What is konva.js? & how to use it?

Hello Friends!!

In today’s blog, I’m writing about Konva.js for beginners.

What is konva.js?

Konva.js is an open-source 2D drawing and animation library for JavaScript that enables high-performance animations, transitions, node nesting, layering, filtering,
caching, event handling for desktop and mobile applications, and much more.

With Konva.js, you can create and manipulate graphical objects such as lines, shapes, images, text, and animations with ease. The library provides a wide range of features, including support for multi-touch gestures, drag-and-drop, hit detection, and event handling. It also includes a rich set of built-in filters, easing functions, and animation controls.

Konva.js is designed to be compatible with modern web technologies and can be used in combination with other libraries such as React, Angular, Vue, and jQuery.

Overall, Konva.js is a powerful and flexible tool for creating interactive and visually-rich web applications that run smoothly across all devices and platforms.

How to use konva.js?

Here are the basic steps to use Konva.js in your web application –

Firstly,

1.) Add the Konva.js library to your project by including it in your HTML file using a script tag –

<script src="https://cdnjs.cloudflare.com/ajax/libs/konva/8.4.2/konva.min.js"></script>

If you are using package managers – Install it by the below command.

npm install konva

Or, you can download the library and include it in your project from a local file.

2.) Create a container element in your HTML file where you want to add the canvas –

<div id="container"></div>

Then, create a new Konva.Stage object that will contain your canvas –

Example –

var stage = new Konva.Stage({
  container: 'container',
  width: 200,
  height: 200
});

In this above example, the container parameter specifies the ID of the HTML element where the canvas will be added. You can also specify the width and height of the canvas.

4.) Create a new Konva.Layer object to add your shapes and other graphical elements which you want to add –

var layer = new Konva.Layer();

5.) Now, create your graphical elements using Konva classes such as Konva.Rect, Konva.Circle, Konva.Line, etc. –

Example –

var rect = new Konva.Rect({
  x: 50,
  y: 50,
  width: 100,
  height: 100,
  fill: 'white',
  stroke: 'black',
  strokeWidth: 2
});

In the above example, a Konva.Rect object is created with a position of x=50, y=50, and a width and height of 100 pixels. The rectangle is filled with white and has a black stroke with a width of 2 pixels.

6.) Now, add your graphical elements to the layer –

layer.add(rect);

7.) Add the layer to the stage –

stage.add(layer);

8.) At last, Render the canvas by calling the stage.draw() method –

stage.draw();

This will draw all the graphical elements you added to the layer and display them in the container element on your web page.

That’s all about the Konva.js. Hope this will be helpful.

If you have any questions please comment below, and we will try to respond to you.

Thanks for visiting the Webkul blog! 🙂