How to set the fill colour of a Triangle using FabricJS?


<p>In this tutorial, we are going to learn how we can change the appearance of a Triangle object by changing its fill colour using FabricJS. Triangle is one of the various shapes provided by FabricJS. In order to create a triangle, we will have to create an instance of <em>fabric.Triangle</em> class and add it to the canvas.</p><p>We can change the fill colour by using the <em>fill</em> property which allows us to specify the colour of the object's fill.</p><h2>Syntax</h2><pre class="just-code notranslate language-javascript" data-lang="javascript">new fabric.Triangle({ fill: String }: Object)</pre><h2>Parameters</h2><ul class="list"><li><p><strong>Options</strong><strong> (optional)</strong> − This parameter is an <em>Object</em> which provides additional customizations to our triangle. 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 <em>fill</em> is a property.</p></li></ul><h2>Options Keys</h2><ul class="list"><li><p><strong>fill</strong> − This property accepts a <strong>String</strong> which allows us to change an object's fill colour. Its default value is <em>rgb(0,0,0)</em> which is the colour black.</p></li></ul><h2>Example 1</h2><p><strong>Default fill colour of a triangle object</strong></p><p>Let's see a code example that shows us the default fill colour of a triangle object in FabricJS. If we completely skip the fill property while creating a triangle object, it will be rendered with the fill colour as black.</p><pre class="demo-code notranslate language-javascript" data-lang="javascript"><!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>Default fill colour of a triangle object</h2>    <p>You can see that the default fill colour of triangle is black</p>    <canvas id="canvas"></canvas>    <script>       // Initiate a canvas instance       var canvas = new fabric.Canvas("canvas");       canvas.setWidth(document.body.scrollWidth);       canvas.setHeight(250);       // Initiate a triangle object       var triangle = new fabric.Triangle({          left: 105,          top: 60,          width: 100,          height: 70,          stroke: "#507d2a",          strokeWidth: 5,       });       // Add it to the canvas       canvas.add(triangle);    </script> </body> </html></pre><h2>Example 2</h2><p><strong>Passing the <em>fill</em> property as key</strong></p><p>We can also assign the <em>fill</em> property any colour name or RGBA value. In this example, we have assigned it a value of "blue" which thus changes the fill colour accordingly.</p><pre class="demo-code notranslate language-javascript" data-lang="javascript"><!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>Passing the fill property as key</h2>    <p>You can see that the fill colour of triangle is blue</p>    <canvas id="canvas"></canvas>    <script>       // Initiate a canvas instance       var canvas = new fabric.Canvas("canvas");       canvas.setWidth(document.body.scrollWidth);       canvas.setHeight(250);       // Initiate a triangle object       var triangle = new fabric.Triangle({          left: 105,          top: 60,          width: 100,          height: 70,          stroke: "#507d2a",          strokeWidth: 5,          fill: "blue",       });       // Add it to the canvas       canvas.add(triangle);    </script> </body> </html></pre>

Updated on: 27-Jun-2022

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