RadioButton

#include <vtkActor.h>
#include <vtkButtonWidget.h>
#include <vtkCameraOrientationWidget.h>
#include <vtkCommand.h>
#include <vtkImageData.h>
#include <vtkInteractorStyleSwitch.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkTexturedButtonRepresentation2D.h>
#include <vtkVersion.h>

#include <array>
#include <vector>

#if VTK_VERSION_NUMBER >= 90520250602ULL
#define USE_VTK5 1
#endif
// #undef USE_VTK5

namespace {

vtkNew<vtkImageData> CreateColorImage(std::string const& color);

class RadioButtonCallback : public vtkCommand
{
public:
  static RadioButtonCallback* New()
  {
    return new RadioButtonCallback;
  }
  void Execute(vtkObject* caller, unsigned long event, void* calldata) override
  {
    if (event == vtkCommand::StateChangedEvent)
    {
      vtkButtonWidget* pressedButton = static_cast<vtkButtonWidget*>(caller);
      int pressedButtonIndex = -1;

      // Find the index of the pressed button.
      for (size_t i = 0; i < this->buttons.size(); ++i)
      {
        if (this->buttons[i] == pressedButton)
        {
          pressedButtonIndex = static_cast<int>(i);
          break;
        }
      }

      // If the pressed button is not already "on", turn it "on" and others
      // "off" Assuming 0 is "off" and 1 is "on".
#ifdef USE_VTK5
      for (size_t i = 0; i < this->buttons.size(); ++i)
      {
        if (i != pressedButtonIndex)
        {
          this->buttons[i]->GetButtonRepresentation()->SetState(0);
        }
        else
        {
          this->buttons[i]->GetButtonRepresentation()->SetState(1);
        }

#else
      if (auto* buttonRep = vtkButtonRepresentation::SafeDownCast(
              pressedButton->GetRepresentation()))
      {
        // Turn "on" the pressed button
        buttonRep->SetState(1);
        // Turn "off" all other buttons in the group
        for (size_t i = 0; i < this->buttons.size(); ++i)
        {
          if (i != pressedButtonIndex)
          {
            buttonRep->SetState(0);
          }
        }
#endif
      }
      // --- Add your radio button specific actions here ---
      // For example, you might print a message indicating
      //  the button pressed and surface selected:
      std::cout << "Radio Button " << pressedButtonIndex << " selected -> ";
      //<< std::endl;
      // Or change the surface property:
      switch (pressedButtonIndex)
      {
      case 1:
        std::cout << "Wireframe" << std::endl;
        actor->GetProperty()->SetRepresentationToWireframe();
        break;
      case 2:
        std::cout << "Points" << std::endl;
        actor->GetProperty()->SetPointSize(10);
        actor->GetProperty()->SetRepresentationToPoints();
        break;
      default:
        std::cout << "Surface" << std::endl;
        actor->GetProperty()->SetRepresentationToSurface();
      }

      // Force a render to update the button appearances.
      if (this->interactor)
      {
        this->interactor->GetRenderWindow()->Render();
      }
    }
  }

  // Add the buttons that belong to this radio group.
  void AddButton(vtkButtonWidget* button)
  {
    this->buttons.push_back(button);
  }

  void SetActor(vtkActor* actor)
  {
    this->actor = actor;
  }
  void SetInteractor(vtkRenderWindowInteractor* interactor)
  {
    this->interactor = interactor;
  }

private:
  std::vector<vtkSmartPointer<vtkButtonWidget>> buttons;
  vtkSmartPointer<vtkRenderWindowInteractor> interactor;
  vtkSmartPointer<vtkActor> actor;
};

} // namespace

int main(int, char*[])
{
  vtkNew<vtkNamedColors> colors;
  colors->SetColor("ParaViewBlueGrayBkg",
                   std::array<unsigned char, 4>{84, 89, 109, 255}.data());
  colors->SetColor("ParaViewWarmGrayBkg",
                   std::array<unsigned char, 4>{98, 93, 90, 255}.data());

  // 1. Create a renderer and render window.
  vtkNew<vtkRenderer> renderer;
  // renderer->SetBackground(colors->GetColor3d("ParaViewBlueGrayBkg").GetData());
  renderer->SetBackground(colors->GetColor3d("ParaViewWarmGrayBkg").GetData());

  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->AddRenderer(renderer);
  renderWindow->SetSize(600, 600);
  renderWindow->SetWindowName("RadioButton");

  // 2. Create an interactor.
  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
  renderWindowInteractor->SetRenderWindow(renderWindow);
  auto is = vtkInteractorStyleSwitch::SafeDownCast(
      renderWindowInteractor->GetInteractorStyle());
  if (is)
  {
    is->SetCurrentStyleToTrackballCamera();
  }

  // 3. Create some geometry.
  vtkNew<vtkSphereSource> sphereSource;
  sphereSource->Update();

  vtkNew<vtkPolyDataMapper> mapper;
  mapper->SetInputConnection(sphereSource->GetOutputPort());

  vtkNew<vtkProperty> actorProp;
  actorProp->SetColor(colors->GetColor3d("Peru").GetData());
  actorProp->SetEdgeColor(colors->GetColor3d("DarkSlateBlue").GetData());
  actorProp->EdgeVisibilityOn();

  vtkNew<vtkActor> actor;
  actor->SetMapper(mapper);
  actor->SetProperty(actorProp);

  // Add the actors to the scene.
  renderer->AddActor(actor);

  // 4. Create textures for button states (on and off).

  // (Assuming you have functions like CreateButtonOn and CreateButtonOff to
  // generate textures) For simplicity, we'll create simple filled squares as
  // textures. You would typically load image files for your desired radio
  // button appearance.
  std::array<std::string, 3> onColors = {"Lavender", "GreenYellow", "Cornsilk"};
  std::array<std::string, 3> offColors = {"Indigo", "ForestGreen", "Sienna"};
  std::array<vtkNew<vtkImageData>, 3> onImages;
  std::array<vtkNew<vtkImageData>, 3> offImages;
  for (int i = 0; i < 3; ++i)
  {
    onImages[i] = CreateColorImage(onColors[i]);
    offImages[i] = CreateColorImage(offColors[i]);
  }
  // vtkNew<vtkImageData> imageOn = CreateImage("Blue");
  // vtkNew<vtkImageData> imageOff = CreateImage("Gray");

  // 5. Create multiple vtkButtonWidget instances.
  std::vector<vtkSmartPointer<vtkButtonWidget>> radioButtons;
  const int numRadioButtons = 3;
  for (int i = 0; i < numRadioButtons; ++i)
  {
    vtkNew<vtkTexturedButtonRepresentation2D> buttonRepresentation;
    buttonRepresentation->SetNumberOfStates(2); // Two states: on and off.
    buttonRepresentation->SetButtonTexture(0, offImages[i]); // State 0: off.
    buttonRepresentation->SetButtonTexture(1, onImages[i]);  // State 1: on.

    // Place the buttons in the scene.
    std::array<double, 6> bounds{0.0, 0.0, 0.0, 100.0, 0.0, 0.0};
    bounds[0] = 215.0 + i * 60.0; // Adjust for spacing.
    bounds[1] = bounds[0] + 50.0;
    buttonRepresentation->PlaceWidget(bounds.data());

    vtkNew<vtkButtonWidget> buttonWidget;
    buttonWidget->SetInteractor(renderWindowInteractor);
    buttonWidget->SetRepresentation(buttonRepresentation);
    buttonWidget->EnabledOn(); // Enable the button.

    radioButtons.push_back(buttonWidget);
  }

  // 6. Create a callback and associate it with the radio buttons.
  vtkNew<RadioButtonCallback> callback;
  callback->SetActor(actor);
  callback->SetInteractor(renderWindowInteractor);
  for (int i = 0; i < numRadioButtons; ++i)
  {
    callback->AddButton(radioButtons[i]);
    radioButtons[i]->AddObserver(vtkCommand::StateChangedEvent, callback);
  }

  // Initialize the first radio button to "on".
  if (!radioButtons.empty())
  {
#ifdef USE_VTK5
    radioButtons[0]->GetButtonRepresentation()->SetState(1);
#else
    if (auto* buttonRep = vtkButtonRepresentation::SafeDownCast(
            radioButtons[0]->GetRepresentation()))
    {
      buttonRep->SetState(1);
    }
#endif
  }

  vtkNew<vtkCameraOrientationWidget> cow;
  cow->SetParentRenderer(renderer);
  // Enable the widget.
  cow->On();

  // 7. Start the interaction.
  renderWindow->Render();
  renderWindowInteractor->Start();

  return 0;
}

namespace {
vtkNew<vtkImageData> CreateColorImage(std::string const& color)
{
  vtkNew<vtkNamedColors> colors;

  std::array<unsigned char, 3> dc{0, 0, 0};
  auto c = colors->GetColor3ub(color).GetData();
  for (auto i = 0; i < 3; ++i)
  {
    dc[i] = c[i];
  }

  vtkNew<vtkImageData> image;
  // Specify the size of the image data.
  image->SetDimensions(10, 10, 1);
  image->AllocateScalars(VTK_UNSIGNED_CHAR, 3);

  auto dims = image->GetDimensions();

  // Fill the image with color.
  for (int y = 0; y < dims[1]; y++)
  {
    for (int x = 0; x < dims[0]; x++)
    {
      unsigned char* pixel =
          static_cast<unsigned char*>(image->GetScalarPointer(x, y, 0));
      for (int i = 0; i < 3; ++i)
      {
        pixel[i] = dc[i];
      }
    }
  }
  return image;
}

} // namespace

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(RadioButton)

find_package(VTK COMPONENTS 
  CommonColor
  CommonCore
  CommonDataModel
  FiltersSources
  InteractionStyle
  InteractionWidgets
  RenderingContextOpenGL2
  RenderingCore
  RenderingFreeType
  RenderingGL2PSOpenGL2
  RenderingOpenGL2
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "RadioButton: Unable to find the VTK build folder.")
endif()

# Prevent a "command line is too long" failure in Windows.
set(CMAKE_NINJA_FORCE_RESPONSE_FILE "ON" CACHE BOOL "Force Ninja to use response files.")
add_executable(RadioButton MACOSX_BUNDLE RadioButton.cxx )
  target_link_libraries(RadioButton PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS RadioButton
  MODULES ${VTK_LIBRARIES}
)

cd RadioButton/build

cmake ..

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

make

./RadioButton