# ShiftAndControl

VTKExamples/Cxx/Interaction/ShiftAndControl

### Description

Some parts of this example are currently broken.

GetAltKey() does not work? The window moves instead.

This example demonstrates how to "control+click" and "shift+click" an actor.

### Code

ShiftAndControl.cxx

    #include <vtkSmartPointer.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkPolyData.h>
    #include <vtkSphereSource.h>
    #include <vtkInteractorStyleTrackballActor.h>
    #include <vtkObjectFactory.h>

    class MouseInteractorStyleShiftAndControl : public vtkInteractorStyleTrackballActor
    {
      public:
        static MouseInteractorStyleShiftAndControl* New();

        virtual void OnLeftButtonDown()
        {
          if(this->Interactor->GetShiftKey())
          {
            std::cout << "Shift held. ";
          }

          if(this->Interactor->GetControlKey())
          {
            std::cout << "Control held. ";
          }

            /* this doesn't work ??? */
          if(this->Interactor->GetAltKey())
          {
            std::cout << "Alt held. ";
          }

          std::cout << "Pressed left mouse button." << std::endl;

          // Forward events
          vtkInteractorStyleTrackballActor::OnLeftButtonDown();
        }

    };

    vtkStandardNewMacro(MouseInteractorStyleShiftAndControl);

    int main (int, char *[])
    {
      vtkSmartPointer<vtkSphereSource> sphereSource =
        vtkSmartPointer<vtkSphereSource>::New();

      // Create a mapper and actor
      vtkSmartPointer<vtkPolyDataMapper> mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      mapper->SetInputConnection(sphereSource->GetOutputPort());

      vtkSmartPointer<vtkActor> actor =
        vtkSmartPointer<vtkActor>::New();
      actor->SetMapper(mapper);

      // A renderer and render window
      vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();
      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->AddRenderer(renderer);

      // An interactor
      vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      renderWindowInteractor->SetRenderWindow(renderWindow);

      // Add the actors to the scene
      renderer->AddActor(actor);
      renderer->SetBackground(1,1,1); // Background color white

      // Render
      renderWindow->Render();

      vtkSmartPointer<MouseInteractorStyleShiftAndControl> style =
        vtkSmartPointer<MouseInteractorStyleShiftAndControl>::New();

      renderWindowInteractor->SetInteractorStyle( style );

      // Begin mouse interaction
      renderWindowInteractor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(ShiftAndControl)

    find_package(VTK REQUIRED)
    include(${VTK_USE_FILE})

    add_executable(ShiftAndControl MACOSX_BUNDLE ShiftAndControl.cxx)

    target_link_libraries(ShiftAndControl ${VTK_LIBRARIES})

### Download and Build ShiftAndControl

Click here to download ShiftAndControl and its CMakeLists.txt file. Once the tarball ShiftAndControl.tar has been downloaded and extracted,

    cd ShiftAndControl/build

If VTK is installed:

    cmake ..

If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:

    cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

Build the project:

    make

and run it:

    ./ShiftAndControl

WINDOWS USERS PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.