im trying to make static grid with a button that can change number of boxes in it (from 16x16 to 64x64 and anything between). Grid is 40rem x 40rem, when i try to change manually number of boxes in makeGrid() function it works fine up to 20 (boxes change size accordingly), but anything above 20 stays the same size and gets cutoff from my grid. If there is no grid css overflow property stated, grid width change depending on number of boxes but boxes themself won't shrink
my code:
size button is not working yet, grid size need to be changed mannualy in makeGrid function
const grid = document.getElementById('grid');
const size = document.getElementById('size');
const eraser = document.getElementById('eraser');
const color = document.getElementById('color');
const gridBorder = document.getElementById('grid-borders');
const clear = document.getElementById('clear');
// grid
function makeGrid(number) {
number = number || 16;
let cellWidth = 40 / number + 'rem';
let cellHeight = 40 / number + 'rem';
grid.style.gridTemplateColumns = `repeat( ${number}, 1fr)`;
grid.style.gridTemplateRows = `repeat(${number}, 1fr)`;
for (let i = 0; i < number * number; i++) {
let cell = document.createElement('div');
grid.appendChild(cell).id = 'box';
cell.classList.add('border');
cell.classList.add('box');
cell.style.backgroundColor = 'white';
cell.style.width = cellWidth;
cell.style.height = cellHeight;
}
size.textContent = `${number} x ${number}`;
}
makeGrid();
// drawing on hover
color.addEventListener('click', function () {
grid.addEventListener('mouseover', function (e) {
e.target !== grid ? (e.target.style.backgroundColor = 'black') : null;
});
});
function changeColor(event) {
event.target.style.backgroundColor = 'black';
}
// erase functionality
eraser.addEventListener('click', function () {
grid.addEventListener('mouseover', function (e) {
e.target !== grid ? (e.target.style.backgroundColor = 'white') : null;
});
});
// grid borders
const allBoxes = document.querySelectorAll('.box');
gridBorder.addEventListener('click', function () {
allBoxes.forEach((box) => {
box.classList.toggle('no-border');
box.classList.toggle('border');
});
});
// clear button
clear.addEventListener('click', function () {
allBoxes.forEach((box) => {
box.style.backgroundColor = 'white';
});
});
// size button
// size.addEventListener('click', function () {
// let number = prompt(`Enter grid size less or equal to 100`);
// if (number !== Number.isInteger()) {
// return;
// } else if (number > 100) {
// number = prompt(`Enter grid size greater or equal to 100`);
// }
// });
* {
margin: 0;
padding: 0;
box-sizing: border-box;
}
body {
height: 100vh;
background-color: aquamarine;
}
#grid {
display: grid;
justify-content: center;
border: 1px solid #ccc;
width: 40rem;
height: 40rem;
min-width: 0;
min-height: 0;
overflow: hidden;
}
.box {
padding: 1em;
}
#title {
display: flex;
align-items: flex-end;
justify-content: center;
height: 180px;
}
#container {
display: flex;
height: 60%;
width: 1259px;
align-items: flex-start;
justify-content: flex-end;
gap: 20px;
padding-top: 20px;
}
#menu {
display: flex;
flex-direction: column;
gap: 10px;
}
.border {
outline: 1px solid black;
}
.no-border {
outline: none;
}
.black-bg {
background: black;
}
.white-bg {
background: white;
}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Etch-a-Sketch</title>
<link rel="stylesheet" href="style.css" />
<script src="script.js" defer></script>
</head>
<body>
<div id="title">
<h1>Etch-a-Sketch</h1>
</div>
<main id="container">
<div id="menu">
<button id="size"></button>
<button id="color">Color</button>
<button id="eraser">Eraser</button>
<button id="clear">Clear</button>
<button id="grid-borders">Grid Borders</button>
</div>
<div id="grid"></div>
</main>
</body>
</html>
"Why won't my grid cells go below 32px?" - have you checked your padding (hint: 32px is exactly equal to 2 * 16px which in turn is exactly equal to your padding of 1em with most browsers implementing a default font-size of 16px). –
David Thomas
box padding was set to 1em which caused my problem, after deleting it my grid worked as intended
Here is my JSFiddle: https://jsfiddle.net/y6pnq7k5/3/
Sorry if it's too much code, I tried to narrow it down.
The main functions to look at are generatorClicked() and progressBarAnimation().
When you click on the boxes (for example fire spell tome), I have a progress bar animation that goes across the div. The problem is that if you spam click the div it will reset the progress bar back at the start, and because this is meant to be an idle game the progress bar should not be affected until it has finished it's job.
One solution I've tried are disabling pointer events via style:
var isClicked = true;
document.GetElementByID(this.id).style.pointerEvents = 'none';
//progress bar animation - after it's done isClicked = false
if(!isClicked) {
document.GetElementByID(this.id).style.pointerEvents = 'auto';
}
This had issues with either the progress bar not being clickable after the first progress bar finished, or it would still allow the click spam to reset the bar, depending on where I made isClicked false.
I've also tried creating a shield like the top answer in this post
Which just stopped the progress bar from moving at all.
I don't have any libraries, just vanilla JS. I know that my implementation of this progress bar animation is also dubious, but even if I refactor it I still would need the progress bar to not be affected by subsequent clicks as it will affect the gameplay.
pointer-events CSS property can be set to 'none' before the progress bar animation starts and reset to its original value after the progress bar animation stops.
var fireGenerators = ["fireSpellTome", "fireWizard", "fireTeacher", "fireSchool"];
var fireGeneratorStrings = ["Fire Spell Tome", "Fire Wizard", "Fire Teacher", "Fire School"];
var fireGeneratorAmount = new Array();
function initFireGenerators() {
for (i = 0; i < fireGenerators.length; i++) {
fireGeneratorAmount.push(0);
var div = document.createElement('div');
div.id = fireGenerators[i];
div.className = "fireGenerators";
div.innerHTML = fireGeneratorStrings[i];
div.onclick = generatorClicked;
var progressBar = document.createElement('div');
progressBar.id = fireGenerators[i] + "ProgressBar";
progressBar.className = "progressBar";
var amount = document.createElement('span');
amount.id = "amountFireGen" + i;
amount.class = "fireAmounts";
amount.innerHTML = "0";
div.appendChild(progressBar);
div.appendChild(amount);
main.appendChild(div);
}
}
function generatorClicked() {
console.log(this.id + " clicked");
progressBarAnimation(this.id);
}
function progressBarAnimation(parentID) {
const progressBarContainer = document.getElementById(parentID);
const progressBar = document.getElementById(parentID + "ProgressBar"); //Get progressBar div element
let id = null;
let currentWidth = 0; //Set the width to 0
clearInterval(id);
progressBarContainer.style.pointerEvents = "none";
id = setInterval(frame, 10); //TEMPORARY - Need to check what generator and match progress with speed
function frame() {
if (currentWidth == 330) {
clearInterval(id);
progressBar.style.width = "0px";
progressBarContainer.style.pointerEvents = "auto";
} else {
currentWidth++;
progressBar.style.width = currentWidth + "px";
}
}
return true;
}
initFireGenerators();
html, body {
height: 100%;
width: 100%;
margin: 0;
font-family: Arial, Helvetica, sans-serif;
user-select: none;
-webkit-user-select: none;
-moz-user-select: none;
-khtml-user-select: none;
-ms-user-select: none;
}
div span {
margin-left: 15px;
}
#main {
width: 100%;
height: 80%;
}
#fireSpellTome {
background-size: 100% 100%;
background-image: url('../images/firetome.png');
background-repeat: no-repeat;
}
.fireGenerators {
position: relative;
width: 330px;
height: 170px;
border:2px solid #000;
margin-top: 1px;
}
.progressBar {
position: absolute;
top: 0;
width: 0;
height: 100%;
background-color: #111;
opacity: 0.5;
}
.noPointers {
pointer-events: none;
}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="stylesheet" href="stylesheets/game.css">
</head>
<body>
<h1><span id="fireMagicAmount">0</span><br></h1>
<div id=main></div>
</body>
</html>
On mobile, it's a common UI pattern to have a scrollable element inside a draggable element. When you reach the end of the scrollable element, you start dragging the outer element. E.g. in this GIF (https://media.giphy.com/media/9MJgBkoZfqA7jRdQop/giphy.gif), after scrolling to the top, if you continuing scrolling, it'll drag the subreddits menu.
I want to implement a similar pattern using JS/CSS. To do this, I need to detect if users continue scrolling after reaching the end. Is this possible? If so, is it possible to determine how much they scroll after reaching the end?
window.onscroll = function(element) {
if ((window.innerHeight + window.pageYOffset) >= document.body.offsetHeight) {
alert("you're at the bottom of the page");
}
};
Using element parameter to know the current exact x y where mouse is now at to calculate more and some how much was scrolled
Javascript: How to detect if browser window is scrolled to bottom?
If You need to keep track of the user activity after the bottom (or the top) of the page has been reached, beside the scroll event, You need to track the the wheel event. Moreover, on mobile, You need to track also touchstart and touchmove events.
Not all these events are normalized across browsers, so I did my own normalization function, which is more or less something like this:
var compulsivity = Math.log2(Math.max(scrollAmount, 0.01) * wheelAmount);
Below is a complete playground. You can test it in Chrome using the Mobile View of the Developer Tools, or in other browsers using the TouchEmulator.
function Tracker(page) {
this.page = page;
this.moveUp = 0;
this.moveDown = 0;
this.startTouches = {};
this.moveTouches = {};
this.lastScrollY = 0;
this.monitor = {};
this.startThreshold = 160;
this.moveThreshold = 10;
this.iOS = /iPad|iPhone|iPod/.test(navigator.userAgent) && !window.MSStream;
this.pullToRefresh = window.chrome || navigator.userAgent.match('CriOS');
this.amplitude = 16 / Math.log(2);
this.page.ownerDocument.addEventListener( 'onwheel' in document ? 'wheel' : 'onmousewheel' in document ? 'mousewheel' : 'DOMMouseScroll', this, { passive: true } );
/* The basic scroll event cannot be canceled, so it does not need to be set passive.*/
this.page.ownerDocument.addEventListener('scroll', this);
this.page.addEventListener('touchstart', this, { passive: true });
/* Maybe we need to cancel pullToRefresh */
this.page.addEventListener('touchmove', this, { passive: false });
return this;
}
Tracker.prototype.handleEvent = function (e) { /* handleEvent is built-in */
var winHeight = (this.iOS ? document.documentElement.clientHeight : window.innerHeight) | 0,
currScrollY = window.pageYOffset | 0,
amountScrollY = (this.lastScrollY - currScrollY) | 0,
elHeight = this.page.offsetHeight | 0,
elTop = -currScrollY, elBottom = winHeight - elHeight + currScrollY,
isTop = elTop >= 0, isBottom = elBottom >= 0;
switch (e.type) {
case 'wheel':
case 'onmousewheel':
case 'mousewheel':
case 'DOMMouseScroll':
var wheelDelta = e.wheelDelta ? e.wheelDelta : e.deltaY ? -e.deltaY : -e.detail,
wheelDir = (wheelDelta > 0) - (wheelDelta < 0),
wheelUp = wheelDir < 0, wheelDown = wheelDir > 0,
wheelAmount = 100 * wheelDir;
if (isTop && wheelDown) {
this.moveUp++;
this.moveDown = 0;
} else if (isBottom && wheelUp) {
this.moveUp = 0;
this.moveDown++;
} else {
this.moveUp = 0;
this.moveDown = 0;
}
var compulsivity = this.amplitude * Math.log(Math.max(this.moveUp, this.moveDown, 0.01) * wheelAmount* wheelDir);
this.monitor[e.type].track(wheelAmount, compulsivity);
break;
case 'scroll':
/* end of scroll event for iOS, start/end of scroll event for other browsers */
this.lastScrollY = currScrollY;
this.monitor[e.type].track(amountScrollY, 0);
break;
case 'touchstart':
var touches = [].slice.call(e.touches), i = touches.length;
while (i--) {
var touch = touches[i], id = touch.identifier;
this.startTouches[id] = touch;
this.moveTouches[id] = touch;
}
break;
case 'touchmove':
var touches = [].slice.call(e.touches), i = touches.length,
currTouches = {},
swipeUp = false, swipeDown = false,
currMoveY = 0, totalMoveY = 0;
while (i--) {
var touch = touches[i], id = touch.identifier;
currTouches[id] = touch;
if (id in this.moveTouches) {
currMoveY = this.moveTouches[id].screenY - touch.screenY;
}
if (id in this.startTouches) {
totalMoveY = this.startTouches[id].screenY - touch.screenY;
}
swipeUp = currMoveY > 0 || totalMoveY > 0;
swipeDown = currMoveY < 0 || totalMoveY < 0;
if (this.pullToRefresh && isTop && swipeDown && e.cancelable) {
e.preventDefault();
console.log('Reload prevented');
}
}
this.moveTouches = currTouches;
var moveDir = (totalMoveY > 0) - (totalMoveY < 0),
longSwipe = moveDir * totalMoveY > this.startThreshold,
shortSwipe = moveDir * totalMoveY > this.moveThreshold,
realSwipe = longSwipe || shortSwipe;
if (isTop && swipeDown) {
if (realSwipe) this.moveUp++;
this.moveDown = 0;
} else if (isBottom && swipeUp) {
this.moveUp = 0;
if (realSwipe) this.moveDown++;
} else {
this.moveUp = 0;
this.moveDown = 0;
}
var compulsivity = this.amplitude * Math.log(Math.max(this.moveUp, this.moveDown, 0.01) * moveDir * totalMoveY);
this.monitor[e.type].track(currMoveY, compulsivity);
break;
}
};
function Monitor(events) {
this.ctx = null;
this.cont = null;
this.events = events;
this.values = [];
this.average = 0;
this.lastDrawTime = 0;
this.inertiaDuration = 200;
return this;
}
Monitor.prototype.showOn = function (container) {
var cv = document.createElement('canvas');
this.ctx = cv.getContext('2d');
this.cont = document.getElementById(container);
cv.width = this.cont.offsetWidth;
cv.height = this.cont.offsetHeight;
cv.style.top = 0;
cv.style.left = 0;
cv.style.zIndex = -1;
cv.style.position = 'absolute';
cv.style.backgroundColor = '#000';
this.cont.appendChild(cv);
var self = this;
window.addEventListener('resize', function () {
var cv = self.ctx.canvas, cont = self.cont;
cv.width = cont.offsetWidth;
cv.height = cont.offsetHeight;
});
return this;
};
Monitor.prototype.track = function (value, average) {
this.average = average;
if (this.values.push(value) > this.ctx.canvas.width) this.values.shift();
if (value) this.lastDrawTime = new Date().getTime();
};
Monitor.prototype.draw = function () {
if (this.ctx) {
var cv = this.ctx.canvas, w = cv.width, h = cv.height;
var i = this.values.length, x = w | 0, y = (0.5 * h) | 0;
cv.style.backgroundColor = 'rgb(' + this.average + ', 0, 0)';
this.ctx.clearRect(0, 0, w, h);
this.ctx.strokeStyle = '#00ffff';
this.ctx.lineWidth = 1;
this.ctx.beginPath();
while (i--) {
x -= 4;
if (x < 0) break;
this.ctx.moveTo(x, y);
this.ctx.lineTo(x + 1, y);
this.ctx.lineTo(x + 1, y - this.values[i]);
}
this.ctx.stroke();
var elapsed = new Date().getTime() - this.lastDrawTime;
/* cool down */
this.average = this.average > 0 ? (this.average * 0.9) | 0 : 0;
if (elapsed > this.inertiaDuration) {
this.track(0, this.average);
}
}
var self = this;
setTimeout(function () {
self.draw();
}, 100);
};
Monitor.prototype.connectTo = function (tracker) {
var events = this.events.split(' '), i = events.length;
while (i--) {
tracker.monitor[events[i]] = this;
}
this.draw();
return this;
};
function loadSomeData(target) {
$.ajax({
url: 'https://jsonplaceholder.typicode.com/users',
method: 'GET',
crossDomain: true,
dataType: 'json',
success: function (users) {
var html = '', $ul = $(target).find('ul');
$.each(users, function (i, user) {
var item = '<li><a class="ui-alt-icon ui-nodisc-icon">';
item += '<h2>' + user.name + '</h2>';
item += '<p><strong>' + user.company.name + '</strong></p>';
item += '<p>' + user.address.zipcode + ', ' + user.address.city + '</p>';
item += '<p>' + user.phone + '</p>';
item += '<p>' + user.email + '</p>';
item += '<p class="ui-body-inherit ui-li-aside ui-li-count"><strong>' + user.id + '</strong></p>';
item += '</a></li>';
html += item;
});
$ul.append(html).listview('refresh');
},
});
}
$(document)
.on('pagecreate', '#page-list', function (e) {
$("[data-role='header'], [data-role='footer']").toolbar({ theme: 'a', position: 'fixed', tapToggle: false });
loadSomeData(e.target);
})
.on('pageshow', '#page-list', function (e, ui) {
var tracker = $.data(this, 'mobile-page', new Tracker(this));
new Monitor('touchstart touchmove').connectTo(tracker).showOn('header');
new Monitor('scroll wheel mousewheel DOMMouseScroll').connectTo(tracker).showOn('footer');
});
.ui-page {
touch-action: none;
}
h1, h2, h3, h4, h5, h6, p {
-webkit-user-select: none;
-moz-user-select: none;
-ms-user-select: none;
user-select: none;
}
/* JQM no frills */
.ui-btn,
.ui-title,
.ui-btn:hover,
.ui-btn:focus,
.ui-btn:active,
.ui-btn:visited {
text-shadow: none !important;
}
* {
-webkit-box-shadow: none !important;
-moz-box-shadow: none !important;
box-shadow: none !important;
-webkit-tap-highlight-color: rgba(0, 0, 0, 0);
}
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Compulsivity</title>
<meta name="description" content="Compulsivity" />
<meta name="HandheldFriendly" content="True" />
<meta name="MobileOptimized" content="320" />
<meta name="viewport" content="user-scalable=no, initial-scale=1, maximum-scale=1, width=device-width, minimal-ui shrink-to-fit=no" />
<meta http-equiv="cleartype" content="on" />
<!-- Add to homescreen for Chrome on Android -->
<meta name="mobile-web-app-capable" content="yes" />
<!-- For iOS web apps. Delete if not needed. -->
<meta name="apple-mobile-web-app-capable" content="yes" />
<meta name="apple-mobile-web-app-status-bar-style" content="black" />
<meta name="apple-mobile-web-app-title" content="Compulsivity" />
<link rel="stylesheet" href="https://code.jquery.com/mobile/1.4.5/jquery.mobile-1.4.5.min.css" />
<!--
<script type="application/javascript" src="lib/touch-emulator.js"></script>
<script> TouchEmulator(); </script>
-->
<script type="application/javascript" src="https://cdn.jsdelivr.net/npm/jquery#2.2.4/dist/jquery.min.js"></script>
<script type="application/javascript" src="https://code.jquery.com/mobile/1.4.5/jquery.mobile-1.4.5.min.js"></script>
</head>
<body>
<div id="header" data-role="header"><h4 style="color: #fff">Compulsivity</h4></div>
<div id="page-list" data-role="page">
<div data-role="content" role="main">
<ul data-role="listview" data-filter="true" data-inset="true"></ul>
</div>
</div>
<div id="footer" data-role="footer"><h4 style="color: #fff">Scroll</h4></div>
</body>
</html>
Among others, You need to be aware also of the pull-to-refresh and inertia (or momentum) of the smooth scroll behaviors.
Please, try to scroll or to swipe and look how the events are tracked: either the top bar or bottom bar will change color to display the user activity after reaching the bottom or the top respectively of the page.
JavaScript:
// get the button
var theBtn = document.getElementById('theBtn');
// get the box
var theBox = document.getElementById('theBox');
// add event to the button on click show/hide(toggle) the box
theBtn.addEventListener('click', () => {
theBox.classList.toggle('active');
});
// when scrolling on the box
theBox.onscroll = function(){
// get the top of the div
var theBoxTop = theBox.scrollTop;
if(theBoxTop <= 0){
// when it reaches 0 or less, hide the box. It'll toggle the class, since it's "show" will "hide"
theBox.classList.toggle('active');
}
};
* {
margin: 0;
padding: 0;
box-sizing: border-box;
}
body {
font-size: 10px;
font-family: 'Arial', sans-serif;
height: 1500px;
}
html {
scroll-behavior: smooth;
}
ul {
list-style-type: none;
}
#theBox ul li {
border: 1px solid;
height: 100px;
}
#navbar-bottom {
height: 100px;
width: 100%;
background: rgb(90, 111, 143);
position: fixed;
bottom: 0;
left: 0;
right: 0;
box-shadow: 0 0 2px 2px rgba(90, 111, 143, 0.562);
display: flex;
justify-content: space-around;
align-items: center;
}
#theBox {
background-color: red;
height: 350px;
width: 100%;
position: fixed;
bottom: 0;
transform: translateY(100%);
transition: all 0.3s;
overflow-y: scroll;
}
#theBox.active{
transform: translateY(0);
}
.myBtns {
width: 50px;
height: 50px;
border-radius: 50%;
border: none;
position: relative;
display: flex;
justify-content: center;
align-items: center;
flex-direction: column;
cursor: pointer;
}
.myBtns span {
height: 3px;
width: 30px;
background-color: black;
margin: 3px 0;
}
<main role="main">
<div id="theBox">
<ul>
<li><p>Text</p></li>
<li><p>Text</p></li>
<li><p>Text</p></li>
<li><p>Text</p></li>
<li><p>Text</p></li>
<li><p>Text</p></li>
<li><p>Text</p></li>
<li><p>Text</p></li>
<li><p>Text</p></li>
</ul>
</div>
<div id="navbar-bottom">
<button class="myBtns"></button>
<button class="myBtns" id="theBtn">
<span></span>
<span></span>
<span></span>
</button>
<button class="myBtns"></button>
</div>
</main>
jQuery:
// add event to the button on click show/hide(toggle) the box
$('#theBtn').click(function(){
$('#theBox').toggleClass('active');
});
// when scrolling on the box
$('#theBox').scroll(function () {
// get the top of the div
var theBoxTop = $('#theBox').scrollTop();
// when it reaches 0 or less, hide the box. It'll toggle the class, since it's "show" will "hide"
if(theBoxTop <= 0){
$('#theBox').toggleClass('active');
}
});
* {
margin: 0;
padding: 0;
box-sizing: border-box;
}
body {
font-size: 10px;
font-family: 'Arial', sans-serif;
height: 1500px;
}
html {
scroll-behavior: smooth;
}
ul {
list-style-type: none;
}
#theBox ul li {
border: 1px solid;
height: 100px;
}
#navbar-bottom {
height: 100px;
width: 100%;
background: rgb(90, 111, 143);
position: fixed;
bottom: 0;
left: 0;
right: 0;
box-shadow: 0 0 2px 2px rgba(90, 111, 143, 0.562);
display: flex;
justify-content: space-around;
align-items: center;
}
#theBox {
background-color: red;
height: 350px;
width: 100%;
position: fixed;
bottom: 0;
transform: translateY(100%);
transition: all 0.3s;
overflow-y: scroll;
}
#theBox.active{
transform: translateY(0);
}
.myBtns {
width: 50px;
height: 50px;
border-radius: 50%;
border: none;
position: relative;
display: flex;
justify-content: center;
align-items: center;
flex-direction: column;
cursor: pointer;
}
.myBtns span {
height: 3px;
width: 30px;
background-color: black;
margin: 3px 0;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<main role="main">
<div id="theBox">
<ul>
<li><p>Text</p></li>
<li><p>Text</p></li>
<li><p>Text</p></li>
<li><p>Text</p></li>
<li><p>Text</p></li>
<li><p>Text</p></li>
<li><p>Text</p></li>
<li><p>Text</p></li>
<li><p>Text</p></li>
</ul>
</div>
<div id="navbar-bottom">
<button class="myBtns"></button>
<button class="myBtns" id="theBtn">
<span></span>
<span></span>
<span></span>
</button>
<button class="myBtns"></button>
</div>
</main>
window.onscroll = function(ev) {
if ((window.innerHeight + window.scrollY) >= document.body.offsetHeight) {
alert("you are at the bottom of the page");
}
};
Link to demo: http://jsfiddle.net/5xpoe4yg/
There are two solutions for this. One is for touch devices and second for devices using mouse.
Using Wheel event
If target is a mouse device, then we will use following method:
document.onwheel = event => ScrollAction(event);
For more info on wheel event, please visit this link.
Touch Devices
If target is a touch device then following method will be useful:
document.ontouchcancel = event => TouchInterrupt(event);
document.ontouchend = event => FingerRemoved(event);
document.ontouchmove = event => FingerDragged(event);
document.ontouchstart = event => FingerPlaced(event);
For more info on touch events, please visit this link.
I think your problem fully is solved by this solution.
Your specific question is solveable by listening to the wheel event, although the result is not terribly precise. The wheel event often fires before the scroll event so this example will sometimes log negative scroll value on the first scroll up from the bottom of the page:
const content = document.querySelector('.content');
for (let i = 0; i < 50; i++) {
const p = document.createElement('p');
p.textContent = 'Content';
content.append(p);
};
content.addEventListener('wheel', e => {
const atBottom = content.scrollHeight - content.scrollTop === content.clientHeight;
if (atBottom) console.log(e.deltaY);
});
* {
padding: 0;
margin: 0;
box-sizing: border-box;
}
body {
height: 100vh;
width: 100%;
}
.content {
overflow-y: scroll;
height: 100%;
}
<div class="content"></div>
As others have suggested, a better approach for your use case might instead be to have an overlay which you can trigger on click/touch and then scroll into view. One issue you might run into is that deeply nested scroll on web browsers can get real ugly real fast, without resorting to pure JS solutions which also have their own performance issues.
This is a popup that, when clicked on, opens and enables you to scroll. When it gets to the top of the page, it's header sticks.
var navbar = document.querySelector('.navbar'),
navheader = document.querySelector('.navheader');
// Toggle navbar
navheader.addEventListener('click', e => {
navbar.classList.toggle('open');
if (!navbar.classList.contains('open')) {
navbar.style.overflow = 'hidden';
document.body.style.overflow = '';
navbar.scrollTop = 0;
stickTop = false;
navbar.classList.remove('sticky');
navbar.style.top = '';
navbar.style.transition = '.2s';
setTimeout(() => {
navbar.style.transition = '';
}, 200);
}
else {
navbar.style.overflow = 'overlay';
navbar.style.transition = '.2s';
setTimeout(() => {
navbar.style.transition = '';
}, 200);
}
})
var prevtop = 0;
var stickTop = false;
// Add scroll listener
navbar.addEventListener('scroll', e => {
// If navbar is open
if (navbar.classList.contains('open')) {
if (!stickTop) {
navbar.style.top = navbar.getBoundingClientRect().top - navbar.scrollTop + 'px';
}
if ((window.innerHeight - navbar.getBoundingClientRect().bottom) >= 0) {
document.body.style.overflow = 'hidden';
navbar.style.overflow = 'auto';
navbar.style.top = 0;
navbar.classList.add('sticky');
stickTop = true;
}
if (navbar.scrollTop == 0) {
navbar.classList.remove('open');
navbar.style.overflow = 'hidden';
document.body.style.overflow = '';
stickTop = false;
navbar.classList.remove('sticky');
navbar.style.top = '';
navbar.style.transition = '.2s';
setTimeout(() => {
navbar.style.transition = '';
}, 200);
}
}
})
body {
font-family: sans-serif;
}
.navbar {
position: fixed;
top: calc(100vh - 50px);
height: 100vh;
left: 0;
width: 100%;
overflow: hidden;
}
.navbar.open {
top: 50vh;
}
.navcontent {
background: black;
width: 100%;
color: white;
}
.navcontent p {
margin: 0;
}
.navheader {
height: 50px;
width: 100%;
background: lightblue;
cursor: pointer;
top: 0;
position: sticky;
display: flex;
justify-content: center;
z-index: 1;
}
.navheader::before {
width: 50px;
height: 3px;
margin-top: 10px;
background: white;
border-radius: 3px;
content: '';
}
<div class="navbar">
<div class="navheader"></div>
<div class="navcontent"><p>S</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>E</p></div>
</div>
<div class="content">
<p>S</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>A</p><p>E</p>
</div>
I wanted a vertical dragBar for resizing two divs. I have created an example for the same but I am facing an issue.
Actual : As and when I resize the the upper div and move the slider down, the area of parent div increases and hence a scroll bar is given.
Expected: When Resizing, if the slider is moved down, it should only show the data contained in the upper div and when slider is moved up, it should show the content of lower div and should not increase the over all length of the parent div.
var handler = document.querySelector('.handler');
var wrapper = handler.closest('.wrapper');
var boxA = wrapper.querySelector('.box1');
var boxB = wrapper.querySelector('.box2');
var isHandlerDragging = false;
document.addEventListener('mousedown', function(e) {
// If mousedown event is fired from .handler, toggle flag to true
if (e.target === handler) {
isHandlerDragging = true;
}
});
document.addEventListener('mousemove', function(e) {
// Don't do anything if dragging flag is false
if (!isHandlerDragging) {
return false;
}
// Get offset
var containerOffsetTop= wrapper.offsetTop;
var containerOffsetBottom= wrapper.offsetBottom;
// Get x-coordinate of pointer relative to container
var pointerRelativeXpos = e.clientY - containerOffsetTop;
var pointerRelativeXpos2 = e.clientY - e.offsetTop + e.offsetHeight;
var boxAminWidth = 30;
boxA.style.height = (Math.max(boxAminWidth, pointerRelativeXpos - 2)) + 'px';
boxA.style.flexGrow = 0;
boxB.style.height = (Math.max(boxAminWidth, pointerRelativeXpos2 - 8)) + 'px';
boxB.style.flexGrow = 0;
});
document.addEventListener('mouseup', function(e) {
// Turn off dragging flag when user mouse is up
isHandlerDragging = false;
});
body {
margin: 40px;
}
.wrapper {
background-color: #fff;
color: #444;
/* Use flexbox */
}
.box1, .box2 {
background-color: #444;
color: #fff;
border-radius: 5px;
padding: 20px;
font-size: 150%;
margin-top:2%;
/* Use box-sizing so that element's outerwidth will match width property */
box-sizing: border-box;
/* Allow box to grow and shrink, and ensure they are all equally sized */
}
.handler {
width: 20px;
height:7px;
padding: 0;
cursor: ns-resize;
}
.handler::before {
content: '';
display: block;
width: 100px;
height: 100%;
background: red;
margin: 0 auto;
}
<div class="wrapper">
<div class="box1">A</div>
<div class="handler"></div>
<div class="box2">B</div>
</div>
Hope I was clear in explaining the issue I am facing in my project. Any help is appreciated.
It looks like your on the right track. You just need to make the wrapper a flexbox with the flex direction column and assign it a height. Also box 2 needs to have a flex of 1 so it can grow and shrink as needed. Finally I needed to remove the code that set the flex grow to 0 in the JavaScript. Here is the result.
var handler = document.querySelector('.handler');
var wrapper = handler.closest('.wrapper');
var boxA = wrapper.querySelector('.box1');
var boxB = wrapper.querySelector('.box2');
var isHandlerDragging = false;
document.addEventListener('mousedown', function(e) {
// If mousedown event is fired from .handler, toggle flag to true
if (e.target === handler) {
isHandlerDragging = true;
}
});
document.addEventListener('mousemove', function(e) {
// Don't do anything if dragging flag is false
if (!isHandlerDragging) {
return false;
}
e.preventDefault();
// Get offset
var containerOffsetTop= wrapper.offsetTop;
var containerOffsetBottom= wrapper.offsetBottom;
// Get x-coordinate of pointer relative to container
var pointerRelativeXpos = e.clientY - containerOffsetTop;
var pointerRelativeXpos2 = e.clientY - e.offsetTop + e.offsetHeight;
var boxAminWidth = 30;
boxA.style.height = (Math.max(boxAminWidth, pointerRelativeXpos - 2)) + 'px';
boxB.style.height = (Math.max(boxAminWidth, pointerRelativeXpos2 - 8)) + 'px';
});
document.addEventListener('mouseup', function(e) {
// Turn off dragging flag when user mouse is up
isHandlerDragging = false;
});
body {
margin: 40px;
}
.wrapper {
background-color: #fff;
color: #444;
/* Use flexbox */
display: flex;
flex-direction: column;
height: 200px;
}
.box1, .box2 {
background-color: #444;
color: #fff;
border-radius: 5px;
padding: 20px;
font-size: 150%;
margin-top:2%;
/* Use box-sizing so that element's outerwidth will match width property */
box-sizing: border-box;
/* Allow box to grow and shrink, and ensure they are all equally sized */
}
.box2 {
flex: 1;
}
.handler {
width: 20px;
height:7px;
padding: 0;
cursor: ns-resize;
}
.handler::before {
content: '';
display: block;
width: 100px;
height: 100%;
background: red;
margin: 0 auto;
}
<div class="wrapper">
<div class="box1">A</div>
<div class="handler"></div>
<div class="box2">B</div>
</div>
May be this is small question. But I couldn't found reason for this. I made a script to change a position of div by dragging it. the code is working fine with chrome browser. but when I trying to test it on Firefox it is not working.
var h = window.innerHeight|| document.documentElement.clientHeight || document.body.clientHeight;
window.onload = function () {
// ------------------lock the div with mouse pointer--------------
// variable dragged is for identified that you are click on the button or not
var dragged = false,
y = 0,pointerDis = 0,
boxElement = document.getElementById('drag'),
drgElement = document.getElementById('titl');
if (boxElement) {
// -----------------check whether the title div is holding by the mouse to lock it with mouse-------
drgElement.addEventListener('mousedown', function() {
dragged = true;
pointerDis = event.clientY - parseInt(window.getComputedStyle(boxElement, null).getPropertyValue("top"));
});
//------------------check whether the title div is released to drop the div-------------------------
document.addEventListener('mouseup', function() {
dragged = false;
});
document.addEventListener('mousemove', function () {
y = event.clientY;
if(dragged == true)
{
y = y -pointerDis;
if(y<0)
{
y = 0;
}
else if(y > window.innerHeight - boxElement.offsetHeight)
{
y = window.innerHeight - boxElement.offsetHeight;
}
boxElement.style.top = y + 'px';
}
});
}
};
.drg {
position: absolute;
top:0;
right: 0;
background: red;
border-top-left-radius: 45px;
border-bottom-left-radius: 45px;
}
#titl{
background: blue;
width: 50px;
text-align: center;
color: white;
font-size: 30px;
border-top-left-radius: 10px;
}
#det{
background: #f9c500;
width: 50px;
border-bottom-left-radius: 10px;
text-align: center;
}
<!DOCTYPE html>
<html>
<head>
<title>test 4</title>
</head>
<body>
<div class = "drg" id="drag">
<div id="titl" unselectable="on" onselectstart="return false;">....</div>
<div id="det">this is the details menu</div>
</div>
</body>
</html>
You can drag it through Y axis by click and drag from blue div. I don't know the reason or I couldn't find a way to fix this work on Firefox. Please help me!
You have to catch the (mousemove or mousedown) events as the input of wrapped functions
drgElement.addEventListener('mousedown', function(event)...
var h = window.innerHeight|| document.documentElement.clientHeight || document.body.clientHeight;
window.onload = function () {
// ------------------lock the div with mouse pointer--------------
// variable dragged is for identified that you are click on the button or not
var dragged = false,
y = 0,pointerDis = 0,
boxElement = document.getElementById('drag'),
drgElement = document.getElementById('titl');
if (boxElement) {
// -----------------check whether the title div is holding by the mouse to lock it with mouse-------
drgElement.addEventListener('mousedown', function(event) {
dragged = true;
pointerDis = event.clientY - parseInt(window.getComputedStyle(boxElement, null).getPropertyValue("top"));
});
//------------------check whether the title div is released to drop the div-------------------------
document.addEventListener('mouseup', function() {
dragged = false;
});
document.addEventListener('mousemove', function (event) {
y = event.clientY;
if(dragged == true)
{
y = y -pointerDis;
if(y<0)
{
y = 0;
}
else if(y > window.innerHeight - boxElement.offsetHeight)
{
y = window.innerHeight - boxElement.offsetHeight;
}
boxElement.style.top = y + 'px';
}
});
}
};
.drg {
position: absolute;
top:0;
right: 0;
background: red;
border-top-left-radius: 45px;
border-bottom-left-radius: 45px;
}
#titl{
background: blue;
width: 50px;
text-align: center;
color: white;
font-size: 30px;
border-top-left-radius: 10px;
}
#det{
background: #f9c500;
width: 50px;
border-bottom-left-radius: 10px;
text-align: center;
}
<!DOCTYPE html>
<html>
<head>
<title>test 4</title>
</head>
<body>
<div class = "drg" id="drag">
<div id="titl" unselectable="on" onselectstart="return false;">....</div>
<div id="det">this is the details menu</div>
</div>
</body>
</html>