How to create a Circle with crosshair cursor on hover over objects using FabricJS?

FabricJSJavascriptHTML5 Canvas

In this tutorial, we are going to create a Circle with a crosshair cursor on hover over objects using FabricJS. crosshair is one of the native cursor styles 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 which are reusing the native cursor underhood. The hoverCursor property sets the style of the cursor when hovered over a canvas object.

Syntax

new fabric.Circle({ hoverCursor: String }: 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 hoverCursor is a property.

Options Keys

  • hoverCursor − This property accepts a String which determines the name of the cursor to be used on hovering over the canvas object. By using this property, we can set the default cursor value when hovering over the circle object on the canvas.

Example 1

Passing the hoverCursor Key to the class

By default, when we hover over a circle object in the canvas, the cursor type is move. Let's see an example to create a canvas with a crosshair cursor while hovering over a circle object 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>Creating a circle with crosshair cursor on hover over objects using FabricJS</h2>
      <p>Move the cursor inside the circle and observe the cursor. Here we have applied <b>hoverCursor</b> property and assigned it the value 'crosshair'.</p>
      <canvas id="canvas"></canvas>

      <script>
         // Initiate a canvas instance
         var canvas = new fabric.Canvas("canvas");
         var circle = new fabric.Circle({
            left: 115,
            top: 100,
            fill: "#a2006d",
            radius: 50,
            stroke: "#c154c1",
            strokeWidth: 5,
            hoverCursor: "crosshair"
         });

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

Example 2

Proof that hoverCursor applies to a specific object

In this example, we are passing the hoverCursor key to the circle class which means that the hoverCursor property would not be changed for every object in the canvas. Changes will only occur for that single object. This is illustrated in the example below −

!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>Creating a circle with crosshair cursor on hover over objects using FabricJS</h2>
      <p> Move the cursor over the objects. You will get to see the <b>crosshair</b> cursor when you hover the mouse over the left circle. </p>
      <canvas id="canvas"></canvas>
   
      <script>
         // Initiate a canvas instance
         var canvas = new fabric.Canvas("canvas");
         var circle = new fabric.Circle({
            left: 115,
            top: 100,
            fill: "white",
            radius: 50,
            stroke: "#c154c1",
            strokeWidth: 5,
            hoverCursor: "crosshair"
         });
         var cir = new fabric.Circle({
            left: 280,
            top: 100,
            fill: "#a2006d",
            radius: 50,
         });

         // Adding it to the canvas
         canvas.add(circle);
         canvas.add(cir);
         canvas.setWidth(document.body.scrollWidth);
         canvas.setHeight(250);
      </script>
   </body>
</html>
raja
Updated on 25-May-2022 07:56:35

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