QSignalWrapper uses wrong Method?

SGaist

Hi and welcome to devnet,

Several things are wrong in your code:

QIcon doesn't inherit from QObject
QIcon is not a QWidget
Casting QIcon to QWidget like that is wrong
Slots don't have return values

What exactly do you want to achieve ?

On a side note, your thread title is a bit wrong QSignalWrapper is not a Qt class

qohelet

I'm coming right from Java (I was doing C++ years ago the last time...), so I assumed the Q*-Classes would all inherit from QObject. Now as I check it I see it's not like that.

As shown in the code I have the slot:

@ int addBtn(QIcon *icon = 0);@

I just want to trigger this event (Parameter included) as someone clicks another button.
How do I achieve that?

SGaist

Like I wrote before, a slot doesn't return anything.

To have something clean, you should rather have a parameterless slot where you will implement the button creation logic.

qohelet

I know that a slot doesn't return anything, that's the reason why I used the QSignalMapper.
But I don't know how to use it with a QIcon

SGaist

You can't do it with QSignalMapper. If I understand correctly when you click on that button a new one should be created with an icon, then what should happen ?

qohelet

So how can I do it? (Preferred not to subclass anything)

Nothing, that's all.

I just want to call the method addBtn(QIcon *icon) with the parameter if someone clicks a button.

SGaist

Like I said, do it indirectly. Have a parameterless slot where you will create the button retrieving the icon has you need it.

qohelet

That's the problem. I need to provide a Slot with a parameter. Otherwise I'd have done so already

SGaist

What are the exact requirements ?

qohelet

A slot with the parameter QIcon which creates a new Button with that QIcon and is called if you click something.

SGaist

Directly, you can't have that. Qt's signals must be connected to slots with matching signatures or less (but still matching) parameters.

QSignalMapper works with either QString, QObjects, or QWidgets. So you can't have a slot with a QIcon * parameter. However and since there's chances that you build your icon using a path to an image file, you could use that to build your new button. But as i've stated before, your slots should not have any return type other than void.