How to make an Ellipse invisible using FabricJS?

FabricJSJavascriptHTML5 Canvas

In this tutorial, we are going to learn how to make an Ellipse invisible using FabricJS. Ellipse is one of the various shapes provided by FabricJS. In order to create an ellipse, we will create an instance of fabric.Ellipse class and add it to the canvas. Our ellipse object can be customized in various ways like changing its dimensions, adding a background color or by making it visible or invisible. We can do this by using the visible property.

Syntax

new fabric.Ellipse( { visible: Boolean }: Object)

Parameters

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

Options Keys

  • visible − This property accepts a Boolean value which allows us to render an object onto the canvas. Its default value is True.

Example 1

Passing visible property as key with a 'true' value

Let's take an example to understand what happens when we pass the visible property a "true" value. By assigning the value as "true", we make sure that our Ellipse object is rendered onto the canvas. This is also the default behaviour in FabricJS.

<!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>How to make an Ellipse invisible using FabricJS?</h2>
      <p>The object is visible on the canvas because we have set the <b>visible</b> property to True. This is the default behavior. </p>
      <canvas id="canvas"></canvas>

      <script>
         // Initiate a canvas instance
         var canvas = new fabric.Canvas("canvas");

         // Initiate an ellipse instance
         var ellipse = new fabric.Ellipse({
            left: 115,
            top: 50,
            rx: 100,
            ry: 70,
            fill: "red",
            visible: true,
         });

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

Example 2

Passing visible property as key with a "false" value

In this example, we are passing the visible property as key with a "false" value. Assigning a false value will make sure that our ellipse object does not get rendered onto the canvas. It simply does not make the object "invisible" but gets rid of it altogether. It can be used to remove an object from canvas without removing its code.

<!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>How to make an Ellipse invisible using FabricJS?</h2>
      <p>Here the ellipse object is invisible because we have set the <b>visible</b> property to False. </p>
      <canvas id="canvas"></canvas>

      <script>
         // Initiate a canvas instance
         var canvas = new fabric.Canvas("canvas");

         // Initiate an ellipse instance
         var ellipse = new fabric.Ellipse({
            left: 115,
            top: 50,
            rx: 100,
            ry: 70,
            fill: "red",
            visible: false,
         });

         // Adding it to the canvas
         canvas.add(ellipse);
         canvas.setWidth(document.body.scrollWidth);
         canvas.setHeight(250);
      </script>
   </body>
</html>
raja
Updated on 24-May-2022 14:05:33

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