Chapter 16 Exercise 19, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

16.19 (Control a group of fans)
Write a program that displays three fans in a group, with
control buttons to start and stop all of them, as shown
in Figure 16.44.

import javafx.animation.Animation;
import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Slider;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Arc;
import javafx.scene.shape.ArcType;
import javafx.scene.shape.Circle;
import javafx.stage.Stage;
import javafx.util.Duration;

public class Exercise_19 extends Application {

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

        BorderPane[] borderPanes = new BorderPane[3];
        FanPane[] fanPanes = new FanPane[3];

        for (int i = 0; i < borderPanes.length; i++) {
            fanPanes[i] = new FanPane(100);
            borderPanes[i] = new BorderPane(fanPanes[i]);
            borderPanes[i].setTop(fanPanes[i].hButtons);
            borderPanes[i].setBottom(fanPanes[i].scrollPane);
            borderPanes[i].setStyle("-fx-border-color: black;");
        }

        // center pane
        HBox hFans = new HBox(borderPanes);

        // bottom pane
        Button btStartAll = new Button("Start All");
        btStartAll.setOnAction(e-> {
            for (FanPane fan : fanPanes) {
                if (fan.fanTimeline.getStatus() != Animation.Status.RUNNING) {
                    fan.playPause.fire();
                }
            }
        });
        Button btStopAll = new Button("Stop All");
        btStopAll.setOnAction(e -> {
            for (FanPane fan : fanPanes) {
                if (fan.fanTimeline.getStatus() == Animation.Status.RUNNING) {
                    fan.stop();
                }
            }
        });
        HBox bottomPane = new HBox(btStartAll, btStopAll);
        bottomPane.setSpacing(10);
        bottomPane.setPadding(new Insets(5));

        bottomPane.setAlignment(Pos.CENTER);

        primaryStage.setScene(new Scene(new BorderPane(hFans, null, null, bottomPane, null)));
        primaryStage.setTitle("Fan");
        primaryStage.show();

    }

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

    private class FanPane extends Pane {

        private Circle c;
        private Arc[] blades = new Arc[4];
        private double increment = 1;

        // Buttons
        Button playPause = new Button("Play/Pause");
        Button increase = new Button("Increase");
        Button decrease = new Button("Decrease");
        Button reverse = new Button("Reverse");

        HBox hButtons = new HBox(playPause,increase,decrease, reverse);
        Timeline fanTimeline;

        Slider mSlider = new Slider();
        HBox scrollPane = new HBox(mSlider);


        FanPane(double radius) {
            double w = radius * 4;
            double h = radius * 2;

            setMinWidth(w);
            setMinHeight(h + radius);
            c = new Circle(w/2  , h / 2 + (radius /2), radius, Color.TRANSPARENT);
            c.setStroke(Color.BLACK);

            double bladeRadius = radius * 0.9;
            for (int i = 0; i < blades.length; i++) {
                blades[i] = new Arc(
                        c.getCenterX(), c.getCenterY(), // center point
                        bladeRadius, bladeRadius, // X and Y radius
                        (i * 90) + 30, 35); // start angle and length
                blades[i].setFill(Color.RED);
                blades[i].setType(ArcType.ROUND);
            }

            getChildren().addAll(c);
            getChildren().addAll(blades);


            KeyFrame keyFrame = new KeyFrame(Duration.millis(10), e -> spin());

            fanTimeline = new Timeline(keyFrame);
            fanTimeline.setCycleCount(Timeline.INDEFINITE);

            // Buttons Play/pause, increase, decrease, reverse
            playPause.setOnAction(e -> {
                if (fanTimeline.getStatus() == Animation.Status.RUNNING) {
                    fanTimeline.pause();
                } else {
                    fanTimeline.play();
                }
            });

            increase.setOnAction(e -> {
                fanTimeline.setRate(fanTimeline.getCurrentRate() + 1);
                mSlider.setValue(fanTimeline.getCurrentRate());
            });

            decrease.setOnAction(e -> {
                fanTimeline.setRate(
                        (fanTimeline.getCurrentRate() - 1 < 0) ? 0 : fanTimeline.getCurrentRate() - 1);
                mSlider.setValue(fanTimeline.getCurrentRate());

            });
            mSlider.setMin(0);
            mSlider.setMax(35);
            mSlider.valueProperty().addListener(e -> {
                final double direction = (fanTimeline.getCurrentRate() >= 0) ? 1 : -1;
                fanTimeline.setRate(mSlider.getValue() * direction);
            });
            mSlider.setMinWidth(200);
            scrollPane.setAlignment(Pos.CENTER);
            scrollPane.setPadding(new Insets(5));

            reverse.setOnAction(e -> increment *= -1);
            hButtons.setSpacing(5);
            hButtons.setAlignment(Pos.CENTER);
            hButtons.setPadding(new Insets(2, 2, 2, 2));

        }


        private void spin() {
            for (Arc blade : blades) {
                double prevStartAngle = blade.getStartAngle();
                blade.setStartAngle(prevStartAngle - increment);
            }
        }

        private void stop(){
            fanTimeline.stop();
        }

    }
}