[vtkusers] AWT + SWT + Event Loops (was Re: VTK6 and Java Cone Example 5)

Sebastien Jourdain sebastien.jourdain at kitware.com
Wed Aug 14 11:40:42 EDT 2013 

Hi Ric,

I have no experience with SWT, so I can't really help you here, but I can
ensure you that VTK works just fine on Mac OS X with Java 6 and
interaction. In fact, I never had any crash at close time.

Does the sample code from the vtk.jar crash in the same manner at close
time ?

Seb


On Wed, Aug 14, 2013 at 11:08 AM, rkwright <rkwright at geofx.com> wrote:

> Sebastien,
>
> (BTW, thank you *very* much for your patience in answering my questions
> in such timely fashion).
>
> I didn't see the SWT option when I built VTK the first time.  However, I
> took a break and quickly built an Eclipse plugin using the code in
> wrapping/java/vtk/rendering.  I created a view based on the
> swtConeRenderer.java code, substituting the parent SWT composite passed to
> the ViewPart creation step, passing that composite to the constructor of
> vtkSwtComponent.  It ALMOST works except that it creates a wholly new
> window outside the actual Eclipse view.  And that view works, complete with
> mouse-wheel scaling.  BUT, when I close that view …  it crashes Eclipse, *
> exactly* as it does in the other demo I put together using the SWT_AWT
> bridge. Same message, same crash in Eclipse.  Clearly, something goes
> horribly awry down in the bowels of the native code in SWT.
>
> So I will continue to experiment with VTK but avoid anything to do with
> interactors.  But I return to my earlier question: Am I likely to run into
> similar problems or is it largely or wholly in the interactors that VTK
> starts/handles its own event loops?  So far the only problems I have seen
> are when interactors are involved (though my experience is rather limited,
> of course).
>
> Thanks
> Ric
>
>
> From: "Sebastien Jourdain-2 [via VTK]" <[hidden email]<http://user/SendEmail.jtp?type=node&node=5722738&i=0>
> >
> Date: Wednesday, August 14, 2013 9:53 AM
>
> To: Ric Wright <[hidden email]<http://user/SendEmail.jtp?type=node&node=5722738&i=1>
> >
> Subject: Re: AWT + SWT + Event Loops (was Re: VTK6 and Java Cone Example
> 5)
>
> You need to build VTK with the SWT component ON. Moreover, vtkRenderWIndowInteractor
> does not spawn a new event loop as VTK is NOT thread safe.
>
>
> On Wed, Aug 14, 2013 at 10:31 AM, rkwright <[hidden email]<http://user/SendEmail.jtp?type=node&node=5722733&i=0>
> > wrote:
>
>> I have been working through the samples in the jar. The only failure so
>> far is the vtkRenderWindowInteractor.
>>
>> I was not aware of a SWT component in VTK.  I see a Java file
>> vtkSwtComponent.java but it isn't clear to me that it is going to solve my
>> problems.   There are two issues I see:
>>
>>    - vtkSwtComponent appears to use the SWT OpenGL canvas widget.  This
>>    is largely unsupported in SWT and was half-broken last time I looked at it.
>>     I gave up on it long ago and turned to JOGL embedding in SWT via the
>>    bridge (which works for me at present)
>>    - It's not clear how this would solve the other issue
>>    where vtkRenderWIndowInteractor spawns its own event loop and that causes
>>    problems with SWT – or does vtkRenderWIndowInteractor not use any AWT
>>    utilities or methods?
>>
>> I'll experiment with the vtkSwtComponent (I see one simple example file,
>> swtConeRendering.java) and see if that helps. Though there is no SWT
>> support in vtk.jar so I'll guess I'll have to include the SWT files
>> directly in my project.
>>
>> Thanks for your advice.
>>
>> Ric
>>
>> BTW, I am running Apple's Java 1.6.0_51-b11-457-11M4509. 64 bit
>>
>> From: "Sebastien Jourdain-2 [via VTK]" <[hidden email]<http://user/SendEmail.jtp?type=node&node=5722724&i=0>
>> >
>> Date: Wednesday, August 14, 2013 8:42 AM
>> To: Ric Wright <[hidden email]<http://user/SendEmail.jtp?type=node&node=5722724&i=1>
>> >
>> Subject: Re: AWT + SWT + Event Loops (was Re: VTK6 and Java Cone Example
>> 5)
>>
>> Just read the sample codes that are provided in the vtk.jar or in the
>> Source code under Wrapping/Java/vtk/sample, they should be pretty strait
>> forward.
>> Moreover, VTK do provide a SWT component for rendering if you build it,
>> so you shouldn't have any event loop issue...
>>
>> Seb
>>
>>
>> On Wed, Aug 14, 2013 at 9:30 AM, Ric Wright <[hidden email]<http://user/SendEmail.jtp?type=node&node=5722710&i=0>
>> > wrote:
>>
>>> So did some more spelunking and it looks like this is just a basic
>>> incompatibility for SWT and AWT – in the specific case where AWT is trying
>>> to start their own event loop once SWT has started.  Previously, in my
>>> other work, I handled events on my own – I didn't ask or expect AWT to
>>> start or manage it's own events. I used AWT basically to host the OpenGL
>>> canvas (based on JOGL).  But when one invokes the vtkRenderWIndowInteractor
>>> an event loop IS spawned and the causes various weird problems.
>>>
>>> There is a fairly long summary of some of the issues here:
>>>
>>> http://marc.info/?l=openjdk-awt-dev&m=135818602009136&w=2
>>>
>>> So the question that comes to my mind is how dependent is the rest of
>>> VTK on starting its own event loops?  I.e. Can I use the rest of VTK and
>>> its pipeline to perform graphics, manage datasets, etc.  I am willing to
>>> give up the Interactor and its mimicking of trackball if everything else is
>>> likely to work.  But if spawning its own event loop(s) is intrinsic to how
>>> most of VTK works then I'm probably dead in the water.
>>>
>>> Thoughts or suggestions?
>>>
>>> Thanks
>>> Ric
>>>
>>>
>>> From: Ric Wright <[hidden email]<http://user/SendEmail.jtp?type=node&node=5722710&i=1>
>>> >
>>>
>>> Date: Tuesday, August 13, 2013 12:59 PM
>>> To: Sebastien Jourdain <[hidden email]<http://user/SendEmail.jtp?type=node&node=5722710&i=2>
>>> >
>>> Cc: Sean McBride <[hidden email]<http://user/SendEmail.jtp?type=node&node=5722710&i=3>>,
>>> vtkusers <[hidden email]<http://user/SendEmail.jtp?type=node&node=5722710&i=4>
>>> >
>>>
>>> Subject: Re: [vtkusers] VTK6 and Java Cone Example 5
>>>
>>> An update on this.  I ported over some of my other Eclipse work and
>>> adapted it to VTK.  It is pushed to my account on github and there is a
>>> writeup here:  http://rkwright.github.io/geofx-pages/vtkview.html.
>>>  There are 3 articles in there.  The latest rev of the code is here:
>>> https://github.com/rkwright/vtkscene in the develop branch.
>>>
>>> Mostly, it works great.  However, when I tried the fifth cone example,
>>> which has the problematic vtkRenderWindowInteractor, I ran into similar
>>> problems as before.  I instantiated it with a valid vtkPanel.RenderWindow
>>> but it still goes off into the ozone, sometimes crashing the native
>>> vtkOpenGL dylib.
>>>
>>> I'm going to skip the interactor for now and move on to see if I run
>>> into more problems. If not, I can probably live without that widget but the
>>> problems there might be symptomatic of deeper problems on OSX 64 bit
>>> systems.
>>>
>>> Any further suggestions would be welcome.
>>>
>>> Thanks
>>> Ric
>>>
>>>
>>> From: Sebastien Jourdain <[hidden email]<http://user/SendEmail.jtp?type=node&node=5722710&i=5>
>>> >
>>>
>>> Date: Tuesday, August 6, 2013 8:56 AM
>>> To: Ric Wright <[hidden email]<http://user/SendEmail.jtp?type=node&node=5722710&i=6>
>>> >
>>> Cc: Sean McBride <[hidden email]<http://user/SendEmail.jtp?type=node&node=5722710&i=7>>,
>>> vtkusers <[hidden email]<http://user/SendEmail.jtp?type=node&node=5722710&i=8>
>>> >
>>>
>>> Subject: Re: [vtkusers] VTK6 and Java Cone Example 5
>>>
>>> In Java you should use the Java specific classes anyway like
>>> vtkPanel/vtkCanvas or the new version of them used in the vtk.sample
>>> package of the vtk.jar...
>>>
>>> The purpose of those example was to show the possible match between the
>>> different languages...
>>>
>>> Nothing more I believe,
>>>
>>> Seb
>>>
>>>
>>> On Tue, Aug 6, 2013 at 8:52 AM, Ric Wright <[hidden email]<http://user/SendEmail.jtp?type=node&node=5722710&i=9>
>>> > wrote:
>>>
>>>> Ah, OK.  Well, I don't know what to do here.  Is this happening to
>>>> others?
>>>>  Should I file a bug?  Just try to work around it by not using
>>>> RenderWindowInteractors (sounds kind of lame).  Or?
>>>>
>>>> Suggestions?
>>>>
>>>> Thanks
>>>> Ric
>>>>
>>>>
>>>> On 8/5/13 4:15 PM, "Sean McBride" <[hidden email]<http://user/SendEmail.jtp?type=node&node=5722710&i=10>>
>>>> wrote:
>>>>
>>>> >On Mon, 5 Aug 2013 16:10:55 -0500, Ric Wright said:
>>>> >
>>>> >>Well, a little playing around didn't seem to help, but I am frankly
>>>> not
>>>> >>an
>>>> >>expert on threads.  However, it seems to me that the source of the
>>>> >>problem
>>>> >>is that the vtkRenderWindowInteractor gets initialized then the
>>>> start()
>>>> >>method creates an event loop that is monitored by the
>>>> >>vtkRenderWindowInteractor.  I suspect that start() method spawns a new
>>>> >>thread to listen to the events and it is the spawning of that thread
>>>> that
>>>> >>causes the exception.
>>>> >
>>>> >VTK's Cocoa classes never create any threads.
>>>> >
>>>> >Cheers,
>>>> >
>>>> >--
>>>> >____________________________________________________________
>>>> >Sean McBride, B. Eng                 [hidden email]<http://user/SendEmail.jtp?type=node&node=5722710&i=11>
>>>>
>>>> >Rogue Research                        www.rogue-research.com
>>>> >Mac Software Developer              Montréal, Québec, Canada
>>>> >
>>>> >
>>>>
>>>>
>>>>
>>>
>>
>> _______________________________________________
>> 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
>>
>>
>> ------------------------------
>>  If you reply to this email, your message will be added to the
>> discussion below:
>>
>> http://vtk.1045678.n5.nabble.com/VTK6-and-Java-Examples-tp5722474p5722710.html
>>  To unsubscribe from VTK6 and Java Examples, click here.
>> NAML<http://vtk.1045678.n5.nabble.com/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml>
>>
>> ------------------------------
>> View this message in context: Re: AWT + SWT + Event Loops (was Re: VTK6
>> and Java Cone Example 5)<http://vtk.1045678.n5.nabble.com/VTK6-and-Java-Examples-tp5722474p5722724.html>
>> Sent from the VTK - Users mailing list archive<http://vtk.1045678.n5.nabble.com/VTK-Users-f1224199.html>at Nabble.com.
>>
>> _______________________________________________
>> 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
>>
>>
>
> _______________________________________________
> 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
>
>
> ------------------------------
>  If you reply to this email, your message will be added to the discussion
> below:
>
> http://vtk.1045678.n5.nabble.com/VTK6-and-Java-Examples-tp5722474p5722733.html
>  To unsubscribe from VTK6 and Java Examples, click here.
> NAML<http://vtk.1045678.n5.nabble.com/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml>
>
> ------------------------------
> View this message in context: Re: AWT + SWT + Event Loops (was Re: VTK6
> and Java Cone Example 5)<http://vtk.1045678.n5.nabble.com/VTK6-and-Java-Examples-tp5722474p5722738.html>
> Sent from the VTK - Users mailing list archive<http://vtk.1045678.n5.nabble.com/VTK-Users-f1224199.html>at Nabble.com.
>
> _______________________________________________
> 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
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.vtk.org/pipermail/vtkusers/attachments/20130814/04a1deb0/attachment.htm>

More information about the vtkusers mailing list