Tutorials

Vertical Scroll Menu with jQuery Tutorial

Written by Kevin Liew on 02 Jun 2009
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119 comments

Introduction

Just last week, I came accross to this website Narrow Design. His scroll menu caught a lot of my attentions, I played with it for a while. Yes, unfortunately, it's built in flash. And, Yes, we are going to implement it with jquery - javascript based scroll menu that will do the same thing. Of course, it will not be 100% the same, because some of the fancy features just not that practical to implement with javascript.

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So, in this tutorial, we will learn how to create a scroll menu. We will achieve the following objectives:

  • Keep html as simple as possible, and let jQuery and CSS do the rest.
  • Scoll up and down according to mouse-Y axis
  • Use jQuery.color plugin to animate the background-color changes - download jQuery.color
    (Yes, you will need this to animate the background color, I thought it will do it by default, obviously it doesn't! )

Just before we start, let me explain 3 important jquery methods we're going to use:

1. Get mouse axis

The following code will return the X and Y Axis values for your mouse pointer.

<script>
$(document).mousemove(function(e) {
$('#mouse_axis').html("X Axis : " + e.pageX + " | Y Axis " + e.pageY);
});
</script>

<div id="mouse_axis"></div>
2. Get objects offset

The following code will get the offset Top and Left for an object.

<script>
$(document).ready(function() {	
$('#offset').html("Top : " + $('#sidebar').offset().top + " |Left " 
+ $('#sidebar').offset().left);
});
</script>

<div id="offset"></div>

<br/>
<br/>
<br/>
<div id="Sidebar">A Empty DIV named sidebar</div>
3. Get the total of selected elements by the selector.

It will return the total of selected elements.

$('#menu li').length;

Graphical Explanation

Please refer to the following div structure:

Structure for jQuery Scroll Menu

2 main DIVs #sidebar and #menu:

#sidebar : its overflow property is set to hidden. Overflow set to hidden will truncate/hide #menu's extra length and display the #menu according to the width and height of the #sidebar.

#menu : its position property is set to relative. So that if top property set to 0, #menu will snap to the top of #sidebar. So, even with no javascript, you can test the menu with random negative numbers, for example -30px, -100px or -500px. You will able to see the menu is going up. So, jQuery's job is to generate this negative values. To dynamicly generate these values, we will use the mouse-Y, because we want to scroll it up and down. It's quite complicated to explain, but we will walk through it in javascript section.

1. HTML

As usual, we always keep the HTML code as simple as possible. It's good to not mix javascript with html code to increase readibility and tidiness.

The SPAN in this example can be taken out, I put it in just to immitate the menu from Narrow Design.

<div id="sidebar">
<ul id="menu">
<li><a href="#">MENU 1 <span> / 2007</span></a></li>
<li><a href="#">MENU SIZE 2 <span> / 2007</span></a></li>
<li><a href="#">MENU SIZE LONG 3 <span> / 2007</span></a></li>
<li><a href="#">MENU 4 <span> / 2007</span></a></li>
<li><a href="#">MENU SIZE 5 <span> / 2007</span></a></li>
<li><a href="#">MENU SIZE LONG 6 <span> / 2007</span></a></li>
......
......
......
</ul>
</div>

2. CSS

I have played with this CSS for quite a while to achieve the effect I want and tested it with IE as well. I was having this IE problem, where the position:relative and overflow:hidden just won't work the way it should. Fortunately, I found the solution through this website - solution to position relative and overflow in IE. Bingo, it displays exactly the same now.

#sidebar has to set as overflow:hidden to make sure the extra length in the menu is hidden. And the rest is just basic styling for the menu.

body {
padding:0;
margin:0 20px;
}

#sidebar {
height:400px;
overflow:hidden;
position:relative;
background-color:#eee;
}	

#menu {
width:100%;
list-style:none;
padding:0;
margin:0;
top:0;
position:relative;
height:100%;
width:300px;
}

#menu li {
padding:10px 0;
text-align:right;
display:block;
cursor:hand;
cursor:pointer;
}

#menu li a {
background:url() repeat #1f1f1f;
color:#ddd;
font-family:helvetica, arial, verdana;
font-size:9px;
font-weight:900;
display:inline;
padding:20px 8px 5px 20px;
text-decoration:none;
}

#menu li span {
font-family:georgia, arial;
font-size:9px;
color:#464646;
}

3. Javascript

In javascript section, I have separated all the configurable variables on the top of the script. It'll be easier to convert it to a plugin.

The most important part of this script is the last section - generate the top value based on the mouse Y value to allow user to scroll through the entire menu, and won't be affected by the offset of the sidebar as well. The mathematic equation I'm using, it's not the perfect one, but it works. If you have better suggestions, please drop me a message. : )

$(document).ready(function() {	

	//Background color, mouseover and mouseout
	var colorOver = '#31b8da';
	var colorOut = '#1f1f1f';

	//Padding, mouseover
	var padLeft = '20px';
	var padRight = '20px'
	
	//Default Padding
	var defpadLeft = $('#menu li a').css('paddingLeft');
	var defpadRight = $('#menu li a').css('paddingRight');
		
	//Animate the LI on mouse over, mouse out
	$('#menu li').click(function () {	
		//Make LI clickable
		window.location = $(this).find('a').attr('href');
		
	}).mouseover(function (){
		
		//mouse over LI and look for A element for transition
		$(this).find('a')
		.animate( { paddingLeft: padLeft, paddingRight: padRight}, { queue:false, duration:100 } )
		.animate( { backgroundColor: colorOver }, { queue:false, duration:200 });

	}).mouseout(function () {
	
		//mouse oout LI and look for A element and discard the mouse over transition
		$(this).find('a')
		.animate( { paddingLeft: defpadLeft, paddingRight: defpadRight}, { queue:false, duration:100 } )
		.animate( { backgroundColor: colorOut }, { queue:false, duration:200 });
	});	
	
	//Scroll the menu on mouse move above the #sidebar layer
	$('#sidebar').mousemove(function(e) {

		//Sidebar Offset, Top value
		var s_top = parseInt($('#sidebar').offset().top);		
		
		//Sidebar Offset, Bottom value
		var s_bottom = parseInt($('#sidebar').height() + s_top);
	
		//Roughly calculate the height of the menu by multiply height of a single LI with the total of LIs
		var mheight = parseInt($('#menu li').height() * $('#menu li').length);
	
		//I used this coordinate and offset values for debuggin
		$('#debugging_mouse_axis').html("X Axis : " + e.pageX + " | Y Axis " + e.pageY);
		$('#debugging_status').html(Math.round(((s_top - e.pageY)/100) * mheight / 2));
			
		//Calculate the top value
		//This equation is not the perfect, but it 's very close	
		var top_value = Math.round(( (s_top - e.pageY) /100) * mheight / 2)
		
		//Animate the #menu by chaging the top value
		$('#menu').animate({top: top_value}, { queue:false, duration:500});
	});

	
});

Conclusion

That's it. Make sure you check out the demo and download the source code to play with it. 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 posts. Thanks!

Demo Download
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119 comments
Ezrad Lionel 10 years ago
Wow, I'm very impressed. This menu is really innovative. Say, in a few weeks will you try porting this to Very Versatile Electronic Document VVED? It's almost identical to JQuery, but it's been in development longer and has lots of built in functionailty. Maybe I'll attempt a port then send it to you. Very good job, sir, you should include a menu open transition or something to make me scratch my head and say how'd they do that?? cheers
Reply
sonichtml 10 years ago
Really Cool~~
Reply
Ezrad Lionel 10 years ago
God damn you graceful degradation psychos.
Reply
me 10 years ago
disable JS, doesn't work - bad times

need to fix this before it could be used in production
Reply
kevin Admin 10 years ago
@me, @Soh: yes, declare overflow:hidden in js will do the trick :)...
Reply
Soh 10 years ago
I think maybe just add overflow hidden in the js so if its disabled, you can still access the menu.

Either way, I think its a great concept and I have learned from this tutorial. Thank you!
Reply
ryan sandagon 10 years ago
Nice!

I've done the same menu -- in flash :)
I think adjusting the tweening to make it smoother will help a lot.

Btw, Kevin I'm not sure if you've heard about jQuery Tool. It's a UI library almost similar to the tutorials you've been giving us. You might want to check it here:

http://rsstudioat.blogspot.com/2009/06/jquery-tools-user-interface-component.html
Reply
kevin Admin 10 years ago
@ryan: thanks for the link! well, it's always good and fun to learn how to create it from scratch :)... and it has some benefits, for example, it'd be easier to read our own code than others, and easier to customize as well! :) tho, might have to invest some times and effort on it...
Reply
ryan sandagon 10 years ago
@kevin: Totally agree with you :) It's an added skill and accomplishment too.
Reply
mrSeanG 10 years ago
This is really great.
any chance of a javascript function to automagically get the stage height and then set your containing divs height?

this way you can have a full screen height sized scroller.
I think that paired with a stage.onResize to keep it current in case of a browser resize would be super AWESOME.

I also noticed a small bug: the top item in the UL is REALLY too close to the top and the bottom goes ALL the way up.
The scrolling should really stop before the last item gets past the bottom of the containing item + it's height + a small margin

this way its more congruent to the top item.
Reply
kevin Admin 10 years ago
@mrSeanG: Yes, you can do the full screen scroller. In fact, that was the first version, you have to use jQuery to set the height #sidebar and do it inside onresize event as well.

For the first LI, I, too having some issue with it, can't seem to get the equation right. :(
Reply
Cedric Dugas 10 years ago
Nice, but this is missing a bit of easing, but good work
Reply
D. Shun-Luoi Fong 10 years ago
Would it be possible to change it so that you can do the same thing on a horizontal list of links, i.e. scrolling left/right based on whether you are moving your mouse left/right over the links?
Reply