Fixed position element pushed out of relative position element? - javascript

So i have the following HTML markup;
<div id ="page_shadow">
<div id="blog_content">
<div id="main_content_container>
Main Content
</div>
<div id="swrapper">
<div id="blog_sidebar">
Sidebar Content
</div>
</div>
</div>
</div>
The following CSS;
#blog_sidebar.fixed {
position: fixed;
top: 0;
}
#swrapper {
position:absolute;
right:0;
}
#blog_sidebar {
width: 330px;
padding:10px;
padding-top:25px;
height:auto;
}
#main_content_container {
width:600px;
float:left;
height:auto;
padding-bottom:15px;
}
#blog_content {
position:relative;
width:960px;
margin-left:auto;
margin-right:auto;
min-height:1300px;
height:auto;
background:#FFFFFF;
z-index:5;
}
#page_shadow {
background:url('../images/background_shadow.png') top center no-repeat;
padding:10px;
margin-top:-60px;
}
The following javascript;
<script>
$(document).ready(function(){
var top = $('#blog_sidebar').offset().top - parseFloat($('#blog_sidebar').css('marginTop').replace(/auto/, 0));
var bottom = $('#blog_content').position().top+$('#blog_content').outerHeight(true) - $('#blog_sidebar').height() - 35;
$(window).scroll(function (event) {
// what the y position of the scroll is
var y = $(this).scrollTop();
// whether that's below the form
if (y >= top) { //&& y <= bottom
// if so, ad the fixed class
$('#blog_sidebar').addClass('fixed');
} else {
// otherwise remove it
$('#blog_sidebar').removeClass('fixed');
}
});
});
</script>
Ok so basically there are two scenarios which occur. IF the page is loaded with the browser viewport above the y position before #blog_sidebar's position is changed to fixed then the element stays within the blog_content container.
HOWEVER, if the page is loaded with if (y >= top) = True resulting in $('#blog_sidebar').addClass('fixed'); the element is then pushed outside the blog_content container.
Again this only occurs if the viewport is = or below the trigger when the page is loaded.
For example if i were to go half way down the page and then click for the page to refresh, the browser loads the page and the element and then jumps to the position it was previously. The fixed position element shown up in the correct position for a split second and then jumps outside #blog_content aligning with the left of the element.
Ive got a little example to show the basics of the layout etc, but i dont think i can show exactly whats happening within jsfiddle. http://jsfiddle.net/ce3V3/
TLDR
Since this is quite confusing. Short version is i am changing a static positioned element with a fixed position element within the DOM, which is resulting in the fixed positioned element being out of place if the window is refreshed and jumps past a certain point. I dont want the fixed position element to jump out of place if a user relaods the page and the window jumps halfway down the page.

Related

Eliminate horizontal scroll of a relative positioned div

I want to keep a div (id='fixedDiv') at the top of the window while the user scrolls up and down the webpage. The page has another much taller div (id='tallDiv'). I want the user to scroll the page up and down to see the content of tallDiv, and fixedDiv to always be displayed at the top of the window during the scrolling.
The problem is if the user does a horizontal scroll, tallDiv appears to move left or right, while fixedDiv stays put. My question is how do I keep tallDiv from "moving?"
I tried to detect a horizontal scroll in the $(window).scroll event by keeping track of $(document).scrollLeft() and setting tallDiv's position to 'fixed' during a horizontal scroll. I then use a timer to set tallDiv's position back to 'relative' But that gets ugly.
Does anyone have any ideas on how I can accomplish what I want? My code follows:
function SetScrollable() {
$('#tallDiv').css('position', 'relative');
}
var lastScrollLeft;
$(window).scroll(function (event) {
// what the y position of the scroll is
var documentScrollLeft = $(document).scrollLeft();
if (lastScrollLeft != documentScrollLeft) {
lastScrollLeft = documentScrollLeft;
$('#tallDiv').css('position', 'fixed');
setTimeout('SetScrollable()', 500);
}
else {
$('#tallDiv').css('position', 'relative');
}
});
<form id="form1" runat="server">
<div id="fixedDiv" style="position:absolute;background-color:yellow; height:40px; width:40px;" >
</div>
<div id="tallDiv" style="position:relative; left:300px; top:0px; background-color:green; height:400px; width:40px;" >
</div>
</form>
can you position the tallDiv absolute and right aligned? (ex:position absolute; right: 100px;)

Finding where element meets top of scrollable div

I have a scrollable div container fits multiple "pages" (or div's) inside of it's container.
My goal is to, at any given moment, figure out where inside my red container does it reach the top of my scrollable container. So it can be a constant on scroll event, or a button that triggers this task.
So for example. If I have a absolute div element inside one of my red boxes at top:50px. And if I scroll to where that div element reaches the top of my scrollable container. The trigger should say that I am at 50px of my red container.
I'm having a hard time grasping how to accomplish this but I've tried things like:
$("#pageContent").scroll(function(e) {
console.log($(this).scrollTop());
});
But it doesn't take into account the separate pages and I don't believe it it completely accurate depending on the scale. Any guidance or help would be greatly appreciated.
Here is my code and a jsfiddle to better support my question.
Note: If necessary, I use scrollspy in my project so I could target which red container needs to be checked.
HTML
<div id="pageContent" class="slide" style="background-color: rgb(241, 242, 247); height: 465px;">
<div id="formBox" style="height: 9248.627450980393px;">
<div class="trimSpace" style="width: 1408px; height: 9248.627450980393px;">
<div id="formScale" style="width: 816px; -webkit-transform: scale(1.7254901960784315); display: block;">
<form action="#" id="XaoQjmc0L51z_form" autocomplete="off">
<div class="formContainer" style="width:816px;height:1056px" id="xzOwqphM4GGR_1">
<div class="formContent">
<div class="formBackground">
<div style="position:absolute;top:50px;left:100px;width:450px;height:25px;background-color:#fff;color:#000;">When this reaches the top, the "trigger" should say 50px"</div>
</div>
</div>
</div>
<div class="formContainer" style="width:816px;height:1056px" id="xzOwqphM4GGR_2">
<div class="formContent">
<div class="formBackground"><div style="position:absolute;top:50px;left:100px;width:450px;height:25px;background-color:#fff;color:#000;">This should still say 50px</div></div>
</div>
</div>
</form>
</div>
</div>
</div>
</div>
CSS
#pageContent {
position:relative;
padding-bottom:20px;
background-color:#fff;
z-index:2;
overflow:auto;
-webkit-overflow-scrolling: touch;
-webkit-transform: translate(0, 0);
-moz-transform: translate(0, 0);
-ms-transform: translate(0, 0);
transform: translate(0, 0);
}
#formBox {
display: block;
position: relative;
height: 100%;
padding: 15px;
}
.trimSpace {
display: block;
position: relative;
margin: 0 auto;
padding: 0;
height: 100%;
overflow: hidden;
}
#formScale::after {
display: block;
content:'';
padding-bottom:5px;
}
#formScale {
position:relative;
width:816px;
margin:0;
-webkit-transform-origin: 0 0;
-moz-transform-origin: 0 0;
transform-origin: 0 0;
-ms-transform-origin: 0 0;
}
.formContainer {
position:relative;
margin : 0 auto 15px auto;
padding:0;
}
.formContent {
position:absolute;
width:100%;
height:100%;
}
.formBackground {
width:100%;
height:100%;
background-color:red;
}
JS
var PAGEWIDTH = 816;
$(window).resize(function (e) {
zoomProject();
resize();
});
function resize() {
$("#pageContent").css('height', window.innerHeight - 45 + 'px');
}
function zoomProject() {
var maxWidth = $("#formBox").width(),
percent = maxWidth / PAGEWIDTH;
$("#formScale").css({
'transform': 'scale(' + percent + ')',
'-moz-transform': 'scale(' + percent + ')',
'-webkit-transform': 'scale(' + percent + ')',
'-ms-transform': 'scale(' + percent + ')'
});
$(".trimSpace").css('width', (PAGEWIDTH * percent) + 'px');
$("#formBox, .trimSpace").css('height', ($("#formScale").height() * percent) + 'px');
}
zoomProject();
resize();
EDIT:
I don't think I am conveying a good job at relaying what I want to accomplish.
At the moment there are two .formContainer's. When I scroll #pageContainer, the .formContainer divs move up through #pageContainer.
So what I want to accomplish is, when a user clicks the "ME" button or #click (as shown in the fiddle below), I'd like to know where in that particular .formContainer, is it touching the top of #pageContainer.
I do use scroll spy in my real world application so I know which .formContainer is closest to the top. So if you just want to target one .formContainer, that is fine.
I used these white div elements as an example. If I am scrolling #pageContainer, and that white div element is at the top of screen as I am scrolling and I click on "ME", the on click trigger should alert to me that .formContainer is touching the top of #pageContainer at 50px from the top. If, the the red container is just touching the top of #pageContainer, it should say it is 0px from the top.
I hope that helps clear up some misconception.
Here is an updated jsfiddle that shows the kind of action that I want to happen.
I am giving this a stab because I find these things interesting. It might just be a starting point since I have a headache today and am not thinking straight. I'd be willing to bet it can be cleaned up and simplified some.
I also might be over-complicating the approach I took, getting the first visible form, and the positioning. I didn't use the getBoundingClientRect function either.
Instead, I approached it trying to account for padding and margin, using a loop through parent objects up to the pageContent to get the offset relative to that element. Because the form is nested a couple levels deep inside the pageContent element you can't use position(). You also can't use offset() since that changes with scroll. The loop approach allowed me to factor the top margin/padding in. I haven't looked at the other solutions proposed fully so there might be a shorter way to accomplish this.
Keeping in mind that the scale will affect the ACTUAL location of the child elements, you have to divide by your scale percentage when getting the actual location. To do that I moved the scalePercentage to a global var so it was usable by the zoom function and the click.
Here's the core of what I did. The actual fiddle has more logging and junk:
var visForm = getVisibleForm();
var formTop = visForm.position().top;
var parents = visForm.parentsUntil('#pageContent');
var truOffset = 0;
parents.each(function() {
truOffset -= $(this).position().top;
});
// actual location of form relative to pageContent visible pane
var formLoc = truOffset - formTop;
var scaledLoc = formLoc / scalePercent;
Updated Fiddle (forgot to account for scale in get func): http://jsfiddle.net/e6vpq9c8/5/
If I understand your question correctly, what you want is to catch when certain descendant elements reach the top of the outer container, and then determine the position of the visible "page" (div with class formContainer) relative to the top.
If so, the first task is to mark the specific elements that could trigger this:
<div class='triggerElement' style="position:absolute;top:50px;left:100px;width:450px;height:25px;background-color:#fff;color:#000;">When this reaches the top, the "trigger" should say 50px"</div>
Then the code:
// arbitrary horizontal offset - customize for where your trigger elements are placed horizontally
var X_OFFSET = 100;
// determine once, at page load, where outer container is on the page
var outerContainerRect;
$(document).ready(function() {
outerContainerRect = $("#pageContent").get(0).getBoundingClientRect();
});
// when outer container is scrolled
$("#pageContent").scroll(function(e) {
// determine which element is at the top
var topElement = $(document.elementFromPoint(outerContainerRect.left+X_OFFSET, outerContainerRect.top));
/*
// if a trigger element
if (topElement.hasClass("triggerElement")) {
// get trigger element's position relative to page
console.log(topElement.position().top);
}
*/
var page = topElement.closest(".formContainer");
if (page.length > 0) {
console.log(-page.get(0).getBoundingClientRect().top);
}
});
EDIT: Changed code to check formContainer elements rather than descendant elements, as per your comment.
http://jsfiddle.net/j6ybgf58/23/
EDIT #2: A simpler approach, given that you know which formContainer to target:
$("#pageContent").scroll(function(e) {
console.log($(this).scrollTop() - $("#xzOwqphM4GGR_1").position().top);
});
http://jsfiddle.net/rL4Ly3yy/5/
However, it still gives different results based on the size of the window. This seems unavoidable - the zoomProject and resize functions are explicitly resizing the content, so you would have to apply the inverse transforms to the number you get from this code if you want it in the original coordinate system.
I do not fully understand what it is that you are needing, but if i am correct this should do the trick
$("#pageContent").scroll(function(e) {
// If more then 50 pixels from the top has been scrolled
// * if you want it to only happen at 50px, just execute this once by removing the scroll listener on pageContent
if((this.scrollHeight - this.scrollTop) < (this.scrollHeight - 50)) {
alert('it is');
}
});
ScrollHeight is the full height of the object including scrollable pixels.
ScrollTop is the amount of pixels scrolled from the top.
You can use waypoints to detect the position of divs based on where you're scrolling.
Here is a link to their official website's example: http://imakewebthings.com/waypoints/shortcuts/inview/

Bring an element to top of the page even if the page does not scroll

Background:
Let's say you have a simple page which has a logo and a heading only and one paragraph
<img src="http://blog.stackoverflow.com/wp-content/uploads/StackExchangeLogo1.png">
<h1>Foo Bar</h1>
<p>ABC12345</p>
This is how that looks like
That page, obviously would not have vertical overflow / scroll bar for almost even tiny scale mobile devices, let alone computers.
Question
How can you bring that heading to the top left of the screen and move the logo out of focus unless someone scrolls up? Open to using any JavaScript library and any CSS framework
Attempts:
Tried using anchors but they only work if the page already had a scroll bar and anchor was out of focus.
Tried window.scrollTo but that also requires the page to have scroll already
Tried $("html, body").animate({ scrollTop: 90}, 100); but that also doesn't work when the page doesn't have overflow
Notes:
Please note that adding some extra <br/> to induce an overflow is not the way to go, it can be done that way but that's a very ordinary workaround
Why is it needed?
Its for a form for mobile devices, simple requirement is to take the first field of the form to top of the page and hide the logo (one can scroll up if they wish to see it) so it doesn't take attention away. Not using jQueryMobile for this particular task.
If you want the user to be able to scroll up and see the logo, then the logo must be within the top boundary of the body tag, because anything outside of that tag will not be viewable. This means you cannot use negative margins or offsetting like that. The only way to achieve this is to have the page scroll to the desired location that is within the top boundary of the body tag. You can set the time for this event to one millisecond, but there will still be a 'jump' in the page when it is loaded. So, the logic is: first make sure the page is long enough to scroll to the right place, then scroll there.
//Change the jQuery selectors accordingly
//The minimum height of the page must be 100% plus the height of the image
$('body').css('min-height',$(document).height() + $('img').height());
//Then scroll to that location with a one millisecond interval
$('html, body').animate({scrollTop: $('img').height() + 'px'}, 1);
View it here.
Alternatively, you can load the page without the image in the first place. Then your form field will be flush with the top of the document. Then you could create the element at the top and similarly scroll the page again. This is a round-a-bout way of doing the same thing though. And the page will still 'jump,' there is no way around that.
Only CSS and anchor link solution
With a pseudo element :
--- DEMO ---
First :
set : html,body{height:100%;}
Second :
Choose one of your existing tags. This tag mustn't have a relatively positioned parent (except if it is the body tag). Preferably the first element in the markup displayed after the logo. For your example it would be the h1 tag. And give it this CSS :
h1:before {
content:"";
position:absolute;
height:100%;
width:1px;
}
This creates an element as heigh as the viewport area. As it is displayed under the logo, the vertical scroll lenght is the same as the logo height.
Third :
Give the first element after logo an id (for this example I gave id="anchor").
Then you can use a link like this your_page_link#anchor and you will automaticaly scroll to the anchor (logo outside/above the viewport).
This works whatever height the logo is.
link to editable fiddle
Full code :
HTML
<img src="http://blog.stackoverflow.com/wp-content/uploads/StackExchangeLogo1.png">
<h1 id="anchor">Foo Bar</h1>
<p>ABC12345</p> Anchor link
CSS
html, body {
height:100%;
margin:0;
padding:0;
}
h1:before {
content:"";
position:absolute;
width:1px;
left:0;
height:100%;
}
You might need to add js functionality to hide the logo if user scrolls down but I guess following code will fullfill the first requirement.
Please see
<script src="js/jquery.js"></script>
<img id='logo' src="http://blog.stackoverflow.com/wp-content/uploads/StackExchangeLogo1.png" style="display:none">
<h1>Foo Bar</h1>
<p>ABC12345</p>
<script type="text/javascript">
var p = $( "p:first" );
var isScrolled=false;
/* For Firfox*/
$('html').on ('DOMMouseScroll', function (e) {
isScrolled = true;
if(p.scrollTop()==0 && isScrolled==true){
$('#logo').css('display','block');
}
});
/* For Chrome, IE, Opera and Safari: */
$('html').on ('mousewheel', function (e) {
isScrolled = true;
if(p.scrollTop()==0 && isScrolled==true){
$('#logo').css('display','block');
}
});
</script>
I have referred this question to find solution.
You could use touchmove event to detect swipe up or down. This is my example. You can try it on mobile device.
<style>
#logo {
position: absolute;
top: -100%;
-webkit-transition: top 0.5s;
-moz-transition: top 0.5s;
-ms-transition: top 0.5s;
-o-transition: top 0.5s;
transition: top 0.5s;
}
#logo.show {
top: 0;
}
</style>
<script>
var perY;
var y;
$(window).on('touchmove', function(e) {
e.preventDefault();
y = window.event.touches[0].pageY;
if(!perY)
perY = y;
else
{
if(y > perY)
$('#logo').addClass('show');
else
$('#logo').removeClass('show');
perY = null;
}
});
</script>
<img id="logo" src="http://blog.stackoverflow.com/wp-content/uploads/StackExchangeLogo1.png">
<h1>Foo Bar</h1>
<p>ABC12345</p>
This is the same problem i've encountered hiding the addressbar without the page overflowing. The only solution that fitted my needs was the following:
Set the min-height of the body to the viewportheight + your logo.
$('body').css('min-height', $(window).height() + 200);
This is a simple solution of getting the height of the contents to see if we can scroll to the part of the header, if not, we add height to the paragraph.
<img id="img" src="http://blog.stackoverflow.com/wp-content/uploads/StackExchangeLogo1.png" />
<h1 id="h" >Foo Bar</h1>
<p id="par" style="background:yellow;">
hello world
</p>
script:
function hola(){
var imgH = $("#img").outerHeight(true);
var titleH = $("#h").outerHeight(true);
var winH = $(window).height();
var parH = $('#par').outerHeight(true);
var contH = (imgH + titleH + parH);
var wishH = (imgH + winH);
console.log("wished height: " + wishH);
console.log("window height: " + winH);
console.log("content height: " + contH);
if(contH < wishH){
console.log("window is smaller than desired :(");
var newH = wishH - contH;
$("#par").height(parH + newH);
$(window).scrollTop(imgH);
}
}
Here is the working example:
http://jsfiddle.net/Uup62/1/
You may like this solution: http://jsfiddle.net/jy8pT/1/
HTML:
<div class="addScroll"></div>
<h1 class="logo"><img src="https://drupal.org/files/images/OQAAAI1PPrJY0nBALB7mkvju3mkQXqLmzMhxEjeb4gp8aujEUQcLfLyy-Sn4gZdkAas6-k8eYbQlGDE-GCjKfF5gIrUA15jOjFfLRv77VBd5t-WfZURdP9V3PdmT.png" height="100" alt="company logo"/></h1>
<h2>This is a sample page heading.</h2>
<p>This is a sample page text.</p>
JS:
function addScroll()
{
$(".addScroll").css({
"height": ($(window).height()+1) + "px",
"width": "100%"
});
}
$(document).ready(function(){
addScroll();
$(window).resize(function(){
addScroll();
});
$(window).scroll(function(){
if($(window).scrollTop() > 0)
{
$(".logo").animate({
marginTop: "-110px"
}, 500);
}
if($(window).scrollTop() == 0)
{
$(".logo").animate({
marginTop: "0"
}, 500);
}
});
});
CSS:
body
{
padding:0;
margin:0;
}
h1.logo
{
display:block;
margin:0 0 10px 0;
padding:0;
outline:0;
}
.addScroll
{
position:absolute;
display:block;
top:0;
left:0;
z-index:-1;
}

How do I stop an inheritly positioned element from jumping up page when I change the div above it to fixed?

Okay so I have a page that uses javascript to fix the header to the top of the page (thus removing the banner) when you scroll past the bottom of the banner (about 200px down page).
On this website I've been using containers that have the position:inherit; property set to contain each part of the page. These then have a relatively positioned element inside them so I can place all my absolutely positioned elements where I like.
My problem is that id="content" keeps jumping to the top of the page when the javascript changes id="header" to position:fixed;
See here: www.obsojb.com
I have tried absolutely positioning id="content" and setting it's top value but it wouldn't work and I'm a bit stuck.
Here is a very simplified version of the HTML:
<body>
<div id="page"> <!--inherit-->
<a id="banner"></a> <!--inherit-->
<div id="header"> <!--inherit-->
<div id="lang"> <!--relative-->
<ul>...</ul> <!--inherit-->
<other divs> <!--absolute-->
</div>
<div id="nav"> <!--relative-->
<ul>..</ul> <!--inherit-->
<a id="userbutton"></a> <!--absolute-->
</div>
</div
<div id="content0"> <!--inherit-->
<div id="content"> <!--relative-->
<PAGE CONTENT> <!--absolute-->
</div>
</div>
<div id="footer"></div>
</div>
</body>
Here is my javascript:
var bannerheight // Glob var
window.onload = function() {
window.bannerheight = $('#bannerimg').height();
checkOffset();
};
window.onscroll = function(oEvent) {
checkOffset();
}
function checkOffset() {
if (window.pageYOffset >= window.bannerheight) {
document.getElementById("header").style.position = "fixed";
document.getElementById("banner").style.display = "none";
document.getElementById("padding").style.height = window.bannerheight+"px";
}
else {
document.getElementById("header").style.position = "inherit";
document.getElementById("banner").style.display = "block";
document.getElementById("padding").style.height = "0px";
}
}
and here is the relevant CSS:
#page {
margin:0px auto;
}
#lang {
position:relative;
}
#nav {
position:relative;
margin:0px auto;
}
#content0 {
height:800px;
}
#content {
position:relative;
margin:0px auto;
}
Try giving the content div a "margin-top" and set it to the number of pixels that the page is "jumping". Then when you scroll up and reset the position, undo the margin-top back to zero.
I've tested this and it solved my jumping issue.
I'm not sure what you expect as output but position: fixed works on the document, globally. It not only ignores element flow (like position: absolute) but it also ignores scrolling.
position: absolute is relative to it's offset parent which can be an item with position: relative.
You typically only want to use position: fixed if something needs to stick to the window, like a little popup that scrolls with as you go down the page. The Facebook header is a good example. Their header bar is fixed to the top of the window and stays there even if you scroll.

How to get the div top position value while scrolling

I am trying to run some script when div reaches to a certain point when it's scrolled. There is a fixed navigation and when the user scrolls the window it suppose change the nav name once it reaches close to the nav. I am using the $(window).scroll function but it only checking the div position once and not updating the value. How to make scroll check the window size every 5-10 px move so that it doesn't take too much memory/processing.
The code is set up at: http://jsfiddle.net/rexonms/hyMxq/
HTML
<div id="nav"> NAVIGATION
<div class="message">div name</div>
</div>
<div id="main">
<div id="a">Div A</div>
<div id ="b"> Div B</div>
<div id ="c"> Div C</div>
</div>​
CSS
#nav {
height: 50px;
background-color: #999;
position:fixed;
top:0;
width:100%;
}
#main{
margin-top:55px;
}
#a, #b, #c {
height:300px;
background-color:#ddd;
margin-bottom:2px;
}
SCRIPT
$(window).scroll(function() {
var b = $('#b').position();
$('.message').text(b.top);
if (b.top == 55) {
$('.message').text("Div B");
}
});​
Try this jsFiddle example
$(window).scroll(function() {
var scrollTop = $(window).scrollTop(),
divOffset = $('#b').offset().top,
dist = (divOffset - scrollTop);
$('.message').text(dist);
if (b.top == 55) {
$('.message').text("Div B");
}
});​
Your original code was only checking the position of the div relative to the top of the document which never changes. You need to calculate in the amount of scroll the window has incurred and calculate accordingly.
Also note the difference beyween jQuery's .position() and .offset() methods. The .position() method allows us to retrieve the current position of an element relative to the offset parent. Contrast this with .offset(), which retrieves the current position relative to the document.

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