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Adding Text on the selected canvas in Fabric js

I have fabric js multiple canvases and I would like to add Text on the selected canvas, instead of the last item of the array.
If a user creates multiple canvases then I need an option to add the text on the selected canvas.
Please run the code snippet or see the codepen demo of the current approach...
Thank you!
//================== Create Canvas start =================
var createCanvas = document.getElementById("createCanvas");
var canvasInstances = [];
createCanvas.addEventListener('click',function(){
var canvasContainer = document.getElementById("canvasContainer");
var newcanvas = document.createElement("canvas");
//newcanvas.classList.add("active");
canvasContainer.append(newcanvas);
var fabricCanvasObj = new fabric.Canvas(newcanvas, {
height: 400,
width: 400,
backgroundColor: '#ffffff',
});
canvasInstances.push(fabricCanvasObj);
console.log(canvasInstances);
})
//================== Create Canvas End =================
//================== Add Text ================
var addText = document.getElementById("addText");
addText.addEventListener('click',function(){
canvasInstances.forEach(function(current,id,array){
if(id === array.length - 1){
const converText = new fabric.IText(`Type Text`,{
type: 'text',
width: 200,
fontSize: 20,
left: 20,
top: 20,
fill: '#444'
});
current.add(converText);
current.renderAll();
return false;
}
})
})
//================== Add End =================
*{
box-sizing: border-box;
}
body{
background:#ccc;
display: flex;
flex-direction: column;
align-items: center;
margin-bottom: 200px;
}
.canvas-container{
margin-bottom:10px;
}
.add-text{
margin: 20px;
width: 400px;
text-align: center;
border:1px dashed red;
padding: 15px;
cursor:pointer;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/4.5.0/fabric.min.js"></script>
<div class="add-text" id="addText">Add Text</div>
<div id="canvasContainer">
</div>
<button id="createCanvas">Create Canvas</button>

Declare canvasobject globally, you can try below code
<script type="text/javascript">
var canvasobject;
window.onload = function () {
canvasobject = new fabric.Canvas('myCanvas');
canvasobject.backgroundColor = '#0056d6';
canvasobject.renderAll();
//
function addtext() {
var textvalue = "Type here";
var fontcolor = "#333";
var fontFamily = "Baloo 2";
var myfont = new FontFaceObserver(fontFamily);
myfont.load()
.then(function () {
// when font is loaded, use it.
var text = new fabric.Text(textvalue, {
left: 100,
top: 100,
fontFamily: fontFamily,
fill: fontcolor,
});
canvasobject.add(text);
canvasobject.renderAll();
}).catch(function (e) {
//console.log(e);
console.log('font loading failed ' + fontFamily);
});
}
}

How to draw via mouse-click without using the canvas-element

I am trying to create an "Etch-A-Sketch"-program, which should let the user draw only by clicking or holding the mouse-button. How can I realize that in JavaScript?
Somehow after the user chooses a color via clicking on the color-button, the color is already drawn as soon as the mouse cursor enters the drawing area (div class="container").
I've tried several functions, but it's still not working as expected...
Could someone please provide a hint?
"use strict";
const divContainer = document.querySelector(".container");
const btnsContainer = document.querySelector(".buttons");
const btnBlack = document.createElement("button");
const btnGreyScale = document.createElement("button");
const btnRgb = document.createElement("button");
const btnErase = document.createElement("button");
const btnShake = document.createElement("button");
function createGrid(col, rows) {
for(let i = 0; i < (col * rows); i++) {
const div = document.createElement("div");
divContainer.style.gridTemplateColumns = `repeat(${col}, 1fr)`;
divContainer.style.gridTemplateRows = `repeat(${rows}, 1fr)`;
divContainer.appendChild(div).classList.add("box");
}
}
createGrid(16,16)
let isDrawing = false;
window.addEventListener("mousedown", () => {
isDrawing = true;
});
window.addEventListener("mouseup", () => {
isDrawing = false;
});
function paintBlack() {
const boxes = divContainer.querySelectorAll(".box");
btnBlack.textContent = "Black";
btnBlack.addEventListener("click", function () {
boxes.forEach(box => box.addEventListener("mouseover", function () {
this.style.background = "#000";
}))
})
btnsContainer.appendChild(btnBlack).classList.add("btn");
}
paintBlack();
function paintGreyScale() {
const boxes = divContainer.querySelectorAll(".box");
btnGreyScale.textContent = "Grey";
btnGreyScale.addEventListener("click", function () {
boxes.forEach(box => box.addEventListener("mouseover", function () {
let randNum = Math.floor(Math.random() * 256);
let grayScale = `rgb(${randNum},${randNum},${randNum})`;
box.style.background = grayScale;
}))
})
btnsContainer.appendChild(btnGreyScale).classList.add("btn");
}
paintGreyScale();
function paintRgb() {
const boxes = divContainer.querySelectorAll(".box");
btnRgb.textContent = "Rainbow";
btnRgb.addEventListener("click", function () {
boxes.forEach(box => box.addEventListener("mouseover", function () {
let r = Math.floor(Math.random() * 256);
let g = Math.floor(Math.random() * 256);
let b = Math.floor(Math.random() * 256);
const rgb = `rgb(${r},${g},${b})`;
box.style.background = rgb;
}))
})
btnsContainer.appendChild(btnRgb).classList.add("btn");
}
paintRgb();
function erase() {
const boxes = divContainer.querySelectorAll(".box");
btnErase.textContent = "Erase";
btnErase.addEventListener("click", function () {
boxes.forEach(box => box.addEventListener("mouseover", function () {
this.style.background = "#FFF";
}))
})
btnsContainer.appendChild(btnErase).classList.add("btn");
}
erase();
function clearCanvas() {
const boxes = divContainer.querySelectorAll(".box");
btnShake.textContent = "Shake it!";
btnShake.addEventListener("click", function () {
boxes.forEach(box => box.style.backgroundColor = "#FFF");
})
btnsContainer.appendChild(btnShake).classList.add("shake");
}
clearCanvas();
btnShake.addEventListener("click", clearCanvas);
*,
*::before,
*::after {
margin: 0;
padding: 0;
-webkit-box-sizing: border-box;
box-sizing: border-box;
}
html {
font-size: 16px;
}
body {
background: linear-gradient(to bottom, #1488CC, #2B32B2);
color: #FFF;
line-height: 1.5;
height: 100vh;
}
#wrapper {
display: flex;
justify-content: center;
align-items: center;
flex-direction: column;
text-align: center;
}
.container {
width: 500px;
height: 500px;
display: grid;
background-color: #FFF;
box-shadow: 0 0 10px;
}
.box {
border: .5px solid #808080;
}
.shake {
animation: shake .5s linear 1;
}
#keyframes shake {
10%,
90% {
transform: translate3d(-1px, 0, 0);
}
20%,
80% {
transform: translate3d(2px, 0, 0);
}
30%,
50%,
70% {
transform: translate3d(-4px, 0, 0);
}
40%,
60% {
transform: translate3d(4px, 0, 0);
}
}
<!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, shrink-to-fit=no">
<title>Etch-A-Sketch</title>
</head>
<body>
<div id="wrapper">
<main>
<div class="container"></div>
<div class="buttons"></div>
</main>
</div>
<script src="etchAsketch.js"></script>
</body>
</html>

The mousedown event
window.addEventListener("mousedown", () => {
isDrawing = true;
});
sets isDrawing to true, and mouseup event to false, but you never use this variable to check whether the color should be drawn.
Solution: for each statement you have that's setting the background color of a square (except for clearCanvas), wrap it in an if statement checking if the user isDrawing:
if (isDrawing){this.style.background = "#000";} //black
if (isDrawing){this.style.background = grayScale;} //gray
if (isDrawing){this.style.background = rgb;} // rainbow
if (isDrawing){this.style.background = "#FFF";} // erase
boxes.forEach(box => box.style.backgroundColor = "#FFF");
}) //leave clearCanvas as it is

Hide scroll bar when page preloader loads

I want to hide scroll bar while preloader is loading the scroll bar will not show until unless preloader disappears which means the user can't able to scroll the page while preloader is loading here I'm using canvas as a preloader. I tried by using body overflow: hidden and some CSS also but unable to achieve the result here I used canvas effect as a preloader. Can anyone point me in the right direction what I'm doing wrong?
/* Preloader Effect */
var noise = function(){
//const noise = () => {
var canvas, ctx;
var wWidth, wHeight;
var noiseData = [];
var frame = 0;
var loopTimeout;
// Create Noise
const createNoise = function() {
const idata = ctx.createImageData(wWidth, wHeight);
const buffer32 = new Uint32Array(idata.data.buffer);
const len = buffer32.length;
for (var i = 0; i < len; i++) {
if (Math.random() < 0.5) {
buffer32[i] = 0xff000000;
}
}
noiseData.push(idata);
};
// Play Noise
const paintNoise = function() {
if (frame === 9) {
frame = 0;
} else {
frame++;
}
ctx.putImageData(noiseData[frame], 0, 0);
};
// Loop
const loop = function() {
paintNoise(frame);
loopTimeout = window.setTimeout(function() {
window.requestAnimationFrame(loop);
}, (1000 / 25));
};
// Setup
const setup = function() {
wWidth = window.innerWidth;
wHeight = window.innerHeight;
canvas.width = wWidth;
canvas.height = wHeight;
for (var i = 0; i < 10; i++) {
createNoise();
}
loop();
};
// Reset
var resizeThrottle;
const reset = function() {
window.addEventListener('resize', function() {
window.clearTimeout(resizeThrottle);
resizeThrottle = window.setTimeout(function() {
window.clearTimeout(loopTimeout);
setup();
}, 200);
}, false);
};
// Init
const init = (function() {
canvas = document.getElementById('noise');
ctx = canvas.getContext('2d');
setup();
})();
};
noise();
$(document).ready(function(){
$('body').css({
overflow: 'hidden'
});
setTimeout(function(){
$('#preloader').fadeOut('slow', function(){
$('body').css({
overflow: 'auto'
});
});
}, 5000);
});
#preloader {
position: fixed;
height: 100vh;
width: 100%;
z-index: 5000;
top: 0;
left: 0;
right: 0;
bottom: 0;
background-color: #fff;
/* change if the mask should have another color then white */
z-index: 10000;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>
<div id="preloader">
<canvas id="noise" class="noise"></canvas>
</div>

Try these Codes, If it works for you. I found this on StackOverflow. Source: Disable scrolling when preload a web page
Js Code
$(window).load(function() {
$(".preloader").fadeOut(1000, function() {
$('body').removeClass('loading');
});
});
Css Code
.loading {
overflow: hidden;
height: 100vh;
}
.preloader {
background: #fff;
position: fixed;
text-align: center;
bottom: 0;
right: 0;
left: 0;
top: 0;
}
.preloader4 {
position: absolute;
margin: -17px 0 0 -17px;
left: 50%;
top: 50%;
width:35px;
height:35px;
padding: 0px;
border-radius:100%;
border:2px solid;
border-top-color:rgba(0,0,0, 0.65);
border-bottom-color:rgba(0,0,0, 0.15);
border-left-color:rgba(0,0,0, 0.65);
border-right-color:rgba(0,0,0, 0.15);
-webkit-animation: preloader4 0.8s linear infinite;
animation: preloader4 0.8s linear infinite;
}
#keyframes preloader4 {
from {transform: rotate(0deg);}
to {transform: rotate(360deg);}
}
#-webkit-keyframes preloader4 {
from {-webkit-transform: rotate(0deg);}
to {-webkit-transform: rotate(360deg);}
}
Code
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<body class="loading">
<div class="preloader">
<div class="preloader4"></div>
</div>
//Code
</body>

You need to set overflow: hidden and height: 100vh both on the body and the html tags.
/* Preloader Effect */
var noise = function(){
//const noise = () => {
var canvas, ctx;
var wWidth, wHeight;
var noiseData = [];
var frame = 0;
var loopTimeout;
// Create Noise
const createNoise = function() {
const idata = ctx.createImageData(wWidth, wHeight);
const buffer32 = new Uint32Array(idata.data.buffer);
const len = buffer32.length;
for (var i = 0; i < len; i++) {
if (Math.random() < 0.5) {
buffer32[i] = 0xff000000;
}
}
noiseData.push(idata);
};
// Play Noise
const paintNoise = function() {
if (frame === 9) {
frame = 0;
} else {
frame++;
}
ctx.putImageData(noiseData[frame], 0, 0);
};
// Loop
const loop = function() {
paintNoise(frame);
loopTimeout = window.setTimeout(function() {
window.requestAnimationFrame(loop);
}, (1000 / 25));
};
// Setup
const setup = function() {
wWidth = window.innerWidth;
wHeight = window.innerHeight;
canvas.width = wWidth;
canvas.height = wHeight;
for (var i = 0; i < 10; i++) {
createNoise();
}
loop();
};
// Reset
var resizeThrottle;
const reset = function() {
window.addEventListener('resize', function() {
window.clearTimeout(resizeThrottle);
resizeThrottle = window.setTimeout(function() {
window.clearTimeout(loopTimeout);
setup();
}, 200);
}, false);
};
// Init
const init = (function() {
canvas = document.getElementById('noise');
ctx = canvas.getContext('2d');
setup();
})();
};
noise();
$(document).ready(function(){
$('body, html').css({
overflow: 'hidden',
height: '100vh'
});
setTimeout(function(){
$('#preloader').fadeOut('slow', function(){
$('body, html').css({
overflow: 'auto',
height: 'auto'
});
});
}, 5000);
});
#preloader {
position: fixed;
height: 100vh;
width: 100%;
z-index: 5000;
top: 0;
left: 0;
right: 0;
bottom: 0;
background-color: #fff;
/* change if the mask should have another color then white */
z-index: 10000;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>
<div id="preloader">
<canvas id="noise" class="noise"></canvas>
</div>

Set the position of body as fixed and when the page is loaded, remove that.
document.body.style.position = "fixed";
window.addEventListener("load", () => {
document.body.style.position = "";
document.querySelector(".preloader").style.display = "none";
});

Setting image size percentage in canvas and jquery

I'm trying to create a one-pager at the moment with a canvas where you can click to add/place images at random. I've gotten most of what I want to work, but being extremely new to jquery and canvas, I still can't figure out how to set a max-size for my images. As far as I've understood, it can be quite hard to make images on a canvas work perfectly when you haven't set the canvas size manually in css, but I have a resizing canvas, so I'm not really sure how I get around that.
I want the images that I place to have a max-height/max-width of 80% of the viewport. I tried setting a max size in css, but it didn't do anything.
Here's a jsfiddle
$(document).ready(function () {
var images = [];
$("#siteload").fadeIn(1500);
$('.put').each(function() {
images.push($(this).attr('src'));
});
(function() {
var
htmlCanvas = document.getElementById('c'),
context = htmlCanvas.getContext('2d');
initialize();
img = new Image();
count = 0;
htmlCanvas.onclick= function(evt) {
img.src = images[count];
var x = evt.offsetX - img.width/2,
y = evt.offsetY - img.height/2;
context.drawImage(img, x, y);
count++;
if (count == images.length) {
count = 0;
}
}
function initialize() {
window.addEventListener('resize', resizeCanvas, false);
resizeCanvas();
}
function resizeCanvas() {
htmlCanvas.width = window.innerWidth;
htmlCanvas.height = window.innerHeight;
}
})();
});
$(".hvr_cnt").mouseenter(function () {
title = $("<div class='hvr_ttl'>" + $(this).children()[0].title + "</div>");
$(this).children()[0].title = "";
$(this).append(title);
});
$(document).mousemove(function(e){
$('.hvr_ttl').css({
top: e.pageY - $(".hvr_ttl").height()/2,
left: e.pageX - $(".hvr_ttl").width()/2
});
});
$(".hvr_cnt").mouseleave(function (e) {
$(this).children()[0].title = $($(this).children()[1]).html();
$(this).children()[1].remove();
});
body {
margin: 0;
padding: 0;
background: rgb(240, 240, 240);
width: 100%;
height: 100%;
border: 0;
color: rgb(40, 40, 40);
overflow: hidden;
display: block;
}
.slides {
display: none
}
#c {
display: block;
position: absolute;
left: 0px;
top: 0px;
}
.hvr_ttl {
display: block;
position: absolute;
pointer-events: none;
cursor: none;
}
.hvr_cnt {
cursor: none;
padding: none;
margin: none;
}
<body ontouchstart="">
<div class="hvr_cnt">
<canvas id="c" title="click"></canvas>
</div>
<ul class="slides">
<li><img src="https://upload.wikimedia.org/wikipedia/commons/thumb/8/85/Smiley.svg/2000px-Smiley.svg.png" class="put" /></li>
<li><img src="https://emojipedia-us.s3.amazonaws.com/thumbs/160/google/56/thumbs-up-sign_1f44d.png" class="put" /></li>
</ul>
</body>
Any help would be appreciated :)

Try this :
htmlCanvas.onclick= function(evt) {
img.src = images[count];
img.width = 80/100* htmlCanvas.width;
img.height = 80/100* htmlCanvas.height;
var x = evt.offsetX - img.width/2,
y = evt.offsetY - img.height/2;
// context.drawImage(img, x, y);
context.drawImage(img, x, y, img.width, img.height);
count++;
if (count == images.length) {
count = 0;
}
}

context.drawImage(img, 0, 0,img.width,img.height,0,0,htmlCanvas.width,htmlCanvas.height);
you also can use background-size:cover;

The max-height/width doesn't work because everything within the canvas is independent from your css.
If you want to set the image to 80% use htmlCanvas.width and htmlCanvas.height to calculate the new size and use context.drawImage(img, x, y, w, h) to set the image size when drawing.
Maybe this post could be helpful.

mo.js animation for multiple items

I need your help.
To apply animation to multiple elements with a single class of "my-button"? Now this only works for a single button.
Replacement querySelector on querySelectorAll not solve the problem, the script becomes not working
Thank you.
var el = document.querySelector('.my-button'),
elSpan = el.querySelector('span'),
// mo.js timeline obj
timeline = new mojs.Timeline(),
scaleCurve = mojs.easing.path('M0,100 L25,99.9999983 C26.2328835,75.0708847 19.7847843,0 100,0'),
// tweens for the animation:
// burst animation
tween1 = new mojs.Burst({
parent: el,
duration: 1500,
shape : 'circle',
fill : [ '#e67e22', '#DE8AA0', '#8AAEDE', '#8ADEAD', '#DEC58A', '#8AD1DE' ],
x: '50%',
y: '50%',
opacity: 0.8,
childOptions: { radius: {20:0} },
radius: {40:120},
angle: {0: 180},
count: 8,
isSwirl: true,
isRunLess: true,
easing: mojs.easing.bezier(0.1, 1, 0.3, 1)
}),
// ring animation
tween2 = new mojs.Transit({
parent: el,
duration: 750,
type: 'circle',
radius: {0: 50},
fill: 'transparent',
stroke: '#2ecc71',
strokeWidth: {15:0},
opacity: 0.6,
x: '50%',
y: '50%',
isRunLess: true,
easing: mojs.easing.bezier(0, 1, 0.5, 1)
}),
// icon scale animation
tween3 = new mojs.Tween({
duration : 900,
onUpdate: function(progress) {
if(progress > 0.3) {
var scaleProgress = scaleCurve(progress);
elSpan.style.WebkitTransform = elSpan.style.transform = 'scale3d(' + scaleProgress + ',' + scaleProgress + ',1)';
elSpan.style.WebkitTransform = elSpan.style.color = '#2ecc71';
} else {
elSpan.style.WebkitTransform = elSpan.style.transform = 'scale3d(0,0,1)';
elSpan.style.WebkitTransform = elSpan.style.color = 'rgba(0,0,0,0.3)';
}
}
});
// add tweens to timeline:
timeline.add(tween1, tween2, tween3);
// when clicking the button start the timeline/animation:
el.addEventListener('mousedown', function() {
timeline.start();
});
.wrapper {
display: flex;
justify-content: center;
align-items: center;
align-content: center;
text-align: center;
height: 200px;
}
.my-button {
background: transparent;
border: none;
outline: none;
margin: 0;
padding: 0;
position: relative;
text-align:center;
}
svg {
top: 0;
left: 0;
}
.send-icon {
position: relative;
font-size: 40px;
color: rgba(0,0,0,0.3);
}
<link href="http://fontawesome.io/assets/font-awesome/css/font-awesome.css" rel="stylesheet"/>
<script src="http://netgon.net/mo.min.js"></script>
<div class="wrapper">
<button class="my-button">
<span class="send-icon fa fa-paper-plane"></span>
</button>
</div>
Codepen

Working CodePen Here!
the "parent element" el must be a single element, so achieving this would be tricky and create a complicated messy code.
so I created a different method that'll create the animations once and set their position using tune() when a button is clicked, this will improve performance since you only have one animation object in the DOM.
instead of creating three animations for each parent/button.
I listen to the all buttons with the class "my-button" set animation's top and left values accordingly
$( ".my-button" ).on( "click", function() {
aniPos = findCenter($(this));
myAnimation1.tune({ top: aniPos.y, left: aniPos.x });
myAnimation2.tune({ top: aniPos.y, left: aniPos.x });
myTimeline.replay();
anipos is calculated with a simple function that'll return an object with .x and .y values
function findCenter ($this) {
var offset = $this.offset();
var width = $this.width();
var height = $this.height();
IDs = {
x: offset.left + (width / 2),
y: offset.top + (height / 2)
};
console.log(offset);
return IDs;
}
I also added a method to animate the clicked button automatically.
elSpan = this.querySelector('span');
new mojs.Tween({
duration : 900,
onUpdate: function(progress) {
if(progress > 0.3) {
var scaleProgress = scaleCurve(progress);
elSpan.style.WebkitTransform = elSpan.style.transform = 'scale3d(' + scaleProgress + ',' + scaleProgress + ',1)';
elSpan.style.WebkitTransform = elSpan.style.color = '#2ecc71';
} else {
elSpan.style.WebkitTransform = elSpan.style.transform = 'scale3d(0,0,1)';
elSpan.style.WebkitTransform = elSpan.style.color = 'rgba(0,0,0,0.3)';
}
}
}).play();
});
please note that my example will require JQuery to work.
I used the exact animations you provided but you can change them as long as you don't change X, Y, top and left properties