JavaFX Buttons

 

Button Control

 

§  Nearly all JavaFX controls generate events.

§  most commonly used control is the button,

§  button events are some of the most frequently handled in a JavaFX program.

 

§  In JavaFX, the push button control is provided by the Button class, which is in javafx.scene.control.

 

§  Button inherits a long list of base classes that includes ButtonBase, Labeled, Region, Control, Parent, and Node.

§  Most of its functionality comes from its base classes.

§  Buttons can contain text, graphics, or both.

§  Button supports a wide array of options, but we will use the default form.

 

 

Button has three constructors.

 

1.    Button(): creates a button with an empty string for its label.

2.    Button(String t): creates a button with the specified text as its label.

3.    Button(String t, Node g): creates a button with the specified text and icon for its label.

 

// JavaFX controls

// Buttons

 

import java.io.*;

import java.net.*;

import javafx.application.*;

import javafx.scene.*;

import javafx.stage.*;

import javafx.scene.layout.*;

import javafx.scene.control.*;

import javafx.event.*;

import javafx.geometry.*;

import javafx.scene.image.*;

import javafx.event.ActionEvent;

import javafx.event.EventHandler;

import javafx.scene.control.Label;

import javafx.stage.Stage;

 

public class JfxBtn extends Application

{  

    public static void main(String[] args)

    {

         // Start the JavaFX application by calling launch().

         launch(args);

    }

 

    // Override the start() method.

    public void start(Stage myStage)

    {

         try

         {

         // Give the stage a title.

         myStage.setTitle("JavaFx controls - Buttons");

 

         // Use a FlowPane for the root node.

         FlowPane fp = new FlowPane(25,10);

 

         // Center the controls in the scene.

         fp.setAlignment(Pos.CENTER);

 

         // Create a scene.

         Scene myScene = new Scene(fp, 500, 100);

 

         // Set the scene on the stage.

         myStage.setScene(myScene);

 

         // Create Three push buttons.

         Button Btn1, Btn2, Btn3;

        

         Btn1 = new Button();

         Btn1.setMinWidth(100);

         Btn2 = new Button("Named button");

         Btn2.setMinWidth(100);

 

         // Use input stream to get image

        FileInputStream input = new FileInputStream("d:\\Subjects\\OOP R2021\\Jpgms\\JavaFX\\home.png");

        

         // create a image

        Image i = new Image(input);

 

        // create a image View and resize icon

        ImageView iv = new ImageView(i);

         iv.setFitHeight(25);

         iv.setFitWidth(25);

   

        // create a button

        Btn3 = new Button("  Home", iv);

         Btn3.setMinWidth(100);

   

         // Add the buttons to the scene graph.

         fp.getChildren().addAll(Btn1, Btn2, Btn3);

         }

         catch(Exception ex)

         {}

 

         // Show the stage and its scene.

         myStage.show();

    }

}

Demonstrating Event Handling and the Button

// Event Handling

// Buttons and labels

 

import javafx.application.*;

import javafx.scene.*;

import javafx.stage.*;

import javafx.scene.layout.*;

import javafx.scene.control.*;

import javafx.event.*;

import javafx.geometry.*;

 

public class JfxEH extends Application

{

     Label respLbl;

    

     public static void main(String[] args)

     {

          // Start the JavaFX application by calling launch().

          launch(args);

     }

 

     // Override the start() method.

     public void start(Stage myStage)

     {

          // Give the stage a title.

          myStage.setTitle("Event handling - Buttons and labels");

 

          // Use a FlowPane for the root node.

          FlowPane fp = new FlowPane(25,10);

 

          // Center the controls in the scene.

          fp.setAlignment(Pos.CENTER);

 

          // Create a scene.

          Scene myScene = new Scene(fp, 300, 100);

 

          // Set the scene on the stage.

          myStage.setScene(myScene);

 

          // Create a label.

          respLbl = new Label("Select a Button");

 

          // Create two push buttons.

          Button Btn1 = new Button("IT");

          Btn1.setMinWidth(50);

          Button Btn2 = new Button("CSE");

          Btn2.setMinWidth(50);

         

          // Handle the action events for the First button.

          Btn1.setOnAction(new EventHandler<ActionEvent>(){

              public void handle(ActionEvent ae)

              {

                   respLbl.setText("IT  was selected.");

              }

          } ) ;

 

          // Handle the action events for the Second button.

          Btn2.setOnAction(new EventHandler<ActionEvent>(){

              public void handle(ActionEvent ae)

              {  

                   respLbl.setText("CSE was selected.");

              }

          } ) ;

 

          // Add the label and buttons to the scene graph.

          fp.getChildren().addAll(Btn1, Btn2, respLbl);

 

          // Show the stage and its scene.

          myStage.show();

     }

}