I try to make drawing app on canvas. It works well in full screen but when I set its width and height according to a div container. It didn't work correctly. It starts painting from the right rather than the top left.
Here is my code pen link: https://codepen.io/pranaysharma995/pen/GRpGVmG.
div class="container">
<div class="col-md-4 col-md-offset-4 " id="canvas-container">
<canvas id="canvas">
</canvas></div>
#canvas-container{
position: relative;
width: 600px;
height: 600px;
background-color: #f3f6f7;
}
You have to offset the mouse position with the canvas.getBoundingClientRect
var canvas = document.querySelector("#canvas");
var container = document.querySelector(".col-md-4");
canvas.width = container.offsetWidth;
canvas.height = container.offsetHeight;
var c = canvas.getContext('2d');
c.fillStyle = "red";
c.strokeStyle = "red";
c.lineWidth = 5;
c.lineCap = "round";
function draw(e) {
var rect = canvas.getBoundingClientRect();
var x = e.clientX - rect.left
var y = e.clientY - rect.top
c.lineTo(x, y);
c.stroke();
}
canvas.addEventListener("mousemove", draw);
.container {
position: absolute;
left: 50px;
top: 25px
}
#canvas-container {
position: relative;
width: 200px;
height: 200px;
background-color: #f3f6f7;
}
<div class="container">
<div class="col-md-4 col-md-offset-4 " id="canvas-container">
<canvas id="canvas"></canvas>
</div>
</div>
Related
l do believe to have an issue regarding an if statement that allows for the detection of where the canvas object, being the image that displays , should be located at within the canvas. There is a reproducible demo provided.
NOTE: I do want to KEEP the css alignment, canvasauto, and not remove it if possible.
var canvas = document.getElementById("c");
var ctx = canvas.getContext("2d");
var the_button = document.getElementById("the_button");
var the_background = document.getElementById("the_background");
var imageXpos = 500;
var imageYpos = 300;
var imageWidth = 110;
var imageHeight = 80;
var imagecheck_Xpos = canvas.width - imageXpos;
var imagecheck_Ypos = canvas.height - imageYpos;
window.onload = function() {
ctx.drawImage(the_background, 0, 0, canvas.width, canvas.height);
ctx.drawImage(the_button, imagecheck_Xpos, imagecheck_Ypos, imageWidth, imageHeight);
}
the_button_function = (event) => {
const {
x,
y
} = event;
/* l believe the issue is here */
if ((x >= imagecheck_Xpos && x < (imagecheck_Xpos + imageWidth)) &&
(y >= imagecheck_Ypos && y < (imagecheck_Ypos + imageHeight))) {
alert("<Button>")
}
}
canvas.addEventListener('click', (e) => the_button_function(e));
html,
body {
width: 100%;
height: 100%;
margin: 0px;
border: 0;
overflow: hidden;
display: block;
}
.canvasauto {
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
}
<html>
<canvas id="c" width="970" height="550" class="canvasauto"></canvas>
<img style="display: none;" id="the_button" src="https://i.imgur.com/wO7Wc2w.png" />
<img style="display: none;" id="the_background" src="https://img.freepik.com/free-photo/hand-painted-watercolor-background-with-sky-clouds-shape_24972-1095.jpg?size=626&ext=jpg" />
</html>
You're using x from the MouseEvent. This is an experimental feature which is an alias of clientX.
The clientX property gives the coordinates relative to the application's viewport.
You probably want offsetX, which is relative to (the padding edge of the) target node.
var canvas = document.getElementById("c");
var ctx = canvas.getContext("2d");
var the_button = document.getElementById("the_button");
var the_background = document.getElementById("the_background");
var imageXpos = 500;
var imageYpos = 300;
var imageWidth = 110;
var imageHeight = 80;
var imagecheck_Xpos = canvas.width - imageXpos;
var imagecheck_Ypos = canvas.height - imageYpos;
window.onload = function() {
ctx.drawImage(the_background, 0, 0, canvas.width, canvas.height);
ctx.drawImage(the_button, imagecheck_Xpos, imagecheck_Ypos, imageWidth, imageHeight);
}
the_button_function = (event) => {
const {
offsetX: x,
offsetY: y
} = event;
/* l believe the issue is here */
if ((x >= imagecheck_Xpos && x < (imagecheck_Xpos + imageWidth)) &&
(y >= imagecheck_Ypos && y < (imagecheck_Ypos + imageHeight))) {
alert("<Button>")
}
}
canvas.addEventListener('click', (e) => the_button_function(e));
html,
body {
width: 100%;
height: 100%;
margin: 0px;
border: 0;
overflow: hidden;
display: block;
}
.canvasauto {
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
}
<html>
<canvas id="c" width="970" height="550" class="canvasauto"></canvas>
<img style="display: none;" id="the_button" src="https://i.imgur.com/wO7Wc2w.png" />
<img style="display: none;" id="the_background" src="https://img.freepik.com/free-photo/hand-painted-watercolor-background-with-sky-clouds-shape_24972-1095.jpg?size=626&ext=jpg" />
</html>
I have 2 canvases side by side , and in the first one I have resizable draggable div as a crop region and I want to display the cropped region on the second canvas . But it is not happening in my case. Any help is appreciated
function crop(){
var x = $("#crop_square").width();
var y = $("#crop_square").height();
var ty = $("#crop_square").offset().top -
$("#area_c").offset().top;
var tx = $("#crop_square").offset().left -
$("#area_c").offset().left;
alert(x);
alert(y);
alert(ty);
alert(tx);
var c = document.getElementById("area_c"); //canvaas1
var c2 = document.getElementById("area_c2"); // canvas2
var ctx2 = c2.getContext("2d");
ctx2.drawImage(c,tx,ty,x,y,0,0,x,y );
}
If you need to "crop" a canvas with a div you may use the div's BoundingClientRect data to draw the image on the other canvas:
I hope this is what you were asking.
let cw = (area_c.width = area_c2.width = 400);
let ch = (area_c.height = area_c2.height = 400);
const ctx1 = area_c.getContext("2d");
const ctx2 = area_c2.getContext("2d");
theImg.onload = function() {
ctx1.drawImage(theImg, 0, 0);
let bcr = crop_square.getBoundingClientRect();
ctx2.drawImage(
theImg,
bcr.x,
bcr.y,
bcr.width,
bcr.height,
bcr.x,
bcr.y,
bcr.width,
bcr.height
);
}
.wrap {
width: 300px;
height: 300px;
border: 1px solid;
display: inline-block;
position: relative;
}
#crop_square {
position: absolute;
width: 150px;
height: 75px;
left: 100px;
top: 53px;
border: 5px solid gold;
}
<div class="wrap">
<canvas id="area_c">
<img id="theImg" src="data:image/jpeg;base64,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"/>
</canvas>
<div id="crop_square"></div>
</div>
<div class="wrap">
<canvas id="area_c2"></canvas>
</div>
I have a canvas that is the only thing on a page I want really want to see. I'm trying to make it such that when I resize my window, I always have the entire canvas viewable with no scroll bars and maintain the aspect ratio.
MCVE
let canvas = document.getElementById('canvas');
let ctx = canvas.getContext('2d');
let w = canvas.width;
let h = canvas.height;
ctx.fillStyle = 'teal';
ctx.fillRect(0, 0, w, h);
ctx.strokeStyle = 'red';
ctx.lineWidth = 10;
ctx.rect(5, 5, w - 5, h - 5);
ctx.stroke();
* {
background-color: white;
max-height: 100%;
max-width: 100%;
margin: 0;
padding: 0;
}
div#canvasDiv {}
canvas#canvas {
display: block;
margin: auto;
}
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
</head>
<body>
<div id="canvasDiv">
<canvas id="canvas" width="500" height="500" />
</div>
</body>
</html>
All here at jsfiddle
With this attempt, it rescales just fine when I resize the width. However, when I resize the height, I get overflow.
Resize Width with appropriate rescaling
Resize Height with unwanted overflow
You may like to read this article: [Centering in CSS: A Complete Guide](https://css-tricks.com/centering-css-complete-guide/
let canvas = document.getElementById('canvas');
let ctx = canvas.getContext('2d');
let w = canvas.width;
let h = canvas.height;
ctx.fillStyle = 'teal';
ctx.fillRect(0, 0, w, h);
ctx.strokeStyle = 'red';
ctx.lineWidth = 10;
ctx.rect(5, 5, w - 5, h - 5);
ctx.stroke();
* {
background-color: white;
max-height: 100%;
max-width: 100%;
margin: 0;
padding: 0;
}
canvas#canvas {
display: block;
margin: auto;
position:absolute;
top:0;bottom:0;
left:0;
right:0;
}
<div id="canvasDiv">
<canvas id="canvas" width="500" height="500"/>
</div>
I looked for solutions to this problem for a long time, found some and I thought I understand but apparently I don't. I'd like to make a canvas that ppl can use to sign to confirm a booking. But I can't get the line to follow the user's cursor. My code looks like this:
HTML:
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Signature Test</title>
<link rel="stylesheet" href="../css/test.css">
<script src="../js/jquery-3.2.0.js"></script>
</head>
<body>
<header id="header">
</header>
<section id="content">
<canvas id="signaturePad">DSorry your browser is rubbish</canvas>
</section>
<footer>
</footer>
<script src="../js/test.js"></script>
</body>
</html>
CSS:
body
{
margin: 0;
padding: 0;
}
header
{
border: 1px solid black;
width: 100%;
height: 50px;
}
#content
{
border: 1px solid blue;
width: 100%;
height: 300px;
position: relative;
}
#content #signaturePad
{
border: 1px solid red;
width: 200px;
height: 200px;
position: absolute;
left: calc(50% - 100px);
top: calc(50% - 100px);
}
footer
{
border: 1px solid black;
width: 100%;
height: 50px;
}
And finally the JS:
var canvas = document.getElementById("signaturePad");
var context = canvas.getContext("2d");
var radius = 1;
var dragging = false;
context.lineWidth = 2*radius;
function displayMousePosition(mouseX, mouseY) {
var header = document.getElementById("header");
header.innerHTML = "X : " + mouseX + "<br />Y : " + mouseY;
}
function getMousePosition(e) {
var mouseX = 0,
mouseY = 0,
elmX = 0,
elmY = 0,
obj = this;
//get mouse position on document crossbrowser
if (!e){e = window.event;}
if (e.pageX || e.pageY){
mouseX= e.pageX;
mouseY = e.pageY;
} else if (e.clientX || e.clientY){
mouseX = e.clientX + document.body.scrollLeft
+ document.documentElement.scrollLeft;
mouseY = e.clientY + document.body.scrollTop
+ document.documentElement.scrollTop;
}
//get parent element position in document
if (obj.offsetParent){
do{
elmX += obj.offsetLeft;
elmY += obj.offsetTop;
} while (obj = obj.offsetParent);
}
displayMousePosition(mouseX, mouseY);
return [mouseX, mouseY];
}
var putPoint = function(e) {
if(dragging) {
var offset = $("#signaturePad").offset();
var mouseX = getMousePosition(e)[0];
var mouseY = getMousePosition(e)[1];
context.lineTo(mouseX, mouseY);
context.stroke();
context.beginPath();
context.arc(mouseX, mouseY, radius, 0, Math.PI*2);
context.fill();
context.beginPath();
context.moveTo(mouseX, mouseY);
}
}
$(document).on("mousedown", "#signaturePad", function(e) {
dragging = true;
putPoint(e);
});
$(document).on("mouseup", "#signaturePad", function() {
dragging = false;
context.beginPath();
});
$(document).on("mousemove", "#signaturePad", function(e) {
putPoint(e);
});
And the fiddle if you wanna see it live: https://jsfiddle.net/Cellendhyll/yxguemf0/7/
I'm making an image drawing application with html and javascript. I made it with canvas and added some buttons(<div>s) on the canvas. Of course, canvas have onmousedown, onmouseup, onmousemove handlers to draw lines. But when I move mouse to the position of buttons or out of the canvas, then return to the canvas area, line breaks.
refer to the code(http://jsfiddle.net/coldmund/MQKMv/) please.
html:
<div>
<div style="position: absolute; margin-top: 0px; margin-left: 0px;"><canvas id="canvas" width="500" height="300" onmousedown="down(event)" onmouseup="up()" onmousemove="move(event)" style="border: 1px solid"></canvas></div>
<div style="position: absolute; margin-top: 100px; margin-left: 100px; width: 100px; height: 100px; background: #ff0000; opacity: 0.5"></div>
</div>
js:
var mouseDown = false;
down = function(e)
{
mouseDown = true;
prevX = e.clientX;
prevY = e.clientY;
};
up = function()
{
mouseDown = false;
};
move = function(e)
{
if( mouseDown === false )
return;
var canvas = document.getElementById('canvas');
var context = canvas.getContext('2d');
context.lineWidth = 5;
context.lineCap = 'round';
context.beginPath();
context.moveTo( prevX, prevY );
context.lineTo( e.clientX, e.clientY );
context.stroke();
prevX = e.clientX;
prevY = e.clientY;
};
Here is a fiddle with a potential solution (fiddle). This basically toggles the buttons css property to pointer-events:none while drawing on the canvas.
The differences between your code and mine basically reduce to the following:
// CSS
.no-pointer-events {
pointer-events:none;
}
// Inside the mousedown handler
document.getElementById( "button1" ).class = "no-pointer-events";
// Inside the mouseup handler
document.getElementById( "button1" ).class = "";