Fix some coding issues

[jmigual]

Fix some (not all) coding issues pointed by @timrae. I've fixed the parented_ptr issue too.

[jmigual]

Oh I found an issue related to the parented_ptr class, some classes have the parent() member private and it gives a compilation error. In this case we should force a u to QObject casting and then parented_ptr should be only used with Qt Objects.

See:
https://travis-ci.org/jmigual/mixxx/jobs/205123907

[timrae]

Yes, good idea, that sounds safer anyway! Actually we can probably remove most of the template code in this case, right?

…

On 25 Feb. 2017 06:47, "Joan" ***@***.***> wrote: Oh I found an issue related to the parented_ptr class, some classes have the parent() member private and it gives a compilation error. In this case we should force a u to QObject casting and then parented_ptr should be only used with Qt Objects. See: https://travis-ci.org/jmigual/mixxx/jobs/205123907 — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#18 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ACsA4npNSVvpX49UYKK1zSlcLtA6DkZcks5rf0_ugaJpZM4MLtUG> .

[daschuer]

Actually we can probably remove most of the template code in this case, right?

If we remove the template nature of parented_ptr, we loose the type safety, having an suspicious up cast on every dereferencing access.

I think it is more save to check if the pointer actually points to a QObject inherited class.
std::is_base_of might be uses to verify it.

I do not understand why parent() is private for some classes.
In case of SavedQueriesTableModel it should be public, need to investigate this more.

[jmigual]

I've tried doing the casting to QObject but this prevents us from using parented_ptr for TreeItem since it does not inherit QObject so checking for QObject inheritance through std::is_base_of might be a good idea.

[timrae]

@jmigual
Which classes have private parent() functions and why?

[jmigual]

Which classes have private parent() functions and why?

QAbstractTableModel has the QModelIndex parent(const QModelIndex &child) const; member and it seems that the compiler gets confused, it's really strange.

Now I've tried compiling with Qt5.7 and Qt5.5 and it does not give a compilation error. Before I was compiling with Qt4.8.

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By the way I found another issue, if you construct a nullptr parented_ptr it gives a segmentation fault related to this line:

explicit parented_ptr(T* t) : m_pObject(t) {
        DEBUG_ASSERT(t->parent() != nullptr);
}

We should check if t == nullptr before doing the assert.

[jmigual]

Ok, it's finally fixed the parent() issue with Qt4.8. So this should be ready for merge and I'll add more code fixes later.

I had to modify the parented_ptr class by adding the nullptr comparison with parented_ptr and adding nullptr checking before doing the assert.

[daschuer]

LGTM! Thank you.