public static boolean isValidTypeDefBaseType(Component parent, DataType dataType) {
		if (dataType instanceof FactoryDataType) {
			Msg.showError(DataTypeManagerPlugin.class, parent, "TypeDef not allowed",
				"TypeDef not allowed on a Factory data-type: " + dataType.getName());
			return false;
		}
		if (dataType instanceof Dynamic) {
			Msg.showError(DataTypeManagerPlugin.class, parent, "TypeDef not allowed",
				"TypeDef not allowed on a Dynamic data-type: " + dataType.getName());
			return false;
		}
		if (dataType.getLength() <= 0) {
			Msg.showError(DataTypeManagerPlugin.class, parent, "TypeDef not allowed",
				"Data-type has unknown length: " + dataType.getName());
			return false;
		}
		return true;
	}
A collection of files that have recently been opened by the user.
@return A collection of files that have recently been opened by the user.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/datamgr/DataTypeManagerPlugin.java