KeypressEvents
VTKExamples/Cxx/Interaction/KeypressEvents
Description¶
This example shows how to catch keypress events. For example, do something if the user presses the 's' key.
Code¶
KeypressEvents.cxx
#include <vtkPolyDataMapper.h> #include <vtkObjectFactory.h> #include <vtkActor.h> #include <vtkSmartPointer.h> #include <vtkRenderWindow.h> #include <vtkRenderer.h> #include <vtkRenderWindowInteractor.h> #include <vtkPolyData.h> #include <vtkSphereSource.h> #include <vtkInteractorStyleTrackballCamera.h> // Define interaction style class KeyPressInteractorStyle : public vtkInteractorStyleTrackballCamera { public: static KeyPressInteractorStyle* New(); vtkTypeMacro(KeyPressInteractorStyle, vtkInteractorStyleTrackballCamera); virtual void OnKeyPress() { // Get the keypress vtkRenderWindowInteractor *rwi = this->Interactor; std::string key = rwi->GetKeySym(); // Output the key that was pressed std::cout << "Pressed " << key << std::endl; // Handle an arrow key if(key == "Up") { std::cout << "The up arrow was pressed." << std::endl; } // Handle a "normal" key if(key == "a") { std::cout << "The a key was pressed." << std::endl; } // Forward events vtkInteractorStyleTrackballCamera::OnKeyPress(); } }; vtkStandardNewMacro(KeyPressInteractorStyle); int main(int, char *[]) { vtkSmartPointer<vtkSphereSource> sphereSource = vtkSmartPointer<vtkSphereSource>::New(); sphereSource->SetCenter(0.0, 0.0, 0.0); sphereSource->SetRadius(5.0); sphereSource->Update(); vtkSmartPointer<vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New(); mapper->SetInputConnection(sphereSource->GetOutputPort()); // Create an actor 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); vtkSmartPointer<KeyPressInteractorStyle> style = vtkSmartPointer<KeyPressInteractorStyle>::New(); renderWindowInteractor->SetInteractorStyle(style); style->SetCurrentRenderer(renderer); renderer->AddActor(actor); renderer->SetBackground(1,1,1); // Background color white renderWindow->Render(); renderWindowInteractor->Start(); return EXIT_SUCCESS; }
CMakeLists.txt¶
cmake_minimum_required(VERSION 2.8) PROJECT(KeypressEvents) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(KeypressEvents MACOSX_BUNDLE KeypressEvents.cxx) target_link_libraries(KeypressEvents ${VTK_LIBRARIES})
Download and Build KeypressEvents¶
Danger
The generation of tar files has not been ported to the new VTKExamples. Some tarballs may be missing or out-of-date.
Click here to download KeypressEvents and its CMakeLists.txt file. Once the tarball KeypressEvents.tar has been downloaded and extracted,
cd KeypressEvents/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:
./KeypressEvents
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.