VTK/Examples/Cxx/Qt/ShowEvent

Description

Small example (not doing anything actually) to show the use of the overwritten QWidget::showEvent() function to initialize the VTK widget when it is actually used, not directly in the constructor.

ShowEventDriver.cxx

#include <QApplication>

#include "ShowEvent.h"

int main(int argc, char *argv[])
{
  QApplication app(argc, argv);
  ShowEvent showEvent;

  showEvent.show();
  return app.exec();
}

ShowEvent.h

#ifndef ShowEventQt_H
#define ShowEventQt_H

#include "ui_ShowEvent.h"

class ShowEvent : public QWidget, private Ui::ShowEvent
{
Q_OBJECT

public:
  ShowEvent(QWidget *parent = 0);

protected:
  void showEvent ( QShowEvent * event );
};

#endif

ShowEvent.cxx

#include <iostream>

#include "ShowEvent.h"

ShowEvent::ShowEvent(QWidget *myParent) : QWidget(myParent)
{
  this->setupUi(this);

  // Do not do anything related to VTK display here!
}

void ShowEvent::showEvent(QShowEvent *)
{
  // Instead, do the VTK display things here!
}

ShowEvent.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>ShowEvent</class>
 <widget class="QWidget" name="ShowEvent">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>312</width>
    <height>243</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>ShowEvent</string>
  </property>
  <layout class="QGridLayout" name="gridLayout">
   <item row="0" column="0">
    <widget class="QGraphicsView" name="graphicsView">
     <property name="backgroundBrush">
      <brush brushstyle="NoBrush">
       <color alpha="255">
        <red>0</red>
        <green>0</green>
        <blue>0</blue>
       </color>
      </brush>
     </property>
    </widget>
   </item>
  </layout>
 </widget>
 <resources/>
 <connections/>
</ui>

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)
 
if(POLICY CMP0020)
  cmake_policy(SET CMP0020 NEW)
endif()

PROJECT(ShowEvent)

find_package(VTK REQUIRED)
include(${VTK_USE_FILE})

if(${VTK_VERSION} VERSION_GREATER "6" AND VTK_QT_VERSION VERSION_GREATER "4")
  # Instruct CMake to run moc automatically when needed.
  set(CMAKE_AUTOMOC ON)
  find_package(Qt5Widgets REQUIRED QUIET)
else()
  find_package(Qt4 REQUIRED)
  include(${QT_USE_FILE})
endif()

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)

if(${VTK_VERSION} VERSION_GREATER "6" AND VTK_QT_VERSION VERSION_GREATER "4")
  qt5_wrap_ui(UISrcs ${UI_FILES} )
  # CMAKE_AUTOMOC in ON so the MOC headers will be automatically wrapped.
  add_executable(ShowEvent MACOSX_BUNDLE
    ${CXX_FILES} ${UISrcs} ${QT_WRAP})
  qt5_use_modules(ShowEvent Core Gui)
  target_link_libraries(ShowEvent ${VTK_LIBRARIES})
else()
  QT4_WRAP_UI(UISrcs ${UI_FILES})
  QT4_WRAP_CPP(MOCSrcs ${QT_WRAP})
  add_executable(ShowEvent MACOSX_BUNDLE ${CXX_FILES} ${UISrcs} ${MOCSrcs})

  if(VTK_LIBRARIES)
    if(${VTK_VERSION} VERSION_LESS "6")
      target_link_libraries(ShowEvent ${VTK_LIBRARIES} QVTK)
    else()
      target_link_libraries(ShowEvent ${VTK_LIBRARIES})
    endif()
  else()
    target_link_libraries(ShowEvent vtkHybrid QVTK vtkViews ${QT_LIBRARIES})
  endif()
endif()

Download and Build ShowEvent

Click here to download ShowEvent. and its CMakeLists.txt file.

Once the tarball ShowEvent.tar has been downloaded and extracted,

cd ShowEvent/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:PATH=/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:

./ShowEvent

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. You may also need to add a Qt related path.