AnchorPane Layout in JavaFX

The Anchor Pane enables the anchoring of child node edges at a specified offset from the anchor pane”s edges. It ensures that nodes maintain a fixed distance from the edge of layout pane. In JavaFX, an anchor pane is represented by a class named AnchorPane which is a part of javafx.scene.layout package.

Suppose, we have a node and we need to set an anchor to it from the bounds of the pane in all directions (Top, Bottom, Right and Left). To set an anchor, the AnchorPane class provides four built-in methods namely setBottomAnchor(), setTopAnchor(), setLeftAnchor() and setRightAnchor(). These methods accepts a double value representing the anchor. The following figure illustrates the same −

Note that if the anchor pane has a border and/or padding set, the offsets are calculated from the inner edge of these insets.

Cosntructors of the AnchorPane class are as follows −

• AnchorPane() − Constructs an empty AnchorPane layout.

• AnchorPane(Node childNodes) − It creates a new AnchorPane layout with the specified nodes.

Example

The following program is an example of the Anchor Pane layout. In this, we are inserting a rotating cylinder in an anchor pane. Save this code in a file with the name AnchorPaneExample.java.

import javafx.animation.RotateTransition; 
import javafx.scene.Scene;
import javafx.scene.layout.AnchorPane; 
import javafx.scene.paint.Color; 
import javafx.scene.paint.PhongMaterial; 
import javafx.scene.shape.Cylinder; 
import javafx.scene.transform.Rotate; 
import javafx.stage.Stage; 
import javafx.util.Duration;          

public class AnchorPaneExample extends Application { 
   @Override 
   public void start(Stage stage) {                     
      //Drawing a Cylinder 
      Cylinder cylinder = new Cylinder();        
      
      //Setting the properties of the Cylinder 
      cylinder.setHeight(180.0f); 
      cylinder.setRadius(100.0f);     
      
      //Preparing the phong material of type diffuse color 
      PhongMaterial material = new PhongMaterial();  
      material.setDiffuseColor(Color.BLANCHEDALMOND); 
      
      //Setting the diffuse color material to Cylinder5 
      cylinder.setMaterial(material);  
       
      //Setting rotation transition for the cylinder 
      RotateTransition rotateTransition = new RotateTransition(); 
      
      //Setting the duration for the transition 
      rotateTransition.setDuration(Duration.millis(1000)); 
      
      //Setting the node for the transition 
      rotateTransition.setNode(cylinder);       
      
      //Setting the axis of the rotation 
      rotateTransition.setAxis(Rotate.X_AXIS);  
      
      //Setting the angle of the rotation 
      rotateTransition.setByAngle(360);
      
      //Setting the cycle count for the transition 
      rotateTransition.setCycleCount(RotateTransition.INDEFINITE); 
      
      //Setting auto reverse value to false 
      rotateTransition.setAutoReverse(false); 
      
      //playing the animation 
      rotateTransition.play(); 
      
      //Creating an Anchor Pane  
      AnchorPane anchorPane = new AnchorPane();  
       
      //Setting the anchor to the cylinder      
      AnchorPane.setTopAnchor(cylinder, 50.0); 
      AnchorPane.setLeftAnchor(cylinder, 50.0); 
      AnchorPane.setRightAnchor(cylinder, 50.0); 
      AnchorPane.setBottomAnchor(cylinder, 50.0);  
      
      //Adding cylinder to the pane 
      anchorPane.getChildren().addAll(cylinder);        
         
      //Creating a scene object 
      Scene scene = new Scene(anchorPane, 400, 300);  
      
      //Setting title to the Stage 
      stage.setTitle("Anchor Pane Example"); 
         
      //Adding scene to the stage 
      stage.setScene(scene); 
          
      //Displaying the contents of the stage 
      stage.show(); 
   } 
   public static void main(String args[]){ 
      launch(args); 
   } 
}

Compile and execute the saved java file from the command prompt using the following commands.

javac --module-path %PATH_TO_FX% --add-modules javafx.controls AnchorPaneExample.java 
java --module-path %PATH_TO_FX% --add-modules javafx.controls AnchorPaneExample

Output

On executing, the above program generates a JavaFX window as shown below.