[vtkusers] KeyPress Events / Callbacks / User Interaction

[David Doria]

On Wed, Mar 10, 2010 at 6:36 AM, Sebastian Gatzka <
sebastian.gatzka at stud.tu-darmstadt.de> wrote:

>  Hello world.
>
> I have found the example for the catching of keys:
> http://vtk.org/Wiki/VTK/Examples/Interaction/KeypressEvents
> This is great news to me, but I want to link different things:
>
>    - Wait for a key to be pressed
>    - On one special key press change the normal direction of a
>    vtkImplicitPlaneWidget2 representation
>    - On a different special key press change the center point of a
>    vtkImplicitPlaneWidget2 representation
>    - Write the new normal direction and center point of the
>    vtkImplicitPlaneWidget2 representation to a textActor to display the new
>    values
>
> So I think I will have to link key press events and callbacks?
> I'm really not sure how to handle this on my own
>
> You will notice that my previous posts are somhow related to the topic.
> This here is the final requirement to the code and include the steps I have
> asked before.
>
> Sebastian
>
>
You need to create a member variable of type vtkImplicitPlaneWidget2* in the
interactor style subclass:

class KeyPressInteractorStyle : public vtkInteractorStyleTrackballCamera
{
  public:
    static KeyPressInteractorStyle* New();

    virtual void OnKeyPress()
    {
      //get the keypress
      vtkRenderWindowInteractor *rwi = this->Interactor;
      std::string key = rwi->GetKeySym();

      //handle a "normal" key
      if(key.compare("a") == 0)
        {
        cout << "The a key was pressed." << endl;
        }

      // forward events
      vtkInteractorStyleTrackballCamera::OnKeyPress();
    }
 vtkImplicitPlaneWidget2* PlaneWidget;

};


Then from main:

vtkImplicitPlaneWidget2* planeWidget = vtkImplicitPlaneWidget2::New();
KeyPressInteractorStyle* style = KeyPressInteractorStyle::New();
style.PlaneWidget = planeWidget;

Then you can do whatever you want to the PlaneWidget from inside

      if(key.compare("a") == 0)
        {
//do something to the PlaneWidget when 'a' is pressed
        }

Thanks,

David
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