Question 2

In the PushCounter program, why was the count primitive variable and the Text object declared at the class level? Why wasn’t anything else, such as the Button?

PushCounter.java

public class PushCounter extends Application {
    private int count;
    private Text countText;

    @Override
    public void start(Stage primaryStage) {
        count = 0; // start the counter at 0
        countText = new Text("Pushes: 0"); // display starting text

        // Create a button
        Button push = new Button("Push Me!");

        // Set the action that happens when the button is pressed
        push.setOnAction(this::processButtonPress);

        // Layout the components using a FlowPane
        FlowPane pane = new FlowPane(push, countText);
        pane.setAlignment(Pos.CENTER);
        pane.setHgap(20); // horizontal spacing between button and text
        pane.setStyle("-fx-background-color: cyan");

        // Set up the scene and stage
        Scene scene = new Scene(pane, 300, 100);
        primaryStage.setTitle("Push Counter");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    // This method runs when the button is pressed
    public void processButtonPress(ActionEvent event) {
        count++; // increment the counter
        countText.setText("Pushes: " + count); // update the text
    }

    public static void main(String[] args) {
        launch(args);
    }
}