Template signals and multiple inheritance

[TrueNova]

@Christian-Ehrlicher yes, I know, thank you, so what can I do to make implement this "use the second one as member" to my class for it to work, can you, please, give me a minimal of code of it?

[Christian Ehrlicher]

I can't and won't provide code since I don't know what you're doing and what you really want to achieve. I don't see a reason why someone would derive two times from QObject.

[TrueNova]

@Christian-Ehrlicher I need to make my Drawer class templated, as I know, QObject can't be so, that's why I divided it into my QObjectSubclass. Also, I need to inherit QWidget(parent) to my constructor, so I derrived my Drawer class from it too. That is why(I am pretty sure) I have this problem with connect() — "non-static member 'connect' has multiple-base class subobjects". Hope that will help you to understand my problem.

[Christian Ehrlicher]

@TrueNova said in Template signals and multiple inheritance:

Hope that will help you to understand my problem.

I understand your problem but you have to fix it another way - you can't derive two times from QObject (as already said) and templates + QObject won't work too so again - you have to find another solution.

[SGaist]

Hi,

You are explaining the problems you are having. Can you explain exactly what you are trying to achieve ?

[TrueNova]

@SGaist I have classes ierarchy like tree: Galaxy->Star->Planet->Satellite and Drawer class for each one of level. I am drawing, for example, a solar system(Sun and planets on their orbits), also, I want to draw planet system(planet and its satellites)of planets of this solar system. User is in the solar system with star in the center and planets are orbiting it, the user clicks on Earth, and now Earth appers on the Screen with Moon on the orbit. I have classes to show everything on the screen for each my type, and everything works well, but I need to be able to make everything with just one template class(as all of these classes are just almost nearly identical). As my class is template, I divided a QObject into another class and then inherited it in Drawer class(found this solution on Qt Forum), but also I need to be able to send signals from this class. Here I got error message from connect().
If you are intend to help my seriously, cause this is a really hard problem, I guess, thank you. Then this may help you: my main goal is to send some signal with undefined type(Planet-, Star-, Satellite pointers) from my template class, when user clicks on orbit item(Planet, for example). Only thing that I need, is to catch this signal from MainWindow and than put the item(this Planet), that signal sent as the central system with its orbits(Satellites) on the screen, how to achieve this goal? Cause I think, there will be a lot of problems with emitting the templated type. Are there any possible way to do, what I need at all? Thank you.

[SGaist]

What message do you want to send ?

[TrueNova]

@SGaist I want to do something like

template<typename T>
//something
signals:
      sendItem( T* item);
connect(item, SIGNAL(clicked()), this, SlOT(itemClicked()));
itemClicked(){
     emit sendItem(currentItem);
} 

[SGaist]

Well, looks like you are currently trying to re-implement the graphics view framework. You really should consider using it.

On a side note, AFAIR, QObject based template class are currently not supported.

That said, you are trying to make your planetary objects and those related to them way too smart. If you want to keep your full custom approach, you should rather give them a render method that you will call from the "main" widget paintEvent rather than trying to make each of them a full blown widget.

[TrueNova]

@SGaist I think I understand your vision on this task. And one more time I will review graphics view framework, but somehow it seems too hard for me now. Thank you!