How to lock the vertical skewing of a Circle using FabricJS?

FabricJSJavascriptHTML5 Canvas

In this tutorial, we are going to learn how to lock the vertical skewing 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 specify whether we want to stop skewing an object vertically. This can be done by using the lockSkewingY property.

Syntax

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

Options Keys

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

Example 1

Default behaviour of a Circle object in the canvas

Let's see a code example to understand the default behaviour of a Circle object when lockSkewingY 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 vertical skewing of a circle using FabricJS</h2>
      <p>Select the object, hold the <b>shift</b> key, and stretch it horizontally or vertically. The object will get skewed freely. This is the default behavior. Here we have not applied the <b>lockSkewingY</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 lockSkewingY as key with 'true' value

In this example we will see how we can cease the ability of a circle object skew vertically using the lockSkewingY property. As we can see, although we can skew the circle object horizontally by pressing the Shift Key, we are not allowed to perform the same action vertically.

<!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 vertical skewing of a circle using FabricJS</h2>
      <p>Select the object, hold the <b>shift</b> key, and try to stretch the circle horizontally or vertically. You will notice that the object gets skewed horizontally, but its vertical skewing is locked. Here we have set <b>lockSkewingY</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,
            lockSkewingY: 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 12:04:22

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