# CaptionWidget

VTKExamples/Cxx/Widgets/CaptionWidget

### Code

CaptionWidget.cxx

    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkPolyData.h>
    #include <vtkSmartPointer.h>
    #include <vtkSphereSource.h>
    #include <vtkCaptionWidget.h>
    #include <vtkCaptionRepresentation.h>
    #include <vtkCaptionActor2D.h>
    #include <vtkTextActor.h>
    #include <vtkTextProperty.h>

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

      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);

      // Create the widget and its representation
      vtkSmartPointer<vtkCaptionRepresentation> captionRepresentation =
        vtkSmartPointer<vtkCaptionRepresentation>::New();
      captionRepresentation->GetCaptionActor2D()->SetCaption("Test caption");
      captionRepresentation->GetCaptionActor2D()->GetTextActor()->GetTextProperty()->SetFontSize(100);

      double pos[3] = {.5,0,0};
      captionRepresentation->SetAnchorPosition(pos);

      vtkSmartPointer<vtkCaptionWidget> captionWidget =
        vtkSmartPointer<vtkCaptionWidget>::New();
      captionWidget->SetInteractor(renderWindowInteractor);
      captionWidget->SetRepresentation(captionRepresentation);

      // Add the actors to the scene
      renderer->AddActor(actor);
      renderer->SetBackground(1,0,0);

      renderWindow->Render();
      captionWidget->On();

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

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(CaptionWidget)

    find_package(VTK COMPONENTS
      vtkCommonCore
      vtkCommonDataModel
      vtkFiltersSources
      vtkInteractionStyle
      vtkInteractionWidgets
      vtkRenderingAnnotation
      vtkRenderingCore
      vtkRenderingFreeType
      vtkRenderingOpenGL2 QUIET)
    if (NOT VTK_FOUND)
      message("Skipping CaptionWidget: ${VTK_NOT_FOUND_MESSAGE}")
      return ()
    endif()
    message (STATUS "VTK_VERSION: ${VTK_VERSION}")
    if (VTK_VERSION VERSION_LESS "8.90.0")
      # old system
      include(${VTK_USE_FILE})
      add_executable(CaptionWidget MACOSX_BUNDLE CaptionWidget.cxx )
      target_link_libraries(CaptionWidget PRIVATE ${VTK_LIBRARIES})
    else ()
      # include all components
      add_executable(CaptionWidget MACOSX_BUNDLE CaptionWidget.cxx )
      target_link_libraries(CaptionWidget PRIVATE ${VTK_LIBRARIES})
      # vtk_module_autoinit is needed
      vtk_module_autoinit(
        TARGETS CaptionWidget
        MODULES ${VTK_LIBRARIES}
        )
    endif ()

### Download and Build CaptionWidget

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

    cd CaptionWidget/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:

    ./CaptionWidget

WINDOWS USERS

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