qt-everywhere-src-5.14.1/qtbase/examples/widgets/mainwindows/sdi/sdi.pro

QT += widgets
requires(qtConfig(filedialog))

HEADERS       = mainwindow.h
SOURCES       = main.cpp \
                mainwindow.cpp
RESOURCES     = sdi.qrc

# install
target.path = $$[QT_INSTALL_EXAMPLES]/widgets/mainwindows/sdi
INSTALLS += target