Design: relations of classes
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Hi. I've got two classes - MainWindow and Updater (inherited from QObject).
Option 1:
- MainWindow calls Updater::checkForUpdates();
- Updater emits signal if updates are available;
- MainWindow catches signal and shows corresponding QMessageBox.
OR option 2:
- MainWindow calls Updater::checkForUpdates();
- Updater shows QMessageBox from itself (without a parent, as a consequence).
The first option allows to easily set MainWindow as a QMessageBox parent.
But the second one is more logical as an object-oriented design abstraction.The overall question: which option is better?
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I think the first option is more logical from a design patterns point of view as it makes a clear difference between UI objects and others. The QMessageBox being a UI Object it is more logical that it is constructed by the QMainWindow. In that way the Updater only does the updating job and doesn't worries about UI.
Moreover, I suppose that the comunication back to the QMainWindow is necessary to update also the QMainWindow itself to show data send by the Updater class.
Hope it helps.