Question

如果鼠标单击事件发生在现有圆圈之外，我希望鼠标单击事件拖动现有圆圈或创建新圆圈。现在代码将拖动圆圈，但也会在另一个圆圈的顶部创建一个新圆圈。我真的很感激有关清理代码并使其完成其中一项的任何帮助。这是代码。我一直试图做各种不同的事情让它发挥作用，但我无法弄清楚如何让它只做一个或另一个。

import javafx.application.Application;
import javafx.scene.Cursor;
import javafx.scene.Group;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.canvas.Canvas;
import javafx.scene.canvas.GraphicsContext;
import javafx.scene.input.MouseEvent;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
import javafx.scene.control.ChoiceBox;
import javafx.collections.FXCollections;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.Pane;

public class Main extends Application {

    double orgSceneX, orgSceneY;
    double orgTranslateX, orgTranslateY;

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

    @Override
    public void start(Stage primaryStage) {
        primaryStage.setTitle("Drawing Operations Test");
        Group root = new Group();
        Pane canvas = new Pane();
        canvas.setStyle("-fx-background-color: black;");
        canvas.setPrefSize(200,200);
        Rectangle rectangle = new Rectangle(100,100,Color.RED);
        rectangle.relocate(70,70);
        canvas.getChildren().add(rectangle);

        canvas.addEventHandler(MouseEvent.MOUSE_PRESSED, 
                new EventHandler<MouseEvent>() {
                    @Override
                    public void handle(MouseEvent e) {
                        Object source = e.getSource();
                        if (!(source instanceof Circle)) {
                            Circle circle = new Circle(20,Color.BLUE);
                            circle.setCursor(Cursor.MOVE);
                            circle.setOnMousePressed(circleOnMousePressedEventHandler);
                        circle.setOnMouseDragged(circleOnMouseDraggedEventHandler);
                        circle.relocate((e.getX()-10),(e.getY()-10));
                        canvas.getChildren().add(circle);
                        System.out.println(source);
                    }


                }

    });

    root.getChildren().add(canvas);
    primaryStage.setScene(new Scene(root));
    primaryStage.show();
}



EventHandler<MouseEvent> circleOnMousePressedEventHandler = 
        new EventHandler<MouseEvent>() {

        @Override
        public void handle(MouseEvent t) {
            orgSceneX = t.getSceneX();
            orgSceneY = t.getSceneY();
            orgTranslateX = ((Circle)(t.getSource())).getTranslateX();
            orgTranslateY = ((Circle)(t.getSource())).getTranslateY();
            System.out.println(t.getSource());

        }
    };

    EventHandler<MouseEvent> circleOnMouseDraggedEventHandler = 
        new EventHandler<MouseEvent>() {

        @Override
        public void handle(MouseEvent t) {
            double offsetX = t.getSceneX() - orgSceneX;
            double offsetY = t.getSceneY() - orgSceneY;
            double newTranslateX = orgTranslateX + offsetX;
            double newTranslateY = orgTranslateY + offsetY;

            ((Circle)(t.getSource())).setTranslateX(newTranslateX);
            ((Circle)(t.getSource())).setTranslateY(newTranslateY);
        }
    };
}

Answer 1

我找到了！对我来说，答案是创建一个if else语句并在圈子上使用该事件。我确信有一种更优雅的方式可以做到这一点，但我在Java中并不太优雅.....。

public class Main extends Application {

double orgSceneX, orgSceneY;
double orgTranslateX, orgTranslateY;
Pane canvas;

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

@Override
public void start(Stage primaryStage) {
    primaryStage.setTitle("Drawing Operations Test");
    Group root = new Group();
    canvas = new Pane();
    canvas.setStyle("-fx-background-color: black;");
    canvas.setPrefSize(200,200);
    Rectangle rectangle = new Rectangle(100,100,Color.RED);
    rectangle.relocate(70,70);
    canvas.getChildren().add(rectangle);
    canvas.setOnMousePressed(MousePressedEventHandler);





    root.getChildren().add(canvas);
    primaryStage.setScene(new Scene(root));
    primaryStage.show();
}



EventHandler<MouseEvent> MousePressedEventHandler = 
        new EventHandler<MouseEvent>() {

        @Override
        public void handle(MouseEvent e) {
            if (e.getSource() instanceof Circle) {
                orgSceneX = e.getSceneX();
                orgSceneY = e.getSceneY();
                orgTranslateX = ((Circle)(e.getSource())).getTranslateX();
                orgTranslateY = ((Circle)(e.getSource())).getTranslateY();
                e.consume();
                System.out.println(e.getSource());

            }
            else {

                Circle circle = new Circle(20,Color.BLUE);
                circle.setCursor(Cursor.MOVE);
                circle.setOnMousePressed(MousePressedEventHandler);
                circle.setOnMouseDragged(MouseDraggedEventHandler);
                circle.relocate((e.getX()-10),(e.getY()-10));
                canvas.getChildren().add(circle);
                System.out.println(e.getSource());
            }
        }
    };

    EventHandler<MouseEvent> MouseDraggedEventHandler = 
        new EventHandler<MouseEvent>() {

        @Override
        public void handle(MouseEvent t) {
            double offsetX = t.getSceneX() - orgSceneX;
            double offsetY = t.getSceneY() - orgSceneY;
            double newTranslateX = orgTranslateX + offsetX;
            double newTranslateY = orgTranslateY + offsetY;

            ((Circle)(t.getSource())).setTranslateX(newTranslateX);
            ((Circle)(t.getSource())).setTranslateY(newTranslateY);
        }
    };

}

Answer 2

您可以在委托父级（窗格）之前在子节点（圆圈）上使用该事件。

EventHandler<MouseEvent> circleOnMousePressedEventHandler = event -> {
    orgSceneX = event.getSceneX();
    orgSceneY = event.getSceneY();
    orgTranslateX = ((Circle) (event.getSource())).getTranslateX();
    orgTranslateY = ((Circle) (event.getSource())).getTranslateY();
    event.consume();
};

根据Javafx中的Object，在鼠标按下时会发生不同的事情

2 个答案: