@Override
	public boolean isDropOk(Object contextObj, DropTargetDragEvent evt) {
		curService = null;

		if (!evt.isDataFlavorSupported(DataTypeTransferable.localDataTypeFlavor) &&
		    !evt.isDataFlavorSupported(DataTypeTransferable.localBuiltinDataTypeFlavor) )
			return false;

		if (contextObj != null  &&  contextObj instanceof ListingActionContext) {
			ListingActionContext pl = (ListingActionContext)contextObj;
			DataService[] services = plugin.getTool().getServices(DataService.class); 
			for (int i=0; i<services.length; i++) {
				if (services[i].isCreateDataAllowed(pl)) {
					curService = services[i];
					return true;
				}
			}
		}
		
		return false;
	}
@see ghidra.app.util.ProgramDropProvider#isDropOk(java.lang.Object, java.awt.dnd.DropTargetDragEvent)
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/datamgr/util/DataDropOnBrowserHandler.java