private boolean dropTargetValidate(DropTargetEvent event, File targetFile) {
		if (targetFile != null && targetFile.isDirectory()) {
			if (event.detail != DND.DROP_COPY && event.detail != DND.DROP_MOVE) {
				event.detail = DND.DROP_MOVE;
			}
		} else {
			event.detail = DND.DROP_NONE;
		}
		return event.detail != DND.DROP_NONE;
	}