java - 在可平移/可缩放 Pane 中选取并移动节点

Question

我正在尝试将一些组件放置在 ScrollPane 中。这些组件应该能够通过鼠标(单击并拖动)在该 Pane 中移动。 ScrollPane 本身可平移和缩放。

现在，如果我选择其中一个并将其拖动到新位置，如果我缩小了鼠标，则鼠标比组件更快。放大时，组件的移动速度比鼠标移动的速度快。

如果不缩放，它会一直工作，直到我到达 ScrollPane 自动平移的特定位置。

它必须对确定的节点坐标做一些事情。有谁知道我必须添加什么才能使其正常工作？

我的 Controller 类:

public class MainWindowController implements Initializable {

    private final double SCALE_DELTA = 1.1;
    private final StackPane zoomPane = new StackPane();
    private Group group = new Group();

    @FXML
    private ScrollPane scrollPane;

    @Override
    public void initialize(URL url, ResourceBundle rb) {
        Node node1 = new Node("Test");
        Node node2 = new Node("Test2", 100, 200);

        group.getChildren().addAll(node1, node2);
        zoomPane.getChildren().add(group);
        Group scrollContent = new Group(zoomPane);
        scrollPane.setContent(scrollContent);
        scrollPane.viewportBoundsProperty().addListener((ObservableValue<? extends Bounds> observable,
                Bounds oldValue, Bounds newValue) -> {
                    zoomPane.setMinSize(newValue.getWidth(), newValue.getHeight());
                });

        zoomPane.setOnScroll(
                (ScrollEvent event) -> {
                    event.consume();
                    if (event.getDeltaY() == 0) {
                        return;
                    }
                    double scaleFactor = (event.getDeltaY() > 0) ? SCALE_DELTA : 1 / SCALE_DELTA;
                    Point2D scrollOffset = figureScrollOffset(scrollContent, scrollPane);
                    group.setScaleX(group.getScaleX() * scaleFactor);
                    group.setScaleY(group.getScaleY() * scaleFactor);
                    repositionScroller(scrollContent, scrollPane, scaleFactor, scrollOffset);
                }
        );

        group.getChildren()
                .add(new Node("Test3", 500, 500));

    }

    private Point2D figureScrollOffset(javafx.scene.Node scrollContent, ScrollPane scroller) {
        double extraWidth = scrollContent.getLayoutBounds().getWidth() - scroller.getViewportBounds().getWidth();
        double hScrollProportion = (scroller.getHvalue() - scroller.getHmin()) / (scroller.getHmax() - scroller.getHmin());
        double scrollXOffset = hScrollProportion * Math.max(0, extraWidth);
        double extraHeight = scrollContent.getLayoutBounds().getHeight() - scroller.getViewportBounds().getHeight();
        double vScrollProportion = (scroller.getVvalue() - scroller.getVmin()) / (scroller.getVmax() - scroller.getVmin());
        double scrollYOffset = vScrollProportion * Math.max(0, extraHeight);
        return new Point2D(scrollXOffset, scrollYOffset);
    }

    private void repositionScroller(javafx.scene.Node scrollContent, ScrollPane scroller, double scaleFactor, Point2D scrollOffset) {
        double scrollXOffset = scrollOffset.getX();
        double scrollYOffset = scrollOffset.getY();
        double extraWidth = scrollContent.getLayoutBounds().getWidth() - scroller.getViewportBounds().getWidth();
        if (extraWidth > 0) {
            double halfWidth = scroller.getViewportBounds().getWidth() / 2;
            double newScrollXOffset = (scaleFactor - 1) * halfWidth + scaleFactor * scrollXOffset;
            scroller.setHvalue(scroller.getHmin() + newScrollXOffset * (scroller.getHmax() - scroller.getHmin()) / extraWidth);
        } else {
            scroller.setHvalue(scroller.getHmin());
        }
        double extraHeight = scrollContent.getLayoutBounds().getHeight() - scroller.getViewportBounds().getHeight();
        if (extraHeight > 0) {
            double halfHeight = scroller.getViewportBounds().getHeight() / 2;
            double newScrollYOffset = (scaleFactor - 1) * halfHeight + scaleFactor * scrollYOffset;
            scroller.setVvalue(scroller.getVmin() + newScrollYOffset * (scroller.getVmax() - scroller.getVmin()) / extraHeight);
        } else {
            scroller.setHvalue(scroller.getHmin());
        }
    }
}

节点类:

public class Node extends Parent {

    private NodeStatus status = NodeStatus.OK;
    private final Image okImage = new Image(getClass().getResourceAsStream("/images/MasterOK.png"));
    private ImageView image = new ImageView(okImage);
    private final Text label = new Text();
    private final Font font = Font.font("Courier", 20);
    double orgSceneX, orgSceneY;
    double layoutX, layoutY;

    public Node(String labelText) {
        this(labelText, 0, 0);
    }

    public Node(String labelText, double x, double y) {
        label.setText(labelText);
        label.setFont(font);
        label.setLayoutX(okImage.getWidth() + 10);
        label.setLayoutY(okImage.getHeight() / 2 + 10);
        getChildren().add(image);
        getChildren().add(label);
        setLayoutX(x);
        setLayoutY(y);
        setCursor(Cursor.MOVE);
        setOnMousePressed(new EventHandler<MouseEvent>() {

            @Override
            public void handle(MouseEvent t) {
                orgSceneX = t.getSceneX();
                orgSceneY = t.getSceneY();
                layoutX = getLayoutX();
                layoutY = getLayoutY();
            }
        });
        setOnMouseDragged(new EventHandler<MouseEvent>() {

            @Override
            public void handle(MouseEvent t) {
                setLayoutX(layoutX + t.getSceneX() - orgSceneX);
                setLayoutY(layoutY + t.getSceneY() - orgSceneY);
            }
        });

    }

    public NodeStatus getStatus() {
        return status;
    }

    public void setStatus(NodeStatus status) {
        this.status = status;
    }

}

class Delta {

    double x, y;
}

和 fxml:

<?xml version="1.0" encoding="UTF-8"?>

<?import java.lang.*?>
<?import java.util.*?>
<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<?import nodes.*?>

<AnchorPane id="AnchorPane" prefHeight="600.0" prefWidth="800.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="cqsmonitor.MainWindowController">
    <children>
        <Pane layoutX="666.0" layoutY="14.0" prefHeight="572.0" prefWidth="114.0" AnchorPane.bottomAnchor="14.0" AnchorPane.rightAnchor="14.0" AnchorPane.topAnchor="14.0">
            <children>
                <TextField layoutY="30.0" prefHeight="25.0" prefWidth="114.0" />
                <Label layoutY="12.0" text="Search:" />
                <ChoiceBox layoutY="90.0" prefHeight="25.0" prefWidth="114.0" />
                <Label layoutY="73.0" text="View:" />
            </children>
        </Pane>
        <ScrollPane fx:id="scrollPane" layoutX="14.0" layoutY="14.0" pannable="true" prefHeight="571.0" prefWidth="644.0" AnchorPane.bottomAnchor="15.0" AnchorPane.leftAnchor="14.0" AnchorPane.rightAnchor="142.0" AnchorPane.topAnchor="14.0">
        </ScrollPane>
    </children>
</AnchorPane>

Answer 1

由于还没有人回答，这里有一些代码。我不想深入研究你的问题并重新发明轮子。

您可以使用鼠标左键拖动来移动节点，使用鼠标滚轮缩放 Pane ，使用鼠标右键平移 Pane 。不需要 ScrollPane。但是，如果您想要 ScrollBars，您可以根据需要随时添加它们。

代码:

import javafx.application.Application;
import javafx.beans.property.DoubleProperty;
import javafx.beans.property.SimpleDoubleProperty;
import javafx.event.EventHandler;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.canvas.Canvas;
import javafx.scene.canvas.GraphicsContext;
import javafx.scene.control.Label;
import javafx.scene.input.MouseEvent;
import javafx.scene.input.ScrollEvent;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;

/**
 * The canvas which holds all of the nodes of the application.
 */
class PannableCanvas extends Pane {

    DoubleProperty myScale = new SimpleDoubleProperty(1.0);

    public PannableCanvas() {

        setPrefSize(600, 600);
        setStyle("-fx-background-color: lightgrey; -fx-border-color: blue;");

        // add scale transform
        scaleXProperty().bind(myScale);
        scaleYProperty().bind(myScale);

        // logging
        addEventFilter(MouseEvent.MOUSE_PRESSED, event -> { 
            System.out.println( 
                    "canvas event: " + ( ((event.getSceneX() - getBoundsInParent().getMinX()) / getScale()) + ", scale: " + getScale())
                    );
            System.out.println( "canvas bounds: " + getBoundsInParent());   
                });

    }

    /**
     * Add a grid to the canvas, send it to back
     */
    public void addGrid() {

        double w = getBoundsInLocal().getWidth();
        double h = getBoundsInLocal().getHeight();

        // add grid
        Canvas grid = new Canvas(w, h);

        // don't catch mouse events
        grid.setMouseTransparent(true);

        GraphicsContext gc = grid.getGraphicsContext2D();

        gc.setStroke(Color.GRAY);
        gc.setLineWidth(1);

        // draw grid lines
        double offset = 50;
        for( double i=offset; i < w; i+=offset) {
            // vertical
            gc.strokeLine( i, 0, i, h);
            // horizontal
            gc.strokeLine( 0, i, w, i);
        }

        getChildren().add( grid);

        grid.toBack();
    }

    public double getScale() {
        return myScale.get();
    }

    /**
     * Set x/y scale
     * @param myScale
     */
    public void setScale( double scale) {
        myScale.set(scale);
    }

    /**
     * Set x/y pivot points
     * @param x
     * @param y
     */
    public void setPivot( double x, double y) {
        setTranslateX(getTranslateX()-x);
        setTranslateY(getTranslateY()-y);
    }
}


/**
 * Mouse drag context used for scene and nodes.
 */
class DragContext {

    double mouseAnchorX;
    double mouseAnchorY;

    double translateAnchorX;
    double translateAnchorY;

}

/**
 * Listeners for making the nodes draggable via left mouse button. Considers if parent is zoomed.
 */
class NodeGestures {

    private DragContext nodeDragContext = new DragContext();

    PannableCanvas canvas;

    public NodeGestures( PannableCanvas canvas) {
        this.canvas = canvas;

    }

    public EventHandler<MouseEvent> getOnMousePressedEventHandler() {
        return onMousePressedEventHandler;
    }

    public EventHandler<MouseEvent> getOnMouseDraggedEventHandler() {
        return onMouseDraggedEventHandler;
    }

    private EventHandler<MouseEvent> onMousePressedEventHandler = new EventHandler<MouseEvent>() {

        public void handle(MouseEvent event) {

            // left mouse button => dragging
            if( !event.isPrimaryButtonDown())
                return;

            nodeDragContext.mouseAnchorX = event.getSceneX();
            nodeDragContext.mouseAnchorY = event.getSceneY();

            Node node = (Node) event.getSource();

            nodeDragContext.translateAnchorX = node.getTranslateX();
            nodeDragContext.translateAnchorY = node.getTranslateY();

        }

    };

    private EventHandler<MouseEvent> onMouseDraggedEventHandler = new EventHandler<MouseEvent>() {
        public void handle(MouseEvent event) {

            // left mouse button => dragging
            if( !event.isPrimaryButtonDown())
                return;

            double scale = canvas.getScale();

            Node node = (Node) event.getSource();

            node.setTranslateX(nodeDragContext.translateAnchorX + (( event.getSceneX() - nodeDragContext.mouseAnchorX) / scale));
            node.setTranslateY(nodeDragContext.translateAnchorY + (( event.getSceneY() - nodeDragContext.mouseAnchorY) / scale));

            event.consume();

        }
    };
}

/**
 * Listeners for making the scene's canvas draggable and zoomable
 */
class SceneGestures {

    private static final double MAX_SCALE = 10.0d;
    private static final double MIN_SCALE = .1d;

    private DragContext sceneDragContext = new DragContext();

    PannableCanvas canvas;

    public SceneGestures( PannableCanvas canvas) {
        this.canvas = canvas;
    }

    public EventHandler<MouseEvent> getOnMousePressedEventHandler() {
        return onMousePressedEventHandler;
    }

    public EventHandler<MouseEvent> getOnMouseDraggedEventHandler() {
        return onMouseDraggedEventHandler;
    }

    public EventHandler<ScrollEvent> getOnScrollEventHandler() {
        return onScrollEventHandler;
    }

    private EventHandler<MouseEvent> onMousePressedEventHandler = new EventHandler<MouseEvent>() {

        public void handle(MouseEvent event) {

            // right mouse button => panning
            if( !event.isSecondaryButtonDown())
                return;

            sceneDragContext.mouseAnchorX = event.getSceneX();
            sceneDragContext.mouseAnchorY = event.getSceneY();

            sceneDragContext.translateAnchorX = canvas.getTranslateX();
            sceneDragContext.translateAnchorY = canvas.getTranslateY();

        }

    };

    private EventHandler<MouseEvent> onMouseDraggedEventHandler = new EventHandler<MouseEvent>() {
        public void handle(MouseEvent event) {

            // right mouse button => panning
            if( !event.isSecondaryButtonDown())
                return;

            canvas.setTranslateX(sceneDragContext.translateAnchorX + event.getSceneX() - sceneDragContext.mouseAnchorX);
            canvas.setTranslateY(sceneDragContext.translateAnchorY + event.getSceneY() - sceneDragContext.mouseAnchorY);

            event.consume();
        }
    };

    /**
     * Mouse wheel handler: zoom to pivot point
     */
    private EventHandler<ScrollEvent> onScrollEventHandler = new EventHandler<ScrollEvent>() {

        @Override
        public void handle(ScrollEvent event) {

            double delta = 1.2;

            double scale = canvas.getScale(); // currently we only use Y, same value is used for X
            double oldScale = scale;

            if (event.getDeltaY() < 0)
                scale /= delta;
            else
                scale *= delta;

            scale = clamp( scale, MIN_SCALE, MAX_SCALE);

            double f = (scale / oldScale)-1;

            double dx = (event.getSceneX() - (canvas.getBoundsInParent().getWidth()/2 + canvas.getBoundsInParent().getMinX()));
            double dy = (event.getSceneY() - (canvas.getBoundsInParent().getHeight()/2 + canvas.getBoundsInParent().getMinY()));

            canvas.setScale( scale);

            // note: pivot value must be untransformed, i. e. without scaling
            canvas.setPivot(f*dx, f*dy);

            event.consume();

        }

    };


    public static double clamp( double value, double min, double max) {

        if( Double.compare(value, min) < 0)
            return min;

        if( Double.compare(value, max) > 0)
            return max;

        return value;
    }
}



/**
 * An application with a zoomable and pannable canvas.
 */
public class ZoomAndScrollApplication extends Application {
    public static void main(String[] args) {
        launch(args);
    }

    @Override
    public void start(Stage stage) {

        Group group = new Group();

        // create canvas
        PannableCanvas canvas = new PannableCanvas();

        // we don't want the canvas on the top/left in this example => just
        // translate it a bit
        canvas.setTranslateX(100);
        canvas.setTranslateY(100);

        // create sample nodes which can be dragged
        NodeGestures nodeGestures = new NodeGestures( canvas);

        Label label1 = new Label("Draggable node 1");
        label1.setTranslateX(10);
        label1.setTranslateY(10);
        label1.addEventFilter( MouseEvent.MOUSE_PRESSED, nodeGestures.getOnMousePressedEventHandler());
        label1.addEventFilter( MouseEvent.MOUSE_DRAGGED, nodeGestures.getOnMouseDraggedEventHandler());

        Label label2 = new Label("Draggable node 2");
        label2.setTranslateX(100);
        label2.setTranslateY(100);
        label2.addEventFilter( MouseEvent.MOUSE_PRESSED, nodeGestures.getOnMousePressedEventHandler());
        label2.addEventFilter( MouseEvent.MOUSE_DRAGGED, nodeGestures.getOnMouseDraggedEventHandler());

        Label label3 = new Label("Draggable node 3");
        label3.setTranslateX(200);
        label3.setTranslateY(200);
        label3.addEventFilter( MouseEvent.MOUSE_PRESSED, nodeGestures.getOnMousePressedEventHandler());
        label3.addEventFilter( MouseEvent.MOUSE_DRAGGED, nodeGestures.getOnMouseDraggedEventHandler());

        Circle circle1 = new Circle( 300, 300, 50);
        circle1.setStroke(Color.ORANGE);
        circle1.setFill(Color.ORANGE.deriveColor(1, 1, 1, 0.5));
        circle1.addEventFilter( MouseEvent.MOUSE_PRESSED, nodeGestures.getOnMousePressedEventHandler());
        circle1.addEventFilter( MouseEvent.MOUSE_DRAGGED, nodeGestures.getOnMouseDraggedEventHandler());

        Rectangle rect1 = new Rectangle(100,100);
        rect1.setTranslateX(450);
        rect1.setTranslateY(450);
        rect1.setStroke(Color.BLUE);
        rect1.setFill(Color.BLUE.deriveColor(1, 1, 1, 0.5));
        rect1.addEventFilter( MouseEvent.MOUSE_PRESSED, nodeGestures.getOnMousePressedEventHandler());
        rect1.addEventFilter( MouseEvent.MOUSE_DRAGGED, nodeGestures.getOnMouseDraggedEventHandler());

        canvas.getChildren().addAll(label1, label2, label3, circle1, rect1);

        group.getChildren().add(canvas);

        // create scene which can be dragged and zoomed
        Scene scene = new Scene(group, 1024, 768);

        SceneGestures sceneGestures = new SceneGestures(canvas);
        scene.addEventFilter( MouseEvent.MOUSE_PRESSED, sceneGestures.getOnMousePressedEventHandler());
        scene.addEventFilter( MouseEvent.MOUSE_DRAGGED, sceneGestures.getOnMouseDraggedEventHandler());
        scene.addEventFilter( ScrollEvent.ANY, sceneGestures.getOnScrollEventHandler());

        stage.setScene(scene);
        stage.show();

        canvas.addGrid();

    }
}

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