让JavaFX等待并继续使用代码

Question

基本上我试图使用JavaFX做一个简短的效果.我有一个心脏的形状(从两个圆圈和一个多边形加起来),我可以使用double值改变大小p."标准尺寸"将是p = 1.0;.

我试图给心脏增加一个泵效应.我有方法pumpOnce():

public void pumpOnce(){
    p = p + 1;
    initHeart();
    //Here goes what ever it takes to make stuff working!!
    p = p - 1;
    initHeart();
}

initHeart()吸取内心的基础p.

我发现Thread.sleep();由于JavaFX中的线程原理,或类似的方法不起作用.

但是我可以用什么呢？

Answer 1

JavaFX的动画是可能的路要走,但"线哲学"在JavaFX是不是很难用,如果你想推出自己的,还是在后台线程其他更复杂的东西的工作.

以下代码将暂停并更改标签中的值(完全公开,我正在重用我为另一个问题编写的代码):

import javafx.application.Application;
import javafx.concurrent.Task;
import javafx.concurrent.WorkerStateEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

public class HelloWorld extends Application {

    private static Label label;

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

    @Override
    public void start(Stage primaryStage) {
        primaryStage.setTitle("Hello World!");
        label = new Label();
        label.setText("Waiting...");
        StackPane root = new StackPane();
        root.getChildren().add(label);
        primaryStage.setScene(new Scene(root, 300, 250));
        primaryStage.show();

        Task<Void> sleeper = new Task<Void>() {
            @Override
            protected Void call() throws Exception {
                try {
                    Thread.sleep(5000);
                } catch (InterruptedException e) {
                }
                return null;
            }
        };
        sleeper.setOnSucceeded(new EventHandler<WorkerStateEvent>() {
            @Override
            public void handle(WorkerStateEvent event) {
                label.setText("Hello World");
            }
        });
        new Thread(sleeper).start();
    }
}

基本的JavaFX后台工具是Task,任何实际做任何事情的JavaFX应用程序都可能会被这些全部乱七八糟.了解如何使用它们.

Answer 2

Dave的解决方案非常适合JavaFX中基于线程的通用工作.

如果您希望使用JavaFX的动画工具,下面的解决方案使用时间轴或ScaleTransition演示这一点.时间轴实现了UI元素的离散比例,因此UI元素的每四分之一秒缩放更大或恢复到原始大小.缩放过渡实现了UI元素的平滑缩放,因此UI元素使用带有默认缓动插值器的插值缩放因子逐渐变大然后变小.

import javafx.animation.*;
import javafx.application.Application;
import javafx.beans.property.*;
import javafx.scene.Scene;
import javafx.scene.image.ImageView;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import javafx.util.Duration;

public class BeatingHeart extends Application {
    public static void main(String[] args) {
        launch(args);
    }

    public void start(Stage stage) {
        ImageView heart = new ImageView(HEART_IMAGE_LOC);

        animateUsingTimeline(heart);
//        animateUsingScaleTransition(heart);

        StackPane layout = new StackPane(heart);
        layout.setPrefWidth(heart.getImage().getWidth() * 2);
        layout.setPrefHeight(heart.getImage().getHeight() * 2);

        Scene scene = new Scene(layout);
        stage.setScene(scene);
        stage.show();
    }

    private void animateUsingTimeline(ImageView heart) {
        DoubleProperty scale = new SimpleDoubleProperty(1);
        heart.scaleXProperty().bind(scale);
        heart.scaleYProperty().bind(scale);

        Timeline beat = new Timeline(
            new KeyFrame(Duration.ZERO,         event -> scale.setValue(1)),
            new KeyFrame(Duration.seconds(0.5), event -> scale.setValue(1.1))
        );
        beat.setAutoReverse(true);
        beat.setCycleCount(Timeline.INDEFINITE);
        beat.play();
    }

    private void animateUsingScaleTransition(ImageView heart) {
        ScaleTransition scaleTransition = new ScaleTransition(
            Duration.seconds(1), heart
        );
        scaleTransition.setFromX(1);
        scaleTransition.setFromY(1);
        scaleTransition.setFromZ(1);
        scaleTransition.setToX(1.1);
        scaleTransition.setToY(1.1);
        scaleTransition.setToZ(1.1);
        scaleTransition.setAutoReverse(true);
        scaleTransition.setCycleCount(Animation.INDEFINITE);
        scaleTransition.play();
    }

    private static final String HEART_IMAGE_LOC =
            "http://icons.iconarchive.com/icons/mirella-gabriele/valentine/128/Heart-red-icon.png";
    // icon obtained from: http://www.iconarchive.com/show/valentine-icons-by-mirella-gabriele/Heart-red-icon.html
    // icon license: Free for non-commercial use, commercial use not allowed.
}