FabricJS – How to move a Line object to the top of the stack of drawn objects?

In this tutorial, we are going to learn about how to move a Line object to the top of the stack of drawn objects using FabricJS. A Line element is one of the basic elements provided in FabricJS. It is used for creating straight lines. Because line elements are geometrically one-dimensional and do not contain an interior, they are never filled. We can create a line object by creating an instance of fabric.Line, specifying the x and y coordinates of the line and adding it to the canvas. In order to move a Line object to the top of the stack of drawn objects, we use the bringToFront method.

Syntax

bringToFront(): fabric.Object

Using bringToFront method

Example

Let’s see a code example to see the output when the bringToFront method is used. The bringToFront method moves an object to the top of the stack of drawn objects. In this case, line1 is moved on top of line2, on using the bringToFront method.


<!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 bringToFront method</h2>
   <p>You can see that line1 (blue) lies above line2 (red)</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 Line object
      var line1 = new fabric.Line([200, 100, 100, 40], {
         stroke: "blue",
         strokeWidth: 20,
      });

      // Initiate another Line object
      var line2 = new fabric.Line([200, 70, 70, 40], {
         stroke: "red",
         strokeWidth: 20,
      });

      // Add both to the canvas
      canvas.add(line1);
      canvas.add(line2);

      // Using bringToFront method
      line1.bringToFront();
   </script>
</body>
</html>

Using bringToFront method with three objects

Example

In this example, we have used three line objects namely line1, line2 and line3. Although they have been added to the canvas according to their numerical order, line1 clearly lies at the very top. This is because we have used the bringToFront method, which sends line1 at the top of the stack of drawn objects.


<!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 bringToFront method with three objects</h2>
   <p>
      You can see that line1 (blue) lies at the top of the stack of drawn objects
   </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 Line object
      var line1 = new fabric.Line([200, 100, 100, 40], {
         stroke: "blue",
         strokeWidth: 20,
      });

      // Initiate another Line object
      var line2 = new fabric.Line([200, 70, 70, 40], {
         stroke: "red",
         strokeWidth: 20,
      });

      // Initiate another Line object
      var line3 = new fabric.Line([200, 30, 30, 90], {
         stroke: "green",
         strokeWidth: 20,
      });

      // Add them all to the canvas
      canvas.add(line1);
      canvas.add(line2);
      canvas.add(line3);

      // Using bringToFront method
      line1.bringToFront();
   </script>
</body>
</html>