(Set clock time) Write a program that displays a clock and sets the time with the input from three text fields, as shown in Figure 16.38b. Use the ClockPane in Listing 14.21. Resize the clock to the center of the pane

import java.util.Calendar;
import java.util.GregorianCalendar;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.scene.shape.Line;
import javafx.scene.text.Text;

public class ClockPane extends Pane {
	private int hour;
	private int minute;
	private int second;

	// Clock pane's width and height
	private double w = 250, h = 250;

	/** Construct a default clock with the current time */
	public ClockPane() {
		setCurrentTime();
	}

	/** Construct a click with specified hour, minute, and second */
	public ClockPane(int hour, int minute, int second) {
		this.hour = hour;
		this.minute = minute;
		this.second = second;
		paintClock();
	}

	/** Return hour */
	public int getHour() {
		return hour;
	}

	/** Set a new hour */
	public void setHour(int hour) {
		this.hour = hour;
		paintClock();
	}

	/** Return minute */
	public int getMinute() {
		return minute;
	}

	/** Set a new minute */
	public void setMinute(int minute) {
		this.minute = minute;
		paintClock();
	}

	/** Return second */
	public int getSecond() {
		return second;
	}

	/** Set a new second */
	public void setSecond(int second) {
		this.second = second;
		paintClock();
	}

	/** Return clock pane's width */
	public double getW() {
		return w;
	}

	/** Set clock pane's width */
	public void setW(double w) {
		this.w = w;
		paintClock();
	}

	/** Return clock pane's height */
	public double getH() {
		return h;
	}

	/** Set clock pane's heigt */
	public void setH(double h) {
		this.h = h;
		paintClock();
	}

	/* Set the current time for the clock */
	public void setCurrentTime() {
		// Construct a Calendar for the current date and time
		Calendar calendar = new GregorianCalendar();

		// Set current hour, minute and second
		this.hour = calendar.get(Calendar.HOUR_OF_DAY);
		this.minute = calendar.get(Calendar.MINUTE);
		this.second = calendar.get(Calendar.SECOND);

		paintClock(); // Repaint the clock
	}
	
	/** Paint the clock */
	protected void paintClock() {
		// Initialize clock parameters
		double clockRadius = Math.min(w, h) * 0.8 * 0.5;
		double centerX = w / 2;
		double centerY = h / 2;

		// Draw circle
		Circle circle = new Circle(centerX, centerY, clockRadius);
		circle.setFill(Color.WHITE);
		circle.setStroke(Color.BLACK);
		Text t1 = new Text(centerX - 5, centerY - clockRadius + 12, "12");
		Text t2 = new Text(centerX - clockRadius + 3, centerY + 5, "9");
		Text t3 = new Text(centerX + clockRadius - 10, centerY + 3, "3");
		Text t4 = new Text(centerX - 3, centerY + clockRadius - 3, "6");

		// Draw second hand
		double sLength = clockRadius * 0.8;
		double secondX = centerX + sLength *
			Math.sin(second * (2 * Math.PI / 60));
		double secondY = centerY - sLength *
			Math.cos(second * (2 * Math.PI / 60));
		Line sLine = new Line(centerX, centerY, secondX, secondY);
		sLine.setStroke(Color.RED);

		// Draw minute hand
		double mLength = clockRadius * 0.65;
		double xMinute = centerX + mLength *
			Math.sin(minute * (2 * Math.PI / 60));
		double minuteY = centerY - mLength *
			Math.cos(minute * (2 * Math.PI / 60));
		Line mLine = new Line(centerX, centerY, xMinute, minuteY);
		mLine.setStroke(Color.BLUE);

		// Draw hour hand 
		double hLength = clockRadius * 0.5;
		double hourX = centerX + hLength *
			Math.sin((hour % 12 + minute / 60.0) * (2 * Math.PI / 12));
		double hourY = centerY - hLength * 
			Math.cos((hour % 12 + minute / 60.0) * (2 * Math.PI / 12));
		Line hLine = new Line(centerX, centerY, hourX, hourY);
		hLine.setStroke(Color.GREEN);

		getChildren().clear();
		getChildren().addAll(circle, t1, t2, t3, t4, sLine, mLine, hLine);
	}
}

Exercise_16_07.java

/*********************************************************************************
* (Set clock time) Write a program that displays a clock and sets the time with  *
* the input from three text fields, as shown in Figure 16.38b. Use the ClockPane *
* in Listing 14.21. Resize the clock to the center of the pane.                  *
*********************************************************************************/
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.stage.Stage;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Pane;
import javafx.scene.layout.VBox;
import javafx.geometry.Pos;
import javafx.geometry.Insets;
import javafx.scene.input.KeyCode;

public class Exercise_16_07 extends Application {
	protected TextField tfHour = new TextField();
	protected TextField tfMinute = new TextField();
	protected TextField tfSecond = new TextField();
	protected ClockPane clock = new ClockPane();

	@Override // Override the start method in the Application class
	public void start(Stage primaryStage) {
		// Set text field properties
		tfHour.setPrefColumnCount(3);
		tfMinute.setPrefColumnCount(3);
		tfSecond.setPrefColumnCount(3);
		tfHour.setAlignment(Pos.CENTER_RIGHT);
		tfMinute.setAlignment(Pos.CENTER_RIGHT);
		tfSecond.setAlignment(Pos.CENTER_RIGHT);
		tfHour.setText(String.valueOf(clock.getHour()));
		tfMinute.setText(String.valueOf(clock.getMinute()));
		tfSecond.setText(String.valueOf(clock.getSecond()));

		// Create a hbox
		HBox paneForTimeFields = new HBox(5);
		paneForTimeFields.setAlignment(Pos.CENTER);
		paneForTimeFields.getChildren().addAll(new Label("Hour"), tfHour, 
			new Label("Minute"), tfMinute, new Label("Second"), tfSecond);

		// Create a vbox
		VBox pane = new VBox(20);
		pane.setPadding(new Insets(5, 5, 5, 5));
		pane.setAlignment(Pos.CENTER);
		pane.getChildren().addAll(clock, paneForTimeFields);

		// Create and register the handler
		tfHour.setOnKeyPressed(e -> {
			if (e.getCode() == KeyCode.ENTER) {
				setClock();
			}
		});

		tfMinute.setOnKeyPressed(e -> {
			if (e.getCode() == KeyCode.ENTER) {
				setClock();
			}
		});

		tfSecond.setOnKeyPressed(e -> {
			if (e.getCode() == KeyCode.ENTER) {
				setClock();
			}
		});

		// Create a scene and place it in the stage
		Scene scene = new Scene(pane);
		primaryStage.setTitle("Exercise_16_07"); // Set the stage title
		primaryStage.setScene(scene); // Place the scene in the stage
		primaryStage.show(); // Display the stage

		// Center clock
		clock.setW(pane.getWidth());
		clock.setH(pane.getHeight() - 30);

		// Create a listener to set a new width for clock 
		pane.widthProperty().addListener(ov ->
			clock.setW(pane.getWidth())
		);

		// Create a listener to set a new height for clock 
		pane.heightProperty().addListener(ov ->
			clock.setH(pane.getHeight() - 30)
		);
	}

	// Set the clock to specified time
	private void setClock() {
		clock.setHour(Integer.parseInt(tfHour.getText()));
		clock.setMinute(Integer.parseInt(tfMinute.getText())); 
		clock.setSecond(Integer.parseInt(tfSecond.getText()));
	}
}