Develop Reference

How to stop a fixed gadget before the footer?

everyone! Searching the internet for solutions related to stick a widget in the sidebar I've found one that I liked. But, the only problem is that it doesn't "break" before the footer. I've already tried a lot of solutions, but without sucess until now. If someone can help me, I thank!
This is the original script:
<script type='text/javascript'>
/*<![CDATA[*/
// Sticky Plugin
// =============
// Author: Anthony Garand
// Improvements by German M. Bravo (Kronuz) and Ruud Kamphuis (ruudk)
// Created: 2/14/2011
// Date: 9/12/2011
// Website: http://labs.anthonygarand.com/sticky
// Description: Makes an element on the page stick on the screen as you scroll
// For Blogger by : http://www.makingdifferent.com
(function($) {
var defaults = {
topSpacing: 0,
bottomSpacing: 0,
className: 'is-sticky',
center: false
},
$window = $(window),
$document = $(document),
sticked = [],
windowHeight = $window.height(),
scroller = function() {
var scrollTop = $window.scrollTop(),
documentHeight = $document.height(),
dwh = documentHeight - windowHeight,
extra = (scrollTop > dwh) ? dwh - scrollTop : 0;
for (var i = 0; i < sticked.length; i++) {
var s = sticked[i],
elementTop = s.stickyWrapper.offset().top,
etse = elementTop - s.topSpacing - extra;
if (scrollTop <= etse) {
if (s.currentTop !== null) {
s.stickyElement.css('position', '').css('top', '').removeClass(s.className);
s.currentTop = null;
}
}
else {
var newTop = documentHeight - s.elementHeight - s.topSpacing - s.bottomSpacing - scrollTop - extra;
if (newTop < 0) {
newTop = newTop + s.topSpacing;
} else {
newTop = s.topSpacing;
}
if (s.currentTop != newTop) {
s.stickyElement.css('position', 'fixed').css('top', newTop).addClass(s.className);
s.currentTop = newTop;
}
}
}
},
resizer = function() {
windowHeight = $window.height();
};
// should be more efficient than using $window.scroll(scroller) and $window.resize(resizer):
if (window.addEventListener) {
window.addEventListener('scroll', scroller, false);
window.addEventListener('resize', resizer, false);
} else if (window.attachEvent) {
window.attachEvent('onscroll', scroller);
window.attachEvent('onresize', resizer);
}
$.fn.sticky = function(options) {
var o = $.extend(defaults, options);
return this.each(function() {
var stickyElement = $(this);
if (o.center)
var centerElement = "margin-left:auto;margin-right:auto;";
stickyId = stickyElement.attr('id');
stickyElement
.wrapAll('<div id="' + stickyId + 'StickyWrapper" style="' + centerElement + '"></div>')
.css('width', stickyElement.width());
var elementHeight = stickyElement.outerHeight(),
stickyWrapper = stickyElement.parent();
stickyWrapper
.css('width', stickyElement.outerWidth())
.css('height', elementHeight)
.css('clear', stickyElement.css('clear'));
sticked.push({
topSpacing: o.topSpacing,
bottomSpacing: o.bottomSpacing,
stickyElement: stickyElement,
currentTop: null,
stickyWrapper: stickyWrapper,
elementHeight: elementHeight,
className: o.className
});
});
};
})(jQuery);
/*]]>*/
</script>

Adding Media Queries to Javascript

I've got a sticky sidebar going on with this code. But I only want it to affect the .fake-sidebar div when at 768px or below. Could anyone explain how to add media queries to my javascript?
var sticky_offset;
$(document).ready(function() {
var original_position_offset = $('.fake-sidebar').offset();
sticky_offset = original_position_offset.top;
$('.fake-sidebar').css('position', 'fixed');
});
$(window).scroll(function () {
var sticky_height = $('.fake-sidebar').outerHeight();
var where_scroll = $(window).scrollTop();
var window_height = $(window).height();
if((where_scroll + window_height) > sticky_offset) {
$('.fake-sidebar').css('position', 'relative');
}
if((where_scroll + window_height) < (sticky_offset + sticky_height)) {
$('.fake-sidebar').css('position', 'fixed');
}
});
Any help is appreciated. Thanks in advance!

You can add the event on window resize, or on document ready, depending of what you want:
$(window).resize(function() {
var width = $(window).width();
if (width < 768) {
$('.fake-sidebar').css('position', 'relative');
}
else {
$('.fake-sidebar').css('position', 'fixed');
}
});

background image resizing is not working when using force reload or navigating back to homepage

In our site www.mydubaitrip.com I have a script that resizes the background image base on the browser width. My problem is whenever I try to press Ctrl+F5 or if I navigate to hotel page and back to home page, the background image doesn't resize correctly and my layout looks messed up. But if I try to press F5 again it will now adjust accordingly. I cannot figure out what is the problem.
Here's the script that I used.
var minWidth = 1024;
var minHeight = 844;
var winRatio = new Array();
var imgReady = new Array();
var orientation = 90;
var debounceId;
var isiPad = navigator.userAgent.match(/iPad/i) != null;
if (isiPad) {
var minWidth = 980;
}
var readyToRotate = false;
var readyToResize = true;
var miniContentWrapperHeight = 444;
// BACKGROUND TRANSITION
var theTimer;
var currBanner = -1;
var totalBanner = 0;
var timeWaiting = parseInt(500);
var timeTextTransIn = parseInt(1000);
var timeTextTransOut = parseInt(1000);
var timeTransCross = parseInt(2000);
var timeTransInit = parseInt(0);
var timeTransInterval = parseInt(7000);
var transitioning = false;
$("#homePageMainPanel").css({ "backgroundColor": "black" });
var hybridMode = true;
if (($.browser.mozilla && $.browser.version == "5.0") ||
$.browser.msie && $.browser.version == "9.0") {
//hybridMode = false;
}
//$("html").css({ "overflow": "hidden" });
function updateOrientation() {
// scroll and hide address bar for iPhone landscape
setTimeout(function() { window.scrollTo(0, 1) }, timeWaiting);
if (window.orientation != undefined)
orientation = Math.abs(window.orientation);
resizeBackground();
}
$(window).load(function() {
resizeBackground();
if (!($.browser.msie && $.browser.version == "6.0")) {
var lang = $('meta[name="language"]').attr("content");
if ((lang == "ar") || (lang == "ir")) {
$(".carouselShadow").css('background', 'url(/media/images/fg_ar_text_bg.png) no-repeat');
}
else {
$(".carouselShadow").css('background', 'url(/media/images/fg_text_bg.png) no-repeat');
}
}
});
$(document).ready(function() {
if (typeof BackgroundInfo != 'undefined' && BackgroundInfo.length > 0) {
$("#carousel").append("<img src=\"" + BackgroundInfo[0].Src + "\" alt=\"" + BackgroundInfo[0].Alt + "\" />");
}
if ($(window).height() > $(document).height() - $("#bottomLayer").height()) {
$("#bottomLayer").css({ 'position': 'absolute', "top": parseInt($(window).height() - $("#bottomLayer").height()) });
$("#carousel img").height($(window).height() - $("#bottomLayer").height());
//alert($("#bottomLayer").offset().bottom);
$(".bookPanel").css({ 'position': 'relative', "bottom": parseInt($(".bookPanel").height() - $("#carousel").height() + 28) });
$(".carouselShadow").css({ 'position': 'relative', "bottom": parseInt($(".carouselShadow").height() - $("#carousel").height()+20) });
setTimeout(function() {
$("#bottomLayer").css({ "position": "relative", "top": parseInt($(window).height() - $("#bottomLayer").height()) });
}, 500);
setTimeout(function() {
$(".bookPanel").css({ "position": "relative", "bottom": parseInt($(".bookPanel").height() - $("#carousel").height() + 28) });
}, 500);
setTimeout(function() {
$(".carouselShadow").css({ "position": "relative", "bottom": parseInt($(".carouselShadow").height() - $("#carousel").height()+20) });
}, 500);
}
//in case the navigation height is longer than prefixed minheight, adjust minheight=navigation height
var homepageHeight = $("#homePageMainPanel").height() + $("#bottomLayer").height();
if (homepageHeight > minHeight)
minHeight = homepageHeight;
//this is only for mobile safari on ipad/iphone
window.onorientationchange = function() {
window.scrollTo(0, 1); // to prevent jumpy and blinky page transitions
updateOrientation();
}
$(window)
.resize(function() {
if (readyToResize) {
clearTimeout(debounceId);
debounceId = setTimeout(resizeEvent, 500);
}
})
.load(function() {
// scroll and hide address bar for iPhone landscape
setTimeout(function() { window.scrollTo(0, 1) }, timeWaiting);
});
initRotateBanner();
});
var winWidth = $(window).width();
var winHeight = $(window).height();
var winNewWidth = -1;
var winNewHeight = -1;
function resizeEvent() {
// JL: Hack to prevent IE 7,8 to have infinite loop when window.resize event
winNewWidth = $(window).width();
winNewHeight = $(window).height();
if (winWidth != winNewWidth || winHeight != winNewHeight) {
clearTimeout(debounceId);
resizeBackground();
}
winWidth = winNewWidth;
winHeight = winNewHeight;
}
function initRotateBanner() {
$('#carousel img').eq(0).one('load', function() {
if (readyToRotate = true) {
if (typeof BackgroundInfo != 'undefined' && BackgroundInfo.length > 0) {
$.each(BackgroundInfo, function(i, v) {
if (i > 0) {
$("#carousel").append("<img src=\"" + BackgroundInfo[i].Src + "\" alt=\"" + BackgroundInfo[i].Alt + "\" />");
}
});
initBackgroundImageReady();
}
imgReady[0] = true;
window.setTimeout("rotateBanner('init')", timeTransInit);
}
//$('#background').children("img").show();
//$('#background').children("img").css({ 'opacity': '1' });
resizeBackground();
}).each(function() {
// $(this).load();
});
/// assign each background text accordingly
var index = 0;
$('.carouselContentContainer').each(function() {
$(this).attr('id', 'text_box_' + index);
index++;
});
}
function initBackgroundImageReady() {
$('#carousel').children("img").each(function() {
//assign each background id accordingly
$(this).attr('id', 'img_box_' + totalBanner);
// flag correspondingly when bg images is loaded
imgReady[totalBanner] = false;
$(this).one('load', function(event) {
var id = $(this).attr('id');
var idArr = new Array();
idArr = id.split('_');
var index = idArr[idArr.length - 1];
//console.log(index + "loaded");
imgReady[index] = true;
resizeBackground();
});
//$(this).load();
totalBanner++;
});
}
function resizeBackground() {
readyToResize = false;
$('html').css({ 'overflow': 'hidden' });
$("#carousel").children("img").each(function() {
var oriWidth = $(this).width('');
var oriHeight = $(this).height('');
var bgWidth = $(window).width();
if (bgWidth < minWidth)
bgWidth = minWidth;
var bgHeight = bgWidth / oriWidth * oriHeight;
if (oriHeight < bgWrapperHeight)
bgWrapperHeight = oriHeight;
$(this).css({ 'position': 'absolute', 'width': bgWidth, 'height': bgHeight });
});
//start with window height & width
var bgWrapperHeight = $(window).height();
var bgWrapperWidth = $(window).width();
// if vertical scrollbar exists, accommodate the scrollbar width (16px)
if ($.browser.webkit == true) {
////$("#log").prepend(document.body.scrollHeight + " : " + document.body.clientHeight + "<br />");
if (document.body.scrollHeight < document.body.clientHeight)
bgWrapperWidth = $(window).width() - 16; // accomdate the scroll bar width (16px)
else
bgWrapperWidth = $(window).width();
}
else {
////$("#log").prepend($(document).height() + " : " + $(window).height() + "<br />");
if ($(window).height() < $(document).height())
bgWrapperWidth = $(window).width() - 17; //
else
bgWrapperWidth = $(window).width();
}
// for screen size > min height (hp-navigation) but < min background image size, adjust to fit without scroller
if (bgWrapperHeight + $('#bottomLayer').height() > $(window).height()) {
bgWrapperHeight = $(window).height() - $('#bottomLayer').height();
}
//wrapper height should not go lower than navigation height
if (bgWrapperHeight < $('#bookPanel').height())
bgWrapperHeight = $('#bookPanel').height();
//wrapper width should not go lower than min width
if (bgWrapperWidth < minWidth)
bgWrapperWidth = minWidth;
// set #hp-content-wrapper height
$('#homePageMainPanel').css({ 'height': bgWrapperHeight, 'width': bgWrapperWidth });
$('#carousel').css({ 'height': bgWrapperHeight, 'width': bgWrapperWidth });
$('#bottomLayer').css({ 'width': bgWrapperWidth });
$('html').css({ 'overflow': 'auto' });
//TODO: better way to center align bg image!
//var nn = 0;
// vertically middle align background
$("#carousel").children("img").each(function() {
// IF document height (minus footer height) is more than background image,
// Expand Background Image Vertically!
if (($(document).height() - $('#bottomLayer').height()) >= $(this).height()) {
var newHeight = $(document).height() - $('#bottomLayer').height();
var newWidth = Math.round((newHeight / $(this).height()) * $(this).width());
var offsetX = ((bgWrapperWidth - newWidth) / 2);
$(this).css({ 'position': 'absolute', 'left': offsetX, 'width': newWidth, 'height': newHeight });
// $("#log").prepend($(document).height() + " : " + $('#footer').height() + "<br />");
// Reset back the image top position to 0;
$(this).css({ 'position': 'absolute', 'top': 0 });
}
else { //TODO: figure out what contributes to offset??
var newWidth = $(document).width();
var newHeight = Math.round((newWidth / $(this).width()) * $(this).height());
var offsetX = ((bgWrapperWidth - newWidth) / 2);
// Reset back the image left position to 0;
$(this).css({ 'position': 'absolute', 'left': 0, 'width': newWidth, 'height': newHeight });
// $(this).css({ 'position': 'absolute', 'left': 0, 'width': '100%', 'height': '' });
if (bgWrapperHeight > $('#bottomLayer').position().top) {
var offsetY = ((bgWrapperHeight - $(this).height()) / 2);
$(this).css({ 'top': offsetY });
}
else {
var offsetY = (($('#bottomLayer').position().top - $(this).height()) / 2);
$(this).css({ 'top': offsetY });
}
}
});
//$(".bookPanel").css({ 'position': 'absolute', "top": parseInt($("#carousel").height()) });
$('#bottomLayer').css({ 'position': 'absolute', 'top': $("#carousel").height() });
$(".bookPanel").css({ "bottom": parseInt($(".bookPanel").height() - $("#carousel").height() + 28) });
$(".carouselShadow").css({ 'position': 'relative', "bottom": parseInt($(".carouselShadow").height() - $("#carousel").height()) });
//when having vertical scroll bar
//known issue: does not work for IE screen onresize, only works onload
if ($(window).height() != $(document).height()) {
//$("#roomreservations").html($(window).width() + ":" + $(document).width() + ":" + minWidth);
if ($(document).width() == minWidth && ($(window).width() != $(document).width())) {
//show horizontal scrollbar (by default)
}
else {
//otherwise hide horizontal scrollbar
$('html').css({ 'overflow-x': 'hidden' });
}
}
setTimeout('checkWidth(' + bgWrapperWidth + ')', 500);
readyToResize = true;
}
function checkWidth(bgWrapperWidth) {
$('#homePageMainPanel').width('100%');
$('#bottomLayer').width('100%');
$('#carousel').width($(document).width());
$("#carousel").children("img").each(function() {
if (($(document).height() - $('#bottomLayer').height()) >= $(this).height()) {
// Resize the image height to $("#background") height, as the image should fill from the top till the footer
$(this).css({ 'width': (($("#carousel").height() / $(this).height()) * $(this).width()), 'height': $("#carousel").height() });
}
});
}
function positionFooter() {
return null;
var footerPosition = $('#carousel').height() - $('#bottomLayer').height() + 1;
if ($('#carousel').height() < minHeight) {
footerPosition = minHeight - $('#carousel').height() + 1;
}
$('#carousel').css({ 'position': 'absolute', 'top': footerPosition });
$('html').css({ 'overflow': 'auto' });
$("#homePageMainPanel").css({ 'height': $('#carousel').height() });
}
var waitingTimeout;
function rotateBanner(param) {
var nextBanner = 0;
nextBanner = parseInt(currBanner) + 1;
if (nextBanner >= totalBanner) { nextBanner = 0; }
// wait until next bg image is fully loaded
if (imgReady[nextBanner] != true) {
waitingTimeout = window.setTimeout("rotateBanner('waiting')", timeWaiting);
return false;
}
clearTimeout(waitingTimeout);
transitionStart();
// cross fade
if (currBanner > -1) {
if (hybridMode) {
window.setTimeout("changeClass('quality','speed')", 500);
window.setTimeout("changeClass('speed','quality')", 1500);
}
fadeBgImg('#text_box_' + String(currBanner), 0, 500);
window.setTimeout("fadeBgImg('#img_box_" + String(currBanner) + "',0," + 1000 + ")", 500);
window.setTimeout("fadeBgImg('#img_box_" + String(nextBanner) + "',1," + 1000 + ")", 500);
window.setTimeout("fadeBgImg('#text_box_" + String(nextBanner) + "',1," + 1000 + ",true)", 1500);
window.setTimeout("transitionComplete()", 2500);
}
else {
if (hybridMode) {
changeClass('quality', 'speed');
window.setTimeout("changeClass('speed','quality')", 1000);
}
fadeBgImg("#img_box_" + String(nextBanner), 1, 1000);
window.setTimeout("fadeBgImg('#text_box_" + String(nextBanner) + "',1," + 1000 + ",true)", 1000);
window.setTimeout("showShadow()", 1000);
window.setTimeout("transitionComplete()", 2000);
}
currBanner = nextBanner;
}
function nextPaging(nextBanner) {
$('#carousel #paging ul li').each(function() {
if ($(this).attr('id') == 'paging_item_' + nextBanner) {
$(this).addClass("active");
}
else {
$(this).removeClass("active");
}
});
}
function changeClass(from, to) {
$("#carousel").removeClass(from).addClass(to);
}
function fadeBgImg(id, inout, duration, triggerTimer) {
$(id).stop(true, true);
if (inout == 1) {
$(id).fadeIn(duration);
}
else {
$(id).fadeOut(duration);
}
//$(id).animate({ 'opacity': inout }, duration);
if (triggerTimer == true) {
window.clearTimeout(theTimer);
if (totalBanner > 1) {
theTimer = window.setTimeout("rotateBanner()", timeTransInit + timeTransInterval);
}
}
}
function transitionStart() {
transitioning = true;
}
function transitionComplete() {
transitioning = false;
}
function Timer(callback, delay) {
var timerId, start, remaining = delay;
this.pause = function() {
window.clearTimeout(timerId);
remaining -= new Date() - start;
};
this.resume = function() {
start = new Date();
timerId = window.setTimeout(callback, remaining);
};
this.resume();
}
var waitingTimeout2;
function onBlur() {
//theTimer.pause();
clearTimeout(waitingTimeout2);
if (transitioning) {
waitingTimeout2 = window.setTimeout("onBlur()", timeWaiting);
return false;
}
window.clearTimeout(theTimer);
};
function onFocus() {
//theTimer.resume();
if (totalBanner > 1) {
window.clearTimeout(theTimer);
theTimer = window.setTimeout("rotateBanner()", timeTransInit + timeTransInterval);
}
};
if (/*#cc_on!#*/false) { // check for Internet Explorer
document.onfocusin = onFocus;
document.onfocusout = onBlur;
readyToRotate = true;
} else {
window.onfocus = onFocus;
window.onblur = onBlur;
readyToRotate = true;
}
function showShadow() {
// Do not fade in shadow png IE8 and below
if ($.browser.msie && parseInt($.browser.version, 10) <= 8) {
$(".carouselShadow").delay(1000).show();
}
else {
$(".carouselShadow").delay(1000).fadeIn();
}
}

While it is great that you've built this yourself, someone has already solved all your problems with Backstretch.

jQuery visible selector not working

trying to use :visible and it's not working.
neither $('.landscape:visible') or $('.landscape').filter(':visible')
My goal is to make a variable of whatever the visible landscape picture is, grab it's height, then apply that to the portrait images for consistency.
For testing purposes , the third navigation button, #w, is set to write what that height is using variable vincent.
test site: http://brantley.dhut.ch/
JavaScript:
(function($){
$.respond = function(callback) {
var element = $('#main');
$('.z').hide();
$(document).ready(function() {
dimensions();
});
$(window).load(function() {
dimensions();
$('#load').fadeOut('fast', function() {
$('.z:first').fadeIn('slow');
$('footer').fadeIn('slow');
});
});
$(window).resize(function() {
dimensions();
});
//Adjust image size
function dimensions() {
return element.each(function() {
var i = $('.z', element);
$(i).each(function(){
var browserWidth = $(window).width();
var imgRatio = $(this).width() / $(this).height()
var availableHeight = ($(window).height() - $('header').height() - $('footer').height() - 80)
var browserRatio = browserWidth / availableHeight
var zzz = $('.z').height();
/* resize functions
$(this).height(availableHeight).width('auto');
$(this).width(browserWidth - 40).height('auto');
*/
/* image sizing logic */
if (imgRatio >= 1) {
$(this).addClass('landscape');
}
var vincent = $('.landscape').filter(':visible').height();
if (browserRatio >= imgRatio) {
if (availableHeight <= 312) {
/* Landscape */
$('body').css('background', 'yellow');
$(this).width(browserWidth - 40).height('auto');
} else {
$(this).height(availableHeight).width('auto');
$('body').css('background', 'green');
}
} else {
if (availableHeight <= 312) {
/* Portrait */
$('body').css('background', 'yellow');
$(this).height(200).width('auto');
} else {
$(this).width(browserWidth - 40).height('auto');
$('body').css('background', 'blue');
}
}
/* horizontally center content */
$(this).css('margin-left', (browserWidth - $(this).width())/2);
$('#w').text(vincent);
});
return false;
});
};
//callback();
};
})(jQuery);

Try if ($('.landscape').is(':visible')){}

Scroll if element is not visible

how to determine, using jquery, if the element is visible on the current page view. I'd like to add a comment functionality, which works like in facebook, where you only scroll to element if it's not currently visible. By visible, I mean that it is not in the current page view, but you can scroll to the element.

Live Demo
Basically you just check the position of the element to see if its within the windows viewport.
function checkIfInView(element){
var offset = element.offset().top - $(window).scrollTop();
if(offset > window.innerHeight){
// Not in view so scroll to it
$('html,body').animate({scrollTop: offset}, 1000);
return false;
}
return true;
}

Improving Loktar's answer, fixing the following:
Scroll up
Scroll to a display:none element (like hidden div's etc)
function scrollToView(element){
var offset = element.offset().top;
if(!element.is(":visible")) {
element.css({"visibility":"hidden"}).show();
var offset = element.offset().top;
element.css({"visibility":"", "display":""});
}
var visible_area_start = $(window).scrollTop();
var visible_area_end = visible_area_start + window.innerHeight;
if(offset < visible_area_start || offset > visible_area_end){
// Not in view so scroll to it
$('html,body').animate({scrollTop: offset - window.innerHeight/3}, 1000);
return false;
}
return true;
}

After trying all these solutions and many more besides, none of them satisfied my requirement for running old web portal software (10 years old) inside IE11 (in some compatibility mode). They all failed to correctly determine if the element was visible. However I found this solution. I hope it helps.
function scrollIntoViewIfOutOfView(el) {
var topOfPage = window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop;
var heightOfPage = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;
var elY = 0;
var elH = 0;
if (document.layers) { // NS4
elY = el.y;
elH = el.height;
}
else {
for(var p=el; p&&p.tagName!='BODY'; p=p.offsetParent){
elY += p.offsetTop;
}
elH = el.offsetHeight;
}
if ((topOfPage + heightOfPage) < (elY + elH)) {
el.scrollIntoView(false);
}
else if (elY < topOfPage) {
el.scrollIntoView(true);
}
}

I made a slightly more generic version of digitalPBK's answer that minimally scrolls an element contained within a div or some other container (including the body). You can pass DOM elements or selectors to the function, as long as the element is somehow contained within the parent.
function scrollToView(element, parent) {
element = $(element);
parent = $(parent);
var offset = element.offset().top + parent.scrollTop();
var height = element.innerHeight();
var offset_end = offset + height;
if (!element.is(":visible")) {
element.css({"visibility":"hidden"}).show();
var offset = element.offset().top;
element.css({"visibility":"", "display":""});
}
var visible_area_start = parent.scrollTop();
var visible_area_end = visible_area_start + parent.innerHeight();
if (offset-height < visible_area_start) {
parent.animate({scrollTop: offset-height}, 600);
return false;
} else if (offset_end > visible_area_end) {
parent.animate({scrollTop: parent.scrollTop()+ offset_end - visible_area_end }, 600);
return false;
}
return true;
}

You can take a look at his awesome link from the jQuery Cookbook:
Determining Whether an Element Is Within the Viewport
Test if Element is contained in the Viewport
jQuery(document).ready(function() {
var viewportWidth = jQuery(window).width(),
viewportHeight = jQuery(window).height(),
documentScrollTop = jQuery(document).scrollTop(),
documentScrollLeft = jQuery(document).scrollLeft(),
$myElement = jQuery('#myElement'),
elementOffset = $myElement.offset(),
elementHeight = $myElement.height(),
elementWidth = $myElement.width(),
minTop = documentScrollTop,
maxTop = documentScrollTop + viewportHeight,
minLeft = documentScrollLeft,
maxLeft = documentScrollLeft + viewportWidth;
if (
(elementOffset.top > minTop && elementOffset.top + elementHeight < maxTop) &&
(elementOffset.left > minLeft && elementOffset.left + elementWidth < maxLeft)
) {
alert('entire element is visible');
} else {
alert('entire element is not visible');
}
});
Test how much of the element is visible
jQuery(document).ready(function() {
var viewportWidth = jQuery(window).width(),
viewportHeight = jQuery(window).height(),
documentScrollTop = jQuery(document).scrollTop(),
documentScrollLeft = jQuery(document).scrollLeft(),
$myElement = jQuery('#myElement'),
verticalVisible, horizontalVisible,
elementOffset = $myElement.offset(),
elementHeight = $myElement.height(),
elementWidth = $myElement.width(),
minTop = documentScrollTop,
maxTop = documentScrollTop + viewportHeight,
minLeft = documentScrollLeft,
maxLeft = documentScrollLeft + viewportWidth;
function scrollToPosition(position) {
jQuery('html,body').animate({
scrollTop : position.top,
scrollLeft : position.left
}, 300);
}
if (
((elementOffset.top > minTop && elementOffset.top < maxTop) ||
(elementOffset.top + elementHeight > minTop && elementOffset.top +
elementHeight < maxTop))
&& ((elementOffset.left > minLeft && elementOffset.left < maxLeft) ||
(elementOffset.left + elementWidth > minLeft && elementOffset.left +
elementWidth < maxLeft)))
{
alert('some portion of the element is visible');
if (elementOffset.top >= minTop && elementOffset.top + elementHeight
<= maxTop) {
verticalVisible = elementHeight;
} else if (elementOffset.top < minTop) {
verticalVisible = elementHeight - (minTop - elementOffset.top);
} else {
verticalVisible = maxTop - elementOffset.top;
}
if (elementOffset.left >= minLeft && elementOffset.left + elementWidth
<= maxLeft) {
horizontalVisible = elementWidth;
} else if (elementOffset.left < minLeft) {
horizontalVisible = elementWidth - (minLeft - elementOffset.left);
} else {
horizontalVisible = maxLeft - elementOffset.left;
}
var percentVerticalVisible = (verticalVisible / elementHeight) * 100;
var percentHorizontalVisible = (horizontalVisible / elementWidth) * 100;
if (percentVerticalVisible < 50 || percentHorizontalVisible < 50) {
alert('less than 50% of element visible; scrolling');
scrollToPosition(elementOffset);
} else {
alert('enough of the element is visible that there is no need to scroll');
}
} else {
// element is not visible; scroll to it
alert('element is not visible; scrolling');
scrollToPosition(elementOffset);
}

The following code helped me achieve the result
function scroll_to_element_if_not_inside_view(element){
if($(window).scrollTop() > element.offset().top){
$('html, body').animate( { scrollTop: element.offset().top }, {duration: 400 } );
}
}

Here is the solution I came up with, working both up and down and using only Vanilla Javascript, no jQuery.
function scrollToIfNotVisible(element) {
const rect = element.getBoundingClientRect();
// Eventually an offset corresponding to the height of a fixed navbar for example.
const offset = 70;
let scroll = false;
if (rect.top < offset) {
scroll = true;
}
if (rect.top > window.innerHeight) {
scroll = true;
}
if (scroll) {
window.scrollTo({
top: (window.scrollY + rect.top) - offset,
behavior: 'smooth'
})
}
}

There is a jQuery plugin which allows us to quickly check if a whole element (or also only part of it) is within the browsers visual viewport regardless of the window scroll position. You need to download it from its GitHub repository:
Suppose to have the following HTML and you want to alert when footer is visible:
<section id="container">
<aside id="sidebar">
<p>
Scroll up and down to alert the footer visibility by color:
</p>
<ul>
<li><span class="blue">Blue</span> = footer <u>not visible</u>;</li>
<li><span class="yellow">Yellow</span> = footer <u>visible</u>;</li>
</ul>
<span id="alert"></span>
</aside>
<section id="main_content"></section>
</section>
<footer id="page_footer"></footer>
So, add the plugin before the close of body tag:
<script type="text/javascript" src="js/jquery-1.12.0.min.js"></script>
<script type="text/javascript" src="js/jquery_visible/examples/js/jq.visible.js"></script>
After that you can use it in a simple way like this:
<script type="text/javascript">
jQuery( document ).ready(function ( $ ) {
if ($("footer#page_footer").visible(true, false, "both")) {
$("#main_content").css({"background-color":"#ffeb3b"});
$("span#alert").html("Footer visible");
} else {
$("#main_content").css({"background-color":"#4aafba"});
$("span#alert").html("Footer not visible");
}
$(window).scroll(function() {
if ($("footer#page_footer").visible(true, false, "both")) {
$("#main_content").css({"background-color":"#ffeb3b"});
$("span#alert").html("Footer visible");
} else {
$("#main_content").css({"background-color":"#4aafba"});
$("span#alert").html("Footer not visible");
}
});
});
</script>
Here a demo

No-JQuery version.
The particular case here is where the scroll container is the body (TBODY, table.body) of a TABLE (scrolling independently of THEAD). But it could be adapted to any situation, some simpler.
const row = table.body.children[ ... ];
...
const bottomOfRow = row.offsetHeight + row.offsetTop ;
// if the bottom of the row is in the viewport...
if( bottomOfRow - table.body.scrollTop < table.body.clientHeight ){
// ... if the top of the row is in the viewport
if( row.offsetTop - table.body.scrollTop > 0 ){
console.log( 'row is entirely visible' );
}
else if( row.offsetTop - table.body.scrollTop + row.offsetHeight > 0 ){
console.log( 'row is partly visible at top')
row.scrollIntoView();
}
else {
console.log( 'top of row out of view above viewport')
row.scrollIntoView();
}
}
else if( row.offsetTop - table.body.scrollTop < table.body.clientHeight ){
console.log( 'row is partly visible at bottom')
row.scrollIntoView();
}
else {
console.log( 'row is out of view beneath viewport')
row.scrollIntoView();
}

I think this is the complete answer. An elevator must be able to go both up and down ;)
function ensureVisible(elementId, top = 0 /* set to "top-nav" Height (if you have)*/) {
let elem = $('#elementId');
if (elem) {
let offset = elem.offset().top - $(window).scrollTop();
if (offset > window.innerHeight) { // Not in view
$('html,body').animate({ scrollTop: offset + top }, 1000);
} else if (offset < top) { // Should go to top
$('html,body').animate({ scrollTop: $(window).scrollTop() - (top - offset) }, 1000);
}
}
}