Good work. I'm only afraid by the fact that we are moving from ArchiveEntry references to Archive::Entry pointers all over the place. This means that we need to be more careful about the memory management, or otherwise we are going to have memory leaks.

In particular, the Entry class is a QObject but doesn't take a QObject parent in the constructor. This is risky and error prone. How about something like this:

Archive::Entry::Entry(QObject *parent)
    : QObject(parent)
    // other stuff
{
    if (qobject_cast<Entry*>(parent) {
        m_parent = parent;
    }

    // other stuff
}

This way we are using the Qt memory model and this will simplify the things.