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
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.