How to make text/div appear when the user stops scrolling - javascript

I'm trying to achieve an effect where the javascript detects whether the user has stopped scrolling/hovering over the page, and slowly shows a piece of text over the page, sort of like a paywall. The effect I'm trying to achieve is a simplified version of this website where when the user is inactive for a certain amount of time, eyes start to appear on the page

You can use setTimeout and clearTimeout to perform an action when the mouse stops moving. Here the text would reappear after 3 seconds of inactivity
var timeout;
var element = document.getElementById("element");
document.addEventListener("mousemove", function(e) {
element.style.opacity = 0;
clearTimeout(timeout);
timeout = setTimeout(function() {
element.style.opacity = 1;
}, 2000);
});
#element {
transition: opacity 0.5s;
opacity 0;
}
<div id="element">I see you<div>

First, you want to define what it means for a user to be "inactive". For example, we can consider a user to be inactive if they haven't moved their mouse or scrolled for 30 seconds. When that happens, we want to fire off some other code to signal that the user has gone inactive.
const addUserInactiveListener = (
onUserInactive,
inactiveTimeMs = 30000
) => {
let timeout = setTimeout(onUserInactive, inactiveTimeMs);
const onUserAction = () => {
clearTimeout(timeout);
timeout = setTimeout(onUserInactive, inactiveTimeMs);
}
document.addEventListener('mousemove', onUserAction);
document.addEventListener('scroll', onUserAction);
}
// console log after 5s of inactivity
addUserInactiveListener(() => console.log('inactive'), 5000)

Related

How to add a loading animation during the calculation in the Website?

I am making a website which performs some calculations and then plots a graph. Now what I want is when the computation is going on, it should show a loading animation and when the calculations are done, that animation should disappear.
P.S. It has nothing to do with page loading so I guess page loader is not an option.
document.getElementById("submitButton").onclick=function()
{
document.getElementById("loader").style.display='flex'; //this is the animation div
const permutationGeneration = (arr = []) => {
let res = []
const helper = (arr2) => {
if (arr2.length==arr.length)
return res.push(arr2)
for(let e of arr)
if (!arr2.includes(e))
helper([...arr2, e])
};
helper([])
delete result;
return;
};
var randArray=Array.from({length : size}, () => Math.floor(Math.random() * 100000));
timeReq = new Date().getTime();
permutationGeneration(randArray);
timeReq = ((new Date().getTime()) - timeReq)/1000;
}
This is the code snippet, now when permutation generation is going on, I want a loading animation.
When I click submit button, display changes from 'none' to 'flex'. Now how to change display back to none, when calculation is done & graph is plotted.
One way you can do it is with setTimeout which sets a timeout before something happens. For example, in this code down here, it loads and gif which is loading gif. After 2-3 seconds, the results go from display:none to display:block; and vice versa with the gif. It shows for 2 seconds, and after that timeout, it gets a style of display:none.
// Listen for submit
document.getElementById('loan-form').addEventListener('submit', function(e){
// Hide results
document.getElementById('results').style.display = 'none';
// Show loader
document.getElementById('loading').style.display = 'block';
setTimeout(calculateResults, 2000);
e.preventDefault();
});

How to show divs when the mouse moves anywhere on screen, not just the element itself?

I managed to hide and show my classes when the user moves his mouse over the specific element. But what I would actually like is that these show when the user moves his mouse anywhere on the screen, not just the selected div's.
This is my current code:
$(window).on('mousemove', function () {
$('.barhide').addClass('show');
try {
clearTimeout(timer);
} catch (e) {}
timer = setTimeout(function () {
$('.barhide').removeClass('show');
}, 1000);
});
And my css:
.barhide {
background: #333;
color: #fff;
display: block;
opacity: 0;
transition: all 1.5s ease;
}
.barhide.show {
opacity: 1;
display: none;
}
So what I would like is that after 3 seconds, the classes with .barhide get hidden and if the user moves his mouse anywhere in screen, they show up again, instead of just when they move over the element.
Also I was wondering if it's not a lot easier to do these things with React?
I have restructured the code a bit and added some comments explaining what's happening and when. Also, lose the try since attempting to clear a timer will never throw an exception.
Keep in mind that mouseover type events are an issue on mobile devices. These two articles may help in that regard:
JQuery's Virtual Mouse Events
Simulated Mouse Events using JQuery
$(function(){
// When page loads, wait 3 seconds and hide all elements with .barhide class:
setTimeout(toggle, 3000);
});
var timer = null;
// General function for adding/removing the "hide" class.
// This is used when the page first loads and each time
// the mouse moves on the page. We're not calling toggle()
// here because a flicker effect can happen which would leave
// the elements showing instead of being hidden.
function toggle(){
$('.barhide').toggleClass('hide');
}
$(window).on('mousemove', function(){
// When anywhere on page is moused over bring back .barhide
// elements for 3 seconds. Removing "hide" simply restores
// the original CSS & layout
$('.barhide').removeClass('hide');
// Kill any previous timers
clearTimeout(timer);
// Wait 3 seconds and hide again
timer = setTimeout(toggle, 3000)
});
.barhide { background-color:blue; }
.hide { display:none; }
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="barhide">ONE</div>
<div class="show">TWO</div>
You just count the nr of timers running and when the last finishes you hide the bar.
var count = 0;
$(window).mousemove(function( event ) {
$('.barhide').show();
count += 1;
setTimeout(function() {
if (count == 1) {
$('.barhide').hide();
}
count -= 1;
}, 3000);
});

setInterval running really slow

I made a website where I need to animate strings that are longer than the containing parent.
This is the website: Here
If you click on next, you can see multiple pages of breeders with long names, that need to animate from left to right, but this only happens after 10 or 15 seconds and it takes a long time for it to start.
Now I have checked my code and this is where I create my functions:
function newsTicker() {
console.log('newsTicker')
verifyLength();
$('.breeder').not('.short-breed-name').each(function() {
var breederNameWidth = $(this).find('.breeder_name').width();
var divBreederNameWidth = $(this).find('.breeder_name_div').width();
var diff = Math.max(parseInt(breederNameWidth - divBreederNameWidth),0);
// console.log('diff:',diff)
$(this).find('.breeder_name').animate({
marginLeft: -diff
}, 3000,
function(){
$(this).animate({
marginLeft : 0
},3000)
})
})
}
function verifyLength() {
// console.log('verifyLength')
$('.breeder.visible').each(function() {
// debugger
var breederNameWidth = $(this).find('.breeder_name').width() + 10;
var divBreederNameWidth = $(this).find('.breeder_name_div').innerWidth();
if(breederNameWidth < divBreederNameWidth) {
$(this).addClass('short-breed-name');
$(this).find('.breeder_name').css({'width':'100%','text-align':'center'})
}
})
}
And this is where I call newsTicker:
function breederAnimate(){
verifyLength();
newsTicker();
setInterval(newsTicker, 1000);
}
Why is it so slow when my times are between 1 and 3 seconds?
You should be calling setTimeout not setInterval because you only want your animation to run once. You're restarting your animations every second
Also, you should be cancelling existing setIntervals when you click next or previous

Javascript fade in doesn't visibly animate

So I've created the following function to fade elements in and passed in a div that I want to fade in which in this case is an image gallery popup that I want to show when a user clicks an image thumbnail on my site. I'm also passing in a speed value (iSpeed) which the timeout uses for it's time value. In this case I'm using 25 (25ms).
I've stepped through this function whilst doing so it appears to be functioning as expected. If the current opacity is less than 1, then it is incremented and it will recall itself after the timeout until the opacity reaches 1. When it reaches one it stops fading and returns.
So after stepping through it, I take off my breakpoints and try to see it in action but for some reason my gallery instantly appears without any sense of fading.
var Effects = new function () {
this.Fading = false;
this.FadeIn = function (oElement, iSpeed) {
//set opacity to zero if we haven't started fading yet.
if (this.Fading == false) {
oElement.style.opacity = 0;
}
//if we've reached or passed max opacity, stop fading
if (oElement.style.opacity >= 1) {
oElement.style.opacity = 1;
this.Fading = false;
return;
}
//otherwise, fade
else {
this.Fading = true;
var iCurrentOpacity = parseFloat(oElement.style.opacity);
oElement.style.opacity = iCurrentOpacity + 0.1;
setTimeout(Effects.FadeIn(oElement, iSpeed), iSpeed);
}
}
}
Here's where I'm setting up the gallery.
this.Show = function (sPage, iImagesToDisplay, oSelectedImage) {
//create and show overlay
var oOverlay = document.createElement('div');
oOverlay.id = 'divOverlay';
document.body.appendChild(oOverlay);
//create and show gallery box
var oGallery = document.createElement('div');
oGallery.id = 'divGallery';
oGallery.style.opacity = 0;
document.body.appendChild(oGallery);
//set position of gallery box
oGallery.style.top = (window.innerHeight / 2) - (oGallery.clientHeight / 2) + 'px';
oGallery.style.left = (window.innerWidth / 2) - (oGallery.clientWidth / 2) + 'px';
//call content function
ImageGallery.CreateContent(oGallery, sPage, iImagesToDisplay, oSelectedImage);
//fade in gallery
Effects.FadeIn(oGallery, 25);
}
Could anyone help me out?
Also, I'm using IE10 and I've also tried Chrome, same result.
Thanks,
Andy
This line:
setTimeout(Effects.FadeIn(oElement, iSpeed), iSpeed);
calls Effects.FadeIn with the given arguments, and feeds its return value into setTimeout. This is exactly like foo(bar()), which calls bar immediately, and then feeds its return value into foo.
Since your FadeIn function doesn't return a function, that would be the problem.
Perhaps you meant:
setTimeout(function() {
Effects.FadeIn(oElement, iSpeed);
}, iSpeed);
...although you'd be better off creating that function once and reusing it.
For instance, I think this does what you're looking for, but without recreating functions on each loop:
var Effects = new function () {
this.FadeIn = function (oElement, iSpeed) {
var fading = false;
var timer = setInterval(function() {
//set opacity to zero if we haven't started fading yet.
if (fading == false) { // Consider `if (!this.Fading)`
oElement.style.opacity = 0;
}
//if we've reached or passed max opacity, stop fading
if (oElement.style.opacity >= 1) {
oElement.style.opacity = 1;
clearInterval(timer);
}
//otherwise, fade
else {
fading = true;
var iCurrentOpacity = parseFloat(oElement.style.opacity);
oElement.style.opacity = iCurrentOpacity + 0.1;
}
}, iSpeed);
};
};
Your code has a lot of problems. The one culpable for the element appearing immediately is that you call setTimeout not with a function but with the result of a function, because Effects.FadeIn will be executed immediately.
setTimeout(function(){Effects.FadeIn(oElement, iSpeed)}, iSpeed);
will probably act as you intend.
But seriously, you probably should not re-invent this wheel. jQuery will allow you to fade elements in and out easily and CSS transitions allow you to achieve element fading with as much as adding or removing a CSS class.
T.J. and MoMolog are both right about the bug: you're invoking the Effects.FadeIn function immediately before passing the result to setTimeout—which means that Effects.FadeIn calls itself synchronously again and again until the condition oElement.style.opacity >= 1 is reached.
As you may or may not know, many UI updates that all take place within one turn of the event loop will be batched together on the next repaint (or something like that) so you won't see any sort of transition.
This jsFiddle includes the suggested JS solution, as well as an alternate approach that I think you may find to be better: simply adding a CSS class with the transition property. This will result in a smoother animation. Note that if you go this route, though, you may need to also include some vendor prefixes.

How to detect/disable inertial scrolling in Mac Safari?

Is there a way to disable or detect that wheel events are from the "inertia" setting on a Mac?
I'd like to be able to tell the difference between real events and the others...or disable that kind of scrolling for a particular page.
I found a solution that works really well for this. Below is some pasted code from my project. It basically comes down to this logic:
A scroll event is from a human when ANY ONE of these conditions are true:
The direction is the other way around than the last one
More than 50 milliseconds passed since the last scroll event (picked 100ms to be sure)
The delta value is at least as high as the previous one
Since Mac spams scroll events with descreasing delta's to the browser every 20ms when inertial scrolling is enabled, this is a pretty failsafe way. I've never had it fail on me at least. Just checking the time since the last scroll won't work because a user won't be able to scroll again if the "virtual freewheel" is still running even though they haven't scrolled for 3 seconds.
this.minScrollWheelInterval = 100; // minimum milliseconds between scrolls
this.animSpeed = 300;
this.lastScrollWheelTimestamp = 0;
this.lastScrollWheelDelta = 0;
this.animating = false;
document.addEventListener('wheel',
(e) => {
const now = Date.now();
const rapidSuccession = now - this.lastScrollWheelTimestamp < this.minScrollWheelInterval;
const otherDirection = (this.lastScrollWheelDelta > 0) !== (e.deltaY > 0);
const speedDecrease = Math.abs(e.deltaY) < Math.abs(this.lastScrollWheelDelta);
const isHuman = otherDirection || !rapidSuccession || !speedDecrease;
if (isHuman && !this.animating) {
this.animating = true; // current animation starting: future animations blocked
$('.something').stop().animate( // perform some animation like moving to the next/previous page
{property: value},
this.animSpeed,
() => {this.animating = false} // animation finished: ready for next animation
)
}
this.lastScrollWheelTimestamp = now;
this.lastScrollWheelDelta = e.deltaY;
},
{passive: true}
);
There's one caveat by the way: Mac also has acceleration on the scrolling, i.e.: at first, the delta value is higher for each successive event. It seems like this does not last more than 100ms or so though. So if whatever action/animation you are firing as a result of the scroll event lasts at least 100ms and blocks all other actions/animations in the meantime, this is never a problem.
Yes and no.
You can use touchdown/up, and scroll as events to look for the page moving about but those won't trigger if the OS is doing an inertial scroll. Fun, right?
One thing that you can continually detect, however, is window.pageYOffset. That value will keep changing while an inertial scroll is happening but won't throw an event. So you can come up with a set of timers to keep checking for an inertial scroll and keep running itself until the page has stopped moving.
Tricky stuff, but it should work.
Oh how is this issue killing me :/
I'm in the process of creating "endless" scrolling large file viewer.
To make situation worse, this editor is embedded in page that has its own scroll bar, because its bigger than one screen.
U use overflow-x scroll for horizontal scroll, but for vertical scroll i need current line highlighter (as seen in most modern IDEs) so i'm using jquery mousewheel plugin, and scrolling moving content for line height up or down.
It works perfectly on ubuntu/chrome but on MacOS Lion/Chrome sometimes, and just sometimes,
when you scroll, it doesn't prevent default scroll on the editor element, and event propagates "up" and page it self starts to scroll.
I cant even describe how much annoying that is.
As for inertial scroll it self, i successfully reduced it with two timers
var self = this;
// mouse wheel events
$('#editorWrapper').mousewheel(function (event, delta, deltax, deltay) {
self._thisScroll = new Date().getTime();
//
//this is entirely because of Inertial scrolling feature on mac os :(
//
if((self._thisScroll - self._lastScroll) > 5){
//
//
// NOW i do actual moving of content
//
//
self._lastScroll = new Date().getTime();
}
5ms is value i found to have most natural feel on my MacBook Pro, and you have to scroll mouse wheel really fast to catch one of those..
Even still, sometimes on Mac listener on mac wrapper doesn't prevent default, and page scrolls down.
Well, (I might be wrong), I think that the "inertia" settings on the Mac are all computed by the system itself, the browser, or any program for that matter would just think that the user is scrolling quickly, rather than slowing down.
I'm not sure about other browsers, but the following event fires during inertial scroll on my Chrome, FF, Safari (mac):
var mousewheelevt=(/Firefox/i.test(navigator.userAgent))? "DOMMouseScroll" : "mousewheel";
function scrollEE (e) {
console.log(e);
}
window.addEventListener(mousewheelevt, scrollEE, false);
I had a big problem with an object animating based on scroll position after the scroll had completed, and the inertial scroll was really messing me around. I ended up calculating the velocity to determine how long the inertial scroll would last and used that to wait before animating.
var currentY = 0;
var previousY = 0;
var lastKnownVelocity = 0;
var velocityRating = 1;
function calculateVelocity() {
previousY = currentY;
currentY = $('#content').scrollTop();
lastKnownVelocity = previousY - currentY;
if (lastKnownVelocity > 20 || lastKnownVelocity < -20) {
velocityRating = 5;
} else {
velocityRating = 1;
}
}
$('#content').scroll(function () {
// get velocity while scrolling...
calculateVelocity();
// wait until finished scrolling...
clearTimeout($.data(this, 'scrollTimer'));
$.data(this, 'scrollTimer', setTimeout(function() {
// do your animation
$('#content').animate({scrollTop: snapPoint}, 300);
}, 300*velocityRating)); // short or long duration...
});
There's a library that solves this problem.
https://github.com/d4nyll/lethargy
After installing it, use it like this:
var lethargy = new Lethargy();
$(window).bind('mousewheel DOMMouseScroll wheel MozMousePixelScroll', function(e){
if(lethargy.check(e) === false) {
console.log('stopping zoom event from inertia')
e.preventDefault()
e.stopPropagation();
}
console.log('Continue with zoom event from intent')
});
Following your instructions with my type of code, I had to set timeout of 270ms on each action activated by scroll to get it all smooth, so if anyone is using something similar to me here is my example if not ignore it, hope it will help you.
//Event action
function scrollOnClick(height) {
$('html').animate({
scrollTop: height
}, 'fast');
return false;
};
// Scroll on PC
let timer = false;
$(window).on('mousewheel', function (event) {
if(timer != true) {
var heightWindow = $(window).height();
var heightCurrent = $(window).scrollTop();
if (event.originalEvent.wheelDelta >= 1) {
if (heightWindow >= heightCurrent) {
timer= true;
scrollOnClick(0)
setTimeout(function (){
timer = false;
},270);
}
} else {
if (heightCurrent < heightWindow) {
timer= true;
scrollOnClick(heightWindow)
setTimeout(function (){
timer = false;
},270);
}
}
}
});

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