In this article, we are going to see how to set the opacity of the border of a moving canvas rectangle using FabricJS. The canvas rectangle means rectangle is movable and can be stretched according to requirement. Further, the rectangle can be customized when it comes to initial stroke color, height, width, fill color, or stroke width.
Approach: To make it possible, we are going to use a JavaScript library called FabricJS. After importing the library, we will create a canvas block in the body tag which will contain the rectangle. After this, we will initialize instances of Canvas and Rect provided by FabricJS and set the opacity of the border of moving canvas rectangle using borderOpacityWhenMoving property and render the Rect on the Canvas as given below.
Syntax:
fabric.Rect({
width: number,
height: number,
borderOpacityWhenMoving: number
});
Parameters: This function accepts three parameters as mentioned above and described below:
- width: It specifies the width of rectangle.
- height: It specifies the height of rectangle.
- borderOpacityWhenMoving: It specifies the opacity of border when moving.
Example: This example uses FabricJS to set the opacity of the border of moving canvas-like rectangle as given below.
<!DOCTYPE html> <html> <head> <title> Fabric.js | Rect borderOpacityWhenMoving Property </title> <!-- Adding the FabricJS library --> <script src= </script> </head> <body> <canvas id="canvas" width="600" height="200" style="border:1px solid #000000"> </canvas> <script> // Initiate a Canvas instance var canvas = new fabric.Canvas("canvas"); // Initiate a Rect instance var rectangle = new fabric.Rect({ width: 200, height: 100, fill: '', stroke: 'green', strokeWidth: 3, borderOpacityWhenMoving: 0 }); // Render the Rect in canvas canvas.add(rectangle); canvas.centerObject(rectangle); </script> </body> </html> |
Output:
