有什么方法可以在 KeyEvent 或其他东西上添加延迟

Question

我写了一个简单的贪吃蛇游戏，但上面有一个小错误。 当我快速按下向上和向左箭头时（这也可能发生在其他方向）蛇的头撞到身体上，游戏就会结束......基本上蛇的头没有得到第一个方向并最终进入我按下的第二个方向。 有什么解决办法吗？ 这是我的整个代码...

public class Main extends Application {

int sceneX = 600;
int sceneY = 400;
int size = 10;
int currentDirection;
int score = 0;
int highScore = 0;
double animationRate = 1.00;
boolean gameOver = false;
ArrayList <Rectangle> snake = new ArrayList<>();
Rectangle food = new Rectangle(size-1, size-1, Color.BLUE);
Rectangle dummy;
Pane pane;
Timeline timeline;
Text scoreBoard;
Text highScoreBoard = new Text(sceneX-100, -13, "High Score: "+highScore);
Button newGame = new Button("New Game");    

private static final int RIGHT = 0;
private static final int LEFT = 1;
private static final int UP = 2;
private static final int DOWN = 3;    

public Node sceneGraph() {
    pane = new Pane();
    pane.setStyle("-fx-background-color:gray;");
    pane.setPrefSize(sceneX, sceneY);
    createSnake();
    createFood();
    createDummy();
    pane.getChildren().add(food);
    pane.getChildren().add(highScoreBoard);
    return pane;        
}

private void run() {
    if (gameOver) {
        Text gameOver = new Text(sceneX/5.5, sceneY/2, "GAME OVER");
        gameOver.setFill(Color.RED);
        gameOver.setFont(Font.font(STYLESHEET_CASPIAN, 70));
        pane.getChildren().add(gameOver);
        pane.getChildren().removeAll(snake.get(0), snake.get(1));
        newGame.setLayoutX((sceneX/5.5)+150);
        newGame.setLayoutY((sceneY/2)+10);  
        newGame.setOnAction(new EventHandler<ActionEvent>() {
            @Override public void handle(ActionEvent e) {
                newGame();
            }
        });     
        pane.getChildren().add(newGame);
        timeline.stop();
        highScore();
    }
    for (int i = snake.size()-1; i>=1; i--) {
        snake.get(i).setLayoutX(snake.get(i-1).getLayoutX());
        snake.get(i).setLayoutY(snake.get(i-1).getLayoutY());
    }   
            
    eatFood();

    switch (currentDirection) {
    case RIGHT:
        snake.get(0).setLayoutX(snake.get(0).getLayoutX()+size);
        break;
    case LEFT:
        snake.get(0).setLayoutX(snake.get(0).getLayoutX()-size);
        break;
    case UP:
        snake.get(0).setLayoutY(snake.get(0).getLayoutY()-size);
        break;
    case DOWN:
        snake.get(0).setLayoutY(snake.get(0).getLayoutY()+size);
        break;
}
    gameOver();
    selfDestruct();
}

private void createSnake() {
    for (int i = 0; i < 3; i++) {
        dummy = new Rectangle(size-1, size-1, Color.BLACK);
        // Position the shapes in the Pane using the layoutX/Y properties.
        dummy.setLayoutX(100);
        dummy.setLayoutY(300);
        dummy.setArcHeight(size-5);
        dummy.setArcWidth(size-5);
        pane.getChildren().add(dummy);
        snake.add(dummy);
    }
}

private void createFood() {
    food.setLayoutX(Math.round(Math.random()*(sceneX-size)/size)*size);
    food.setLayoutY(Math.round(Math.random()*(sceneY-size)/size)*size);
    food.setArcHeight(5);
    food.setArcWidth(5);
}

private void createDummy() {
    dummy = new Rectangle(size-1, size-1, Color.BLACK);
    dummy.setLayoutX(-100);
    dummy.setLayoutY(-100);
    dummy.setArcHeight(size-5);
    dummy.setArcWidth(size-5);
    pane.getChildren().add(dummy);
}       

private void eatFood() {
    if (snake.get(0).getLayoutX() == food.getLayoutX() && snake.get(0).getLayoutY() == food.getLayoutY()) {
        createFood();
        snake.add(dummy);
        createDummy();
        score +=5;
        scoreBoard.setText("Score: "+score);            
        animationRate += 0.05;
        timeline.setRate(animationRate);
        timeline.play();
    }   
}   

private void gameOver() {
    if (snake.get(0).getLayoutX() < 0 || snake.get(0).getLayoutY() < 0 
            || snake.get(0).getLayoutX() >= (sceneX) || snake.get(0).getLayoutY() >= (sceneY)) {
        gameOver = true;
    }   
    
}

private void selfDestruct() {
    for (int i = 1; i< snake.size(); i++) {
        if (snake.get(0).getLayoutX() == snake.get(i).getLayoutX() && 
                snake.get(0).getLayoutY() == snake.get(i).getLayoutY()) {
            gameOver = true;
        }
    }
    
}

private void highScore() {
    if (highScore < score) {
        highScore = score;
    }
    highScoreBoard.setText("High Score: "+highScore);       
}


private void newGame() {
    gameOver = false;
    pane.getChildren().clear();
    snake = new ArrayList<>();
    createSnake();
    createFood();
    createDummy();
    pane.getChildren().add(food);
    pane.getChildren().add(highScoreBoard);
    currentDirection = RIGHT;
    score = 0;
    scoreBoard.setText("Score: "+score);            
    animationRate = 1;
    timeline.setRate(animationRate);
    timeline.play();
}

@Override
public void start(Stage primaryStage) {
    primaryStage.setTitle("SNAKE");
    GridPane root = new GridPane();
    root.setPadding(new Insets(10));
    root.setHgap(10);
    root.setVgap(10);
    root.addRow(0, scoreBoard = new Text("Score: "+score));
    root.addRow(1, sceneGraph());
    Scene scene = new Scene (root);
    primaryStage.setScene(scene);
    primaryStage.show();
    
    scene.setOnKeyPressed(new EventHandler<KeyEvent>() {
        @Override
        public void handle(KeyEvent event) {
            KeyCode code = event.getCode();
            if (code == KeyCode.RIGHT || code == KeyCode.D) {
                
                
                if (currentDirection != LEFT) {
                    currentDirection = RIGHT;
                }
            } else if (code == KeyCode.LEFT || code == KeyCode.A) {
                if (currentDirection != RIGHT) {
                    currentDirection = LEFT;
                }
            } else if (code == KeyCode.UP || code == KeyCode.W) {
                if (currentDirection != DOWN) {
                    currentDirection = UP;
                }
            } else if (code == KeyCode.DOWN || code == KeyCode.S) {
                if (currentDirection != UP) {
                    currentDirection = DOWN;
                }
            }
        }
    });
            
    timeline = new Timeline(new KeyFrame(Duration.millis(130), e -> run()));
    timeline.setCycleCount(Animation.INDEFINITE);
    timeline.play();   

}