[vtk-developers] [Paraview-developers] Moving vtkMemberFunctionCommand to VTK

[Utkarsh Ayachit]

Works for me.

Utkarsh

On Wed, Oct 6, 2010 at 11:59 AM, David Gobbi <david.gobbi at gmail.com> wrote:
> A reinterpret_cast gives an undefined result when casting an object
> with multiple inheritance.  So I think that it is better to live with
> the overhead of a dynamic cast, just in case someone tries using this
> with a class like vtkQtView (it multi-inherits from QObject).
>
>  David
>
>
> On Wed, Oct 6, 2010 at 9:51 AM, Utkarsh Ayachit
> <utkarsh.ayachit at kitware.com> wrote:
>> You actually need a reinterpret_cast<>.
>>
>> Utkarsh
>>
>> On Wed, Oct 6, 2010 at 11:45 AM, David Gobbi <david.gobbi at gmail.com> wrote:
>>> The dynamic_cast is necessary, after all.  The problem is here:
>>>
>>>  T* handler = static_cast<T*>(this->Handler.GetPointer());
>>>
>>> The GetPointer() returns a vtkObjectBase, so this line of
>>> code refuses to compile for "other" objects.
>>>
>>>  David
>>>
>>> On Wed, Oct 6, 2010 at 7:48 AM, Marcus D. Hanwell
>>> <marcus.hanwell at kitware.com> wrote:
>>>> I was about to ask if a static_cast would work in this case, and it seems
>>>> preferable (and equivalent to) a C-style cast. I was just looking at the new
>>>> API, and it looks great to me. I think this is a great addition to our C++
>>>> API, and am very much in favor of making it slicker where we can.
>>>> Marcus
>>>> On Wed, Oct 6, 2010 at 9:25 AM, David Gobbi <david.gobbi at gmail.com> wrote:
>>>>>
>>>>> I was wondering about that dynamic_cast but I thought there
>>>>> was a reason for it... but I can change it to a static_cast
>>>>> for my commit.
>>>>>
>>>>> So I'll stage and commit as soon as I can afford a full VTK
>>>>> rebuild.
>>>>>
>>>>>  David
>>>>>
>>>>> On Wed, Oct 6, 2010 at 7:06 AM, Utkarsh Ayachit
>>>>> <utkarsh.ayachit at kitware.com> wrote:
>>>>> > I like your changes. In absence of your changes, if a developer does
>>>>> > indeed want to achieve same effect he'll be doing something similar
>>>>> > and will indeed have the onus of worrying about dangling ptrs. So I
>>>>> > don't think this makes it any more confusing. We should probably add
>>>>> > documentation to that effect and that pretty much should do it.
>>>>> >
>>>>> > About the dynamic_cast, yea static_cast should be fine too and totally
>>>>> > safe in this case. If the developer was stupid enough to pass in a ptr
>>>>> > as a wrong type when making the AddObserver call, he deserves the side
>>>>> > effects :).
>>>>> >
>>>>> > I'd vote for committing your changes. (You should use the stage, add
>>>>> > your commit to the "member_function_observers" branch and then merge
>>>>> > it in).
>>>>> >
>>>>> > Utkarsh
>>>>> >
>>>>> > On Wed, Oct 6, 2010 at 8:24 AM, David Gobbi <david.gobbi at gmail.com>
>>>>> > wrote:
>>>>> >> On Wed, Oct 6, 2010 at 6:01 AM, David Doria <daviddoria at gmail.com>
>>>>> >> wrote:
>>>>> >>>
>>>>> >>> David G,
>>>>> >>>
>>>>> >>> Are you suggesting this in place of what Utkarsh pushed? Utkarsh, can
>>>>> >>> you take a look and let David G know if he should push it? I think it
>>>>> >>> is a good idea to allow event handling from as many places as possible
>>>>> >>> (i.e. I support NOT requiring the class to derive from vtkObjectBase).
>>>>> >>
>>>>> >> I'm just putting it out for discussion.  It does come with some danger,
>>>>> >> for example you should not use it instead of vtkEventQtSlotConnect,
>>>>> >> because Qt's signal/slot mechanism is safe, and this is not.  It's only
>>>>> >> safe when the listener is a vtkObjectBase class.
>>>>> >>
>>>>> >>  David
>>>>> >>
>>>>> > _______________________________________________
>>>>> > Powered by www.kitware.com
>>>>> >
>>>>> > Visit other Kitware open-source projects at
>>>>> > http://www.kitware.com/opensource/opensource.html
>>>>> >
>>>>> > Follow this link to subscribe/unsubscribe:
>>>>> > http://www.vtk.org/mailman/listinfo/vtk-developers
>>>>> >
>>>>> >
>>>>> _______________________________________________
>>>>> Powered by www.kitware.com
>>>>>
>>>>> Visit other Kitware open-source projects at
>>>>> http://www.kitware.com/opensource/opensource.html
>>>>>
>>>>> Follow this link to subscribe/unsubscribe:
>>>>> http://www.vtk.org/mailman/listinfo/vtk-developers
>>>>>
>>>>
>>>>
>>>
>>
>