How to change selection background color of a canvas circle using Fabric.js ?

Last Updated : 12 May, 2020

In this article, we are going to see how to change the selection background color of a canvas circle using FabricJS. The canvas means the circle is movable and can be stretched according to requirement. Further, the circle can be customized when it comes to initial stroke color, fill color, stroke width or radius.

Approach: To make it possible, we are going to use a JavaScript library called FabricJS. After importing the library using CDN, we will create a canvas block in the body tag which will contain our circle. After this, we will initialize instances of Canvas and Circle provided by FabricJS and change the selection background color of the circle using selectionBackgroundColor property and render the Circle on the Canvas as given in the example below.

Syntax:

fabric.Circle({
    radius: number,
    selectionBackgroundColor: string
});

Parameters: This function accepts two parameters as mentioned above and described below:

radius: It specifies the radius.
selectionBackgroundColor: It specifies the color of selection background.

Example: This example uses FabricJS to change selection background color of a canvas circle. Note that you have to click on the object to see its selection background color.

<!DOCTYPE html> 
<html> 
  
<head> 
    <title> 
        How to change selection background color 
        of a canvas circle using FabricJS? 
    </title> 
  
    <!-- FabricJS CDN -->
    <script src= 
"https://cdnjs.cloudflare.com/ajax/libs/fabric.js/3.6.2/fabric.min.js"> 
    </script> 
</head> 
  
<body> 
    <canvas id="canvas" width="600" height="200"
        style="border:1px solid #000000"> 
    </canvas> 
  
    <script> 
  
        // Initiate a Canvas instance 
        var canvas = new fabric.Canvas("canvas"); 
  
        // Initiate a Circle instance 
        var circle = new fabric.Circle({ 
            radius: 50, 
            selectionBackgroundColor: 'green' 
        }); 
  
        // Render the circle in canvas 
        canvas.add(circle); 
    </script> 
</body> 
  
</html> 