[vtkusers] QVTKWidget only partially redrawing itself on win7 without AERO.

[Alex Malyushytskyy]

Clint,

You actually helped me at least to find a temporary workaround.

I removed Qt::MSWindowsOwnDC flag and problem seems fixed and there is
no visually other problem occurred during quick testing.

It still seems a bug in QT ( such change supposed to affect ONLY top
level widgets ).
and in my application QVTKWidget  is not top level.
But since it fixed an issue, I will keep it until it lasts.

It might not work with QT 5.0, but due to new grapics implementation I
expect more problems during transition anyway.

Thanks and regards,
   Alex


> On Wed, May 2, 2012 at 5:20 PM, Clinton Stimpson <clinton at elemtech.com> wrote:
>> It was "fixed" then reverted because the fix was incorrect.
>>
>> I've narrowed the problem down to a change of behavior in the Qt library, and reported it.
>> https://bugreports.qt-project.org/browse/QTBUG-23425
>>
>> But I've not had much time to look further into it.
>> I would suggest working with the Qt developers to get this fixed.  If you can help with that, that would be great.
>> I think part of the problem is their QtGui library has code to make a QGLWidget work, but its difficult to turn the same code on for any other OpenGL based QWidget that doesn't derive from QGLWidget.
>>
>> If you haven't voted for it, please do, so other Qt developers will notice.
>>
>> Clint
>>
>> On May 2, 2012, at 5:56 PM, Alex Malyushytskyy wrote:
>>
>>> Problem on stable release of vtk 5.8.0
>>>
>>> My application displays splash screen  while model is drawn.
>>> When splash screen is gone and user starts interaction with model,
>>> only part of the QVTKWidget is displaying correct picture,
>>> most area which was not  covered by splash screen remains unchanged
>>> (has whatever it displayed before interaction started).
>>> If QVTKWidget is minimized/maximized it fixes the problem.
>>>
>>> If AERO is on everything works as expected.
>>> vtk version 4.* did not have such problem.
>>>
>>> It seems any drawing which happens when QVTKWidget widget is
>>> covered(not only to the case of splashscreen)
>>> leeds to such nasty behaviour.
>>>
>>> This makes vtk unusable on win 7 since I can't inforce user to have
>>> AERO on, not even counting that some computers might not be able to
>>> support it physically.
>>>
>>> It was an old  conversation about related topic at:
>>> http://vtk.1045678.n5.nabble.com/Problem-with-QVTKWidget-not-expanding-in-win7-td4533383.html
>>>
>>> Even though it was stated that problem should be fixed in 5.8., it
>>> still remains.
>>>
>>> Could anybody point which changes should be made to fix a problem and
>>> is there a way to push patch that problem finally is fixed in an
>>> official version?
>>>
>>> Regards,
>>>
>>> Alex
>>> _______________________________________________
>>> Powered by www.kitware.com
>>>
>>> Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html
>>>
>>> Please keep messages on-topic and check the VTK FAQ at: http://www.vtk.org/Wiki/VTK_FAQ
>>>
>>> Follow this link to subscribe/unsubscribe:
>>> http://www.vtk.org/mailman/listinfo/vtkusers
>>