How to create a canvas with a help cursor using FabricJS?


In this article, we are going to create a canvas with a help cursor using FabricJS. The question mark in a help pointer indicates that useful information for the user is present. It is also often accompanied by useful links and can be seen while using a new application. help is one of the native cursor style available which can be used in the FabricJS canvas too.

FabricJS provides various types of cursors like default, all-scroll, crosshair, col-resize, row-resize, etc., that reuse the native cursor under the hood. Each of these cursors look slightly different based on operating system.

Syntax

new fabric.Canvas(element: HTMLElement|String, { defaultCursor: String }: Object)

Parameters

  • element − This parameter is the <canvas> element itself which can be derived using document.getElementById() or the id of the <canvas> element itself. The FabricJS canvas will be initialized on this element.

  • options (optional) − This parameter is an Object which provides additional customizations to our canvas. Using this parameter color, cursor, border width and a lot of other properties can be changed related to the canvas, of which defaultCursor is a property with which we can set the type of cursor that we want.

Example 1

The defaultCursor property accepts a String which determines the name of the cursor to be used on the canvas. We will set it to help to use the help cursor. Let's see a code to create a canvas with a help cursor 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>Canvas with a help cursor using FabricJS</h2>
   <p>Bring the cursor inside the canvas to see the changed shape of cursor</p>
   <canvas id="canvas"></canvas>
   <script>
      //Initiate a canvas instance
      var canvas = new fabric.Canvas("canvas", {
         defaultCursor: "help"
      });
      canvas.setWidth(document.body.scrollWidth);
      canvas.setHeight(250);
   </script>
</body>
</html>

Example 2

In this example, we will add a circle to the canvas along with the help cursor.

<!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>Canvas with help cursor using FabricJS</h2>
   <p>Here we have added a circle to the canvas along with a help cursor</p>
   <canvas id="canvas"></canvas>
   <script>
      //Initiate a canvas instance
      var canvas = new fabric.Canvas("canvas", {
         defaultCursor: "help"
      });
      // Initiate a Circle instance
      var circle = new fabric.Circle({
         radius: 50,
         fill: "green"
      });
      // Render the circle in canvas
      canvas.add(circle);
      canvas.setWidth(document.body.scrollWidth);
      canvas.setHeight(250);
   </script>
</body>
</html>

Updated on: 19-May-2022

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