BorderWidgetQt

Description¶

This example draws a border around a region selected with the mouse. Note that the default border color is white - so if you have a white background you will not see anything!

Also see the BorderWidget example.

Question

If you have a question about this example, please use the VTK Discourse Forum

Code¶

BorderWidgetQt.cxx

#include "BorderWidgetQt.h"
#include "ui_BorderWidgetQt.h"

#include <vtkBorderRepresentation.h>
#include <vtkBorderWidget.h>
#include <vtkCamera.h>
#include <vtkCommand.h>
#include <vtkGenericOpenGLRenderWindow.h>
#include <vtkLookupTable.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPlatonicSolidSource.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkVersion.h>
#include <vtkWidgetCallbackMapper.h>
#include <vtkWidgetEvent.h>

#include <iostream>
#include <string>

#if VTK_VERSION_NUMBER >= 89000000000ULL
#define VTK890 1
#endif

namespace {
/** Get a specialised lookup table for the platonic solids.
 *
 * Since each face of a vtkPlatonicSolidSource has a different
 * cell scalar, we create a lookup table with a different colour
 * for each face.
 * The colors have been carefully chosen so that adjacent cells
 * are colored distinctly.
 *
 * @return The lookup table.
 */
vtkNew<vtkLookupTable> GetPlatonicLUT();

class vtkCustomBorderWidget : public vtkBorderWidget
{
public:
  static vtkCustomBorderWidget* New();
  vtkTypeMacro(vtkCustomBorderWidget, vtkBorderWidget);

  static void EndSelectAction(vtkAbstractWidget* w);

  vtkCustomBorderWidget();
};

vtkStandardNewMacro(vtkCustomBorderWidget);

} // namespace

// Constructor
BorderWidgetQt::BorderWidgetQt(QWidget* parent)
  : QMainWindow(parent), ui(new Ui::BorderWidgetQt)
{
  this->ui->setupUi(this);

  vtkNew<vtkNamedColors> colors;

  vtkNew<vtkGenericOpenGLRenderWindow> renderWindow;
#if VTK890
  this->ui->qvtkWidget->setRenderWindow(renderWindow);
#else
  this->ui->qvtkWidget->SetRenderWindow(renderWindow);
#endif

  auto lut = GetPlatonicLUT();

  vtkNew<vtkPlatonicSolidSource> source;
  source->SetSolidTypeToDodecahedron();

  vtkNew<vtkPolyDataMapper> mapper;
  mapper->SetInputConnection(source->GetOutputPort());
  mapper->SetLookupTable(lut);
  mapper->SetScalarRange(0, 19);

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

  vtkNew<vtkRenderer> renderer;
  renderer->AddActor(actor);
  renderer->GetActiveCamera()->Elevation(30.0);
  renderer->GetActiveCamera()->Azimuth(180.0);
  renderer->ResetCamera();
  renderer->SetBackground(colors->GetColor3d("SteelBlue").GetData());

  // Connect VTK with Qt.
#if VTK890
  this->ui->qvtkWidget->renderWindow()->AddRenderer(renderer);
#else
  this->ui->qvtkWidget->GetRenderWindow()->AddRenderer(renderer);
#endif

  // Add a border widget to the renderer.
  this->BorderWidget = vtkNew<vtkCustomBorderWidget>();
#if VTK890
  this->BorderWidget->SetInteractor(this->ui->qvtkWidget->interactor());
#else
  this->borderWidget->SetInteractor(this->ui->qvtkWidget->GetInteractor());
#endif
  this->BorderWidget->CreateDefaultRepresentation();
  this->BorderWidget->SelectableOff();
  this->BorderWidget->On();
}

BorderWidgetQt::~BorderWidgetQt()
{
  delete this->ui;
}

namespace {

vtkNew<vtkLookupTable> GetPlatonicLUT()
{
  vtkNew<vtkLookupTable> lut;
  lut->SetNumberOfTableValues(20);
  lut->SetTableRange(0.0, 19.0);
  lut->Build();
  lut->SetTableValue(0, 0.1, 0.1, 0.1);
  lut->SetTableValue(1, 0, 0, 1);
  lut->SetTableValue(2, 0, 1, 0);
  lut->SetTableValue(3, 0, 1, 1);
  lut->SetTableValue(4, 1, 0, 0);
  lut->SetTableValue(5, 1, 0, 1);
  lut->SetTableValue(6, 1, 1, 0);
  lut->SetTableValue(7, 0.9, 0.7, 0.9);
  lut->SetTableValue(8, 0.5, 0.5, 0.5);
  lut->SetTableValue(9, 0.0, 0.0, 0.7);
  lut->SetTableValue(10, 0.5, 0.7, 0.5);
  lut->SetTableValue(11, 0, 0.7, 0.7);
  lut->SetTableValue(12, 0.7, 0, 0);
  lut->SetTableValue(13, 0.7, 0, 0.7);
  lut->SetTableValue(14, 0.7, 0.7, 0);
  lut->SetTableValue(15, 0, 0, 0.4);
  lut->SetTableValue(16, 0, 0.4, 0);
  lut->SetTableValue(17, 0, 0.4, 0.4);
  lut->SetTableValue(18, 0.4, 0, 0);
  lut->SetTableValue(19, 0.4, 0, 0.4);
  return lut;
}

vtkCustomBorderWidget::vtkCustomBorderWidget()
{
  this->CallbackMapper->SetCallbackMethod(
      vtkCommand::MiddleButtonReleaseEvent, vtkWidgetEvent::EndSelect, this,
      vtkCustomBorderWidget::EndSelectAction);
}

void vtkCustomBorderWidget::EndSelectAction(vtkAbstractWidget* w)
{
  vtkBorderWidget* borderWidget = dynamic_cast<vtkBorderWidget*>(w);

  // Get the actual box coordinates/planes.
  // vtkNew<vtkPolyData> polydata;

  // Get the bottom left corner.
  auto lowerLeft =
      static_cast<vtkBorderRepresentation*>(borderWidget->GetRepresentation())
          ->GetPosition();
  std::cout << "Lower left: " << lowerLeft[0] << " " << lowerLeft[1]
            << std::endl;

  auto upperRight =
      static_cast<vtkBorderRepresentation*>(borderWidget->GetRepresentation())
          ->GetPosition2();
  std::cout << "Upper right: " << lowerLeft[0] + upperRight[0] << " "
            << lowerLeft[1] + upperRight[1] << std::endl;

  vtkBorderWidget::EndSelectAction(w);
}

} // namespace

BorderWidgetQt.h

#ifndef BorderWidgetQt_H
#define BorderWidgetQt_H

#include <QMainWindow>
#include <vtkSmartPointer.h>

class vtkBorderWidget;

/*
 * See "The Single Inheritance Approach" in this link:
 * [Using a Designer UI File in Your C++
 * Application](https://doc.qt.io/qt-5/designer-using-a-ui-file.html)
 */
namespace Ui {
class BorderWidgetQt;
}

class BorderWidgetQt : public QMainWindow
{
  Q_OBJECT
public:
  // Constructor/Destructor
  explicit BorderWidgetQt(QWidget* parent = nullptr);
  virtual ~BorderWidgetQt();

private:
  vtkSmartPointer<vtkBorderWidget> BorderWidget;
  // Designer form
  Ui::BorderWidgetQt* ui;
};

#endif

BorderWidgetQtDriver.cxx

#include <QApplication>
#include <QSurfaceFormat>
#include <QVTKOpenGLNativeWidget.h>

#include "BorderWidgetQt.h"

int main(int argc, char* argv[])
{
  // needed to ensure appropriate OpenGL context is created for VTK rendering.
  QSurfaceFormat::setDefaultFormat(QVTKOpenGLNativeWidget::defaultFormat());

  QApplication app(argc, argv);

  BorderWidgetQt borderWidgetQt;
  borderWidgetQt.show();

  return app.exec();
}

BorderWidgetQt.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>BorderWidgetQt</class>
 <widget class="QMainWindow" name="BorderWidgetQt">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>572</width>
    <height>583</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>BorderWidgetQt</string>
  </property>
  <property name="windowIcon">
   <iconset resource="Icons/icons.qrc">
    <normaloff>:/Icons/help.png</normaloff>:/Icons/help.png</iconset>
  </property>
  <property name="iconSize">
   <size>
    <width>22</width>
    <height>22</height>
   </size>
  </property>
  <widget class="QWidget" name="centralwidget">
   <widget class="QVTKOpenGLNativeWidget" name="qvtkWidget" native="true">
    <property name="geometry">
     <rect>
      <x>10</x>
      <y>20</y>
      <width>511</width>
      <height>541</height>
     </rect>
    </property>
   </widget>
  </widget>
  <action name="actionOpenFile">
   <property name="enabled">
    <bool>true</bool>
   </property>
   <property name="icon">
    <iconset resource="Icons/icons.qrc">
     <normaloff>:/Icons/fileopen.png</normaloff>:/Icons/fileopen.png</iconset>
   </property>
   <property name="text">
    <string>Open File...</string>
   </property>
  </action>
  <action name="actionExit">
   <property name="icon">
    <iconset>
     <normaloff/>
    </iconset>
   </property>
   <property name="text">
    <string>Exit</string>
   </property>
  </action>
  <action name="actionPrint">
   <property name="icon">
    <iconset resource="Icons/icons.qrc">
     <normaloff>:/Icons/print.png</normaloff>:/Icons/print.png</iconset>
   </property>
   <property name="text">
    <string>Print</string>
   </property>
  </action>
  <action name="actionHelp">
   <property name="icon">
    <iconset resource="Icons/icons.qrc">
     <normaloff>:/Icons/help.png</normaloff>:/Icons/help.png</iconset>
   </property>
   <property name="text">
    <string>Help</string>
   </property>
  </action>
  <action name="actionSave">
   <property name="icon">
    <iconset resource="Icons/icons.qrc">
     <normaloff>:/Icons/filesave.png</normaloff>:/Icons/filesave.png</iconset>
   </property>
   <property name="text">
    <string>Save</string>
   </property>
  </action>
 </widget>
 <customwidgets>
  <customwidget>
   <class>QVTKOpenGLNativeWidget</class>
   <extends>QWidget</extends>
   <header>QVTKOpenGLNativeWidget.h</header>
  </customwidget>
 </customwidgets>
 <resources>
  <include location="Icons/icons.qrc"/>
 </resources>
 <connections/>
</ui>

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

if(POLICY CMP0020)
  cmake_policy(SET CMP0020 NEW)
  cmake_policy(SET CMP0071 NEW)
endif()

PROJECT(BorderWidgetQt)

find_package(VTK COMPONENTS 
  GUISupportQt
  RenderingQt
)

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

if(NOT(TARGET VTK::GUISupportQt))
  message(FATAL_ERROR "BorderWidgetQt: VTK not built with Qt support.")
endif()

if(NOT DEFINED VTK_QT_VERSION)
  set(VTK_QT_VERSION 5)
endif()

set(qt_components Core Gui Widgets)
if(${VTK_QT_VERSION} VERSION_GREATER_EQUAL 6)
  list(APPEND qt_components OpenGLWidgets)
endif()
list(SORT qt_components)
# We have ui files, so this will also bring in the macro:
#   qt5_wrap_ui or qt_wrap_ui from Widgets.
find_package(Qt${VTK_QT_VERSION} QUIET
  REQUIRED COMPONENTS ${qt_components}
)

foreach(_qt_comp IN LISTS qt_components)
  list(APPEND qt_modules "Qt${VTK_QT_VERSION}::${_qt_comp}")
endforeach()

message (STATUS "VTK_VERSION: ${VTK_VERSION}, Qt Version: ${Qt${VTK_QT_VERSION}Widgets_VERSION}")

# Instruct CMake to run moc and uic automatically when needed.
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTOUIC ON)

include_directories(${CMAKE_CURRENT_SOURCE_DIR} ${CMAKE_CURRENT_BINARY_DIR})

file(GLOB UI_FILES *.ui)
file(GLOB QT_WRAP *.h)
file(GLOB CXX_FILES *.cxx)

# For VTK versions greater than or equal to 8.90.0:
#  CMAKE_AUTOUIC is ON so we handle uic automatically for Qt targets.
#  CMAKE_AUTOMOC is ON so we handle moc automatically for Qt targets.

# 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.")
# CMAKE_AUTOMOC in ON so the MOC headers will be automatically wrapped.
add_executable(BorderWidgetQt MACOSX_BUNDLE
  ${CXX_FILES} ${UISrcs} ${QT_WRAP}
)
if (Qt${VTK_QT_VERSION}Widgets_VERSION VERSION_LESS "5.11.0")
  qt5_use_modules(BorderWidgetQt ${qt_components})
else()
  target_link_libraries(BorderWidgetQt ${qt_modules})
endif()
target_link_libraries(BorderWidgetQt ${VTK_LIBRARIES})
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS BorderWidgetQt
  MODULES ${VTK_LIBRARIES}
)

Download and Build BorderWidgetQt¶

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

 cd BorderWidgetQt/build

This example requires Qt and VTK.

If VTK and Qt are 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=/home/me/vtk_build ..

If Qt is not found on your system, you will need to tell CMake where to find qmake:

cmake -DQT_QMAKE_EXECUTABLE:FILEPATH=/usr/something/qmake  ..

Build the project:

make

and run it:

./BorderWidgetQt

WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time. You may also need to add a Qt related path.