@Override
	public void dragOver(DropTargetDragEvent dtde) {
		tree.cancelEditing();

		Point dragLocation = dtde.getLocation();
		TreePath path = tree.getClosestPathForLocation(dragLocation.x, dragLocation.y);
		if (path == null) {
			return;  // no program open, so not even a root node available
		}

		gTree.setActiveDropTargetNode(null);
		tree.repaint();
		GTreeNode dropNode = (GTreeNode) path.getLastPathComponent();
		if (dragNDropHandler.isDropSiteOk(dropNode, dtde.getCurrentDataFlavors(),
			dtde.getDropAction())) {
			gTree.setActiveDropTargetNode(dropNode);
			dtde.acceptDrag(dtde.getDropAction());
			return;
		}
		dtde.rejectDrag();
	}
Paint each of the given nodes that is inside of the clips
Ghidra/Framework/Docking/src/main/java/docking/widgets/tree/internal/GTreeDragNDropAdapter.java