Re: [Interest] How can I use QPointer as an argument?

2015-01-14 Thread Guenther Boelter 

  
  

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Thanks  Constantin, Bo and André,

it's working now.

And yes, it was not really a good question but that day I was a
little bit nervous because the end of my timeline was very near
already.

I'm sure, you know what I mean ...

Best regards

Guenther


On 01/13/2015 11:13 AM, Guenther Boelter wrote:

   Sorrry,
  
   I have a 'small' problem and my timeline is running so fast
  ...
  
   How can I use QPointer as an argument? A simple
  
  
   void myFunction( QPointer *myPointer )
   {
   // do something
   }
  
   myFunction( myPointer );
  
  
   returns 'error: ‘QPointer’ is not a type'.
  
  
   Thanks in advance and best regards
  
   Guenther
  

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Re: [Interest] How can I use QPointer as an argument?

2015-01-13 Thread Bo Thorsen 
Den 13-01-2015 kl. 04:13 skrev Guenther Boelter:
 I have a 'small' problem and my timeline is running so fast ...

 How can I use QPointer as an argument? A simple

 void myFunction( QPointer *myPointer )
 {
  // do something
 }

 myFunction( myPointer );


 returns 'error: ‘QPointer’ is not a type'.

You don't need to copy the QPointer. A QPointer is a weak pointer class. 
It is told by the object it holds, if it's deleted, and then switch to a 
null pointer.

So in your case, you simply give the object it holds to your function 
instead.

If you want to, you can create a QPointer in your function.

void myFunction(QObject* o) {
   QPointer p(o);
   // do something
}

QPointer p(theRealObject);
myFunction(p.data());

I hope this helps.

Bo.

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Re: [Interest] How can I use QPointer as an argument?

2015-01-13 Thread André Somers 
Guenther Boelter schreef op 13-1-2015 om 04:13:
 Sorrry,

 I have a 'small' problem and my timeline is running so fast ...

 How can I use QPointer as an argument? A simple


 void myFunction( QPointer *myPointer )
 {
  // do something
 }

 myFunction( myPointer );


 returns 'error: ‘QPointer’ is not a type'.


 Thanks in advance and best regards

As Constatin already stated: QPointer on its own does not exist. What I 
am wondering though, is why you feel the need to pass a _pointer_to_ a 
QPointer as an argument to myFunction? QPointer is a smart-pointer: it 
acts as a normal pointer, and then provides some other cleverness. In 
this case, the cleverness provided is that it automatically resets to 0 
if the QObject you point to is deleted, so it can't become a dangling 
pointer.

Passing a QPointer* is possible of course, but probably not what you 
wanted to do. Smart pointers are small enough to just copy as values. A 
valid use case for passing a QPointerMyClass* is if you are really 
passing an array of QPointers, though I'd probably go for another 
solution like a QVectorQPointerMyClass then.

André

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[Interest] How can I use QPointer as an argument?

2015-01-12 Thread Guenther Boelter 

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Hash: SHA1

Sorrry,

I have a 'small' problem and my timeline is running so fast ...

How can I use QPointer as an argument? A simple


void myFunction( QPointer *myPointer )
{
// do something
}

myFunction( myPointer );


returns 'error: ‘QPointer’ is not a type'.


Thanks in advance and best regards

Guenther
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Re: [Interest] How can I use QPointer as an argument?

2015-01-12 Thread Constantin Makshin 
QPointer is a template class and therefore can't be used by itself, i.e.
without specifying the template parameter.

In your case you should either:
1) specify a particular QObject-related class in the
declaration/definition of myFunction(), e.g.
   void myFunction (QPointerQWidget* myPointer)
   {
   // do something
   }
2) define myFunction() as a template function, e.g.
   template class T
   void myFunction (QPointerT* myPointer)
   {
   // do something
   }

On 01/13/2015 06:13 AM, Guenther Boelter wrote:
 
 Sorrry,
 
 I have a 'small' problem and my timeline is running so fast ...
 
 How can I use QPointer as an argument? A simple
 
 
 void myFunction( QPointer *myPointer )
 {
 // do something
 }
 
 myFunction( myPointer );
 
 
 returns 'error: ‘QPointer’ is not a type'.
 
 
 Thanks in advance and best regards
 
 Guenther



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