This question already has answers here:
How to check if element is visible after scrolling?
(46 answers)
Closed 5 years ago.
Function to check if the div class "media" is within the browsers visual viewport regardless of the window scroll position.
<HTML>
<HEAD>
<TITLE>My first HTML document</TITLE>
</HEAD>
<BODY>
<div class="main">
<div class="media"></div>
</div>
</BODY>
</HTML>
Trying to use this plugin https://github.com/customd/jquery-visible with this function but
I don't know how to make it work.
$('#element').visible( true );
You can write a jQuery function like this to determine if an element is in the viewport.
Include this somewhere after jQuery is included:
$.fn.isInViewport = function() {
var elementTop = $(this).offset().top;
var elementBottom = elementTop + $(this).outerHeight();
var viewportTop = $(window).scrollTop();
var viewportBottom = viewportTop + $(window).height();
return elementBottom > viewportTop && elementTop < viewportBottom;
};
Sample usage:
$(window).on('resize scroll', function() {
if ($('#Something').isInViewport()) {
// do something
} else {
// do something else
}
});
Note that this only checks the top and bottom positions of elements, it doesn't check if an element is outside of the viewport horizontally.
Check if element is visible in viewport using jquery:
First determine the top and bottom positions of the element. Then determine the position of the viewport's bottom (relative to the top of your page) by adding the scroll position to the viewport height.
If the bottom position of the viewport is greater than the element's top position AND the top position of the viewport is less than the element's bottom position, the element is in the viewport (at least partially). In simpler terms, when any part of the element is between the top and bottom bounds of your viewport, the element is visible on your screen.
Now you can write an if/else statement, where the if statement only runs when the above condition is met.
The code below executes what was explained above:
// this function runs every time you are scrolling
$(window).scroll(function() {
var top_of_element = $("#element").offset().top;
var bottom_of_element = $("#element").offset().top + $("#element").outerHeight();
var bottom_of_screen = $(window).scrollTop() + $(window).innerHeight();
var top_of_screen = $(window).scrollTop();
if ((bottom_of_screen > top_of_element) && (top_of_screen < bottom_of_element)){
// the element is visible, do something
} else {
// the element is not visible, do something else
}
});
This answer is a summary of what Chris Bier and Andy were discussing below. I also used an answer to the following question to formulate my answer: Show Div when scroll position.
According to the documentation for that plugin, .visible() returns a boolean indicating if the element is visible. So you'd use it like this:
if ($('#element').visible(true)) {
// The element is visible, do something
} else {
// The element is NOT visible, do something else
}
You can see this example.
// Is this element visible onscreen?
var visible = $(#element).visible( detectPartial );
detectPartial :
True : the entire element is visible
false : part of the element is visible
visible is boolean variable which indicates if the element is visible or not.
var visible = $(".media").visible();
Related
This question already has answers here:
How to check if element is visible after scrolling?
(46 answers)
Closed 5 years ago.
Function to check if the div class "media" is within the browsers visual viewport regardless of the window scroll position.
<HTML>
<HEAD>
<TITLE>My first HTML document</TITLE>
</HEAD>
<BODY>
<div class="main">
<div class="media"></div>
</div>
</BODY>
</HTML>
Trying to use this plugin https://github.com/customd/jquery-visible with this function but
I don't know how to make it work.
$('#element').visible( true );
You can write a jQuery function like this to determine if an element is in the viewport.
Include this somewhere after jQuery is included:
$.fn.isInViewport = function() {
var elementTop = $(this).offset().top;
var elementBottom = elementTop + $(this).outerHeight();
var viewportTop = $(window).scrollTop();
var viewportBottom = viewportTop + $(window).height();
return elementBottom > viewportTop && elementTop < viewportBottom;
};
Sample usage:
$(window).on('resize scroll', function() {
if ($('#Something').isInViewport()) {
// do something
} else {
// do something else
}
});
Note that this only checks the top and bottom positions of elements, it doesn't check if an element is outside of the viewport horizontally.
Check if element is visible in viewport using jquery:
First determine the top and bottom positions of the element. Then determine the position of the viewport's bottom (relative to the top of your page) by adding the scroll position to the viewport height.
If the bottom position of the viewport is greater than the element's top position AND the top position of the viewport is less than the element's bottom position, the element is in the viewport (at least partially). In simpler terms, when any part of the element is between the top and bottom bounds of your viewport, the element is visible on your screen.
Now you can write an if/else statement, where the if statement only runs when the above condition is met.
The code below executes what was explained above:
// this function runs every time you are scrolling
$(window).scroll(function() {
var top_of_element = $("#element").offset().top;
var bottom_of_element = $("#element").offset().top + $("#element").outerHeight();
var bottom_of_screen = $(window).scrollTop() + $(window).innerHeight();
var top_of_screen = $(window).scrollTop();
if ((bottom_of_screen > top_of_element) && (top_of_screen < bottom_of_element)){
// the element is visible, do something
} else {
// the element is not visible, do something else
}
});
This answer is a summary of what Chris Bier and Andy were discussing below. I also used an answer to the following question to formulate my answer: Show Div when scroll position.
According to the documentation for that plugin, .visible() returns a boolean indicating if the element is visible. So you'd use it like this:
if ($('#element').visible(true)) {
// The element is visible, do something
} else {
// The element is NOT visible, do something else
}
You can see this example.
// Is this element visible onscreen?
var visible = $(#element).visible( detectPartial );
detectPartial :
True : the entire element is visible
false : part of the element is visible
visible is boolean variable which indicates if the element is visible or not.
var visible = $(".media").visible();
I have a page that had dropdown and images at the top, then a price grid at the bottom (bellow the fold). The price grid is scroll-able inside a div element. On load there is a price on the grid selected, but it is hidden, so you have to scroll the table down to see it.
My problem is, I want to scroll the table within the div element to show the active - but I do not want to scroll the page as well. On load the user should not see anything moving, the table should scroll to show the without them aware (below the fold). When they scroll down the page they should then see the table is displaying the active (selected price) and the table will be scrolled.
const activeRow = $('#prices_table').find('tr td.active');
activeRow[0].scrollIntoView({block: 'center', behavior: 'smooth' });
The problem with my code is it scrolls the user down to the price grid and then scrolls the price grid. I want the user to be left to scroll down to the price grid themselves.
I have found many similar questions, all of these result in the whole page scrolling to the div, and then the div scrolling to show the active class. I need a solution where the page does not scroll.
I have no come up with a solution in JQuery.
var hasScrolled = false;
function isInViewport() {
if (!hasScrolled) {
var elem = $('#prices_table');
if (elem !== undefined) {
var elementTop = elem.offset().top;
var elemBottom = elementTop + elem.outerHeight();
var viewportTop = $(window).scrollTop();
var viewportBottom = viewportTop + $(window).height();
// return elemBottom > viewportTop && elemTop < viewportBottom;
if (elemBottom > viewportTop && elementTop < viewportBottom) {
var activeRow = $('#prices_table').find('tr td.active');
var containerToScroll = $('#prices_table').find('tbody');
var tdHeight = activeRow.outerHeight();
if (activeRow) {
if (activeRow[0] !== undefined{
$(containerToScroll).scrollTop(($('#prices_table').find('tr td.active').offset().top - $('#prices_table').find('tbody').offset().top) - (tdHeight * 2));
hasScrolled = true;
}
}
}
}
}
}
$(window).scroll(function() {
isInViewport('#prices_table');
});
I have a few variables to check before actually scrolling, as sometimes the element is in the correct place on load, and once it has scrolled once I don't want it to move.
On Scroll I now check if element is in view.
I then check if element has previously scrolled, if it hasn't then I will continue.
I set element, if it doesn't exist then I don't continue.
I do some calculations to check the difference the scroll needs to move, if there is no difference I don't continue.
I then do my calculation and update variable hasScrolled to true so this never fires again.
Bit of a longer approach than I was looking for but it works a treat.
so I want to know how I can get what section or part of my html I’m currently on. An example
So how do I know if a user has already scrolled down over part 2 using JavaScript
Or if they’re currently at part 1
<html>
<head>
</head>
<body>
<section class=“part 1”>
</section>
<section class= “part2>
</section>
</body>
</html>
The following codes will give you a little idea about how to handle this situation. Essentially you are going to want to get the scrollbar position which you can do using:
document.documentElement.scrollTop
You also want to get a range where the element you are looking for resides, in our case, it is .part1 and .part2. We can get that range by using offsetTop as the beginning of the limit and offsetTop + clientHeight to determine the end.
You are going to have to keep track of the window scroll event.
The following example is generic:
$(window).scroll(function(e) {
if (document.documentElement.scrollTop > 0
&& document.documentElement.scrollTop < $('.part2').offset().top ) {
$('div').html("At part1")
} else {
$('div').html("At part2")
}
});
JSFiddle
Likewise, if you want a little bit of modularity:
$(window).scroll(function(e) {
let watchList = ['part1', 'part2', 'part3'];
let scrollTop = document.documentElement.scrollTop;
for (var classname of watchList) {
let el = document.getElementsByClassName(classname)[0];
if (scrollTop > el.offsetTop &&
scrollTop < el.offsetTop + el.clientHeight) {
$('div').html("At <strong>"+classname+"</strong>");
}
}
});
JSFiddle
The possibilities are limitless to continue and make this more useful, but I'll leave that up to you.
you can use is[":focus"] function to find which div has focus currently.
if($(".part1").is(":focus"))
{
//you code
}
else if($(".part2").is(":focus"))
{
//you code
}
you can use mouseenter function it fires when the mouse goes into that div for the first time.
$(".part1").on('mouseenter', function(){
//your command
});
you can use mouseover function to find where is mouse right now. it fires when mouse moves inside that div.
$(".part1").on('mouseover', function(){
//your command
});
You can use javascripts offsetTop functionality. This is a parameter that returns how far down from the top a div is in the number of pixels.
It can also return how far down the user has scrolled when called on the window object itself. Then it's just a matter of math. See if the user has scolled down far enough to be past the div in reference.
For example:
var part1DivOffset = document.getElementsByClassName("part 1")[0].offsetTop;
var part2DivOffset = document.getElementsByClassName("part2")[0].offsetTop;
var scrollTop = (window.pageYOffset !== undefined) ? window.pageYOffset : (document.documentElement || document.body.parentNode || document.body).scrollTop;
This code will get you 3 variables. The first 2 lines save the offsetTop of the div's. While the third line detects how far down the user has scrolled. Then you can do math with the variables:
if(scrollTop >= part1DivOffset){
//we are past part1
}
if(scrollTop >= part2DivOffset){
//We are past part 2
}
if(scrollTop >= part1DivOffset && scrollTop < part2DivOffset){
//We are past part 1 but not past part 2
}
I am trying to add a class when the bottom of a div reaches the top of the window, but am not sure of how to do it.
I have managed to add the class when the top of the div gets to the top of the window, but am not having much luck with the bottom of the div.
Code I am using:
$(document).ready(function() {
var menuLinksTop = $('.container').offset().top;
var menuLinks = function(){
var scrollTop = $(window).scrollTop();
if (scrollTop > menuLinksTop) {
$('header').addClass('black-links');
} else {
$('header').removeClass('black-links');
}
};
menuLinks();
$(window).scroll(function() {
menuLinks();
});
Any help is appreciated.
You should use javascript's getBoundingClientRect() method, watch $(window).scroll event, and look at element's rectangle, its bottom value will give you what you need (if it's negative, your element is all the way up)
$(window).scroll(function() {
console.log($("div.watch")[0].getBoundingClientRect());
if ($("div.watch")[0].getBoundingClientRect().bottom < 0)
alert ("i'm out :3");
});
see jsFiddle http://jsfiddle.net/ja5nnbwr/2/
Add the height of the div. Assuming it is the .container :
var menuLinksTop = $('.container').offset().top + $('.container').height();
This question already has answers here:
How to check if element is visible after scrolling?
(46 answers)
Closed 5 years ago.
Function to check if the div class "media" is within the browsers visual viewport regardless of the window scroll position.
<HTML>
<HEAD>
<TITLE>My first HTML document</TITLE>
</HEAD>
<BODY>
<div class="main">
<div class="media"></div>
</div>
</BODY>
</HTML>
Trying to use this plugin https://github.com/customd/jquery-visible with this function but
I don't know how to make it work.
$('#element').visible( true );
You can write a jQuery function like this to determine if an element is in the viewport.
Include this somewhere after jQuery is included:
$.fn.isInViewport = function() {
var elementTop = $(this).offset().top;
var elementBottom = elementTop + $(this).outerHeight();
var viewportTop = $(window).scrollTop();
var viewportBottom = viewportTop + $(window).height();
return elementBottom > viewportTop && elementTop < viewportBottom;
};
Sample usage:
$(window).on('resize scroll', function() {
if ($('#Something').isInViewport()) {
// do something
} else {
// do something else
}
});
Note that this only checks the top and bottom positions of elements, it doesn't check if an element is outside of the viewport horizontally.
Check if element is visible in viewport using jquery:
First determine the top and bottom positions of the element. Then determine the position of the viewport's bottom (relative to the top of your page) by adding the scroll position to the viewport height.
If the bottom position of the viewport is greater than the element's top position AND the top position of the viewport is less than the element's bottom position, the element is in the viewport (at least partially). In simpler terms, when any part of the element is between the top and bottom bounds of your viewport, the element is visible on your screen.
Now you can write an if/else statement, where the if statement only runs when the above condition is met.
The code below executes what was explained above:
// this function runs every time you are scrolling
$(window).scroll(function() {
var top_of_element = $("#element").offset().top;
var bottom_of_element = $("#element").offset().top + $("#element").outerHeight();
var bottom_of_screen = $(window).scrollTop() + $(window).innerHeight();
var top_of_screen = $(window).scrollTop();
if ((bottom_of_screen > top_of_element) && (top_of_screen < bottom_of_element)){
// the element is visible, do something
} else {
// the element is not visible, do something else
}
});
This answer is a summary of what Chris Bier and Andy were discussing below. I also used an answer to the following question to formulate my answer: Show Div when scroll position.
According to the documentation for that plugin, .visible() returns a boolean indicating if the element is visible. So you'd use it like this:
if ($('#element').visible(true)) {
// The element is visible, do something
} else {
// The element is NOT visible, do something else
}
You can see this example.
// Is this element visible onscreen?
var visible = $(#element).visible( detectPartial );
detectPartial :
True : the entire element is visible
false : part of the element is visible
visible is boolean variable which indicates if the element is visible or not.
var visible = $(".media").visible();