java - 如何在 JavaFX 中以编程方式触发鼠标事件？

Question

以下代码显示了两个面板，黄色和蓝色，其中蓝色是黄色的子级。

如果我点击蓝色面板的中心，两个面板都会处理鼠标事件。

如何以编程方式模拟相同的行为？

在 Fire event 按钮中，我尝试这样做，但失败了:生成的事件似乎仅由黄色 Pane 处理。

是否可以发布事件，以便所有 child 都处理它，就好像它发生在“本地”事件中一样？

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.Event;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.geometry.Point2D;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.input.MouseButton;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.*;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

public class FireMouseEventProgrammatically extends Application {

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

      BorderPane root = new BorderPane();




      AnchorPane yellowPane = new AnchorPane();
      yellowPane.setBackground(new Background(new BackgroundFill(Color.YELLOW, CornerRadii.EMPTY, Insets.EMPTY)));
      yellowPane.setOnMouseClicked(new EventHandler<MouseEvent>() {
         @Override
         public void handle(MouseEvent event) {
            System.out.print("yellowPane clicked ");
            printMouseEvent(event);
            System.out.println("");
         }
      });

      root.setCenter(yellowPane);


      Pane bluePane = new Pane();
      bluePane.setBackground(new Background(new BackgroundFill(Color.BLUE, CornerRadii.EMPTY, Insets.EMPTY)));
      bluePane.setOnMouseClicked(new EventHandler<MouseEvent>() {
         @Override
         public void handle(MouseEvent event) {
            System.out.print("bluePane clicked ");
            printMouseEvent(event);
            System.out.println("");
         }
      });

      AnchorPane.setLeftAnchor(bluePane, 200.);
      AnchorPane.setRightAnchor(bluePane, 200.);
      AnchorPane.setTopAnchor(bluePane, 200.);
      AnchorPane.setBottomAnchor(bluePane, 200.);


      yellowPane.getChildren().add(bluePane);




      FlowPane buttonPane = new FlowPane();
      buttonPane.setHgap(5);
      buttonPane.setPadding(new Insets(5, 5, 5, 5));

      root.setBottom(buttonPane);



      Button fireEventButton = new Button();
      fireEventButton.setText("Fire event");
      fireEventButton.setOnAction(new EventHandler<ActionEvent>() {
         @Override
         public void handle(ActionEvent event) {

            double blueX = bluePane.getWidth()/2;
            double blueY = bluePane.getHeight()/2;

            Point2D screenCoords = bluePane.localToScreen(blueX, blueY);
            Point2D sceneCoords = bluePane.localToScene(blueX, blueY);

            Event.fireEvent(yellowPane, new MouseEvent(MouseEvent.MOUSE_CLICKED,
               sceneCoords.getX(), sceneCoords.getY(), screenCoords.getX(), screenCoords.getY(), MouseButton.PRIMARY, 1,
               true, true, true, true, true, true, true, true, true, true, null));

         }
      });

      buttonPane.getChildren().add(fireEventButton);


      Scene scene = new Scene(root, 800, 600);
      primaryStage.setScene(scene);
      primaryStage.show();

   }

   private void printMouseEvent(MouseEvent event) {
      System.out.print(String.format("x = %f, y = %f, xScreen = %f, yScreen = %f", event.getX(), event.getY(), event.getScreenX(), event.getScreenY()));
   }

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

}

更新

我不能明确提及子节点，因为在一般情况下它可以是无数个子节点。

我怎么知道要定位哪一个？

我想传递坐标让系统自动判断目标。

Answer 1

实际(物理)点击和程序点击之间的区别在于，在第一种情况下，原始事件目标是 bluePane(因为它是“最上面的”节点 视觉上)，在后一种情况下，目标是 yellowPane。

因此，当路由构造发生时(请引用 Event Delivery Process section )在第一种情况下路由将是 root -> yellowPane -> bluePane，在第二种情况下，它只是 root -> yellowPane，因此 bluePane 未被事件触及。

基于此，您可以定位 bluePane:

Event.fireEvent(bluePane, new MouseEvent(MouseEvent.MOUSE_CLICKED,
   sceneCoords.getX(), sceneCoords.getY(), screenCoords.getX(), screenCoords.getY(), MouseButton.PRIMARY, 1,
   true, true, true, true, true, true, true, true, true, true, null));

或者您可以使用 机器人 来生成点击:

try {
    robot = new java.awt.Robot();

    robot.mouseMove((int)screenCoords.getX(), (int)screenCoords.getY());
    robot.mousePress(16);
    robot.mouseRelease(16);
    robot.mouseMove((int) originalLocation.getX(), (int)originalLocation.getY());
} catch (AWTException e) {
    e.printStackTrace();
}

---

更新 1:

如果您想坚持使用 JavaFX 方式，现在的问题是如何确定位置上的“最上层”节点。

这是不可能以干净的方式实现的一件事。已经有一个feature request关于这个。

我在 fxexperience 的辅助方法中找到了这个可用于确定某个位置上的 Node:

public static Node pick(Node node, double sceneX, double sceneY) {
    Point2D p = node.sceneToLocal(sceneX, sceneY, true /* rootScene */);

    // check if the given node has the point inside it, or else we drop out
    if (!node.contains(p)) return null;

    // at this point we know that _at least_ the given node is a valid
    // answer to the given point, so we will return that if we don't find
    // a better child option
    if (node instanceof Parent) {
        // we iterate through all children in reverse order, and stop when we find a match.
        // We do this as we know the elements at the end of the list have a higher
        // z-order, and are therefore the better match, compared to children that
        // might also intersect (but that would be underneath the element).
        Node bestMatchingChild = null;
        List<Node> children = ((Parent)node).getChildrenUnmodifiable();
        for (int i = children.size() - 1; i >= 0; i--) {
            Node child = children.get(i);
            p = child.sceneToLocal(sceneX, sceneY, true /* rootScene */);
            if (child.isVisible() && !child.isMouseTransparent() && child.contains(p)) {
                bestMatchingChild = child;
                break;
            }
        }

        if (bestMatchingChild != null) {
            return pick(bestMatchingChild, sceneX, sceneY);
        }
    }

    return node;
}

你可以像这样使用:

Node pick = pick(root, sceneCoords.getX(), sceneCoords.getY());
Event.fireEvent(pick, new MouseEvent(MouseEvent.MOUSE_CLICKED,
   sceneCoords.getX(), sceneCoords.getY(), screenCoords.getX(), screenCoords.getY(), MouseButton.PRIMARY, 1,
   true, true, true, true, true, true, true, true, true, true, null));

---

更新2:

您还可以使用已弃用的方法 Node.impl_pickNode(PickRay pickRay, PickResultChooser result) 获取场景位置上相交的Node :

PickRay pickRay = new PickRay((int) sceneCoords.getX(), (int) sceneCoords.getY(), 1.0, 1.0, 1.0);
PickResultChooser pickResultChooser = new PickResultChooser();
root.impl_pickNode(pickRay,  pickResultChooser);
Node intersectedNode = pickResultChooser.getIntersectedNode();

您也可以类似地使用此节点作为目标。