JavaFX Introduction

15 March 2015

JavaFX is a software platform for creating Rich Internet Applications that can run across variety of platforms[1].It has a collection of Java Packages with ability to add fancy GUI to your Java application. JavaFX is official standard part of Java platform. JavaFX is considered as a successor of Swing and can be easily understood by a Swing developer. You can get the latest in JavaFX in early access preview of JavaFX in Java 8 EA 40

History: Formerly it was called in F3(Form Follows function) and developed by Oliver Smith at Sun Microsystems. JavaFX was initially developed as a scripting language however it was later discontinued by Oracle and declared dead in Java One 2010. Now JavaFX has a clean Java API.

JavaFX Lingo In order to understand JavaFX well one needs to familiarize with the Jargon used

Stage - Top level container for all Java Objects
Scene - A scene is a hierarchical node structure that contains all scenes components
Group - Group is a general purpose container node

Stage: Stage is implicitly created by JavaFX. JavaFX makes you think like a designer and stage is where you will host your scene

Scene:A scene is a hierarchical node structures that contains all scene’s components

Group:Group is general purpose container node. This is analogous to a layout creates

Various possibilities with JavaFX

CSS Support
Visual Effects: Shadow,reflect,blur perspective
Animation- rotate,scale,translate etc
Chars
3D Object - cubes,cylinder,spheres etc
Touch Interface
Property bindings

JavaFX Application Life Cycle

init (): Default implementation of init does nothing. One can override to perform any processing before application UI is displayed
start (): No default implementation and is declared abstract. Your app must override this. Build and display the UI
Wait for application to End. Typically happens when user signals end of program
stop(): Default implementation does not do anything One can override to to perform any necessary processing as program terminates



package sampleapplication;

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

/**
 *
 * @author rvvaidya
 */
public class SampleApplication extends Application {
    
    @Override
    public void start(Stage primaryStage) {
        Button btn = new Button();
        btn.setText("Say 'Hello World'");
        btn.setOnAction(new EventHandler() {
            
            @Override
            public void handle(ActionEvent event) {
                System.out.println("Hello World!");
            }
        });
        
        StackPane root = new StackPane();
        root.getChildren().add(btn);
        
        Scene scene = new Scene(root, 300, 250);
        
        primaryStage.setTitle("Hello World!");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        launch(args);
    }
    
}

Code Walk through

Any JavaFX application must extend javafx.application.Application
The start method is overriden. The override also passes the Stage object
Button object is instantiated and event handler is associated
A stack pane is created. This is a layout and corresponds to the group
Create the Scene object and pass the group reference
The scene is hosted on the stage
In main (the main entry point for java application) launch is called. This launches the JavaFX application.