtml/) | element. detachevent ))
Name = 'keylow ';
If (element. removeeventlistener)
{
Element. removeeventlistener (name, observer, usecapture );
}
Else if (element. detachevent)
{
Element. detachevent ('on' + name, observer );
};
}
}
);