Draggable Issue

DragContext

package javafxtest;

/**
 * Info needed to properly drag a node
 * A copy of http://docs.oracle.com/javafx/2/events/DraggablePanelsExample.java.htm
 * @author jeffreyguenther
 */
public class DragContext {
    
    private double mouseAnchorX;
    private double mouseAnchorY;
    
    private double initialTranslateX;
    private double initialTranslateY;

    public DragContext() {
        this(0, 0, 0, 0);
    }

    public DragContext(double mouseAnchorX, double mouseAnchorY, double initialTranslateX, double initialTranslateY) {
        this.mouseAnchorX = mouseAnchorX;
        this.mouseAnchorY = mouseAnchorY;
        this.initialTranslateX = initialTranslateX;
        this.initialTranslateY = initialTranslateY;
    }
    
    public double getDragDestX(double destX){
        return initialTranslateX + destX - mouseAnchorX;
    }
    
    public double getDragDestY(double destY){
        return initialTranslateY + destY - mouseAnchorY;
    }
    

    /**
     * Get the value of initialTranslateY
     *
     * @return the value of initialTranslateY
     */
    public double getInitialTranslateY() {
        return initialTranslateY;
    }

    /**
     * Set the value of initialTranslateY
     *
     * @param initialTranslateY new value of initialTranslateY
     */
    public void setInitialTranslateY(double initialTranslateY) {
        this.initialTranslateY = initialTranslateY;
    }

    

    /**
     * Get the value of initialTranslateX
     *
     * @return the value of initialTranslateX
     */
    public double getInitialTranslateX() {
        return initialTranslateX;
    }

    /**
     * Set the value of initialTranslateX
     *
     * @param initialTranslateX new value of initialTranslateX
     */
    public void setInitialTranslateX(double initialTranslateX) {
        this.initialTranslateX = initialTranslateX;
    }

    /**
     * Get the value of mouseAnchorY
     *
     * @return the value of mouseAnchorY
     */
    public double getMouseAnchorY() {
        return mouseAnchorY;
    }

    /**
     * Set the value of mouseAnchorY
     *
     * @param mouseAnchorY new value of mouseAnchorY
     */
    public void setMouseAnchorY(double mouseAnchorY) {
        this.mouseAnchorY = mouseAnchorY;
    }


    /**
     * Get the value of mouseAnchorX
     *
     * @return the value of mouseAnchorX
     */
    public double getMouseAnchorX() {
        return mouseAnchorX;
    }

    /**
     * Set the value of mouseAnchorX
     *
     * @param mouseAnchorX new value of mouseAnchorX
     */
    public void setMouseAnchorX(double mouseAnchorX) {
        this.mouseAnchorX = mouseAnchorX;
    }

    @Override
    public String toString() {
        return "DragContext{" + "mouseAnchorX=" + mouseAnchorX + ", mouseAnchorY=" + mouseAnchorY + ", initialTranslateX=" + initialTranslateX + ", initialTranslateY=" + initialTranslateY + '}';
    }
    
    

}

DragTest

package javafxtest;

import javafx.application.Application;
import static javafx.application.Application.launch;
import javafx.beans.property.SimpleDoubleProperty;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.ScrollPane;
import javafx.scene.control.TextField;
import javafx.scene.input.ContextMenuEvent;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

/**
 *
 * @author jeffreyguenther
 */
public class NodeLayout extends Application {
    

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

    @Override
    public void start(Stage stage) throws Exception {
        stage.setTitle("NodeLayout");
        
        
        // create a node on screen
        Group node = createNodeControl();
        Group sceneRoot = new Group(node);
        
        
        // create the scene
        Scene scene = new Scene(sceneRoot, 800.0, 600.0);
        stage.setScene(scene);
        stage.show();
    }

    private void createPortControl(VBox ports) {
        HBox port = new HBox();
        port.setPadding(Insets.EMPTY);
        port.setSpacing(5);
        ports.getChildren().add(port);

        Label portName = new Label("Port Name");
        portName.setPrefWidth(100);
        TextField portExpression = new TextField();
        port.getChildren().addAll(portName, portExpression);
    }

    private Group createNodeControl() {
        final DragContext dragContext = new DragContext();
        
        
        final BorderPane container = new BorderPane();
        container.setStyle("-fx-background-color: lavender");

        HBox titleBar = new HBox();
        titleBar.setStyle("-fx-background-color: lightgray;");
        titleBar.setPadding(new Insets(5, 5, 5, 5));
        
        titleBar.setOnMouseClicked(new EventHandler<MouseEvent>() {
            @Override
            public void handle(MouseEvent t) {
                System.out.println("title bar clicked");
            }
        });

        Label nodeName = new Label("Node Name");
        titleBar.getChildren().add(nodeName);

        VBox ports = new VBox();
        ports.setPadding(new Insets(5, 5, 5, 5));
        ports.setSpacing(10);
        
        createPortControl(ports);
        createPortControl(ports);
        createPortControl(ports);
        createPortControl(ports);
        createPortControl(ports);

        container.setTop(titleBar);
        container.setCenter(ports);
        
        container.setOnMousePressed( new EventHandler<MouseEvent>() {

            @Override
            public void handle(MouseEvent me) {
                dragContext.setMouseAnchorX(me.getX());
                dragContext.setMouseAnchorY(me.getY());
                dragContext.setInitialTranslateX(container.getTranslateX());
                dragContext.setInitialTranslateY(container.getTranslateY());
                
                System.out.println("To initialize " + dragContext);
            }
        });
        
        container.setOnMouseDragged( new EventHandler<MouseEvent>() {

            @Override
            public void handle(MouseEvent me) {
                System.out.println("Before move: " + container.getTranslateX() + ", " + container.getTranslateY());
                
                container.setTranslateX(dragContext.getInitialTranslateX()
                        + me.getX() - dragContext.getMouseAnchorX());
                container.setTranslateY(dragContext.getInitialTranslateY()
                        + me.getY() - dragContext.getMouseAnchorY());
                
                System.out.println("After move: " + container.getTranslateX() + ", " + container.getTranslateY());           
            }
        });
        
        
        Group wrapper = new Group(container);
        
        return wrapper;
    }
}