Develop Reference

Scrolling based on mouse position retaining click events in the foreground

So I have a very wide div within a smaller div. The inner div scrolls left and right depending on mouse position.
I adapted the code from this answer... https://stackoverflow.com/a/6137535/3656408
There are two transparent divs on top of everything, from which the position of the mouse is attained, which gives a speed at which to scroll.
The problem with this is anything underneath these divs is not clickable.
My div has a fixed width and height so I potentially could calculate the scroll speed from where the mouse is on the page ( ie. the page is 620px wide so I know 310 is half way )
Unfortunately my maths is terrible and I can't figure out how to convert my thought process into acceptable working code.
Anyone have any suggestions?
Heres how it currently figures out the rate at which to move the page...
$('.direction', backdrop).mousemove(function(e){
var $this = $(this);
var left = $this.is('.left');
if (left){
var w = $this.width();
rate = (w - e.pageX - $(this).offset().left + 1)/w;
}
else{
var w = $this.width();
rate = -(e.pageX - $(this).offset().left + 1)/w;
}
});
.. and you can see it in action here http://thetally.efinancialnews.com/tallyassets/20years/index.html

OK I figure it out...
$( document ).mousemove(function(e){ //if mouse moves on page
if (e.pageX <= 620 && e.pageY <= 600){ //and if its not outside the extents of the div
if (e.pageX <= 310){ //if its less than half way across
rate = (310 - e.pageX)/50;
} else { // if its more than half way across
rate = -( e.pageX - 310)/50;
}
}
});

jQuery height doesn't equal scrollTop

In my jquery I am trying to calculate when the scrollbar is 100px from the bottom, and when it gets there I will do an ajax query (for now I am doing an alert as you can see).
$(document).on("scroll", function(e){
var scrollHeight = $(document).height();
var offset = $(document).scrollTop();
console.log(scrollHeight);
console.log(offset);
if(scrollHeight - offset <= 100){
alert("here");
}
});
For some reason that I can not figure out it doesn't work. If I scroll to the bottom I would assume that the height() would equal scrollTop() but it doesn't, and here is what it shows:
scrollHeight = 1923
offset = 998
Am I using the wrong methods for this?

You need to add the height of the window with scrollTop. Link
$(document).on('scroll', function () {
var docHeight = $(document).height(),
scrollTop = $(document).scrollTop(),
windowHeight = $(window).height();
if (docHeight - (scrollTop + windowHeight) <= 100) {
alert(docHeight - (scrollTop + windowHeight));
}
});

Looks like you might be forgetting to subtract the pane's view-able height. I've done something similar in my code here:
var scrollPos = $('#viewable-div').height() - $('#scrolling-content').height();
if ($("#scrolling-content").scrollTop() > (scrollPos - 100)) {
//load more
}

When you scroll the element all the way down, scrollHeight should be equal to scrollTop + clientHeight.
If the element has no scrollbars scrollWidth/Height should be equal to clientWidth/Height.
• When the element has no scrollbars IE makes the scrollHeight equal to the actual height of the content; and not the height of the element. scrollWidth is correct, except in IE8, where it’s 5 pixels off.
• Opera gives odd, incorrect values.

You can use a statement like this
((container.scrollTop() + container.height() + detectionOffset) >=
container.get(0).scrollHeight)
Where container could be the document.body and detectionOffset would be 100

This has been answered a few times before, including here
One piece of code that I'm using and is always working (even on Opera) is this:
$(window).on("scroll", function () {
var scrollHeight = $(document).height();
var scrollPosition = $(window).height() + $(window).scrollTop();
if ((scrollHeight - scrollPosition) / scrollHeight === 0) {
/* Do something */
}
});

Change position of div based on mouse pointer

I am trying to position a div based on mouse position, I managed to get it to work 50%.
The problem is that DIV always seems to be much lower than the actual mouse position, I try to minus the offset, no luck.
Basically what I want is to float the div(the NEXT link in jsfiddle) vertically, but the DIV should not be able to go outside of the container it is in(the div that has the image in the jsfiddle)
here is the jsfiddle: http://jsfiddle.net/LYmVH/7/
below is the JS, which is also in the jsfiddle:
$('.post-single-content').mousemove(function(e){
var height=e.pageY,
height1 =$('.content-top').height();
$('.btnNext').css({top: (e.pageY + 50) + "px"});
});

You need measure against the top of the parent element since it's absolutely positioned in it.
Try changing your JS to:
$('.post-single-content').mousemove(function(e){
var top = (e.pageY - $(this).offset().top) + 'px';
$('.btnNext').css({ top: top });
});
Upon reading some comments lemme update, by making use some basic math and create "collision". Somthing like:
$('.post-single-content').mousemove(function(e){
var y = e.pageY, // mouse y axis position
tHeight = $(this).height(), // container height
bHeight = $('.btnNext').height(), // button height
oTop = $(this).offset().top, // offset top position of container
abBot = tHeight - $('.btnNext').height(), // absolute top of button when at bottom
bHalf = bHeight / 2, // half button height
top = y - oTop - bHalf, // initial top pos of button
bot = y - oTop + bHalf; // bottom of button while moving
if (top < 0) top = 0; // ensure button doesn't go to far north
else if (bot > tHeight) top = abBot; // ensure it cant go past south
$('.btnNext').css({ top: top }); // 'px' not neccesary
});
jsFiddle

Animate {"Top"} how to stop scrolling div on top position being 0 px - Jquery

Trying to create a scrolling div. Wanted to stop (thescrollingdiv) div once it has reached a particular top position and scrolled all the way to the bottom and not overshoot the parent div into infinity scrolling zone. thescrollingdiv does not have any height specified but its parent div does.Thanks.
$('#div a).click(function(e){
e.preventDefault();
$('#thescrollingdiv').stop(true,true).animate({ "top": '-=100px'}, 500)

ScrollTop tells you where you are at. Check the existing top against scrolltop and work the math to set your limits.
var scrollTop = $('#thescrollingdiv').scrollTop();
var newTop = parseFloat($('#thescrollingdiv').css('top')) - 100;
if (scrollTop < 0) {
newTop = 0;
}
$('#thescrollingdiv').stop(true,true).animate({ "top": newTop}, 500)
UPDATE
Something like this.
var topLimit = 0;
var bottomLimit = 800;
var containerTop = parseFloat($('container').css('top'));
var containerBottom = parseFloat($('container').css('height')) + containerTop;
var destination = containerTop - 100;
// compensate for going too far up
destination = (destination < 0) ? 0 : destination;
// compensate for going too far up
destination = (containerBottom > bottomLimit) ? bottomLimit : destination;
// now that you know you are within your custom limits, animate it.
animate(destination);
This is almost pseudo code as I don't know what your code looks like, but it gives you an idea. You have to actually DO THE WORK in setting the limits for your 'newTop', before you call animate in the first place.
You can figure it out. Don't be a lazy programmer, though.

How to determine if you have scrolled to the bottom of an element?

How will you determine if you have reached the bottom of an element? For instance you have a div with a height of 2000px, then the viewport is only 600px tall. With these in place, how will you know how much scroll value you need to know if it's already the bottom of the 2000px div?

You can use something like this:
var $element = $('div');
$(window).scroll(function() {
var scroll = $(window).scrollTop() + $(window).height();
var offset = $element.offset().top + $element.height();
if (scroll > offset) {
$element.css('background', 'blue');
} else {
$element.css('background', 'red');
}
});
Demo: http://jsfiddle.net/eNjEs/5/