[vtkusers] who 'observes' event?

[Amy Henderson]

At 12:22 PM 6/2/2004, A J wrote:
>Thanks Amy for your patience,
>
>I guess my final question then is how do I go about making my own event 
>loop.. Are there any examples of this? In the vtkXRenderWindowInteractor 
>theres the following in the Start() method:
>
>do
>    {
>    XEvent event;
>    XtAppNextEvent(vtkXRenderWindowInteractor::App, &event);
>    XtDispatchEvent(&event);
>    }
>  while (this->BreakLoopFlag == 0);
>
>Is this something like what I'm supposed to replace the loop I posted 
>earlier with?
>I'm just not familiar with XEvent and XtAppNextEvent and XtDispatchEvent, 
>which libraries do they come from and is this somethign like what I should use?

I'm afraid I don't know enough about X programming either to answer your 
question.  Maybe someone else on the list has some advice?

- Amy

>=S
>
>thank you in advance...
>
>
>
>
>>The problem is that there has to be an event loop for events to be 
>>processed.  You either have to use iren->Start() or write your own event 
>>loop. The problem is not in the interactor style; events are sent to the 
>>interactor style from the render window interactor.  From 
>>vtkRenderWindowInteractor.h:
>>
>>// vtkRenderWindowInteractor provides a platform-independent interaction
>>// mechanism for mouse/key/time events. It serves as a base class for
>>// platform-dependent implementations that handle routing of mouse/key/timer
>>// messages to vtkInteractorStyle and its subclasses.
>>// vtkRenderWindowInteractor also provides controls for picking,
>>// rendering frame rate, and headlights.
>>
>>- Amy
>>
>>At 11:52 AM 6/2/2004, you wrote:
>>>So I guess this is the problem then..? How do I get around this? Now am 
>>>I supposed to make my own InteractorStyle?  Or is there a simpler way to 
>>>go about this..?
>>>
>>>Below is the structure of my code (I am just switching between two 
>>>scenes, the "AnImportantFunction()" updates/modifies data in one 
>>>renderer, and the "AnotherImportantFunction" modifies data in the ohter 
>>>renderer)
>>>
>>>
>>>CallbackCommand->SetCallback( MyClass::DoStuff(0 );
>>>Iren->AddObserver( vtkCommand::KeyPressEvent, CallbackCommand );
>>>
>>>int sample = 0;
>>>while(1)
>>>{
>>>
>>>         if ( Flag == 0 )
>>>         {
>>>                 AnImportantFunction(  sample );
>>>                 Iren->Render();
>>>                 sample++;
>>>         }
>>>         else
>>>         {
>>>                AnotherImportantFunction(  sample );
>>>                 sample++;
>>>                 Iren->Render();
>>>
>>>         }
>>>
>>>}
>>>
>>>
>>>
>>>void MyClass::DoStuff( vtkObject* caller, unsigned long eid, void* 
>>>clientdata, void* calldata)
>>>{
>>>
>>>        cout<<Flag <<endl;
>>>
>>>         Flag = !Flag;
>>>
>>>
>>>return;
>>>}
>>>
>>>_________________________________________________________________
>>>Get fast, reliable Internet access with MSN 9 Dial-up ­ now 3 months 
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>>
>>
>>
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