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Div blinking while resize

I am working on a bootstrap based website and I have the following case :
A main container and a floating left navigation menu.
The floating left navigation menu, is set to position fixed, because it is following the user scroll.
What I would like is when the end user resize the window, and when the main content meets the left menu (overlap), the left menu becomes hidden, and when there is enough space the left menu comes back.
Actually, it is not really working, it is blinking. I have written a little bit of jquery binded to the resize function.
Here is the jsfiddle :
https://jsfiddle.net/cuw46rsv/5/
function getDiffLeftMenu(div1, div2) {
var value = ($(div1).offset().left - $(div2).offset().left);
console.log(value - $(div2).width());
if(value - $(div2).width() < 0){
return true;
}
}
$(window).on('resize', function(event) {
var value = ($('.central-content').offset().left - $('#sectionsMenu').offset().left);
if(getDiffLeftMenu('.central-content','#sectionsMenu')){
$('#sectionsMenu').hide();
}
else {
$('#sectionsMenu').show();
}
}).resize();
Is this possible to not have this blinking effet ?
Thanks a lot for any help.
Regards.

Here's the solution with your logic, .hide() method causes it to have offset 0 and that's why it's blinking (it can get stuck as hidden all the time).
https://jsfiddle.net/cuw46rsv/7/
function getDiffLeftMenu(div1, div2) {
var value = ($(div1).offset().left - $(div2).offset().left);
console.log(value - $(div2).width());
if(value - $(div2).width() < 0){
return true;
}
}
By using opacity offset will stay there.
$(window).on('resize', function(event) {
var value = ($('.central-content').offset().left - $('#sectionsMenu').offset().left);
if(getDiffLeftMenu('.central-content','#sectionsMenu')){
$('#sectionsMenu').css('opacity', 0);
}
else {
$('#sectionsMenu').css('opacity', 1);
}
}).resize();

well you are doing it wrong, but you can solve it like this (as a workaround):
$(window).on('resize', function(event) {
var value = ($('.central-content').offset().left - $('#sectionsMenu').offset().left);
if(getDiffLeftMenu('.central-content','#sectionsMenu')){
setTimeout(function(){$('#sectionsMenu').hide();},20);
}
else {
$('#sectionsMenu').show();
}
}).resize();
https://jsfiddle.net/cuw46rsv/6/

How do I code JQuery so that when I scroll to a certain element, Nav bar appears at top, when I scroll back up past that element, nav bar disappears

I have a div called #menu which I want to display when I scroll past the element #section3, if I scroll up past that element again, I want #menu to disappear
How would I code this?

Maybe something like this?
scrolled = "no"
$(window).scroll(function(){
scr = $("body").scrollTop();
if (scr > 100 && scrolled == "no"){
$("#menu").css({"display:block"})
displayed = "yes"
}
if (displayed == "yes" && scrolled = "yes"){
$("#menu").css({"display:none"})
}
});
The above assumes that #section3 is 100 pixels down the page. If you do not know where its going to be on the page then you could use the method outlined here:
Trigger event when user scroll to specific element - with jQuery

With jQuery you can get the scroll position with $("body").scrollTop();.
Expanding on what #Ned Hulton said, I recommend comparing the scroll position to the top of a "container element" (or 'row') in your page like this:
if ($('body').scrollTop() > $('#someRow').offset().top){
//do something
}
That way you can account for your container appearing at a variable distance down the page (which will come in handy for mobile browsing or cases where your text wraps to additional lines)

I just whipped this up in jsfiddle
https://jsfiddle.net/rb56j0yu/
it uses jQuery, and checks the scroll position against the target div. Css sets the menu as position: fixed, and defaults to hidden.
$(window).scroll(function(){
var yPos = $("body").scrollTop();
var yCheck = $("#c3").position().top;
if (yPos > yCheck && !$("#menu").is(":visible"))
{
$("#menu").show();
}
if (yPos <= yCheck && $("#menu").is(":visible"))
{
$("#menu").hide();
}
});

First, get your #section3 top offset and height. Which will be used as the threshold whether #section3 is actually on the window screen.
var top = $('#section3').offset().top;
var bot = topOffset + $('#section3').height();
Then, detect it on your scroll event.
$(window).on('scroll', function () {
var scrollTop = $(window).scrollTop();
if (scrollTop >= top && scrollTop <= bot) {
// #section3 is within the screen.
$('#menu').show();
}
else {
// #section3 is out of screen.
$('#menu').hide();
}
});

This is a common use case, I wrote following code:
// what does "Auto Header" mean, goto https://www.yahoo.com/
// scroll down and you will see the purple part auto fixed to top,
// while when scroll up, it restores and does not be fixed.
// 1. multiple auto header elements handled
// 2. dynamically create/remove elements issue handled
// 3. no unnecessary dom operation, high performance
// usage: just add 'class="auto-header"' to any element you want to auto header
// suggest set each auto-header element specific width and height
// do not guarantee it works when resize or scroll left/right
$(document).ready(function() {
var rawTops = [],
rawLefts = [],
rawStyles = [],
$locations = [], // record next sibling so that element easily find where to restore
fixed = []; // mark whether this element is fixed
$(".auto-header").each(function() {
var $this = $(this),
offset = $this.offset();
rawTops.push(offset.top);
rawLefts.push(offset.left);
rawStyles.push($this.attr("style"));
$locations.push($this.siblings().eq($this.index()));
fixed.push(false);
});
$(window).on("scroll", function() {
$(".auto-header").each(function(i, e) {
if(!fixed[i] && $(window).scrollTop() > rawTops[i]) {
var $te = $(this).clone(true);
$(this).remove();
$locations[i].before($te);
$te.css({
"position": "fixed",
"top": 0,
"left": rawLefts[i],
"z-index": 100
});
fixed[i] = true;
} else if(fixed[i] && $(window).scrollTop() < rawTops[i]) {
$(this).removeAttr("style").attr("style", rawStyles[i]);
fixed[i] = false;
}
});
});
});

Form validation autoscroll modification javascript

I am working on a javascript validation of a form. My problem is, that upon submitting the form, the browser jumps automatically to the empty cells. This is not a problem and I like it this way. My problem is that, there is a fixed header displayed on my page, and this header covers up the form-field. Is there any way to get around it? Thanks!

I had the same problem and fixed it like this:
EventListener binding:
$('input').on('invalid',function() {
scrollToInvalid();
});
Function:
function scrollToInvalid() {
//Height of your nav bar with some offset
var navHeight = $('nav#main').height() + 20;
// Offset of the first input element minus your nav height
var firstInvalidPosTop = $('input:invalid').first().offset().top;
var newScrollPos = firstInvalidPosTop - navHeight;
// return true if the invalid element is already within the window view.
// If you return false, the validation will stop.
if ( newScrollPos > (window.pageYOffset + navHeight) &&
newScrollPos < (window.pageYOffset + window.innerHeight - navHeight)) {
return true;
} else {
// If the first invalid input is not within the current view, scroll to the new position.
$('html, body').scrollTop(newScrollPos);
}
};

Toggle class when object visible in the viewport

I need a script which toggle a class when another class or section is visible in the viewport (during scrolling).
Here I have an script which works for precised distance from top, but can somebody help me to modify it for my needs?
$(window).scroll(function(){
if ($(this).scrollTop() > 50) {
$('#viewport').addClass('turn_on');
} else {
$('#viewport').removeClass('turn_on');
}
});

A couple of things. First the scroll event (as well as the resize event) fire multiple times. Traditionally, developers have used something called debouncing to limit the number of times a function fires. I've never got it to work correctly, so instead I check if a condition is met before continuing. You are basically doing this already.
var bool = false
$(window).on('scroll', function(){
if(!bool){
bool = true;
//fire the function and then turn bool back to false.
};
});
The next thing you need is to identify the element to add the class to. Let's say it has an id of foo.
var yOffset = $('#foo').offset().top;
From here, you'll need to compare the current vertical scroll position with that of the yOffset. You may also need to add the height of the element for when it scrolls out of frame.
var elHeight = $('#foo').height();
The element should be completely in frame with the $(window).scrollTop() equals the yOffset and out of frame when the $(window).scrollTop() is greater than yOffset + elHeight.
This is all assuming the element isn't in the frame to begin with. If it is, it will be trickier but it's a start.

Working fiddle
Try to add function that detect if element passed in argument is visible :
function isVisisble(elem){
return $(elem).offset().top - $(window).scrollTop() < $(elem).height() ;
}
$(window).scroll(function(){
if (isVisisble( $('your_element') ))
$('#viewport').addClass('turn_on');
} else {
$('#viewport').removeClass('turn_on');
}
});
Hope this helps.

Thx everyone for help.
Here I found the solution: LINK
And here is the modified script:
$(document).ready(function () {
var windowHeight = $(window).height(),
gridTop = windowHeight * 0.1,
gridBottom = windowHeight * 1;
$(window).on('scroll', function () {
$('.inner').each(function () {
var thisTop = $(this).offset().top - $(window).scrollTop();
if (thisTop > gridTop && (thisTop + $(this).height()) < gridBottom) {
$(this).addClass('on');
}
});
});
});

How can I set my browser window's scrollbar or a div scrollbar to scroll in increments using animate and scrollTop?

The general idea to the site i am designing is to scroll through a set of menu items horizontally and incrementally underneath a static div that will magnify(increase dimensions and pt size) the contents of a menu items. I don't really need help with the magnify portion because i think it's as simple as adding a mag class to any of the menuItem divs that go underneath the static div. I have been messing with this for a few weeks and the code I have for incrementally scrolling, so far, is this:
$(document).ready(function () {
currentScrollPos = $('#scrollableDiv').scrollTop(120); //sets default scroll pos
/*The incrementScroll function is passed arguments currentScrollPos and UserScroll which are variables that i have initiated earlier in the program, and then initiates a for loop.
-The first statement sets up the variables: nextScrollPos as equal to the currentScrollPos(which by default is 120px) plus 240px(the distance to next menuItem), prevScrollPos as equal to the currentScrollPos(which by default is 120px) minus 240px(the distance to next menuItem).
-The second Statement checks to see if the user has scrolled using var userScroll
-The third statement sets: var CurrentScroll equal to the new scroll position and var userScroll to false*/
function incrementScroll(currentScrollPos, userScroll) {
for (var nextScrollPos = parseInt(currentScrollPos + 240, 10),
prevScrollPos = parseInt(currentScrollPos - 240, 10); //end first statement
userScroll == 'true'; console.log('dude'), //end second statement and begining of third
currentScrollPos = scrollTop(), userScroll = 'false') {
if (scrollTop() < currentScrollPos) {
$('#scrollableDiv').animate({
scrollTop: (parseInt(prevScrollPos, 10))
}, 200);
console.log('scrolln up')
} else if (scrollTop() > currentScrollPos) {
$('#scrollableDiv').animate({
scrollTop: (parseInt(nextScrollPos, 10))
}, 200);
console.log('scrolln down')//fire when
}
}
}
$('#scrollableDiv').scroll(function () {
userScroll = 'true';
_.debounce(incrementScroll, 200); //controls the amount of times the incrementScroll function is called
console.log('straight scrolln')
});
});
I have found a variety of solutions that are nigh close: such as a plugin that snaps to the next or previous div horizontally demo, another solution that also snaps and is based on setTimeout demo, but nothing that nails incrementally scrolling through divs. I also found a way to control the rate at which a user may scroll through the menuItems using debounce which is included in the above code.
The console.logs inside the loop do not fire when I demo the code in jsfiddle which leads me to believe the problem lies within the loop. I'm a noob though so it could be in syntax or anywhere else in the code for that matter. Also in the second demo, i have provided the css for the horizontal static div, but the moment I put it in my html it keeps the js from working.
I would like to write the code instead of using a plugin and any help would be appreciated! Also, thank you ahead of time!

Try this fiddle. Menu container height is 960px to show 4 menu items. "Zoom" div is positioned absolutely at top. When you scroll mouse over this div, menu items shifts to top/bottom. I had to add additional div to bottom to be able to scroll to last 3 menu items. JS code:
jQuery(document).ready(function($){
var current = 0;
var menu = $('.menu-container').scrollTop(0);
var items = menu.find('.menu-item');
var zoom = $('.zoom');
function isVerticalScroll(event){
var e = event.originalEvent;
if (e.axis && e.axis === e.HORIZONTAL_AXIS)
return false;
if (e.wheelDeltaX)
return false;
return true;
}
function handleMouseScroll(event){
if(isVerticalScroll(event)){
var delta = event.originalEvent.wheelDelta * -1 || event.originalEvent.detail;
current += (delta > 0 ? 1 : -1);
if(current < 0)
current = 0;
if(current >= items.length){
current = items.length - 1;
}
menu.stop().animate({
"scrollTop": current * 240
}, 300);
items.removeClass('current').eq(current).addClass('current');
event && event.preventDefault();
return false;
}
}
zoom.on({
"MozMousePixelScroll": handleMouseScroll,
"mousewheel": handleMouseScroll
});
});
Hope it will help.