JavaFX学习之样例8

  该代码实现一个简单的时钟

 

package clock;

import java.util.Calendar;

import javafx.animation.Animation;
import javafx.animation.Interpolator;
import javafx.animation.KeyFrame;
import javafx.animation.KeyValue;
import javafx.animation.Timeline;
import javafx.beans.property.DoubleProperty;
import javafx.scene.Group;
import javafx.scene.control.Label;
import javafx.scene.shape.Circle;
import javafx.scene.shape.Line;
import javafx.scene.transform.Rotate;
import javafx.util.Duration;

/**
 * Displays an animated AnalogueClock face.
 * Time is the system time for the local timezone.
 * see: analogue-clock.css for css formatting rules for the clock.
 */
public class AnalogueClock extends Group {
  final int HOUR_HAND_LENGTH   = 50;
  final int MINUTE_HAND_LENGTH = 75;
  final int SECOND_HAND_LENGTH = 88;
  final int SECOND_HAND_OFFSET = 15;

  AnalogueClock(String brandName, double clockRadius) {
    setId("analogueClock");

    getStylesheets().add(
      ResourceResolver.getResourceFor(
        getClass(),
        "analogue-clock.css"
      )
    );

    // construct the analogueClock pieces.
    final Circle face       = createClockFace(clockRadius);  //钟表面
    final Label  brand      = createBrand(face, brandName);  //钟表名
    final Line   hourHand   = createHand(                    //钟时指针
      "hourHand",
      clockRadius,
      0,
      percentOf(HOUR_HAND_LENGTH, clockRadius)
    );
    final Line   minuteHand = createHand(                    //钟分指针
      "minuteHand",
      clockRadius,
      0,
      percentOf(MINUTE_HAND_LENGTH, clockRadius)
    );
    final Line   secondHand = createHand(                    //钟秒指针
      "secondHand",
      clockRadius,
      percentOf(SECOND_HAND_OFFSET, clockRadius),
      percentOf(SECOND_HAND_LENGTH, clockRadius)
    );

    // animate the hands with the time.
    bindClockHandsToTime(hourHand, minuteHand, secondHand);

    getChildren().addAll(
      face,
      brand,
      createTicks(clockRadius),
      createSpindle(clockRadius),
      hourHand,
      minuteHand,
      secondHand
    );
  }

  //创建12条时间线
  /** @return radial ticks around the clock center to mark time. */
  private Group createTicks(double clockRadius) {
    final double TICK_START_OFFSET = percentOf(83, clockRadius);
    final double TICK_END_OFFSET   = percentOf(93, clockRadius);

    final Group  ticks = new Group();
    for (int i = 0; i < 12; i++) {
      Line tick = new Line(0, -TICK_START_OFFSET, 0, -TICK_END_OFFSET);
      tick.getStyleClass().add("tick");
      tick.setLayoutX(clockRadius);
      tick.setLayoutY(clockRadius);
      tick.getTransforms().add(new Rotate(i * (360 / 12)));
      ticks.getChildren().add(tick);
    }
    return ticks;
  }

  //创建中心点
  /** @return a rendered spindle around which the clockwork rotates */
  private Circle createSpindle(double clockRadius) {
    final Circle spindle = new Circle(clockRadius,  clockRadius, 5);
    spindle.setId("spindle");
    return spindle;
  }

  //创建圆
  private Circle createClockFace(double clockRadius) {
    final Circle face = new Circle(clockRadius, clockRadius, clockRadius);
    face.setId("face");
    return face;
  }

   //创建时，分，秒钟指针 
  private Line createHand(String handId, double clockRadius, double handOffsetLength, double handLength) {
    final Line secondHand = new Line(0, handOffsetLength, 0, -handLength);
    secondHand.setLayoutX(clockRadius);
    secondHand.setLayoutY(clockRadius);
    secondHand.setId(handId);
    return secondHand;
  }

  //创建名字
  private Label createBrand(Circle face, String brandName) {
    final Label brand = new Label(brandName);
    brand.setId("brand");
    brand.layoutXProperty().bind(face.centerXProperty().subtract(brand.widthProperty().divide(2)));
    brand.layoutYProperty().bind(face.centerYProperty().add(face.radiusProperty().divide(2)));
    return brand;
  }

  //绑定时间
  private void bindClockHandsToTime(final Line hourHand, final Line minuteHand, final Line secondHand) {
    // determine initial rotation for the clock hands.
    Calendar time = Calendar.getInstance();
    final double initialHourhandDegrees   = calculateHourHandDegrees(time);
    final double initialMinuteHandDegrees = calculateMinuteHandDegrees(time);
    final double initialSecondHandDegrees = calculateSecondHandDegrees(time);

    // animate the clock movements using timelines.
    createRotationTimeline(              // the hour hand rotates twice a day.
        createRotate(hourHand, initialHourhandDegrees).angleProperty(),  //创建一个Rotate，并获取角度属性
        Duration.hours(12),
        initialHourhandDegrees
    );
    createRotationTimeline(              // the minute hand rotates once an hour.
        createRotate(minuteHand, initialMinuteHandDegrees).angleProperty(),
        Duration.minutes(60),
        initialMinuteHandDegrees
    );
    createRotationTimeline(              // move second hand rotates once a minute.
        createRotate(secondHand, initialSecondHandDegrees).angleProperty(),
        Duration.seconds(60),
        initialSecondHandDegrees
    );
  }

  private Rotate createRotate(Line hand, double initialHandDegrees) {
    final Rotate hourRotate = new Rotate(initialHandDegrees);
    hand.getTransforms().add(hourRotate);
    return hourRotate;
  }

  /**
   * Performs a 360 degree rotation of the angleProperty once in every duration.
   * rotation starts from initialRotation degrees.
   */
  private void createRotationTimeline(DoubleProperty angleProperty, Duration duration, double initialRotation) {
    
	  Timeline timeline = new Timeline(
      new KeyFrame(
        duration,
        new KeyValue(
          angleProperty,
          360 + initialRotation,  
          Interpolator.LINEAR
        )  //转一圈
      )
    );
    timeline.setCycleCount(Animation.INDEFINITE);
    timeline.play();
  }

  //获取当前秒占多少度（1秒占360/60度）
  private int calculateSecondHandDegrees(Calendar time) {
	System.out.println(time.get(Calendar.SECOND) * (360 / 60));
    return time.get(Calendar.SECOND) * (360 / 60);  
  }

  private double calculateMinuteHandDegrees(Calendar time) {
    return (time.get(Calendar.MINUTE) + calculateSecondHandDegrees(time) / 360.0) * (360 / 60);
  }

  private double calculateHourHandDegrees(Calendar time) {
    return (time.get(Calendar.HOUR)   + calculateMinuteHandDegrees(time) / 360.0) * (360 / 12);
  }

  private double percentOf(double percent, double clockRadius) {
    return percent / 100 * clockRadius;
  }
  
  public static void main(String args[]){
	  Calendar calendar = Calendar.getInstance();
  }
}

主要是该类实现时钟
其中，关于line的移动疑惑了好久，为什么围绕着中心点转，自己弄了个例子调试了下，原来line是围绕着layoutX,layoutY转，上面设置了line的layoutX,layoutY为中心点，所以就围绕着中心点转。
其主要就是给line添加一个rotate，然后rotate的angerProperty一直变化。


这里有个javafx学习的中文网站，我把内容都丢那上面去了。
http://www.jfxee.com/