Qt plugin: access application classes from the plugin?

[abey]

You are exporting SomeWidget class in your plugin to the application, aren't you?

If yes, then it is not that "application has a repertoire of subclasses of BaseWidget ", but a plugin has them.

Agreed.

In the mockup that you provided it looks like that any class in your plugin that implements BaseWidget interface will have an access to DataSource. But, as far as I know, only one class can be exported from the plugin, except multiple inheritance construct of type (then you can cast returned "instance" it to the base types)

I'm not sure I understand your point. I agree that my mockup lacks the Qt-isms specific to plug-ins. And yes, I don't expect plug-in to export more than a single class. The question was about the use in the plugin of facilities sitting in the application.