I would like an image to become fixed where it is once it appears on screen during a scroll, but become unfixed if the user scrolls back up.
However, when I use a JS on scroll function to change the image position to fixed, it suddenly "jumps"/resizes, and I'm not sure why. My fix was to create variables that alter the width and left values of the image after it becomes fixed, but I want to do this will multiple images on a page and each one seems to require a different width and left adjustment. I'm not sure what is conceptually causing this issue. Simply resetting the width and left to their original values does not work. Does a fixed position resize and image.
Here is a jsfiddle of the issue. And here is the code. JS:
var sitckyImageWidth = "38.4%";
var normalImageWidth = "48%";
document.addEventListener("scroll", function(){
var windowTop = $(window).scrollTop();
var windowWidth = window.innerWidth;
var windowHeight = window.innerHeight;
//loop through each div and grab top/bottom/midpoint info and find id
$('.articles').each(function(i){
var top = $(this).offset().top;
var bottom = top+ $(this).height();
var midPoint = (bottom+top)/2;
var thisId = this.id;
var newId;
//use container div info to find media info
var newId = thisId+"Media";
var sectionImage=document.getElementById(newId);
var sectionImageTop = $(sectionImage).offset().top;
//if article is on the page, change position to fixed and set top position
if (top<=windowTop&&bottom>windowTop){
$(sectionImage).css("top","10px")
$(sectionImage).css("position","fixed")
//$(sectionImage).css("width",sitckyImageWidth)
}
//if container is not at top of the page, return to relative
if (bottom<=windowTop||(bottom>windowTop&&top>windowTop)){
$(sectionImage).css("position","relative")
}
})
}); //end scroll
Position fixed means that an element will have relative sizes and positioning in relation to the viewport, not their parent elements.
Specifically what is happening here is that your div with ID article1Media is set to have a width of 48%. When it has the CSS property of position: relative then that resolves as 48% of the width of it's containing element (the div with id article1) however when it is position fixed that resolves as 48% of the width of the viewport. Since there is an implicit 8px margin on the <body> element then these are different.
There are a few different solutions to this, and how you tackle it depends on how you want to build your site.
Example fix 1
A simple fix for your immediate example is to simply add the following CSS.
body{
margin:0px;
}
.image{
margin:8px;
}
https://jsfiddle.net/Chipmo/k56qkk5b/13/
This moves the implicit margin onto the image element. Of course you can set it to whatever you like, or omit it entirely.
Look into CSS resets for more information about overriding implicit default styles, though be warned that it is possible to cause problems with overzealous reset codes.
( Edit: To be clear the above code is definitely not a drop in code for this problem everywhere. It will only work on quite simple HTML pages like your jsFiddle. )
Example fix 2
Another technique you could consider is locking the width and height to it's initial values using jQuery .width() and .height() functions. This would be inflexible, and you would have to do extra work to make it responsive (for mobile etc), but could be appropriate in some circumstances.
Example fix 3
A more portable solution might be to eschew relative sizing in favour of fixed widths and then use CSS media queries for reponsivity. Something like this:
.image{
width:500px;
}
#media(min-width:800px){
width:300px;
}
Example fix 4
If you wish to preserve the 'fluid' nature of using percentages I would suggest looking into using calc along with an offset that gets applied when the position is fixed (so, you add a class when you make the image fixed) that adjusts the sizing appropriately.
.media.image-fixed{
position:fixed;
width:calc(48% - 8px);
}
See this example https://jsfiddle.net/Chipmo/6mu2Lt9g/2/
Above behavior is observed since because of applying the position property not because of the scroll.Please take a look at the following link Position Properties
Position Fixed : Fixed position elements relative to document not on
any parent container.Hence occupies the complete width available.
Position Relative: Relative positioned elements behaves relative to hosted
containers.And inner elements consumes the hosted parent width.
Related
I have a page where I display a long list of results from a DB query.. and I also show a Google Map to the RIGHT of this long list.
Map is roughly 240px wide and maybe 600px long/height.
This MAP is inside a container DIV (#mapContainer).. that contains the map, and a dropdown box above the map canvas.
Currently, the mapContainer scrolls along with the page itself.. what I would like to do is have it be static/fixed element. So it starts/displays/is placed where I have it currently on the page.... if I scroll the page.. the map should stay fixed.. until the end (bottom) of the results are scrolled to..
(I dont want the mapContainer to scroll and cover the footer element/div)
Following this tutorial:
http://www.webgeekly.com/tutorials/jquery/a-simple-guide-to-making-a-div-static-as-you-scroll-past-it/
It doesnt stay fixed..
//sticky map placement
$(function () {
var msie6 = $.browser == 'msie' && $.browser.version < 7;
if (!msie6) {
console.log("NOT IE 6");
var top = $('#mapContainer').offset().top;
$(window).scroll(function (event) {
console.log("scrolling.......");
var y = $(this).scrollTop();
if (y >= top) {
$('#mapContainer').addClass('fixed');
console.log("class added");
}else {
$('#mapContainer').removeClass('fixed');
console.log("class removed");
}
});
}
});
The first console.log() outputs fine.. but nothign in the window.scroll() portion fires ever.
Rest of code used:
#mapContainer{
display:table;
width:240px;
float:right;
/* sticky map */
position: absolute;
top: 458px;
left: 50%;
/* width: 100px; */
margin-left: 339px;
}
#<span class="skimlinks-unlinked">mapContainer.fixed</span> {
position: fixed;
}
On the tutorials page itself.. he has a toolbar on the left side..
that stops 'being fixed' when you scroll all the way to the top.. (it will start to move with the rest of the page scroll at a certain point).. and it doesnt go all the way down to cover the footer either.
I'm not clear why the jQuery portion isnt firing.. and I'm not clear what that last style is for? (seems odd looking)
All this absolute, fixed, relative, to parent, to viewport..etc.. is confusing.
Any easy to read/follow/understand tutorials that will get me to where I want to be? Or suggestions on what I am doing wrong with the correct approach?
I looked at your Fiddle and noticed a couple things:
Your "fixed" class was not represented in the CSS. When I looked into the CSS I saw a span element wrapping a ".fixed" reference with a position property set.
You are styling the mapContainer div using the ID. This is a very rigid selector as the order of CSS selectors goes. The hierarchy of CSS selectors is specifid and IDs will override types and classes. See: http://htmlhelp.com/reference/css/structure.html
The when scrolling, I am seeing the console logging in my dev tools. Also, when inspecting the element, I am seeing it add and remove the class name.
Based on my observations, modifying the CSS selector for your container should do the trick. Adding the ID to the class will keep the CSS rule specific enough:
#mapContainer.fixed { position: fixed; }
Refer to this updated Fiddle for an example with these changes in place:
http://jsfiddle.net/pmurst8e/4/
Update: For demonstration purposes of what I was referring to with the resize I modified your example a bit. It isn't the prettiest, but it conveys the point: http://jsfiddle.net/pmurst8e/6/
Update: There are a couple issues with the latest Fiddle (v12):
The sidebar will always go fixed the moment you scroll because "top" is never calculated. It's being set to zero, and the offset calculation is commented out.
Absolute positioning is relative to the closest positioned parent. If no parent is positioned, it's relative to the window. To constrain an absolute positioned element, set the constraining parent to "position:relative;".
Instead of using a percentage and left position rule, consider positioning the sidebar to the right, relative to the "contentContainer", by a set number of pixels.
When the fixed position takes effect, we also need to set the sidebar fixed left position. Otherwise, it will use the positioning in the CSS. In contrast to absolute positioning, Fixed positioning is relative to the window, meaning an absolute element "right: 10px" will be 10px from the right of the positioned parent, but will appear 10px from the right of the window when fixed.
You don't need a float when you have absolute positioning. Absolute position removes an element from the normal flow of the document, and because of this float does not apply.
I updated the Fiddle to show how to make these adjustments. I cleaned out the float and margin from the mapContainer and left the absolute positioning. With that I set the contentContainer to relative to constrain mapContainer to it. You will also see, on the script side, I added a line to set the offset of mapContainer. Without this, when it becomes fixed it will be 10px off the right border of the window.
Updated Fiddle: http://jsfiddle.net/pmurst8e/14/
Also, you want to leave your top offset line in tact. Without that, it goes fixed the moment the scroll moves and never goes back. When that becomes the case, you're better off just setting fixed permanently.
var top = $('#mapContainer').offset().top; // you want this
Regarding the bottom boundary, you can do a couple things:
Resize the sidebar so that it shrinks to the window size. This is demoed in my example from my first post in this and the downside is it forces the sidebar to become a scrollable div so the child content is all visible.
Use a check for the bottom so that when you hit the limit, the container goes back to an absolute position, but one set at the bottom: 0 of the parent.
Something like:
var limit = $('footer').offset().top;
var $mc = $('#mapContainer');
var pos = $mc.offset().top + $mc.outerHeight();
if (pos >= limit) {
$mc.removeClass('fixed')
.addClass('bottom-set').css('left',''); // define this in CSS for bottom absoluteness
}
#mapContainer.bottomFixed {
bottom: 0;
top: auto;
}
And to be fully honest, you might save yourself some time working this all out if you take a look at the ScrollToFixed plug-in (https://github.com/bigspotteddog/ScrollToFixed). I seem to be mentioning it quite a bit lately, but this issue seems to be a popular one right now.
Incidentally, go to your OP and click the Edit button. Shrink the height of your browser and scroll down. You should see SO has a fixed sidebar that passed the footer. ;)
So I am redesigning my website: http://staging.slackrmedia.com/keenanpayne/, but I am coming across a small issue. I want each "pane" of the website to be the exact height of the window, no matter what the size. I also want the content therein to be exactly positioned in the center.
I am trying to accomplish this with jQuery at the moment:
function setSectionHeight() {
// Set section heights
windowHeightPadding = $(window).height() / 2;
firstSectionPadding = ($(window).height() - $('header').height()) / 2;
// Apply proper styling
$('section').css({"padding-top":windowHeightPadding,"padding-bottom":windowHeightPadding});
$('section.home').css({"padding-top": firstSectionPadding,"padding-bottom":windowHeightPadding});
}
setSectionHeight();
// Adjust section heights on window resize
$(window).on('resize', function(){
setSectionHeight();
});
So what this is doing is calculating the window height and dividing it by 2, so I can set the top and bottom padding on each section.
However, for the first section, to get the proper top and bottom padding, I need to subtract the height of the header, which is why I have a firstSectionPadding variable.
Then I just add the CSS to each section tag on my website, with separate styling for the home section tag.
This works pretty well, but as you can see when you visit my site, for some reason the heights are not correct.
Right now it looks like:
And it should look like:
I have absolutely no idea where this extra padding or space is coming from on the top. I think my equations are right, but perhaps there isn't something I'm taking into consideration?
This could be done with CSS. One div set to 100% height and width, with text-align:center; A second div within set to display:table and 100% height and width. Finally, a third div set to display:table-cell and vertical-align:center;
I have <div> elements as pages, and "next" and "back" buttons to switch between them. When the "next" button is clicked, the current page fades out and the next page fades in, using jQuery. As I've been doing it so far, the only way to ensure that the divs sit on top of each other instead of sitting next to each other is to style them position:absolute. However, this forces the divs to also overlay anything else on the page that they would otherwise push out of the way.
Is there any way to make divs basically positioned absolute only relative to each other, and still act as though they are positioned relative to the rest of the page? I've tried putting them inside a container that is positioned relatively, but the divs overflow their container, making it more or less useless.
Edit:
Basic fiddle: http://jsfiddle.net/9AXS4/4/
Yes, I mix up $ and jQuery. I've been using jQuery a lot after calling jQuery.noConflict()
If your pages, as you call them, are of fixed width and height, then you can set their container to be position:relative and also have the width and height of the pages..
.container{
position:relative;
width:500px; /*the total width of a page, including padding and borders*/
height:400px; /*the total height of a page, including padding and borders*/
}
This way the container element will handle the pushing around of the other elements
Here is your corrected fiddle: http://jsfiddle.net/gaby/9AXS4/2/
(the width/height of the container must account for paddings and border on the page elements)
Also you were targeting the container with .pagecontainer instead of #pagecontainer (since you used an id)
Update (after comment about arbitrary heights..)
Since your pages height is not fixed, you will need to resort to jQuery to resize the container..
Here is a full demo : http://jsfiddle.net/gaby/9AXS4/7/
The divs can't be positioned absolute in relation to each other, but they can be positioned absolutely in relation to an outer div. The container that holds the page divs should have position: relative in order to contain the inner page divs that are absolutely positioned.
If there is unwanted overlap, you can use overflow: hidden or overflow: auto on the outer div to hide it, depending on whether or not you want to allow for scrolling. If you are going to use the overflow property, be sure to include a height and width so the browser knows where the overflow should be.
http://jsfiddle.net/vkTXs/
$(".page").each(function(){
jQuery(this).hide();
});
$(".page").first().show();
$(".next").click(function() {
jQuery(this)
.parent().fadeOut()
.next().fadeIn();
var page = $(this).parent().next();
resizeContainer(page);
});
$(".back").click(function() {
jQuery(this)
.parent().fadeOut()
.prev().fadeIn();
var page = $(this).parent().next();
resizeContainer(page);
});
function resizeContainer(page){
// get height of next page
var newPageHeight = $(page).height();
// add padding and border
newPageHeight = newPageHeight + 14;
$('#pagecontainer').height(newPageHeight);
}
I'm trying to place an element in a web site at a certain fixed amount of pixels from the viewport top border. The problem is that despite of using absolute positioning, the positioning still depends of the body style. For instance, if the body has relative positioning and a margin top value, then the position of my absolute-positioned element will be increased by the body margin top value.
So, how can I make it independent of body style?
Note: I can't use any framework, just plain JS.
UPDATE:
I want the position to be affected by the scroll, so "fixed" positioning is not an option. I also want it to be cross browser.
You just need to set position to fixed.
var div = document.createElement("div");
div.style.position = "fixed";
div.style.top = "0";
div.style.left = "0";
div.appendChild(document.createTextNode("Some Text"));
document.getElementsByTagName("body")[0].appendChild(div);
It's quite simple, however it won't work in IE7. You can use position:fixed to position an element in relation to the viewport(browser edges), regardless of what margins, padding or whatever else parent elements have.
To do this with javascript:
var container = document.getElementById('container');// This is your container. Replace accordingly.
var elementToInsert = document.createElement("div");// Create a new element.
elementToInsert.style.position ='fixed';// It will now position in relation to the viewport, regardless of where it is nested, etc.
elementToInsert.style.top = '100px';// Always add pixels, won't work otherwise.
elementToInsert.style.left = '300px';// Always add pixels, won't work otherwise.
elementToInsert.style.width = '500px';// Always add pixels, won't work otherwise.
elementToInsert.style.height = '500px';// Always add pixels, won't work otherwise.
container.appendChild(elementToInsert);// Append the new div to the container.
Also, you don't really need JS for this. Plain old HTML + CSS will do the trick just as well. Read more about CSS position:fixed; HERE
Oops - I did this in jQuery anyway - I will leave it for future reference. Hope the downvoters can leave it too
This works in Chrome, Fx, IE8, IE9
DEMO
$(function() {
$("img").on("click",function() {
$(this).offset({top:0,left:0});
});
});
which means you could do
$(function() {
$("#myimg").offset({top:0,left:0});
});
One trick that web developers use to iron out the differences between browsers is to use a css file to reset properties like body margins.
Example here: http://meyerweb.com/eric/tools/css/reset/
This assumes it isn't your css adding margins to the body.
This is a followup to my question here. I would like to understand why applying position:absolute to the CSS of a div via jQuery fails, while applying it in a static style works. Here are two jsfiddle examples:
Works: http://jsfiddle.net/jasper/Ty6Af/2/
No worky: http://jsfiddle.net/Ty6Af/3/
Note that the only difference between the two is where I apply position:absolute. Vertical centering always works, but horizontal centering does not work when the page loads for the first time. If you manually re-size the window the div will center correctly.
All of my testing has been on Chrome under Ubuntu thus far.
Anyway, I'm just now delving into the world of web development and these are exactly the kinds of 'quirks' that I need to begin understanding.
EDIT:
#Jasper found something interesting. If you make two calls to .css(), first applying position and subsequently applying a margin, it works. I would love to understand why. Here is an example: http://jsfiddle.net/jasper/Ty6Af/5/
So the issue is with how the width of the div is calculated by the browser depending on its position.
If the div is set to position : static (by default) then it's width is 100% of it's parents width and the element is not allowed to move around the page.
If the div is set to position : relative then it's width is 100% of it's parents width but it can be moved around with left.
If the div is set to position : absolute then its width is determined by the actual content of the div, for instance if there is only a 200px wide <span> element within the div then the div will be 200px wide.
You can test these observations by changing the CSS of your jsfiddle to specify position : relative (etc...) and remove the JavaScript that makes the div position : absolute, then use your Developer Tools to inspect the element and it's calculated width.
The problem with your code is that it sets the position : absolute at the same time it sets the margin of the element by using its width/height (which are calculated differently depending on the position of the element).
If you want to set the position of the div in JavaScript then you can do something like this:
$(function() {
//notice I cached the selector so it can be used in the future as well as set the position of the div
$signuparea = $('#signuparea').css({position : 'absolute'});
$(window).resize(function() {
$signuparea.css({
'margin-top' : '-' + Math.round($signuparea.height() / 2) + 'px',
'margin-left' : '-' + Math.round($signuparea.width() / 2) + 'px',
});
}).trigger('resize');
});
Here's a jsfiddle: http://jsfiddle.net/jasper/Ty6Af/8/
I believe the problem is that when you apply your left and right in your second fiddle, you have yet to add position absolute to the div. Hence, the browser has no idea what do with the left and right values and ignores them initially.
Practically speaking in your second fiddle, you only actually add the position:absolute on the resize trigger. So before you resize your actual div has no positioning.
If you instead add the position absolute on load it works fine:http://jsfiddle.net/Ty6Af/9/
Notice that if you give it position:relative from the start (like this http://jsfiddle.net/Ty6Af/11/ ) it allready applies both the left and right value. The reason you can't actually see the effect of "left" is because it is a block element.
I hope that answers your question, I'm not quite clear on where you are stuck.
http://jsfiddle.net/Ty6Af/7/ this should work, the trigger function in jquery has bugs with chrome so you have to run the function on load too.
The problem seems to be that position:absolute; negates the current layout and requires you to position it.....
See: http://jsfiddle.net/ZHaRD/
Which Jasper explains much more eloquently than myself!