I created this function to set a waypoint to fire if the following conditions are met. however on the main build I cannot access it like this due to it being built with Angular and the "header" section stays the same, so the body id and class cannot be changed.
I tried adding a div with the id="home" currently associated with the body tag but this does not work. any ideas how i could solve this dilemma?
var windowWidth = $(window).width();
function myWayPoint() {
// Search form stick to top using waypoints.js
if(windowWidth > 768 && $('body').attr('id') == 'home'){
var sticky = new Waypoint.Sticky({
element: $('.thm-search')[0],
offset: 54
});
}
}
myWayPoint();
Try like this.
<div id="home"></div>
Replace $('body').attr('id') WIth
$("body").find('div').attr('id')
JS
function myWayPoint() {
// Search form stick to top using waypoints.js
if(window.innerWidth; > 768 && $("body").find('div').attr('id') == 'home'){
var sticky = new Waypoint.Sticky({
element: $('.thm-search')[0],
offset: 54
});
}
}
myWayPoint();
Related
I'm currently making an element visible when my nav is at the top of the page. I'd like the element to be hidden if the page gets to max-width: 900px;. I've tried using modernizer for JS media queries but I ca't seem to get it to work.
Code:
var a = $(".menu").offset().top;
function scrollListener(){
if($(document).scrollTop() > a)
{$('.hidden-logo').css({"opacity": "1","display": "block"});
$('.menu').css({"margin-left": "-130px"})
} else {
$('.hidden-logo').css({"opacity": "0","display": "none"});
$('.menu').css({"margin-left": "0px"})
}
};
$(document).scroll(scrollListener);
You were checking the scroll position the wrong way - I think you want the logo to disappear when the current scroll is greater than the top of the logo, not less.
I added a msgS div (for demo purposes only) that will show you the current scroll value against the top-of-menu static value. I also added a 100px fudge factor to the menu location to make it more clear in the demo when the current scroll reaches that position. I use these temporary msg divs myself when working out my code, and then remove them when I've got it all sorted and ready for production.
And this is all you need to check the media query in javascript:
var winmed = window.matchMedia("(max-width: 700px)");
if (winmed.matches){ //do something }
And that can go into a listener function exactly like your scroll listener.
var gloShowLogo = true;
var a = $(".menu").offset().top;
var fudge = 100; //100px fudge factor so can SEE div disappear
function scrollListener(){
updateScrollMsg();
var currScroll = $(document).scrollTop();
var topOfMenu = a+fudge;
if( gloShowLogo && currScroll < topOfMenu ){
$('.hidden-logo').css({"opacity": "1","display": "block"});
$('.menu').css({"margin-left": "-130px"})
} else {
$('.hidden-logo').css({"opacity": "0","display": "none"});
$('.menu').css({"margin-left": "0px"})
}
};
function resizeListener(){
updateMediaMsg();
var winmed = window.matchMedia("(max-width: 500px)");
if (winmed.matches){
$('.hidden-logo').css({"opacity": "1","display": "block"});
gloShowLogo = true;
} else {
$('.hidden-logo').css({"opacity": "0","display": "none"});
gloShowLogo = false;
}
}
$(window).scroll(scrollListener);
$(window).resize(resizeListener);
function updateScrollMsg(){
$('#msgS').html( $(document).scrollTop() +' // ' + $(".menu").offset().top );
}
function updateMediaMsg(){
var winmed = window.matchMedia("(max-width: 500px)");
var medmsg = (winmed.matches) ? '< 500' : '> 500';
console.log(medmsg);
$('#msgM').html(medmsg);
}
.menu{background:green;text-align:center;}
.content{height:200vh;background:palegreen;text-align:center;}
.hidden-logo{position:fixed;top:1vh;right:1vw;padding:15px; background:pink;z-index:2;}
#msgS{position:fixed;top:0;left:0;padding:10px;background:wheat;z-index:2;}
#msgM{position:fixed;top:40px;left:0;padding:10px;background:lightblue;z-index:2;}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>
<div class="menu">Menu Div</div>
<div class="content">Lengthy content Div..<br><br><br><br>100<br></div>
<div class="hidden-logo">LOGO</div>
<div id="msgS"></div>
<div id="msgM"></div>
Update:
Sorry, I had the media query a bit backwards myself - I think you want the logo to display when the screen-size is < 900px and to be hidden if wider than 900px, yes?
I added a msgM div so you can watch the media query kick-in -- but getting the best width for the demo was a bit of a challenge. I finally settled at 500px as a width that can be demoed (StackOverflow resizes its StackSnippets container as the browser window resizes, which throws things into confusion at each of their resize breakpoints)
I have 2 divs on my webpage. first div is "#pattern" (red one), and second on is "#projets".(blue one)
when use scrolls for the first time, the window scrolls automaticaly to the the second div "#projets". I'm using jquery scroll-To plugin.
it works nice, even if when the users scroll with a large amount of scroll there could be on offset from the "#projets" div... If someone has an idea to correct this would be nice, but that's not my main trouble...
Now i'm trying to scroll back to the top of the page ("#pattern" div) as soon as "#pattern" div reappears when scrolling, the red one. so basically it should be as soon as the offset from the top of my screen of my div "#projets" is supperior to 1.
I've tried so many solutions without results, using flags, multiple conditions... it can be the same kind of thing as on this page, but user should be abble to scroll freely inside the page, not scrolling from hash to hash :
http://www.thepetedesign.com/demos/onepage_scroll_demo.html
here is my html :
<div id="pattern"></div>
<div id="projets"></div>
my css :
#pattern {
height:300px;
width: 100%;
background-color:red
}
#projets {
height:800px;
width: 100%;
background-color:blue
}
and my jquery :
var flag=0 ;
$(window).on('scroll',function(){
var top_projets_position = $("#projets").offset().top - $(window).scrollTop();
if((flag==0) && $(window).scrollTop()>1){
$(window).scrollTo('#projets', 500);
flag=1;
}
if($(window).scrollTop()==0){
flag=0;
}
});
here is jsfiddle :
http://jsfiddle.net/jdf9q0sv/
hope someone can help me with this, I can't figure out what I'm doing wrong, maybe a wrong method ! thanks
It looks like you need to track 3 things:
The scroll direction occurs.
The area you are currently viewing.
If scroll animation is currently happening (we need to wait until it's done, or problems will occur).
http://jsfiddle.net/vx69t5Lt/
var prev_scroll = 0; // <-- to determine direction of scrolling
var current_view ="#pattern"; // <-- to determine what element we are viewing
var allowed = true; // <-- to prevent scrolling confusion during animation
var top_projets_position = $("#projets").offset().top + 1;
$(window).on('scroll',function(){
var current_scroll = $(window).scrollTop();
if(current_scroll < top_projets_position && current_view=="#projets" && current_scroll < prev_scroll){
scrollToTarget("#pattern");
}
if($(window).height() + current_scroll > top_projets_position && current_view=="#pattern" && current_scroll > prev_scroll){
scrollToTarget("#projets");
}
prev_scroll = current_scroll;
});
function scrollToTarget(selector){
if(allowed){
allowed = false;
$(window).scrollTo(selector, {
'duration':500,
'onAfter': function(){ allowed = true; current_view = selector;}
});
}
}
This is just a quick solution based on your original code. A better solution would be to do something more Object Oriented (OOP) and track values in an object. Perhaps take an array of elements on object creation, grab all the boundaries and use the boundaries in your scroll handler to determine when to scroll to the next div.
On my website, I have a sidebar DIV on the left and a text DIV on the right. I wanted to make the sidebar follow the reader as he or she scrolls down so I DuckDuckGo'ed a bit and found this then modified it slightly to my needs:
<script type='text/javascript'>//<![CDATA[
$(window).load(function(){
$(function(){
var $sidebar = $('#sidebar'),
sidebarOffset = $sidebar.offset(),
$window = $(window),
gap = $('#header').css('marginBottom').replace(/[^-\d\.]/g, ''),
distance = ($window.scrollTop()) - (sidebarOffset.top - gap),
footerHeight = $('#footer').outerHeight();
$window.scroll(function(){
distance = ($window.scrollTop()) - (sidebarOffset.top - gap);
if ( distance > 0 ) {
$sidebar.css({'top': gap + 'px', 'position' : 'fixed'});
} else {
$sidebar.css({'top': '0', 'position': 'relative'});
}
})
});
});//]]>
</script>
And it works just like I want it to. However, my website uses Skeleton framework to handle responsive design. I've designed it so that when it goes down to mobile devices (horizontal then vertical), sidebar moves from being to the left of the text to being above it so that text DIV can take 100% width. As you can probably imagine, this script causes the sidebar to cover parts of text as you scroll down.
I am completely new to jQuery and I am doing my best through trial-and-error but I've given up. What I need help with is to make this script not execute if a certain DIV has a certain CSS value (i.e. #header-logo is display: none).
Ideally, the script should check for this when user resizes the browser, not on website load, in case user resizes the browser window from normal size to mobile size.
I imagine it should be enough to wrap it in some IF-ELSE statement but I am starting to pull the hair out of my head by now. And since I don't have too much hair anyway, I need help!
Thanks a lot in advance!
This function will execute on window resize and will check if #header-logo is visible.
$(window).resize(function() {
if ($('#header-logo').is(':visible')) {
// Your code
}
});
I think you need to check this on load to, because you don't know if the user will start with mobile view or not. You could do something like this:
$(window).resize(function() {
if ($('#header-logo').is(':visible')) {
// Your code
}
}).resize();
This will get executed on load and on resize.
EDIT: You will probably need to turn off the scroll function if #header-logo is not visible. So, instead of create the function inside the scroll event, you need to create it outside:
$(window).resize(function() {
if ($('#header-logo').is(':visible')) {
var $sidebar = $('#sidebar'),
sidebarOffset = $sidebar.offset(),
$window = $(window),
gap = $('#header').css('marginBottom').replace(/[^-\d\.]/g, ''),
distance = ($window.scrollTop()) - (sidebarOffset.top - gap),
footerHeight = $('#footer').outerHeight();
function myScroll() {
distance = ($window.scrollTop()) - (sidebarOffset.top - gap);
if ( distance > 0 ) {
$sidebar.css({'top': gap + 'px', 'position' : 'fixed'});
} else {
$sidebar.css({'top': '0', 'position': 'relative'});
}
}
$window.on('scroll', myScroll);
} else {
$(window).off('scroll', myScroll);
}
});
Didn't test it, but you get the idea.
$("#headerLogo").css("display") will get you the value.
http://api.jquery.com/css/
I also see you only want this to happen on resize, so wrap it in jquery's resize() function:
https://api.jquery.com/resize/
These if statements are always making me dizzy. If have a page with a header, and a hidden header above that in the markup.
<div id="headerfloat" style="display:none;">
<p>Floated header</p>
</div>
<div id="header">
<p>Header</p>
</div>
The idea is that whenever the page is scrolled down more than 225px, the #headerfloat should appear, and dissapear when topScroll is less than 225px. And I managed to get this working with javascript and jQuery, but when I test it on iPhone, it's very sluggish. And I'm pretty sure it's because the code is run at each scroll event. And even if #headerfloat is visible, the code still executes. Even though it doesn't have to at that point.
So, I need to make sure the code only run once, when it's needed. My first thought was to add and remove classes like .open and .closed to #headerfloat. And run if statements on those during the scroll event. But is that the most efficient way of doing it?
My so far, ugly snippet:
jQuery(window).scroll(function () {
var headerfloat = $("#header_float");
var top = jQuery(window).scrollTop();
if (top > 225) // height of float header
{
if (!$(headerfloat).hasClass("closed")) {
$(headerfloat).addClass("boxshadow", "", 100, "easeInOutQuad").slideDown().addClass("open").removeClass("closed");
}
} else {
$(headerfloat).removeClass("boxshadow", "", 100, "easeInOutQuad").removeClass("closed").slideUp();
}
});
Edit: So after laconbass's awesome response, this is the code I ended up with:
var mainHeader = $('#header')
, top_limit = mainHeader.outerHeight()
, $window = $(window)
;
var header_float = $('#header_float')
bindEvent();
function bindEvent() {
$window.scroll( scrollEvent );
}
function scrollEvent() {
var top = $window.scrollTop();
// avoid any logic if nothing must be done
if ( top < top_limit && !header_float.is(':visible')
|| top > top_limit && header_float.is(':visible')
) return;
// unbind the scroll event to avoid its execution
// until slide animation is complete
$window.unbind( 'scroll' );
// show/hide the header
if ( top > top_limit ) {
header_float.slideDown( 400, bindEvent );
} else {
header_float.slideUp( 400, bindEvent );
}
};
The snippet you started from seems a bit ugly.
I've made one on jsfiddle for your pleasure and reference
I've assumed the following:
you want a fixed positioned header when the page scrolls down (aka fixed header).
fixed headed is a clone of the page main header, with the class fixed.
fixed header is shown when the page scrolls down more than the header height.
fixed header is hidden when the page scrolls up enough to show the main page header.
Performance tips:
cache the jQuery objects to avoid making a new query each time the event handler is executed.
unbind the event handler before the show/hide animations, rebind it after.
on the event handler, return as soon as posible to avoid unnecesary logic. Remember while JavaScript is executed the browser render process is blocked.
var mainHeader = $('header')
, header = mainHeader.clone().addClass('fixed').appendTo('body')
, top_limit = header.outerHeight()
;
bindEvents();
function bindEvents() {
$(window).scroll( scrollEvent );
}
function scrollEvent() {
var top = $(window).scrollTop();
// avoid any logic if nothing must be done
if ( top < top_limit && !header.is(':visible')
|| top > top_limit && header.is(':visible')
) return;
// unbind the scroll event to avoid its execution
// until slide animation is complete
$(window).unbind( 'scroll' );
// show/hide the header
if ( top > top_limit ) {
header.slideDown( 400, bindEvents );
} else {
header.slideUp( 400, bindEvents );
}
};
<header>
<h1>Awesome header</h1>
</header>
<div>
<!-- the page content -->
</div>
/* the real code needed */
header.fixed {
display: none;
position: fixed;
top: 0;
}
two way:
1,on scroll,and if you have done your want, remove the scroll event.
2,var a variable,default is false, on scroll, if the variable is false,to do you want,and set the variable to true; if the variable is true already, do nothing(or others you want)
I am having this problem where i have a set of 6 UL's having a common class x.Each of them consist of a specific section of the page.Now i have 6 menus that are related to each of the section.What i have to do is highlight the menu when its related section is in users view.
For this i thought that may be jQuery position(); or offset(); could have helped but they give the top and left of the element.I also tried using jQuery viewport plugin but apparently view port is big it can show more than one UL at a time hence i cant apply element specific logic here.I am not familliar to this but does anything changes of an element on scrolling?If yes then how to access it?
Please share your views.
Regards
Himanshu Sharma.
Is very easy to do it using jQuery and a dummy fixed HTML block that helps you find the current position of the viewport.
$(window).on("scroll load",function(){
var once = true;
$(".title").each(function(ele, index){
if($(this).offset().top > $("#viewport_helper").offset().top && once){
var index = $(this).index(".title");
$(".current").removeClass('current')
$("#menu li").eq(index).addClass('current')
once = false;
}
});
})
Check out a working example: http://jsfiddle.net/6c8Az/1/
You could also do something similar with the jQuery plugin, together with the :first selector:
$(window).on("scroll load",function(){
$(".title:in-viewport:first").each(function(){
var index = $(this).index(".title");
$(".current").removeClass('current')
$("#menu li").eq(index).addClass('current')
});
})
You can get the viewport's width and height via $(document).width() and $(document).height()
You can get how many pixels user scrolls via $(document).scrollTop() and $(document).scrollLeft
Combining 1 and 2, you can calculate where the viewport rectangle is
You can get the rectangle of an element using $(element).offset(), $(element).width() and $(element).height()
So the only thing left to you is to determine whether the viewport's rectangle contains (or interacts) the elements's rectangle
So the whole code may look like:
/**
* Check wether outer contains inner
* You can change this logic to matches what you need
*/
function rectContains(outer, inner) {
return outer.top <= inner.top &&
outer.bottom >= inner.bottom &&
outer.left <= inner.left &&
outer.right >= inner.right;
}
/**
* Use this function to find the menu related to <ul> element
*/
function findRelatedMenu(element) {
return $('#menu-' + element.attr('id'));
}
function whenScroll() {
var doc = $(document);
var elem = $(element);
var viewportRect = {
top: doc.scrollTop(),
left: doc.scrollLeft(),
width: doc.width(),
height: doc.height()
};
viewportRect.bottom = viewportRect.top + viewportRect.height;
viewportRect.right = viewportRect.left + viewportRect.width;
var elements = $('ul.your-class');
for (var i = 0; i < elements.length; i++) {
var elem = $(elements[i]);
var elementRect = {
top: elem.offset().top,
left: elem.offset().left,
width: elem.width(),
height: elem.height()
};
elementRect.bottom = elementRect.top + elementRect.height;
elementRect.right = elementRect.left + elementRect.width;
if (rectContains(viewportRect, elementRect)) {
findRelatedMenu(elem).addClass('highlight');
}
}
}
$(window).on('scroll', whenScroll);
Let's see if i understood well. You have a page long enough to scroll, and there is an element that when it appears in the viewport, you wanna do something with it. So the only event that's is triggered for sure on the time the element gets in the viewport is the 'scroll'. So if the element is on the page and the scroll is on the viewport, what you need to do is bind an action to the scroll event to check if the element is in the view each time the event is trigger. Pretty much like this:
$(window).scroll(function() {
check_element_position();
});
Now, in order for you to know if the element is in the viewport, you need 3 things. The offset top of that element, the size of the viewport and the scroll top of the window. Should pretty much look like this:
function check_element_position() {
var win = $(window);
var window_height = win.height();
var element = $(your_element);
var elem_offset_top = element.offset().top;
var elem_height = element.height();
var win_scroll = win.scrollTop();
var pseudo_offset = (elem_offset_top - win_scroll);
if (pseudo_offset < window_height && pseudo_offset >= 0) {
// element in view
}
else {
// elem not in view
}
}
Here, (elem_offset_top - win_scroll) represent the element position if there was no scroll. Like this, you just have to check if the element offset top is higher then the window viewport to see if it's in view or not.
Finally, you could be more precise on you calculations by adding the element height (variable already in there) because the code i just did will fire the event even if the element is visible by only 1 pixels.
Note: I just did that in five minutes so you might have to fix some of this, but this gives you a pretty darn good idea of what's going on ;)
Feel free to comment and ask questions