Drag and drop with JavaFX TreeView - events

Question

I implemented Drag and Drop feature as recommended in other threads in this forum. I have a cellFactory on a TreeView and set the events on the cells.
tvProject.setCellFactory(new Callback<TreeView<PlanningItem>, TreeCell<PlanningItem>>() {
#Override
public PlanningCheckBoxTreeCell call(TreeView<PlanningItem> siTreeView) {
final PlanningCheckBoxTreeCell source = new PlanningCheckBoxTreeCell();
final PlanningCheckBoxTreeCell target = new PlanningCheckBoxTreeCell();
source.setOnDragDetected(new EventHandler<MouseEvent>() {
public void handle(MouseEvent event) {
/* drag was detected, start drag-and-drop gesture */
System.out.println("onDragDetected");
/* allow any transfer mode */
Dragboard db = source.startDragAndDrop(TransferMode.ANY);
/* put a string on dragboard */
ClipboardContent content = new ClipboardContent();
content.putString(source.getText());
db.setContent(content);
event.consume();
}
});
target.setOnDragOver(new EventHandler<DragEvent>() {
public void handle(DragEvent event) {
/* data is dragged over the target */
System.out.println("onDragOver");
...
event.consume();
}
});
The setOnDragDetected is executed/hit as wanted but all other events are NOT (I did not post them all here: setOnDragOver,setOnDragEntered,setOnDragExited,setOnDragDropped,setOnDragDone).
The PlanningCheckBoxTreeCell is a custom implementation of a treecell as follows:
public class PlanningCheckBoxTreeCell extends CheckBoxTreeCell<PlanningItem> {
public PlanningCheckBoxTreeCell() {
}
#Override
public void updateItem(PlanningItem item, boolean empty) {
super.updateItem(item, empty);
if (!empty) {
setText(null);
}
}
}
UPDATE PlanningItem:
package at.v2c2.testplaygroundui;
import java.io.Serializable;
public class PlanningItem implements Serializable {
private static final long serialVersionUID = 1L;
private Double scene = null;
private Integer path = null;
private String move = null;
/**
* #return the scene
*/
public Double getScene() {
return scene;
}
/**
* #param scene the scene to set
*/
private void setScene(Double scene) {
this.scene = scene;
}
/**
* #return the path
*/
public Integer getPath() {
return path;
}
/**
* #param path the path to set
*/
private void setPath(Integer path) {
this.path = path;
}
/**
* #return the move
*/
public String getMove() {
return move;
}
/**
* #param move the move to set
*/
private void setMove(String move) {
this.move = move;
}
public PlanningItem(Object item) {
super();
if (item instanceof Double) {
setScene((Double) item);
} else if (item instanceof Integer) {
setPath((Integer) item);
} else if (item instanceof String) {
setMove((String) item);
}
}
}
UPDATE The MCVE:
package at.v2c2.testplaygroundui;
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.TreeCell;
import javafx.scene.control.TreeItem;
import javafx.scene.control.TreeView;
import javafx.scene.input.ClipboardContent;
import javafx.scene.input.DataFormat;
import javafx.scene.input.DragEvent;
import javafx.scene.input.Dragboard;
import javafx.scene.input.MouseEvent;
import javafx.scene.input.TransferMode;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import javafx.util.Callback;
public final class TestplaygroundUi extends Application {
private final DataFormat objectDataFormat = new DataFormat("application/x-java-serialized-object");
/**
* Constructor.
*/
public TestplaygroundUi() {
// empty.
}
/**
* #param args Program arguments.
*/
public static void main(final String[] args) {
launch(args);
}
#Override
public void start(final Stage primaryStage) throws Exception {
TreeItem<PlanningItem> treeItemRoot = new TreeItem<>(new PlanningItem(1.0));
TreeItem<PlanningItem> nodeItemA = new TreeItem<>(new PlanningItem(2));
TreeItem<PlanningItem> nodeItemB = new TreeItem<>(new PlanningItem(2));
treeItemRoot.getChildren().addAll(nodeItemA, nodeItemB);
TreeItem<PlanningItem> nodeItemA1 = new TreeItem<>(new PlanningItem("A1"));
TreeItem<PlanningItem> nodeItemB1 = new TreeItem<>(new PlanningItem("B1"));
nodeItemA.getChildren().addAll(nodeItemA1);
nodeItemB.getChildren().addAll(nodeItemB1);
TreeView<PlanningItem> treeView = new TreeView<>(treeItemRoot);
treeView.setCellFactory(new Callback<TreeView<PlanningItem>, TreeCell<PlanningItem>>() {
#Override
public TreeCell<PlanningItem> call(TreeView<PlanningItem> siTreeView) {
final TreeCell<PlanningItem> cell = new TreeCell<>();
cell.setOnDragDetected(new EventHandler<MouseEvent>() {
public void handle(MouseEvent event) {
/* drag was detected, start drag-and-drop gesture */
System.out.println("onDragDetected");
/* allow any transfer mode */
Dragboard db = cell.startDragAndDrop(TransferMode.MOVE);
/* put a string on dragboard */
ClipboardContent content = new ClipboardContent();
content.put(objectDataFormat, cell.getItem());
// content.putString("Hello");// cell.getText());
db.setContent(content);
event.consume();
}
});
cell.setOnDragOver(new EventHandler<DragEvent>() {
public void handle(DragEvent event) {
/* data is dragged over the target */
System.out.println("onDragOver");
/*
* accept it only if it is not dragged from the same node and if it has a string data
*/
if (event.getGestureSource() != cell && event.getDragboard().hasString()) {
/* allow for both copying and moving, whatever user chooses */
event.acceptTransferModes(TransferMode.COPY_OR_MOVE);
}
event.consume();
}
});
cell.setOnDragEntered(new EventHandler<DragEvent>() {
public void handle(DragEvent event) {
/* the drag-and-drop gesture entered the target */
System.out.println("onDragEntered");
/* show to the user that it is an actual gesture target */
if (event.getGestureSource() != cell && event.getDragboard().hasString()) {
// target.setFill(Color.GREEN);
}
event.consume();
}
});
cell.setOnDragExited(new EventHandler<DragEvent>() {
public void handle(DragEvent event) {
System.out.println("onDragExited");
/* mouse moved away, remove the graphical cues */
// target.setFill(Color.BLACK);
event.consume();
}
});
cell.setOnDragDropped(new EventHandler<DragEvent>() {
public void handle(DragEvent event) {
/* data dropped */
System.out.println("onDragDropped");
/* if there is a string data on dragboard, read it and use it */
Dragboard db = event.getDragboard();
boolean success = false;
if (db.hasString()) {
cell.setText(db.getString());
success = true;
}
/*
* let the source know whether the string was successfully transferred and used
*/
event.setDropCompleted(success);
event.consume();
}
});
cell.setOnDragDone(new EventHandler<DragEvent>() {
public void handle(DragEvent event) {
/* the drag-and-drop gesture ended */
System.out.println("onDragDone");
/* if the data was successfully moved, clear it */
if (event.getTransferMode() == TransferMode.MOVE) {
cell.setText("");
}
event.consume();
}
});
return cell;
};
});
StackPane root = new StackPane();
root.getChildren().add(treeView);
Scene scene = new Scene(root, 300, 250);
primaryStage.setScene(scene);
primaryStage.setTitle("Test TreeView");
primaryStage.show();
}
}
Thanks in advance