Object Deletion in Fabric.js 5: Effortlessly Remove Selected Elements Programmatically

Fabric.js 5 is an exceptional JavaScript library that empowers developers to effortlessly within the HTML5 canvas. Among the various canvas functionalities, the ability to delete selected objects is frequently sought after. create stunning graphical objects and manipulate them In this comprehensive blog post, we will delve into the implementation of programmatically deleting selected objects in Fabric.js 5. By following this tutorial, you will gain a profound understanding of leveraging the remove method to selectively remove polygons and circles from your canvas. 1: Understanding the Fabric.js 5 Polygon Object and Delete Operation 1.1: The fabric.Polygon Object in Fabric.js 5 The object in Fabric.js 5 is a crucial element for constructing closed shapes made up of connected straight-line segments. fabric.Polygon Now, let's delve into an example that illustrates the creation of a object: fabric.Polygon // Initialize a canvas instance var canvas = new fabric.Canvas("canvas"); canvas.setWidth(document.body.scrollWidth); canvas.setHeight(250); // Define the coordinates for the first polygon var points1 = [ { x: 30, y: 50 }, { x: 70, y: 50 }, { x: 0, y: 0 }, { x: 70, y: 0 } ]; // Create the first fabric.Polygon object var polygon1 = new fabric.Polygon(points1, { left: 100, top: 40, fill: "#1e90ff", strokeWidth: 4, stroke: "black", scaleX: 1.2, scaleY: 1.2 }); // Define the coordinates for the second polygon var points2 = [ { x: 60, y: 90 }, { x: 45, y: 30 }, { x: 20, y: 48 } ]; // Create the second fabric.Polygon object var polygon2 = new fabric.Polygon(points2, { left: 30, top: 30, fill: "#080808", strokeWidth: 4, stroke: "red", scaleX: 2, scaleY: 2 }); // Add both polygon objects to the canvas canvas .add(polygon1, polygon2); We define the coordinates for the two polygons by utilizing the variables and . These variables represent the vertices of the polygons, outlining their shape and structure. These polygons are then created using the constructor. Each polygon is uniquely customized with specific properties, including its position, fill color, stroke width, stroke color, and scaling. These properties are assigned individually to each polygon, allowing for distinct visual characteristics and appearance. points1 points2 fabric.Polygon Finally, we add both the polygon objects, to the canvas using the method. This action ensures that the polygons are displayed and become visible on the canvas. canvas.add() This code sets up a canvas with two polygons rendered on it, ready for further manipulation or interaction. 1.2: Introducing the Remove Method for Deleting Objects The remove method in Fabric.js 5 is a pivotal feature that allows the deletion of objects from the canvas. Let's examine its usage through a concise example: // Removing an object from the canvas using the remove canvas method canvas.remove(polygon); By comprehending the object and the remove method, you will possess the essential knowledge to implement the delete operation selectively for objects in your Fabric.js 5 applications. fabric.Polygon 2: Implementing Delete Operation for Selected Polygon Objects Programmatically 2.1: Creating the deletePolygonHandler Function for Removing Selected Polygons To enable the delete operation for selected polygon objects in Fabric.js 5, we can implement a handy function called . This function will be triggered when a event occurs, allowing identification and removal of the selected object from the canvas. deletePolygonHandler mouse:down Example code: // Function to handle deletion of polygons var deletePolygonHandler = function(obj) { var selectedObject = obj.target; canvas.remove(selectedObject); // Remove the selected polygon from the canvas canvas.renderAll(); // Render the updated canvas }; // Binding the deletePolygonHandler function to the mouse:down event canvas.on("mouse:down", deletePolygonHandler); By binding the deletePolygonHandler function to the mouse:down event, you can effortlessly delete selected polygons within your Fabric.js 5 application. In the subsequent sections, we will further enhance this functionality and explore additional examples. 2.2: Enabling Selective Deletion of Circle Objects Programmatically In this section, we will demonstrate how to enable the selective deletion of circle objects in Fabric.js 5. By following a similar approach to the one used for polygons, we will introduce the deleteCircleHandler function. This function will be responsible for removing the selected circle object from the canvas upon a mouse:down event. Let's examine the updated code snippet: // Initialize a canvas instance var canvas = new fabric.Canvas("canvas"); canvas.setWidth(document.body.scrollWidth); canvas.setHeight(250); // Define the properties for the first circle var circle1 = new fabric.Circle({ radius: 30, left: 100, top: 80, fill: "#1e90ff", strokeWidth: 4, stroke: "black", scaleX: 1.2, scaleY: 1.2 }); // Define the properties for the second circle var circle2 = new fabric.Circle({ radius: 15, left: 30, top: 30, fill: "#080808", strokeWidth: 4, stroke: "red", scaleX: 2, scaleY: 2 }); // Add both circle objects to the canvas canvas.add(circle1, circle2); // Function to handle deletion of circles var deleteCircleHandler = function(obj) { var selectedObject = obj.target; canvas.remove(selectedObject); // Remove the selected circle from the canvas canvas.renderAll(); // Render the updated canvas }; // Bind the deleteCircleHandler function to the mouse:down event canvas.on("mouse:down", deleteCircleHandler); With the addition of the function, you can now effortlessly delete selected circle objects within your Fabric.js 5 application. deleteCircleHandler Conclusion In this in-depth blog post, we have explored the process of programmatically deleting selected objects in Fabric.js 5. By mastering the remove method and implementing delete handlers for both polygons and circles, you can empower your canvas-based applications with efficient and intuitive delete functionality. Armed with the knowledge gained from this tutorial, you are now equipped to elevate your skills and confidently implement powerful object deletion capabilities in your own projects. Fabric.js 5