Chapter 16 Exercise 7, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

16.7  (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.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.collections.ObservableList;
import javafx.geometry.Point2D;
import javafx.scene.Node;
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;
import javafx.util.Duration;

import java.util.Calendar;
import java.util.Collections;
import java.util.GregorianCalendar;

public class ClockPane extends Pane {

    private int hour;
    private int minute;
    private int second;
    private boolean hourHandVisible = true;
    private boolean minuteHandVisible = true;
    private boolean secondHandVisible = true;
    private Timeline timeline;

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

    /** Construct a default clock with the current time*/
    public ClockPane() {
        setPrefHeight(h);
        setPrefWidth(w);
        timeline = new Timeline(new KeyFrame(Duration.seconds(1), e -> update()));
        timeline.setCycleCount(Timeline.INDEFINITE);
        setCurrentTime();
    }

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

    public ClockPane(int hour, int minute, int second, double width, double height) {
        this(hour, minute, second);
        this.w = width;
        this.h = height;
        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 height */
    public void setH(double h) {
        this.h = h;
        paintClock();
    }

    public boolean isHourHandVisible() {
        return hourHandVisible;
    }

    public void setHourHandVisible(boolean hourHandVisible) {
        this.hourHandVisible = hourHandVisible;
        paintClock();
    }

    public boolean isMinuteHandVisible() {
        return minuteHandVisible;
    }

    public void setMinuteHandVisible(boolean minuteHandVisible) {
        this.minuteHandVisible = minuteHandVisible;
        paintClock();
    }

    public boolean isSecondHandVisible() {
        return secondHandVisible;
    }

    public void setSecondHandVisible(boolean secondHandVisible) {
        this.secondHandVisible = secondHandVisible;
        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 */
    private void paintClock() {
        // Initialize clock parameters
        double clockRadius = Math.min(w, h) * 0.8 * 0.5;
        double centerX = w / 2;
        double centerY = h / 2;
        Point2D center = new Point2D(centerX, centerY);
        // Draw circle
        Circle circle = new Circle(centerX, centerY, clockRadius);
        circle.setFill(Color.WHITE);
        circle.setStroke(Color.BLACK);

        // Draw time numbers
        Text[] texts = new Text[12];
        for (int i = 0; i < 12; i++) {
            int time = (i + 3 > 12) ? i + 3 - 12 : i + 3;
            Point2D b = new Point2D(
                    centerX + clockRadius * Math.cos(i * 2 * Math.PI / 12),
                    centerY + clockRadius * Math.sin(i * 2 * Math.PI / 12));
            b = getPointBCloserToA(center, b, 0.82);
            texts[i] = new Text(b.getX() - (clockRadius * 0.03125), b.getY() + (clockRadius * 0.025), "" + time);
        }

        // Draw dashes
        Line[] dashes = new Line[60];
        for (int i = 0; i < dashes.length; i++) {
            Point2D start = new Point2D(
                    centerX + clockRadius * Math.cos(i * 2 * Math.PI / 60),
                    centerY + clockRadius * Math.sin(i * 2 * Math.PI / 60));
            double coefficient = (i % 5 == 0) ? 0.91 : 0.955;
            Point2D end = getPointBCloserToA(center,start, coefficient);
            dashes[i] = new Line(start.getX(), start.getY(), end.getX(), end.getY());
        }

        // 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);
        sLine.setVisible(isSecondHandVisible());

        // 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);
        mLine.setVisible(isMinuteHandVisible());

        // 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);
        hLine.setVisible(isHourHandVisible());
        // Draw time HH:MM:SS
        String s = "" + getHour() + ":" + getMinute() + ":" + getSecond();
        Text timeText = new Text(getW() * 0.4, getH() - 10, s);

        // Adding nodes to pane
        getChildren().clear();
        ObservableList<Node> list = getChildren();
        list.add(circle);
        Collections.addAll(list, dashes);
        Collections.addAll(list, texts);
        list.addAll(sLine, mLine, hLine, timeText);
    }

    public void start(){
        timeline.play();
    }

    public void stop(){
        timeline.pause();
    }

    private void update(){
        setCurrentTime();
        paintClock();
    }

    private Point2D getPointBCloserToA(Point2D a, Point2D b, double coefficient) {

        double deltaX = b.getX() - a.getX();
        double deltaY = b.getY() - a.getY();

        return new Point2D(
                a.getX() + coefficient * deltaX,
                a.getY() + coefficient * deltaY);
    }
}

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.ContentDisplay;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;

public class Exercise_07 extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception {

        ClockPane clockPane = new ClockPane();

        // Hour
        TextField tfHour = new TextField(clockPane.getHour() + "");
        tfHour.setPrefColumnCount(2);
        Label lblHour = new Label("Hour:", tfHour);
        lblHour.setContentDisplay(ContentDisplay.RIGHT);
        tfHour.setOnAction(e-> clockPane.setHour(Integer.parseInt(tfHour.getText())));

        // Minutes
        TextField tfMinutes = new TextField(clockPane.getMinute() + "");
        tfMinutes.setPrefColumnCount(2);
        Label lblMinutes = new Label("Minute:", tfMinutes);
        lblMinutes.setContentDisplay(ContentDisplay.RIGHT);
        tfMinutes.setOnAction(e-> clockPane.setMinute(Integer.parseInt(tfMinutes.getText())));

        // Seconds
        TextField tfSeconds = new TextField(clockPane.getSecond() + "");
        tfSeconds.setPrefColumnCount(2);
        Label lblSeconds = new Label("Second:", tfSeconds);
        lblSeconds.setContentDisplay(ContentDisplay.RIGHT);
        tfSeconds.setOnAction(e-> clockPane.setSecond(Integer.parseInt(tfSeconds.getText())));


        BorderPane pane = new BorderPane(clockPane);
        BorderPane.setAlignment(clockPane, Pos.CENTER);

        HBox textFieldPane = new HBox(5);
        textFieldPane.setAlignment(Pos.CENTER);
        textFieldPane.getChildren().addAll(lblHour, lblMinutes, lblSeconds);
        textFieldPane.setPadding(new Insets(5));

        pane.setBottom(textFieldPane);
        primaryStage.setScene(new Scene(pane));
        primaryStage.setTitle("Clock");
        primaryStage.show();
        clockPane.setFocusTraversable(true);
    }

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