How to lock the horizontal skewing of Ellipse using FabricJS?

FabricJSJavascriptHTML5 Canvas

In this tutorial, we are going to learn how to lock the horizontal skewing of an Ellipse using FabricJS. Just as we can specify the position, color, opacity and dimension of an ellipse object in the canvas, we can also specify whether we want to stop skewing an object horizontally. This can be done by using the lockSkewingX property.

Syntax

new fabric.Ellipse({ lockSkewingX : 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 lockSkewingX is a property.

Options Keys

  • lockSkewingX − This property accepts a Boolean value. If we assign it a 'true' value, then the object's horizontal skewing will be locked.

Example 1

Default behaviour of an Ellipse object in the canvas

Let's take an example to understand the default behaviour of an Ellipse object when lockSkewingX property is not used. Skewing the object in both horizontal and vertical directions is feasible by pressing the shift key and then dragging along the horizontal or vertical direction.

<!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>Locking the horizontal skewing of Ellipse using FabricJS</h2>
      <p>Select the object. Hold the "shift" and try to stretch the object (not diagonally). You can skew the object both horizontally and vertically. 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,
            fill: "white",
            rx: 80,
            ry: 50,
            stroke: "black",
            strokeWidth: 5,
         });

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

Example 2

Passing lockSkewingX as key with 'true' value

In this example we will see how we can cease the ability of an Ellipse object to skew horizontally using the lockSkewingX property. Although we can skew the ellipse object vertically, we are not allowed to perform the same action horizontally.

<!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 horizontal skewing of Ellipse using FabricJS?</h2>
      <p>Select the object; hold the "shift" key and try to stretch the object horizontally. You cannot skew the object horizontally because we have set <b>lockSkewingX</b> to True. </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,
            fill: "white",
            rx: 80,
            ry: 50,
            stroke: "black",
            strokeWidth: 5,
            lockSkewingX: true,
         });
         // 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 12:58:31

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