透明 JavaFX 阶段捕获滚动事件如果后面还有另一个 window

Question

鼠标事件和滚动事件的行为方式不同

鼠标事件：

事件被mainStage捕获
事件被mainStage
事件未捕获

滚动事件：

事件被mainStage捕获
事件被secondStage
事件未捕获

透明secondStage有什么办法不捕获滚动事件吗？

我的代码：

Pane mainPane = new Pane(new Label("Main Stage"));
mainPane.setPrefSize(300, 300);
mainStage.setScene(new Scene(mainPane));

Stage secondStage = new Stage();
Pane secondPane = new Pane(new Label("Second Stage"));
secondPane.setBackground(new Background(new BackgroundFill(Color.TRANSPARENT, CornerRadii.EMPTY, Insets.EMPTY)));
secondPane.setBorder(new Border(
    new BorderStroke(Color.BLACK, BorderStrokeStyle.SOLID, CornerRadii.EMPTY, new BorderWidths(2))));
secondPane.setPrefSize(300, 300);
secondStage.setScene(new Scene(secondPane, Color.TRANSPARENT));
secondStage.initStyle(StageStyle.TRANSPARENT);

mainStage.getScene().setOnScroll(event -> System.out.println("Scroll in main stage"));
secondStage.getScene().setOnScroll(event -> System.out.println("Scroll in second stage"));
mainStage.getScene().setOnMouseClicked(event -> System.out.println("Click in main stage"));
secondStage.getScene().setOnMouseClicked(event -> System.out.println("Click in second stage"));

mainStage.show();
secondStage.show();

Java版本：1.8.0_201（64位），Windows10

编辑：这个例子是一个只有两个 windows 的简化。以编程方式触发事件意味着发现哪个阶段立即较低，这本身就是另一个问题。

Answer 1

您可以创建一个自定义事件调度程序来忽略您不想要的事件：

public class CustomEventDispatcher extends BasicEventDispatcher {
    @Override
    public Event dispatchEvent(Event event, EventDispatchChain tail) {
        if(event instanceof ScrollEvent) {
            return null;
        } else {
            return super.dispatchEvent(event, tail);
        }
    }
}

然后将其设置在您的舞台上：

secondStage.setEventDispatcher(new CustomEventDispatcher());

Answer 2

不知道对不对，可以绑定属性：

secondStage.getScene().onScrollProperty().bind(mainStage.getScene().onScrollProperty());

Answer 3

我不知道这在阶段的上下文中是如何工作的，但对于简单的形状，将填充颜色设置为 Color.TRANSPARENT 还是 null 会有所不同。使用任何 Color 捕获事件，而 null 不捕获事件。

Answer 4

你可以通过使用@Slaw 的这个答案使用事件调度程序忽略第二阶段的事件来做到这一点你可以理解关于 EventDispatcher
的一切
然后你可以使用 DVarga 的这个答案来触发你自己的事件抱歉，我没有时间尝试制作一个完整的示例

Answer 5

这可能是一个很大的巧合，因为没有管理阶段的z-index的功能，我们也有同样的透明解决方案window。我们遇到了与您完全相同的问题。即，滚动事件不会传播到基础阶段。我们使用了下面的方法，不知道能不能帮到你：

首先，我们构造了一个单例 class 来保存当前悬停的节点的引用。

然后，当我们创建任何普通阶段时，我们将以下处理程序包含到该新阶段的场景中。这里的关键是，鼠标事件仍然能够通过透明阶段传递到底层window，跟踪鼠标下的节点。

scene.addEventFilter(MouseEvent.MOUSE_EXITED_TARGET, e -> {
    hoverNode.set(null);
});
scene.addEventFilter(MouseEvent.MOUSE_MOVED, e -> {
    hoverNode.set(e.getTarget());
});

在透明场景window中，我们包含了以下处理程序来将滚动事件委托给底层节点。

scene.addEventFilter(ScrollEvent.SCROLL, e -> {
    if (hoverNode.get() != null) {
        Event.fireEvent(hoverNode.get(), e);
    }
});
scene.addEventHandler(ScrollEvent.SCROLL, e -> {
    if (hoverNode.get() != null) {
        Event.fireEvent(hoverNode.get(), e);
    }
});

我很确定这不是最理想的方式。但这解决了我们的问题。 :)

下面是我的意思的快速演示代码。

import javafx.application.Application;
import javafx.beans.property.DoubleProperty;
import javafx.beans.property.SimpleDoubleProperty;
import javafx.event.Event;
import javafx.event.EventTarget;
import javafx.geometry.Insets;
import javafx.geometry.Rectangle2D;
import javafx.scene.Cursor;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.CheckBox;
import javafx.scene.control.Label;
import javafx.scene.control.ScrollPane;
import javafx.scene.input.MouseEvent;
import javafx.scene.input.ScrollEvent;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Pane;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.stage.Screen;
import javafx.stage.Stage;
import javafx.stage.StageStyle;

import java.util.stream.IntStream;

public class ScrollThroughTransparentStage_Demo extends Application {
    @Override
    public void start(Stage stage) throws Exception {
        stage.setTitle("Main Window");
        VBox root = new VBox(buildScrollPane());
        root.setStyle("-fx-background-color:#888888;");
        root.setSpacing(10);
        root.setPadding(new Insets(10));

        Button normalStageBtn = new Button("Normal Stage");
        normalStageBtn.setOnAction(e -> {
            Stage normalStage = new Stage();
            normalStage.initOwner(stage);
            Scene normalScene = new Scene(buildScrollPane(), 300, 300);
            addHandlers(normalScene);
            normalStage.setScene(normalScene);
            normalStage.show();
        });

        CheckBox allowScrollThrough = new CheckBox("Allow scroll through transparency");
        allowScrollThrough.setSelected(true);

        HBox buttons = new HBox(normalStageBtn);
        buttons.setSpacing(20);
        root.getChildren().addAll(allowScrollThrough,buttons);
        Scene scene = new Scene(root, 600, 600);
        addHandlers(scene);
        stage.setScene(scene);
        stage.show();

        /* Transparent Stage */
        Stage transparentStage = new Stage();
        transparentStage.initOwner(stage);
        transparentStage.initStyle(StageStyle.TRANSPARENT);
        Pane mainRoot = new Pane();
        Pane transparentRoot = new Pane(mainRoot);
        transparentRoot.setStyle("-fx-background-color:transparent;");
        Scene transparentScene = new Scene(transparentRoot, Color.TRANSPARENT);
        transparentStage.setScene(transparentScene);
        transparentScene.addEventFilter(ScrollEvent.SCROLL, e -> {
            if (allowScrollThrough.isSelected() && HoverNodeSingleton.getInstance().getHoverNode() != null) {
                Event.fireEvent(HoverNodeSingleton.getInstance().getHoverNode(), e);
            }
        });
        transparentScene.addEventHandler(ScrollEvent.SCROLL, e -> {
            if (allowScrollThrough.isSelected() && HoverNodeSingleton.getInstance().getHoverNode() != null) {
                Event.fireEvent(HoverNodeSingleton.getInstance().getHoverNode(), e);
            }
        });
        determineStageSize(transparentStage, mainRoot);
        transparentStage.show();

        Button transparentStageBtn = new Button("Transparent Stage");
        transparentStageBtn.setOnAction(e -> {
            MiniStage miniStage = new MiniStage(mainRoot);
            ScrollPane scrollPane = buildScrollPane();
            scrollPane.setPrefSize(300, 300);
            miniStage.setContent(scrollPane);
            miniStage.show();
        });
        buttons.getChildren().add(transparentStageBtn);
    }

    private static void determineStageSize(Stage stage, Node root) {
        DoubleProperty width = new SimpleDoubleProperty();
        DoubleProperty height = new SimpleDoubleProperty();
        DoubleProperty shift = new SimpleDoubleProperty();
        Screen.getScreens().forEach(screen -> {
            Rectangle2D bounds = screen.getVisualBounds();
            width.set(width.get() + bounds.getWidth());

            if (bounds.getHeight() > height.get()) {
                height.set(bounds.getHeight());
            }
            if (bounds.getMinX() < shift.get()) {
                shift.set(bounds.getMinX());
            }
        });
        stage.setX(shift.get());
        stage.setY(0);
        stage.setWidth(width.get());
        stage.setHeight(height.get());
        root.setTranslateX(-1 * shift.get());
    }

    private void addHandlers(Scene scene) {
        scene.addEventFilter(MouseEvent.MOUSE_EXITED_TARGET, e -> {
            HoverNodeSingleton.getInstance().setHoverNode(null);
        });
        scene.addEventFilter(MouseEvent.MOUSE_MOVED, e -> {
            HoverNodeSingleton.getInstance().setHoverNode(e.getTarget());
        });
    }

    private ScrollPane buildScrollPane() {
        VBox vb = new VBox();
        vb.setSpacing(10);
        vb.setPadding(new Insets(15));
        IntStream.rangeClosed(1, 100).forEach(i -> vb.getChildren().add(new Label(i + "")));
        ScrollPane scrollPane = new ScrollPane(vb);
        return scrollPane;
    }

    class MiniStage extends Group {
        private Pane parent;
        double sceneX, sceneY, layoutX, layoutY;
        protected BorderPane windowPane;
        private BorderPane windowTitleBar;
        private Label labelTitle;
        private Button buttonClose;

        public MiniStage(Pane parent) {
            this.parent = parent;
            buildRootNode();
            getChildren().add(windowPane);
            addEventHandler(MouseEvent.MOUSE_PRESSED, e -> toFront());
        }

        @Override
        public void toFront() {
            parent.getChildren().remove(this);
            parent.getChildren().add(this);
        }

        public void setContent(Node content) {
            // Computing the bounds of the content before rendering
            Group grp = new Group(content);
            new Scene(grp);
            grp.applyCss();
            grp.requestLayout();
            double width = grp.getLayoutBounds().getWidth();
            double height = grp.getLayoutBounds().getHeight() + 30; // 30 title bar height
            grp.getChildren().clear();

            windowPane.setCenter(content);
            // Centering the stage
            Rectangle2D screenBounds = Screen.getPrimary().getBounds();
            setX(screenBounds.getWidth() / 2 - width / 2);
            setY(screenBounds.getHeight() / 2 - height / 2);
        }

        public Node getContent() {
            return windowPane.getCenter();
        }

        public void setX(double x) {
            setLayoutX(x);
        }

        public void setY(double y) {
            setLayoutY(y);
        }

        public void show() {
            if (!parent.getChildren().contains(this)) {
                parent.getChildren().add(this);
            }
        }

        public void hide() {
            parent.getChildren().remove(this);
        }

        private void buildRootNode() {
            windowPane = new BorderPane();
            windowPane.setStyle("-fx-border-width:2px;-fx-border-color:#444444;");
            labelTitle = new Label("Mini Stage");
            labelTitle.setStyle("-fx-font-weight:bold;");
            labelTitle.setMaxHeight(Double.MAX_VALUE);
            buttonClose = new Button("X");
            buttonClose.setFocusTraversable(false);
            buttonClose.setStyle("-fx-background-color:red;-fx-background-radius:0;-fx-background-insets:0;");
            buttonClose.setOnMouseClicked(evt -> hide());

            windowTitleBar = new BorderPane();
            windowTitleBar.setStyle("-fx-border-width: 0 0 2px 0;-fx-border-color:#444444;-fx-background-color:#BBBBBB");
            windowTitleBar.setLeft(labelTitle);
            windowTitleBar.setRight(buttonClose);
            windowTitleBar.setPadding(new Insets(0, 0, 0, 10));
            windowTitleBar.getStyleClass().add("nonfocus-title-bar");
            windowPane.setTop(windowTitleBar);
            assignTitleBarEvents();
        }

        private void assignTitleBarEvents() {
            windowTitleBar.setOnMousePressed(this::recordWindowLocation);
            windowTitleBar.setOnMouseDragged(this::moveWindow);
            windowTitleBar.setOnMouseReleased(this::resetMousePointer);
        }

        private final void recordWindowLocation(final MouseEvent event) {
            sceneX = event.getSceneX();
            sceneY = event.getSceneY();
            layoutX = getLayoutX();
            layoutY = getLayoutY();
            getScene().setCursor(Cursor.MOVE);
        }

        private final void resetMousePointer(final MouseEvent event) {
            // Updating the new layout positions
            setLayoutX(layoutX + getTranslateX());
            setLayoutY(layoutY + getTranslateY());

            // Resetting the translate positions
            setTranslateX(0);
            setTranslateY(0);
            getScene().setCursor(Cursor.DEFAULT);
        }

        private final void moveWindow(final MouseEvent event) {
            double offsetX = event.getSceneX() - sceneX;
            double offsetY = event.getSceneY() - sceneY;
            setTranslateX(offsetX);
            setTranslateY(offsetY);
            event.consume();
        }
    }
}

/**
 * Singleton class.
 */
class HoverNodeSingleton {
    private static HoverNodeSingleton INSTANCE = new HoverNodeSingleton();
    private EventTarget hoverNode;

    private HoverNodeSingleton() {
    }

    public static HoverNodeSingleton getInstance() {
        return INSTANCE;
    }

    public EventTarget getHoverNode() {
        return hoverNode;
    }

    public void setHoverNode(EventTarget hoverNode) {
        this.hoverNode = hoverNode;
    }
}

透明 JavaFX 阶段捕获滚动事件如果后面还有另一个 window

Transparent JavaFX stage capture scrolling events if there is another window behind

java

javafx

openjfx