problem with qvariant_casting to a usertype

[caduel]

please show us your code where you declare your custom variant type and where you use it

[skydave]

Hi caduel,

I do it quite the usual way I guess. ViewStateInfo derives from QObject somewhere up in the inheritance chain. Thanks for taking a look mate.

So this is the header of the usertype.

#pragma once
#include "ViewStateInfo.hpp"
 
 
 
namespace composer
{
	namespace model
	{
		//
		//
		//
		class LabelStateInfo : public ViewStateInfo
		{
		public:
 
			LabelStateInfo();                                                                             // constructor
 
 
		// [...]
 
		private:
		};
	}
}
Q_DECLARE_METATYPE(composer::model::LabelStateInfo*)

#pragma once
#include "ViewStateInfo.hpp"



namespace composer
{
	namespace model
	{
		//
		//
		//
		class LabelStateInfo : public ViewStateInfo
		{
		public:

			LabelStateInfo();                                                                             // constructor


		// [...]

		private:
		};
	}
}
Q_DECLARE_METATYPE(composer::model::LabelStateInfo*)

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David

[wysota]

QVariant can accept pointers to QObject right out of the box so you don't have to declare the metatype for your own class - you can store it normally and then after retrieving it, cast it to proper type.

[skydave]

Hi Wysota, thanks for your reply.

I will try what you proposed once Im at home. I didnt know that and it sounds like a good idea especially because I have a templated wrapper to the qvariant casting in my app already.

Out of curiosity: In theory what I was trying to do should work, shouldnt it?

Cheers,
David

[wysota]

Yes, but without seeing the actual code it is hard to say what you did wrong.

[skydave]

Hi, sorry but I like to bring this up again (as I hate unsolved problems and the proposed workaround of using QObjects would pose some nasty additional expenses on client code side):

The thing is, that the qmetatype registration obviously seems to work because my type has an id(257) which is successfully retrieved within qvariant_cast. So if you register a couple of usertypes shouldnt they get all an id from 256+ ?

I try to find out whether the usertype registration is working or not. And from what I see it is working. And if it is working then there really isnt anything else I can do wrong, isnt there?

David

P.S.: does somebody understand the == comarison in line 4 of the initial code snippet and explain it to me? I would expect it to be >= since there isnt only one usertype of id 256 qvariant_cast may cast to, but there are any numbers 256+

[wysota]

Can you show us the exact code you use?