extending Group

Here is the program that creates to above picture. The program defines an Emoji class that can be used like any Shape class. You can construct several Emoji objects and put them in a scene graph.

import javafx.application.*;
import javafx.stage.*;
import javafx.scene.*;  
import javafx.scene.shape.*;
import javafx.scene.paint.*;
import javafx.scene.layout.*; 

class Emoji extends Group
{
  double width = 400.0;
  
  public Emoji( double width )
  {   
    // call the constructor of the superclass
    super();  
    
    // get the parameter
    this.width  = width;
    
    // create an emoji, based on the width parameter
    double radiusFace  = width/3.0; 
    double radiusEye   = radiusFace*0.13;
    double radiusMouth = radiusFace*0.25;
    double mouthX      = 0.0;
    double mouthY      = radiusFace*0.35;
    double eyeY        = -radiusFace*0.26;
    double leftEyeX    = -radiusFace*0.30;
    double rightEyeX   = -leftEyeX;
        
    Circle face = new Circle( radiusFace );
    face.setFill( new Color( 0.98, 0.82, 0.38, 1.0 ) );
    
    Circle mouth = new Circle( mouthX, mouthY, radiusMouth );
    mouth.setFill( new Color( 0.45, 0.35, 0.15, 1.0 ) );
    
    Circle leftEye = new Circle( leftEyeX, eyeY, radiusEye );
    leftEye.setFill( new Color( 0.45, 0.35, 0.15, 1.0 ) );
    Circle rightEye = new Circle( rightEyeX, eyeY, radiusEye );
    rightEye.setFill( new Color( 0.45, 0.35, 0.15, 1.0 ) );
    
    // add the shape objects to this Group
    super.getChildren().addAll( face, mouth, leftEye, rightEye);   
  }  
}

public class EmojiAsGroup extends Application
{
  
  public void start( Stage primaryStage )
  {
    // Create two Emoji objects
    Emoji emojiL = new Emoji( 300 );
    Emoji emojiR = new Emoji( 200 );

    // Add them to a HBox, a type of Panel
    HBox hbx = new HBox( emojiL, emojiR );    
  
    // The Panel is the root of the scene graph
    Scene scene = new Scene( hbx, Color.LIGHTCYAN );
    
    primaryStage.setTitle("Two Surprised Faces");
    primaryStage.setScene( scene );
    primaryStage.show();
  }
} 

To run this program, copy all of the above to one file EmojiAsGroup.java, compile and run it as usual:

% javac EmojiAsGroup.java
% java EmojiAsGroup

Better: make two files, one per class: Emoji.java and EmojiAsGroup.java. Declare public class Emoji in the first file. You will need to have the import statements in both files. Compile and run the files.

% javac Emoji.java EmojiAsGroup.java
% java EmojiAsGroup

HBox hbx = new HBox( emojiL, emojiR );