How to lock the flipping during scaling of Circle using FabricJS?

FabricJSJavascriptHTML5 Canvas

In this tutorial, we are going to learn how to lock the flipping during scaling of a Circle using FabricJS. Just as we can specify the position, colour, opacity and dimension of a circle object in the canvas, we can also stop flipping of an object during scaling. This can be done by using the lockScalingFlip property.

Syntax

new fabric.Circle({ lockScalingFlip : 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 lockScalingFlip is a property.

Options Keys

  • lockScalingFlip − This property accepts a Boolean value. If we assign it a 'true' value, then the object will not be allowed to flip during scaling.

Example 1

Default behaviour of a Circle object in the canvas

Let's see an example to understand the default behaviour of a Circle object when lockScalingFlip property is not used.

<!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 lock the flipping during scaling of circle using FabricJS</h2>
      <p>Select the circle and try to scale it up or down. You will notice that the circle flips while scaling. This is the default behavior. Here we haven't used the <b>lockScalingFlip</b> property but by default it is set to False.</p>
      <canvas id="canvas"></canvas>

      <script>
         // Initiate a canvas instance
         var canvas = new fabric.Canvas("canvas");
         var circle = new fabric.Circle({
            left: 115,
            top: 50,
            fill: "white",
            radius: 50,
            stroke: "black",
            strokeWidth: 5,
         });

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

Example 2

Passing lockScalingFlip as key with 'true' value

In this example, we will see how we can cease the ability of a circle object to flip while scaling by using the lockScalingFlip property. As we can see, although we try to flip the circle object, it is no longer allowed.

<!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 lock the flipping during scaling of circle using FabricJS</h2>
      <p>Select the object and try to scale it up or down. Observe that the circle will no longer flip during scaling, as we have set <b>lockScalingFlip</b> to True. </p>
      <canvas id="canvas"></canvas>

      <script>
         // Initiate a canvas instance
         var canvas = new fabric.Canvas("canvas");
         var circle = new fabric.Circle({
            left: 115,
            top: 50,
            fill: "white",
            radius: 50,
            stroke: "black",
            strokeWidth: 5,
            lockScalingFlip: true
         });

         // Adding it to the canvas
         canvas.add(circle);
         canvas.setWidth(document.body.scrollWidth);
         canvas.setHeight(250);
      </script>
   </body>
</html>
raja
Updated on 25-May-2022 09:12:32

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