How to make the controlling corners of a Circle transparent using FabricJS?

In this tutorial, we are going to learn how to make the controlling corners of Circle transparent using FabricJS. Circle is one of the various shapes provided by FabricJS. In order to create a circle, we will create an instance of fabric.Circle class and add it to the canvas. The transparentCorners property allows us to make the controlling corners of Circle transparent.

Syntax

new fabric.Circle( { transparentCorners: Boolean }: Object)

Parameters

options (optional) − This parameter is an Object which provides additional customizations to our circle. Using this parameter, properties such as colour, cursor, stroke width and a lot of other properties can be changed related to the object of which transparentCorners is a property.

Options Keys

transparentCorners − This property accepts a Boolean value which allows us to render the controlling corners of an object as transparent. Its default value is True.

Example 1

Passing transparentCorners property as key with a 'false' value

Let's see a code example to create a circle object with controlling corners that are not transparent. To achieve this, we need to pass the transparentCorners property a False value.

<!DOCTYPE html>
<html>
   <head>
      <!-- Adding the Fabric JS Library-->
      <script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/510/fabric.min.js"></script>
   </head>

   <body>
      <h2>Making the controlling corners of a circle transparent using FabricJS</h2>
      <p>Select the object and observe its controlling corners. Here we have set <b>transparentCorners</b> to False. </p>
      <canvas id="canvas"></canvas>

      <script>
         // Initiate a canvas instance
         var canvas = new fabric.Canvas("canvas");
         var cir = new fabric.Circle({
            left: 215,
            top: 100,
            fill: "#adff2f",
            radius: 50,
            stroke: "#228b22",
            transparentCorners: false
         });

         // Adding it to the canvas
         canvas.add(cir);
         canvas.setWidth(document.body.scrollWidth);
         canvas.setHeight(250);
      </script>
   </body>
</html>

Example 2

Passing transparentCorners as key with a 'true' value

In this example, we are passing the transparentCorners property a True value. This will make sure that the controlling corners are rendered as transparent. Note, that this is also the default behaviour.

<!DOCTYPE html>
<html>
   <head>
      <!-- Adding the Fabric JS Library-->
      <script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/510/fabric.min.js"></script>
   </head>

   <body>
      <h2>Making the controlling corners of a circle transparent using FabricJS</h2>
      <p>Select the object and observe its controlling corners. Here we have set <b>transparentCorners</b> to True, so the corners are transparent. </p>
      <canvas id="canvas"></canvas>

      <script>
         // Initiate a canvas instance
         var canvas = new fabric.Canvas("canvas");
         var cir = new fabric.Circle({
            left: 215,
            top: 100,
            fill: "#adff2f",
            radius: 50,
            stroke: "#228b22",
            transparentCorners: true
         });

         // Adding it to the canvas
         canvas.add(cir);
         canvas.setWidth(document.body.scrollWidth);
         canvas.setHeight(250);
      </script>
   </body>
</html>