Tutorials

jQuery Dock Menu Tutorial Revisit - Dock at Bottom

Written by Kevin Liew on 15 Jun 2009
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56 comments

Introduction

Alright, just before we start, you might want to read this post - Dock Content Tutorial with jQuery and jQuery Easing Plugin. That tutorial teaches us how to create a dock at the top of a website. I have received many requests in the comment section and my emails, so I have decided to make a revisit. In this tutorial, we're going to learn how to make it dock at the bottom.

However, we are going to enhance this dock even better and smarter.

  • Reduce the amount of HTML and CSS code
  • Smarter javascript to handle the height and position
  • Graceful degradation, make sure the dock display correctly even if javascript is disabled.

Dock at the bottom is different with the one on the top, we have some questions to answer. For example, the browser scrollbar problem. What if the page length is too long? How are we going to set the position of the dock and so on.

Please refer to the image below:

Structure for jQuery Scroll To Tab Menu

There are two sections:

  • #fake_body : With this DIV, we will able to solve the page length problem. We will set the overflow to auto, so that it will display a scrollbar. The height of this DIV is always calculated with jQuery to make sure the browser's default scrollbar is hidden. The height of #fake_body equal to the height of browser window minus the dock's height.
  • #dock : We will use javascript to set the position to absolute and top value for this DIV. In case browser doesnt support javascript, everything will just display correctly.

1. HTML

It's so simple and clean, I guess, I don't have to explain anything about it. :)

<div id="fake-body">

	<!-- Put your entire website in this section -->

</div>

<div id="dock">
	<!-- Put your dock in this section -->
</div>

2. CSS

There are three things:

  1. BODY : body's margin and padding must set to 0, otherwise, it will mess up the height calculation in jQuery.
  2. #fake-body : Overflow is set to auto, so that a scroll bar is displayed.
  3. #dock : You need to set the Expanded Height for the #dock. It's has two reasons: if javascript is disabled, the dock in full size will be displayed in the bottom of the page and we will need it for jquery calculations (position and height for #fake_body and #dock).
/* 
margin and padding must be 0,
otherwise, you have to set it in jQuery
*/
body {
margin:0; 
padding:0
}

#fake-body {
overflow:auto;
z-index:1;
}

#dock {
background:#ccc;
height:200px;
z-index:100;
width:100%;
}

3. Javascript

I have put comments in every single lines, if you have any questions, please drop me a comment.

$(document).ready(function() {

	//Transition you want :)
	var easing_type = 'easeOutBounce';
	
	//The default height for the dock (on mouse out)
	var default_dock_height = '40';
	
	//Expanded height, the height of the dock on mouse over, you have to set it in CSS
	var expanded_dock_height = $('#dock').height();
	
	//Fake body height
	var body_height = $(window).height() - default_dock_height;
	
	//Set the size of #fake_body
	$('#fake-body').height(body_height);
	
	//Set the CSS attribute for #dock
	$('#dock').css({'height': default_dock_height, 'position':'absolute', 'top': body_height});
	
	//In case the user resize the browser, we will need to recalculate the height and top for #fake_body and #dock
	$(window).resize(function () {
		
		//Grab the updated height/top
		updated_height = $(window).height() - default_dock_height;
		
		//Set the updated height for #fake_body and top for #dock
		$('#fake-body').height(updated_height);		
		$('#dock').css({'top': updated_height});
	});
		
	//The main event for the dock bottom menu
	$('#dock').mouseover(function () {
		
		//Recalculate expanded height (always get the latest height), in case user has resized the window
		expanded_height = $(window).height() - expanded_dock_height;
		
		//Animate the height change, set the height to expanded_dock_height and set the top value as well
		$(this).animate({'height':expanded_dock_height,'top': expanded_height},{queue:false, duration:800, easing: easing_type});
		
	}).mouseout(function () {
		
		//Recalculate default body height (always get the latest height), in case user has resized the window
		body_height = $(window).height() - default_dock_height;
		
		//Animate the height change, set the height to default_dock-height and set the top value as well
		$(this).animate({'height':default_dock_height,'top': body_height},{queue:false, duration:800, easing: easing_type});
		
	});
	
});

Conclusion

That's it. I'm so tempted to create a plugin for this. Anyway, make sure you check out the demo and download the source code to play with it. If you have created your own, feel free to drop your link in the comment section to show off! : )

Last but not least, I need your support :) If you like this article, please help me to promote it by adding this post into your bookmark. Or you can subscribe to my RSS for more jQuery tutorial posts! Thanks!

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56 comments
Csaba 10 years ago
This is really something new and interesting. JQuery is great and your tutorial too. Keep your great work !
Reply
Özgür Vestanbul 10 years ago
Really Great tutorial. I liked it...
Reply
JDStraughan 10 years ago
Added to tutlist.com. Great tutorial
Reply
Better Tomo 10 years ago
Great tutorial !
I like it .
Reply
Pradeep CD 10 years ago
Nice technique.. thanks..
Reply
Joe 10 years ago
It's nice but it plays with my scroll bars in Firefox (3.0.11). It overlaps them before you hover and when you hover it makes them flicker. I like this tutorial though :)
Reply
Eric Slaton 10 years ago
What is the deal with this thing docking in the middle of a page when you extend your content down!
Anyone implemented this into a full site?
Reply
kevin Admin 10 years ago
@eric: Hi Eric,

you have implemented it wrongly.

You forgot to wrap your content with the #fake_body DIV. It will look something like this:

<body>
<div id="#fake_body">
..... your entire web content put in here...
</div>
<div id="#dock">
..... dock content.....
</div>
</body>
Reply
Eric Slaton 10 years ago
Even if i change fake_body to body_wrapper or some other name in my CSS/js and html, shouldnt it work?
Reply
kevin Admin 10 years ago
@Eric: Yes, you did the changes correctly, but your header is not in the bodywrapper. The height of the bodywrapper is calculated based on the height of the window. But, because of your header, it adds extra 100++px and causing the display of browser default scrollbar.

you need to put ur bodywrapper after <body> ...

Reply
Eric Slaton 10 years ago
Hey Kevin, I just saw that while ago! But now my header is cutting off on the sides.
I am just going to recode the page and my CSS
This is just too awesome to give up on! Man you respond quickly!!! Thanks!
Reply
kevin Admin 10 years ago
@Eric: no worries, I'm right in front of my computer now, so I can respond your question... anyway, thanks for your support :)
Reply
Eric Slaton 10 years ago
Awesome Kevin! I will be here all night i am sure! LOL
I have been neglecting jumping into jQuery since my clients dont understand it, they dont want any of it! So I am just doing it, adding in some plug-ins, until I build up my own personal arsenal of jQuery knowledge.
But I built upon the fake_body instead of adding in my CSS beyond that so therefore the mess up in my height!
Reply