[vtkusers] bugs on Qt wiki Examples

[Juan Cardelino]

Thanks Bill and David,
             The situation is very clear now. I will change what I can
using your suggestions. And I will try to write something down
whenever I have the time.
Best,
       Juan

On Mon, Oct 22, 2012 at 5:56 PM, David Doria <daviddoria at gmail.com> wrote:
> Juan,
>
> Thank you for your interest, feedback, and offer to help! I have addressed
> each of your concerns inline below:
>
>> 1) For a long time ITK and VTK user, it is faster and more comfortable
>> to use the examples from GIT rather than from the wiki.
>
>
> I completely agree. We are working on systems that will allow working on the
> examples directly through the repository.
>
>> When I got the examples from git I found two issues:
>> a) The qt examples and the wiki are not in sync. At first I couldn't
>> make them work, because I didn't know some files where generated from
>> the .ui file, which BTW is missing from the git repo.
>
>
> You are correct, the UI files are missing from the repository. Bill
> mentioned that he will fix that shortly.
>
>>
>> b) The qt examples are not built by default and I did not find an easy
>> way to enable them. Maybe the missing .ui file is related to this
>> issue.
>
>
> You're right, they are currently not setup to build in the repository. I
> will look into doing that once the ui files are scraped nightly.
>
>>
>> c) either a) and b) are correct, or I am missing something. If I'm
>> missing something, this means that we need a better documentation to
>> make whats needed clear.
>
>
> At the top of the Qt section (http://www.vtk.org/Wiki/VTK/Examples/Cxx#Qt) ,
> there is a link to "Qt Setup"
> (http://www.vtk.org/Wiki/VTK/Tutorials/QtSetup) Perhaps this would be a good
> place to explain the current process?
>
>>
>> 2) After failing with the git examples, I've fallen back to the wiki.
>> Once copy/pasted everything I found out two problems:
>> a) On osx with cmake 2.8.6, it will fail, because some escape
>> sequences were missing. See the following post for an explanation:
>> http://www.vtk.org/pipermail/vtk-developers/2012-May/011548.html.
>> Using cmake 2.8.9 the problem is gone.
>
>
>  I'm not sure there is a fix that we can do for that as it was a problem in
> CMake itself?
>
>> b) The CMakeLists.txt is incorrect. The line: TARGET_LINK_LIBRARIES(
>> RenderWindowUIMultipleInheritance QVTK ) does not work. I don't have
>> libQVTK on any of my systems. It should read: TARGET_LINK_LIBRARIES(
>> RenderWindowUIMultipleInheritance ${VTK_LIBRARIES} ${QT_LIBRARIES} )
>> or at least:
>> TARGET_LINK_LIBRARIES( RenderWindowUIMultipleInheritance
>> ${VTK_LIBRARIES} ). I did not test the second one.
>
>
>  QVTK was for VTK 5.x. With 6.0, you are correct that ${VTK_LIBRARIES} is
> the correct thing to use. On this page:
> http://www.vtk.org/Wiki/VTK/Examples/Cxx/Images/ImageSlice you can see how
> we check for the condition that requires the old or new way (I suppose we
> could also explicitly check the VTK version number?). If you could modify
> the CMakeLists.txt files on the Qt examples pages to use QVTK or only
> ${VTK_LIBRARIES} conditionally that would be great.
>
>>
>> All those minor issues are really a stopper for a newcomer to Qt, even
>> being proficient in Cmake and VTK. I'm not asking for any work, but
>> offering it. I volunteer to correct those minor things. It passed some
>> time since I contributed examples so I don't remember the proper way
>> to correct them. Is directly the wiki the proper place?
>
>
> Changes to the code (h/cxx) files should be done directly on the wiki. The
> CMakeLists.txt files are not scraped/used in the repository, because there
> is a testing framework in place that generates the necessary files to test
> the examples, and those are much different from the CMakeLists.txt that a
> user would need to build a single example. To modify the build system of the
> examples, you should fork the repository and send a merge request.
>
>>
>> The cmake issue in particular, made me think about the necessity of
>> adding a little readme to the each example, or at least to the whole
>> wiki section. Is there a standard way to do it? Because that cmake
>> issue will occur in every Qt example and putting a small notice could
>> help the newcomer.
>
>
> Perhaps we could make a MediaWiki macro called {{QT_VTKExample}} or
> something similar that would post a sentence with a link to the Qt tutorial
> page that I linked to earlier? This way at least this would be in a
> centralized place so if we want to change what it says/links to we wouldn't
> have to do it in every Qt example separately in the future.
>
> Thanks again for your input, and let us know if you have any trouble or any
> more questions.
>
> David