Develop Reference

jQuery Menu how to contain submenus within Div

I am trying to create an 'application' contained in a div on a web page. This can't be any larger than certain dimensions (lets say: 550px by 280px). I have a menu with at least 1-3 sub menus for each item. The problem is, while I know the submenu is no larger than 280px high, the submenus often extend beyond the parent div's bounds (except for the last one which always grows upward not down).
Is there any way to make the menus grow up or down depending on whether it will extend beyond the div's bounds?
Here is a JSFiddle: http://jsfiddle.net/3FqcG/
Notice how the "Salzburg" submenu grows down beyond the bounds of the black DIV? I want that to grow up if it is too long and down if there is enough room.
Currently, I am just using the basic initialization: $( "#menu" ).menu();
Thanks!

I don't believe you can do this in CSS.
This leaves us with javascript. The basic idea is to:
calculate the baseline of the menu
if this lies outside the boundary
move the menu upwards to correct the position
live almost happily ever after
But, we have one major issue:
Though we capture the focus of an element, we don't know when its submenu is displayed & positioned. So although your problem is technically solved, it is by far not a desirable solution.
UPDATE
The best workaround I could come up with was to:
Turn off the animation (to avoid ugly glitches)
Add a watcher that would constantly monitor the element that is about to be opened
If opened, apply the position correction
Anyway, if you consider coming this far, you might as well override the default positioning of the jquery ui component, with the note that you will not be able to easily update the library. Update: or try Rudy Garcia's version if it works
Demo
Code of the demo:
var BASE_OFFSET = $('#menuContainer').offset().top;
var MAX_OFFSET = $('#menuContainer').height(); // get the offset of the container
var whenVisible = function($el, callback){ //executes callback when $el is visible
if($el.is(':visible')){ // if visible
callback(); // execute callback
}else{ // otherwise
setTimeout(function(){whenVisible($el, callback);},10); // do the same check in 10 ms
}
};
var fixPosition = function($menu){ // correct the position of the menu in respect to #menuContainer
var h = $menu.outerHeight(true); // take the height of the menu
var menuBottom = $menu.offset().top + h - BASE_OFFSET; // the baseline of the menu (taking into consideration the BASE_OFFSET)
if(menuBottom > MAX_OFFSET){ // if this is outside the MAX height
var diff = MAX_OFFSET - menuBottom; // calculate the difference
var newTop = $menu.position().top + diff; // modify current positioning with the calculated diff value
$menu.css('top', newTop + 'px'); // apply it to top (which is also used by jquery to position submenus
}
$.fx.off = false; // switch animations back on
};
$( "#menu" ).menu().on('menufocus', function(ev, ui){ // on the event menufocus
var $ui = $(ui.item); //take the focused element
var $menu = $ui.children('ul'); // take its related submenu
if($menu.length === 0){ // if there is none
return; // just terminate
}
$.fx.off = true; // switch off jQuery effects (otherwise you'll have glitches)
whenVisible($menu, function(){fixPosition($menu);}); // execute fixPosition when $menu is visible
});

You could also look at the API for this widget:
http://api.jqueryui.com/menu/
You can use the position option to position the elements how you want.
This will change the position so that they are within the box, however you will want to dynamically access the last to give it the position you want as the code below will change all menu items to move up 50.
$( "#menu" ).menu({ position: { my: "left top", at: "right+5 top-50" } });
A complete list of positioning options are also found here: http://api.jqueryui.com/position/
Apparently jquery UI has accounted for this and has given the option "within" to make sure your element stays within another element of your choice.
Therefore Your solution should be this:
$( "#menu" ).menu({ position: {within: '#menuContainer' } });

How to check each new scroll and avoid Apple mouses issue (multiple-scroll effect)

I try to make a mousewheel event script, but getting some issues since I'm using an Apple Magic Mouse and its continue-on-scroll function.
I want to do this http://jsfiddle.net/Sg8JQ/ (from jQuery Tools Scrollable with Mousewheel - scroll ONE position and stop, using http://brandonaaron.net/code/mousewheel/demos), but I want a short animation (like 250ms) when scrolling to boxes, AND ability to go throught multiple boxes when scrolling multiple times during one animation. (If I scroll, animation start scrolling to second box, but if I scroll again, I want to go to the third one, and if I scroll two times, to the forth, etc.)
I first thought stopPropagation / preventDefault / return false; could "stop" the mousewheel velocity (and the var delta) – so I can count the number of new scroll events (maybe with a timer) –, but none of them does.
Ideas?
EDIT : If you try to scroll in Google Calendars with these mouses, several calendars are switched, not only one. It seems they can't fix that neither.
EDIT 2 : I thought unbind mousewheel and bind it again after could stop the mousewheel listener (and don't listen to the end of inertia). It did not.
EDIT 3 : tried to work out with Dates (thanks to this post), not optimal but better than nothing http://jsfiddle.net/eZ6KE/

Best way is to use a timeout and check inside the listener if the timeout is still active:
var timeout = null;
var speed = 100; //ms
var canScroll = true;
$(element).on('DOMMouseScroll mousewheel wheel', function(event) {
// Timeout active? do nothing
if (timeout !== null) {
event.preventDefault();
return false;
}
// Get scroll delta, check for the different kind of event indexes regarding delta/scrolls
var delta = event.originalEvent.detail ? event.originalEvent.detail * (-120) : (
event.originalEvent.wheelDelta ? event.originalEvent.wheelDelta : (
event.originalEvent.deltaY ? (event.originalEvent.deltaY * 1) * (-120) : 0
));
// Get direction
var scrollDown = delta < 0;
// This is where you do something with scrolling and reset the timeout
// If the container can be scrolling, be sure to prevent the default mouse action
// otherwise the parent container can scroll too
if (canScroll) {
timeout = setTimeout(function(){timeout = null;}, speed);
event.preventDefault();
return false;
}
// Container couldn't scroll, so let the parent scroll
return true;
});
You can apply this to any scrollable element and in my case, I used the jQuery tools scrollable library but ended up heavily customizing it to improve browser support as well as adding in custom functionality specific to my use case.
One thing you want to be careful of is ensuring that the timeout is sufficiently long enough to prevent multiple events from triggering seamlessly. My solution is effective only if you want to control the scrolling speed of elements and how many should be scrolled at once. If you add console.log(event) to the top of the listener function and scroll using a continuous scrolling peripheral, you will see many mousewheel events being triggered.
Annoyingly the Firefox scroll DOMMouseScroll does not trigger on magic mouse or continuous scroll devices, but for normal scroll devices that have a scroll and stop through the clicking cycle of the mouse wheel.

I had a similar problem on my website and after many failed attempts, I wrote a function, which calculated total offset of selected box and started the animation over. It looked like this:
function getOffset() {
var offset = 0;
$("#bio-content").children(".active").prevAll().each(function (i) {
offset += $(this)[0].scrollHeight;
});
offset += $("#bio-content").children(".active")[0].scrollHeight;
return offset;
}
var offset = getOffset();
$('#bio-content').stop().animate( {
scrollTop: offset
}, animationTime);
I hope it gives you an idea of how to achieve what you want.

you can try detecting when wheel stops moving, but it would add a delay to your response time
$(document).mousewheel(function() {
clearTimeout($.data(this, 'timer'));
$.data(this, 'timer', setTimeout(function() {
alert("Haven't scrolled in 250ms!");
//do something
}, 250));
});
source:
jquery mousewheel: detecting when the wheel stops?
or implement flags avoiding the start of a new animation
var isAnimating=false;
$(document).bind("mousewheel DOMMouseScroll MozMousePixelScroll", function(event, delta) {
event.preventDefault();
if (isAnimating) return;
navigateTo(destination);
});
function navigateTo(destination){
isAnimating = true;
$('html,body').stop().animate({scrollTop: destination},{complete:function(){isAnimating=false;}});
}

javascript bind an event handler to horizontal scroll

Is there a way in javascript to bind an event handler to a horizontal scroll as opposed to the generic scroll event which is fired when the user scrolls horizontally and vertically? I want to trigger an event only when the user scrolls horizontally.
I searched around for an answer to this question, but couldn't seem to find anything.
Thanks!
P.S. My apologies if I'm using some terminology incorrectly. I'm fairly new to javascript.
UPDATE
Thanks so much for all your answers! In summary, it looks like you are all saying that this isn't supported in javascript, but I that I can accomplish the functionality with something like this (using jQuery) (jsFiddle):
var oldScrollTop = $(window).scrollTop();
$(window).bind('scroll', function () {
if (oldScrollTop == $(window).scrollTop())
//scrolled horizontally
else {
//scrolled vertically
oldScrollTop = $(window).scrollTop();
}
});​
That's all I needed to know. Thanks again!

Answering from my phone, so unable to provide code at the moment.
What you'll need to do is subscribe to the scroll event. There isn't a specific one for vertical/horizontal.
Next, you'll need to get some measurements about the current display area. You'll need to measure the window.clientHeight and window.clientWidth.
Next, get window.top and window.left. This will tell you where position of the viewport is, ie if it's greater than 0 then scroll bars have been used.
It's pretty simple math from here to get what you need. If no one else has provided a code example in the next few hours I'll try to do so.
Edit:
A bit further information.
You must capture the scroll event. You also need to store the initial window.top and window.left properties somewhere. Whenever the scroll event happens, do a simple check to see if the current top/left values differ from the stores value.
At this point, if either are different you can trigger your own custom events to indicate vertical or horizontal scrolling. If you are using jQuery, this is very easy. If you are writing js without library assistance, it's easy too but a little more involved.
Do some searches for event dispatching in js.
You can then write any other code you want to subscribe to your custom events without needing to tie them together with method calls.

I wrote a jQuery plugin for you that lets you attach functions to the scrollh event.
See it in action at jsfiddle.net.
/* Enable "scrollh" event jQuery plugin */
(function ($) {
$.fn.enableHScroll = function() {
function handler(el) {
var lastPos = el
.on('scroll', function() {
var newPos = $(this).scrollLeft();
if (newPos !== lastPos) {
$(this).trigger('scrollh', newPos - lastPos);
lastPos = newPos;
}
})
.scrollLeft();
}
return this.each(function() {
var el = $(this);
if (!el.data('hScrollEnabled')) {
el.data('hScrollEnabled', true);
handler(el);
}
});
}
}(jQuery));
It's this easy to use:
$('#container')
.enableHScroll()
.on('scrollh', function(obj, offset) {
$('#info').val(offset);
});
Please note that scroll events come very fast. Even if you click in the scrollbar to jump to a new position, many scroll events are generated. You may want to adjust this code to wait a short time and accumulate all the changes in position during that time before firing the hscroll event.

You can use the same scroll event, but within your handler use the scrollLeft function to see if the scrollbar moved horizontally from the last time the event was fired. If the scrollbar did not move then just return from your handler. Otherwise update your variable to the new position and take action.

You can check if the the x value of the page changes and ignore your y value.
If the x value changes: There is your horizontal scroll.

With page-load, store the initial scrollbar positions for both in two variables (presumably both will be 0). Next, whenever a scroll event occurs, find the scrollleft and scrolltop properties. If the scrollleft property's value is different and scrolltop's value is same as compared to their earlier values, that's a horizontal scroll. Then set the values of the variables to the new scroll values.

No, there is no special event for scroll horizontal (it is for global scroll), but you can try to check the position of content by property .scrollLeft and if it's different from the previous value it means that the user scrolled content horizontally.

How do I stop a bouncy JQuery animation?

In a webapp I'm working on, I want to create some slider divs that will move up and down with mouseover & mouseout (respectively.) I currently have it implemented with JQuery's hover() function, by using animate() and reducing/increasing it's top css value as needed. This works fairly well, actually.
The problem is that it tends to get stuck. If you move the mouse over it (especially near the bottom), and quickly remove it, it will slide up & down continuously and won't stop until it's completed 3-5 cycles. To me, it seems that the issue might have to do with one animation starting before another is done (e.g. the two are trying to run, so they slide back and forth.)
Okay, now for the code. Here's the basic JQuery that I'm using:
$('.slider').hover(
/* mouseover */
function(){
$(this).animate({
top : '-=120'
}, 300);
},
/* mouseout*/
function(){
$(this).animate({
top : '+=120'
}, 300);
}
);
I've also recreated the behavior in a JSFiddle.
Any ideas on what's going on? :)
==EDIT== UPDATED JSFiddle

It isn't perfect, but adding .stop(true,true) will prevent most of what you are seeing.
http://jsfiddle.net/W5EsJ/18/
If you hover from bottom up quickly, it will still flicker because you are moving your mouse out of the div causing the mouseout event to fire, animating the div back down.
You can lessen the flicker by reducing the delay, however it will still be present until the delay is 0 (no animation)
Update
I thought about it and realized that there is an obvious solution to this. Hoverintent-like functionality!
http://jsfiddle.net/W5EsJ/20/
$(document).ready(function() {
var timer;
$('.slider').hover(
/* mouseover */
function(){
var self = this;
timer = setTimeout(function(){
$(self).stop(true,true).animate({
top : '-=120'
}, 300).addClass('visible');
},150)
},
/* mouseout*/
function(){
clearTimeout(timer);
$(this).filter(".visible").stop(true,true).animate({
top : '+=120'
}, 300).removeClass("visible");
}
);
});

You could use .stop() and also use the outer container position
$(document).ready(function() {
$('.slider').hover(
/* mouseover */
function(){
$(this).stop().animate({
top : $('.outer').position().top
}, 300);
},
/* mouseout*/
function(){
$(this).stop().animate({
top : $('.outer').position().top + 120
}, 300);
}
);
});
​
DEMO
Hope this helps

Couldn't reproduce your issue but I believe that hover is getting called multiple times. To work around this you can check if the div is already in animation. If yes, then don't run another animation again.
Add following piece of code to check if the div is already 'animating':
if ($(this).is(':animated')) {
return;
}
Code: http://jsfiddle.net/W5EsJ/2/
Reference:http://api.jquery.com/animated-selector/

I understand the problem and reproduced it, it happens when hovering from the bottom up. The hovering with the mouse is what's causing the problem since the animation function will be called when the mouse hovers over the image. You need to control what happens here by using mouse enter and mouse leave, check out a similar example: Jquery Animate on Hover

The reason it's like that is because the hover is getting queued up causing it to slide up and down multiple times. There's a plug-in called hoverIntent which fixes the issue. http://cherne.net/brian/resources/jquery.hoverIntent.html
If you do decide to use hoverIntent, the only thing you have to change in your code is .hover > .hoverIntent

jquery scroll speed?

this is a script i got from a the internet, and it works perfectly, what it deos it scrolls automatically on the movement of the mouse, over a div in this case scroll, but i cnt seem to find where i can find the speed, or can make it slower!! im so confused!!
$("#scroll").mousemove(function(e){
/* The scrollable quote container */
if(!this.hideDiv)
{
/* These variables are initialised only the firts time the function is run: */
this.hideDiv = $(this);
this.scrollDiv = $('#scroll');
this.pos = this.hideDiv.offset();
this.pos.top+=20;
/* Adding a 20px offset, so that the scrolling begins 20px from the top */
this.slideHeight = this.scrollDiv.height();
this.height = this.hideDiv.height();
this.height-=20;
/* Adding a bottom offset */
this.totScroll = this.slideHeight-this.height;
}
this.scrollDiv.css({
/* Remember that this.scrollDiv is a jQuery object, as initilised above */
marginTop:'-'+this.totScroll*(Math.max(e.pageY-this.pos.top,0)/this.height)+'px'
/* Assigning a negative top margin according to the position of the mouse cursor, passed
with e.pageY; It is relative to the page, so we substract the position of the scroll container */
});
});

The code seems to be just setting the margin directly:
marginTop:'-'+this.totScroll*(Math.max(e.pageY-this.pos.top,0)/this.height)+'px'
That is, it doesn't call any scroll jquery function that could easily be animated. To achieve that you would have to do some rewriting of that code, probably using jquery animate() function with the marginTop css.
The only problem is that the code is called on mousemove, which means that it could easily be called again while the animation is still active. So you will have to come up with some workaround there, like maybe checking first if there is an animation present and aborting it in that case.