composition.pro Example File
painting/composition/composition.pro
  SOURCES += main.cpp composition.cpp
  HEADERS += composition.h
  SHARED_FOLDER = ../shared
  include($$SHARED_FOLDER/shared.pri)
  RESOURCES += composition.qrc
  qtHaveModule(opengl):!qtConfig(dynamicgl) {
      DEFINES += USE_OPENGL
      QT += opengl
  }
  QT += widgets
  # install
  target.path = $$[QT_INSTALL_EXAMPLES]/widgets/painting/composition
  INSTALLS += target