JavaFX Dragboard setContent interfering with setOnMouseDragged? - drag-and-drop

Question

I would like to use drag and drop in JavaFX and have a feature where you can visually see the item being dragged. I've implemented what I thought would be a working solution, but there seems to be an issue with the API.
According to the API startDragAndDrop(TransferMode...) MUST be initialized inside setOnDragDetected. This is where I use a Dragboard to store content I'd like to transfer to another node.
EDIT: This appears to have something to do with the TrasferMode. If I use TransferMode.NONE there is no issue, but use of COPY, ANY, LINK always results in this problem.
But calling dragBoard.setContent(some clipboard content) only allows very small increments of movement with the mouse (a max of 4 pixels in any direction!). Removing this line of code, I can then drag the item and see it being dragged anywhere, but of course, I then can't store clipboard content.
The problem I see is that setOnMouseDragged(..) gets called before setOnDragDetected! It doesn't make much sense why setOnMouseDragged gets run before setOnDragDetected...
Is there something obvious to you in my code that's maybe causing a problem? I'd simply like to be able to see the imgView moving when dragging and be able to drop it on a target as usual, with the clipboard content.
EDIT 2: Updated code below to reflect using only Drag events, rather than Drag and Mouse events. Using both caused issues. The problem that still remains is that I'm unable to drop on a target, since using setOnDragOver makes the dragged node always right below the cursor.
protected ImageView initImageView(Image img){
final Pane ldzPane = GameBoard.getInstance().getLDZpane();
final ObjectProperty<Point2D> dragAnchor = new SimpleObjectProperty<>();
final ImageView imgView = new ImageView(img);
final DoubleProperty initX = new SimpleDoubleProperty();
final DoubleProperty initY = new SimpleDoubleProperty();
final DoubleProperty dragX = new SimpleDoubleProperty();
final DoubleProperty dragY = new SimpleDoubleProperty();
final DoubleProperty newXPosition = new SimpleDoubleProperty();
final DoubleProperty newYPosition = new SimpleDoubleProperty();
final int buffer = 3;
imgView.setOnDragDetected(new EventHandler<MouseEvent>() {
public void handle(MouseEvent event) {
initX.set(imgView.getTranslateX());
initY.set(imgView.getTranslateY());
dragAnchor.set(new Point2D(event.getSceneX(), event.getSceneY()));
ClipboardContent content = new ClipboardContent();
content.putString(RHSIconizedToken.this.tokenLookupInfo());
Dragboard db = imgView.startDragAndDrop(TransferMode.ANY);
db.setContent(content);
event.consume();
}
});
imgView.setOnDragOver(new EventHandler<DragEvent>(){
#Override
public void handle(DragEvent event) {
imgView.toFront();
dragX.set(event.getSceneX() - dragAnchor.get().getX());
dragY.set(event.getSceneY() - dragAnchor.get().getY());
imgView.setOpacity(0.5);
newXPosition.set(initX.get() + dragX.get());
newYPosition.set(initY.get() + dragY.get());
//if( (Math.abs((newXPosition.get() - ldzPane.getWidth())) <= ldzPane.getWidth() + startX + buffer) &&
// ((newXPosition.get() + startX + imgView.getImage().getWidth()+ buffer)<= ldzPane.getWidth()))
imgView.setTranslateX(newXPosition.get());
//if( (Math.abs((newYPosition.get() - ldzPane.getHeight())) <= ldzPane.getHeight() + startY + buffer) &&
// ((newYPosition.get() + startY + imgView.getImage().getHeight()+ buffer)<= ldzPane.getHeight()))
imgView.setTranslateY(newYPosition.get());
event.consume();
}
});
imgView.setOnDragDone(new EventHandler<DragEvent>() {
public void handle(DragEvent event) {
LinkedList<RHSIconizedToken> iTokens = GameBoard.getInstance().getTokenBayItokens();
if (event.getTransferMode() == TransferMode.MOVE) {
RHSIconizedToken element = iTokens.remove(index);
iTokens.add(index, new RHSIconizedToken(element.getImage(), new SourceToken("removed", "removed"), index));
imgView.setVisible(false);
GameBoard theGameBoard = GameBoard.getInstance();
GUI theGUI = GUI.getInstance();
//was this the last one removed from the rhs?
//if so we need to signal the CompileButton to be turned on!
if(theGameBoard.isRHSempty())
theGUI.enableCompileButton();
else
theGUI.disableCompileButton();
}
event.consume();
}
});
imgView.setOnMouseEntered(new EventHandler <MouseEvent>() {
public void handle(MouseEvent event) {
imgView.setEffect(new Glow(0.5));
event.consume();
}
});
imgView.setOnMouseExited(new EventHandler <MouseEvent>() {
public void handle(MouseEvent event) {
imgView.setEffect(new Glow(0.0));
imgView.setOpacity(1);
event.consume();
}
});
return imgView;
}

Answer 1

Java 8 is scheduled to ship with more support for visual drag and drop. DragBoard's setDragView (Image, XOffset, YOffset) method works great, and is available with the Java 8 beta.
imgView.setOnDragDetected(new EventHandler<MouseEvent>() {
public void handle(MouseEvent event) {
ClipboardContent content = new ClipboardContent();
content.putString(RHSIconizedToken.this.tokenLookupInfo());
Dragboard db = imgView.startDragAndDrop(TransferMode.ANY);
db.setDragView(image, 7, 7);
db.setContent(content);
event.consume();
}
});

Answer 2

I think this would help you:
DraggablePanelsExample.java
I usedd this for my Panels too, and it works for ImageView like a charm.
EDIT:
You are combining this false! You can not combine DragDetected with MouseDragged.
If you start dragging in JavaFX, the mouseevents does not get fired anymore.
If you want a Drag-Board-String then simply save you String in you class.
ps: replace DragDone with MouseReleased