CODEWITHSUNDEEP
javaswingdrag-and-dropjtree
Jeff Storey
Jeff Storey

Reputation: 57162

JTree drop index between nodes

I've implemented drag and drop in my JTree and it works, but I find this to be a bit confusing. In the picture, I'm showing how the drop location between item4 and item5 can vary depending on how far down between the nodes you are. I'm guessing this is because the row boundaries for item4 and item5 meet in the middle between them, and depending on which side you are on, you are actually in a different row.

From a user perspective, I think this is not natural. I would think that if I dropped above a node, the drop would occur above it. If I dropped below the node, the drop would occur below it. Is there a way to configure that sort of behavior?

enter image description here

EDIT: Adding code to show how to get drop location

    DropLocation dropLoc = support.getDropLocation();
    Point dropPoint = dropLoc.getDropPoint();
    tree.getTree().getPathForLocation(dropPoint.x, dropPoint.y);

Note that support is a TransferSupport object

EDIT 2: I seemed to have solved this problem by checking if the drop point is above or below the halfway point of the node. Then I can tell if the drop was above or below which node.

Upvotes: 4

Views: 546

Answers (1)

chenyi1976
chenyi1976

Reputation: 1122

You have sort out of the answer, but since i have sort out the code, thinking still worth to post it.

        public void dragOver(DropTargetDragEvent dtde)
        {
            Point dropPoint = dtde.getLocation();
            TreePath path = tree.getPathForLocation(dropPoint.x, dropPoint.y);
            Rectangle pathBounds = tree.getPathBounds(path);
            Rectangle topHalf = new Rectangle(pathBounds.x, pathBounds.y, pathBounds.width, pathBounds.height / 2);
            if (topHalf.contains(dropPoint))
            {
                System.out.println("top half");
            }
            else
            {
                System.out.println("bottom half");
            }
         }

Upvotes: 2

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