From: Arturo Bonechi <arturo.bonechi@...>
Date: 2010-11-22T00:05:32+09:00
Subject: Re: Qt-Ruby implementation of the "Address Book Example"

Stefano Crocco wrote in post #962925:
> Yes, using an array here is correct. Everytime you see a collection
> looking
> like a list in C++ (for example, whenever they use QStringList), you
> need to
> replace it with an array in qtruby

Ok, thank you.

> I don't think you can do that. It seems that neither QHash nor QMap are
> implemented in qtruby, and passing a native ruby hash doesn't seem to
> work. In my opinion, being restricted to using C++ types is one of the
> most serious weaknesses of qtruby. In your case, I think the best option
> would be to declare both signal with a string argument, then convert the
> hash to a string (using Marshal or YAML) before emitting the signal and
> converting it back in the slot.

So, I suppose that I need to do this conversion with arrays too... If
that is the price to pay it's Ok for me.

> No, it's another limitation of qtruby. It's caused by the fact that
> calling
> signals creates a method taking a number of parameters according to the
> signature you specified. Calling it again with the same name attempts to
> create another method with the same name and (maybe) a different number
> of
> arguments. Since ruby doesn't allow to have different methods with the
> same
> name, however, this effectively overwrites the first method.

Ok, thanks for the explanation.

One last question :
In the Qt-Ruby declaration of signals and slots, the C++ keywords
"const" and "&" are sometimes added, but they aren't added in the code
when a slot is "connected" (only the C++ type is mentioned).

For example :
...
slots 'a_slot(const QString&)'
...
connect an_object, SIGNAL('a_signal(QString)'), self,
SLOT('a_slot(QString)')
...

Must I add those keywords to the declaration or are they optional? When
do I know that I have to add them?

Thank you.

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