[vtkusers] vtkCocoaRenderWindow bug?

[Antoine Rosset]

Ok, thanks. You are right.

Yes, I'm having problems with this cocoamanager variable and memory  
management:

To create your own NSWindow, you create a subclass of vtkCocoaGLView  
and you initialize it with:

-(id)initWithFrame:(NSRect)frame {

     if ( self = [super initWithFrame:frame])
	{
         	_renderer = vtkRenderer::New();
		_cocoaRenderWindow = vtkCocoaRenderWindow::New();
		_cocoaRenderWindow->SetWindowId( [self window]);
		_cocoaRenderWindow->SetDisplayId( self);
		
		_cocoaRenderWindow->AddRenderer(_renderer);
        		 _interactor = vtkCocoaRenderWindowInteractor::New();
		_interactor->SetRenderWindow(_cocoaRenderWindow);

and a destructor

-(void)dealloc
{
     	_renderer->Delete();
	_cocoaRenderWindow->Delete();
	_interactor->Delete();
	[super dealloc];
}

By calling _cocoaRenderWindow->SetDisplayId( self);, you increase the  
retain count of the NSView, because you add it to the cocoamanager  
NSDictionary

Hence, the NSView will not be released automatically, because you will  
remove this NSView from the cocoamanager in the destructor of  
vtkCocoaRenderWindow AND the destructor of vtkCocoaRenderWindow will  
be called from the dealloc of the NSView, that cannot be called  
because the cocoamanager retains the NSView. (I hope it's not too  
confuse... :-))

To avoid this memory leak, I had to create a 'prepareForRelease'  
function, that I call from my NSWindowController dealloc : [myVTKView  
prepareForRelease]

- (void) prepareForRelease
{
	_cocoaRenderWindow->SetWindowId( 0L);
	_cocoaRenderWindow->SetDisplayId( 0L);
}

Then, the NSView will be released.

To identify the problem, put an NSLog in your dealloc of your VTKView  
subclass, to see if it is called.

The solution would be to put the 'displayId' in a variable, instead of  
adding it to the NSDictionary.

What do you think? Is there another way of subclassing the VTKView ?


On 5 avr. 08, at 01:35, Sean McBride wrote:
> On 4/4/08 11:49 PM, Antoine Rosset said:
>
>> In 'vtkCocoaRenderWindow::vtkCocoaRenderWindow()' you create a
>> CocoaManager variable with a NSMutableDictionary. This variable is
>> created as an autorelease object : that means that this object is not
>> retained and can be released by the OS when it quits the function
>> (during the next runloop).
>>
>> In my opinion, it should be
>>
>> this->SetCocoaManager(reinterpret_cast<void *>( [[NSMutableDictionary
>> dictionary] retain]));
>> instead of
>> this->SetCocoaManager(reinterpret_cast<void *>( [NSMutableDictionary
>> dictionary]));
>>
>> and then in the destructor
>>
>> // Release the cocoa object manager.
>> NSMutableDictionary* manager = reinterpret_cast<NSMutableDictionary
>> *>(this->GetCocoaManager());
>> [manager release];
>> this->SetCocoaManager(NULL);
>>
>> What do you think?
>
> Look at the implementation of SetCocoaManager() itself, it does the
> retain and release.  Is this code giving you problems?  Or did it just
> look weird on inspection?
>
> --
> ____________________________________________________________
> Sean McBride, B. Eng                 sean at rogue-research.com
> Rogue Research                        www.rogue-research.com
> Mac Software Developer              Montréal, Québec, Canada
>