JavaFX预加载程序线程

Question

public void init(){
    System.out.println("Thread Preloader ID:"+ Thread.currentThread().getId());
    System.out.println("  ------  ");

    Pane effectRegion = LoaderFrame.getInstance().getEffectPane();
    JFXFillTransition fill = new JFXFillTransition();
    fill.setDuration(Duration.millis(400));
    fill.setRegion(effectRegion);
    fill.setAutoReverse(true);
    fill.setCycleCount(Animation.INDEFINITE);
    fill.setFromValue(Color.WHITE);
    fill.setToValue(Color.rgb(0,77,147));

    fill.play();

}

@Override
public void start(Stage primaryStage){
    System.out.println("Thread Preloader(start) ID:"+ Thread.currentThread().getId());
    System.out.println("  ------  ");
    LoaderFrame.getInstance().show();

}

public class LoaderFrame extends Stage {

public static LoaderFrame getInstance(){
    return instance;
}


private Scene scene;
private AnchorPane root;
private BorderPane wraper;
private StackPane effectPane;

private JFXButton loaderPathButton;


public LoaderFrame(){
    initScene();
    this.initStyle(StageStyle.TRANSPARENT);
    this.getIcons().add(new Image("file:imgs/favico/icon48.png"));
}

public void initScene(){
    FXMLLoader loader = new FXMLLoader(Main.class.getResource("xml/loader_frame.fxml"));
    root = null;

    try {
        root = loader.load();
        wraper = (BorderPane) root.lookup("#rootPane");
        loaderPathButton = (JFXButton) root.lookup("#loaderPathButton");
        effectPane = (StackPane) root.lookup("#effectPane");
        scene = new Scene(root);
        scene.setFill(Color.TRANSPARENT);
        scene.getStylesheets().add("file:css/loader.css");
        this.setScene(scene);
    } catch (IOException e) {
        e.printStackTrace();
    }

}


public Pane getEffectPane(){
    return effectPane;
}

}

Answer 1

要研究preloader生命周期，可以将以下行添加到preloader类中：

    @Override
    public void handleStateChangeNotification(StateChangeNotification info) {
        System.out.println("state: " + info.getType());
    }

在应用程序类中，可以在init/start方法中添加system.out.prinln消息。这将显示preloader通过其不同状态运行:before_load、before_init、before_start。

当JavaFXThread调用preloaders start方法时，必须将对thread.sleep的调用封装在platform.runlater中。

public class App extends Application {

    private static final int PRELOADER_SHOWTIME_MILLIS = 2000;

    @Override
    public void init() throws Exception {
        long start = System.currentTimeMillis();

        // time consuming initializations

        long duration = System.currentTimeMillis() - start;
        long remainingShowTime = PRELOADER_SHOWTIME_MILLIS - duration;

        if(remaingShowTime > 0 ){
            Thread.sleep(remainingShowTime);
        }
    }

    @Override
    public void start(Stage primaryStage) {
        StackPane root = new StackPane(new Label("application"));
        Scene scene = new Scene(root, 400, 400);

        primaryStage.setScene(scene);
        primaryStage.show();
    }

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

public class TestPreloader extends Preloader {

    private Stage stage;  

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

        Rectangle rect = new Rectangle(200, 200, Color.RED);
        FadeTransition transition = new FadeTransition(Duration.seconds(2), rect);
        transition.setFromValue(0);
        transition.setToValue(1);

        Label lbl = new Label("preloader");
        StackPane root = new StackPane(rect, lbl);

        primaryStage.setScene(new Scene(root));
        primaryStage.show();

        transition.play();
    }

    @Override
    public void handleStateChangeNotification(StateChangeNotification info) {
        if (info.getType() == Type.BEFORE_START) {
           stage.hide();
        }
     }

}

public class Main {

    public static void main(String[] args) {
        LauncherImpl.launchApplication(App.class, TestPreloader.class, args);
    }

}