Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
How to get the opacity of Text object using FabricJS?
In this tutorial, we are going to learn how to get the opacity of Text using FabricJS. We can display text on canvas by adding an instance of fabric.Text. Not only does it allow us to move, scale and change the dimensions of the text but it also provides additional functionality like text alignment, text decoration, line height which can be obtained by the properties textAlign, underline and lineHeight respectively. We can also find the opacity of an object by using the getObjectOpacity method.
Syntax
getObjectOpacity()
Example 1
Using the getObjectOpacity method
Let's see a code example to see the logged output when the getObjectOpacity method is used. In this case, the default opacity will be displayed in the console which is 1.
<!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>Using the getObjectOpacity method</h2>
<p>You can open console from dev tools and see that the opacity value is being displayed in the console</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 text object
var text = new fabric.Text("Add sample\ntext here", {
width: 300,
fill: "green",
fontWeight: "bold",
});
// Add it to the canvas
canvas.add(text);
// Using getObjectOpacity method
console.log("The opacity is", text.getObjectOpacity());
</script>
</body>
</html>
The opacity is 1
Example 2
Using the getObjectOpacity method and passing the opacity property
Let's see a code example to see the logged output when the getObjectOpacity method is used in conjunction with the opacity property. In this case, the opacity of the text object has been assigned a value of 0.7 and hence the logged output will be 0.7.
<!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>Using the getObjectOpacity method and passing the opacity property</h2>
<p>You can open console from dev tools and see that the opacity value is being displayed in the console</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 text object
var text = new fabric.Text("Add sample\ntext here", {
width: 300,
fill: "green",
fontWeight: "bold",
opacity: 0.7,
});
// Add it to the canvas
canvas.add(text);
// Using getObjectOpacity method
console.log("The opacity is", text.getObjectOpacity());
</script>
</body>
</html>
The opacity is 0.7
How It Works
The getObjectOpacity() method returns the current opacity value of a FabricJS object. Opacity values range from 0 (completely transparent) to 1 (completely opaque). When no opacity property is set during object creation, the default value of 1 is returned.
Conclusion
The getObjectOpacity() method provides a simple way to retrieve the current opacity value of FabricJS text objects. This is useful for maintaining consistency in opacity settings across multiple objects or for dynamic opacity adjustments.
273 Views
