箭头循环移动动画 JavaFX方式

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/haoranhaoshi/article/details/85623922

package pathmove;

import javafx.animation.Interpolator;
import javafx.animation.PathTransition;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.geometry.Point2D;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.*;
import javafx.stage.Stage;
import javafx.util.Duration;

import java.util.ArrayList;
import java.util.List;

public class PathMoveTest extends Application {
    /**
     * 箭头流速，每秒120
     */
    private final static double speed = 120;

    /**
     * 箭头路径点
     */
    private final static List<Point2D> points = getPoints();

    /**
     * 箭头是否是正方向
     */
    private final static boolean isForward = true;

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

    @Override
    public void start(Stage primaryStage) {
        Pane pane = new Pane();
        pane.setPrefHeight(400);
        pane.setPrefWidth(800);

        Polyline polyline = new Polyline();
        polyline.setStroke(Color.BLUE);
        polyline.setStrokeWidth(1);
        for (Point2D point2D : points) {
            polyline.getPoints().addAll(new Double[]{point2D.getX(), point2D.getY()});
        }

        pane.getChildren().add(polyline);

        // 获得箭头颜色
        Polygon flowTri = new Polygon();
        flowTri.getPoints().addAll(new Double[]{
                0.0, 3.0,
                0.0, -3.0,
                8.0, 0.0});
        Color color = Color.RED;
        flowTri.setFill(color);
        flowTri.setStroke(color);

        flowTri.setCache(true);

        pane.getChildren().add(flowTri);

        PathTransition pathTransition = new PathTransition();
        pathTransition.setNode(flowTri);
        double dist = distance(points);
        pathTransition.setDuration(Duration.seconds(dist / (speed)));

        List<Point2D> point2DList = new ArrayList<>();
        if(isForward){
            point2DList = points;
        }else {
            for (int i = points.size()-1; i >= 0; i--) {
                point2DList.add(points.get(i));
            }
        }

        pathTransition.setPath(getPath(point2DList));

        pathTransition.setOrientation(PathTransition.OrientationType.ORTHOGONAL_TO_TANGENT);
        pathTransition.setCycleCount(Timeline.INDEFINITE);
        pathTransition.setAutoReverse(false);
        pathTransition.setInterpolator(Interpolator.LINEAR);
        pathTransition.play();

        primaryStage.setScene(new Scene(pane, 800, 400));
        primaryStage.show();
    }

    private Shape getPath(List<Point2D> point2DList) {
        Path flowPath = new Path();
        for (int i = 0; i < point2DList.size(); i++) {
            Point2D point2D = point2DList.get(i);
            if (i == 0) {
                flowPath.getElements().add(new MoveTo(point2D.getX(), point2D.getY()));
            }else{
                flowPath.getElements().add(new LineTo(point2D.getX(), point2D.getY()));
            }
        }

        return flowPath;
    }

    /**
     * 计算一条路径的长度
     *
     * @param points
     * @return double
     */
    private static double distance(List<Point2D> points) {
        double distance = 0.0D;
        for (int i = 1; i < points.size(); i++) {
            Point2D p1 = points.get(i);
            Point2D p2 = points.get(i - 1);
            distance += p1.distance(p2);
        }
        return distance;
    }

    private static List<Point2D> getPoints() {
        List<Point2D> points = new ArrayList<>();
        points.add(new Point2D(50, 50));
        points.add(new Point2D(50, 100));
        points.add(new Point2D(100, 100));
        points.add(new Point2D(50, 200));
        points.add(new Point2D(200, 200));
        return points;
    }
}