How to link Qt 5.9 in ROS? - cmake

Question

The following CMakeList produces errors which have been listed below:
cmake_minimum_required(VERSION 2.8.12)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
set(CMAKE_INCLUDE_CURRENT_DIR ON)
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)
project(draw_on_images)
find_package(catkin REQUIRED COMPONENTS
roscpp
rospy
std_msgs
)
find_package(OpenCV 2.4.8 REQUIRED)
find_package(Qt5 COMPONENTS Core Qml Quick REQUIRED)
qt5_add_resources(RESOURCES qml.qrc)
catkin_package(
CATKIN_DEPENDS roscpp rospy std_msgs
)
include_directories(
${catkin_INCLUDE_DIRS}
)
add_executable(${PROJECT_NAME} ${RESOURCES} src/main.cpp src/draw_on_qimage.cpp src/provide_qpixmap_to_qml.cpp )
qt5_use_modules(${PROJECT_NAME} Core Qml Quick)
target_link_libraries(${PROJECT_NAME} Qt5::Core Qt5::Qml Qt5::Quick ${OpenCV_LIBS})
The way I run it:
catkin_make -DCMAKE_PREFIX_PATH="/opt/Qt5.9.1/5.9.1/gcc_64/lib/" -DWITH_QT:BOOL=ON
Yes I have sourced it.
Errors:
Base path: /home/.../ros_workspace_test
Source space: /home/.../ros_workspace_test/src
Build space: /home/.../ros_workspace_test/build
Devel space: /home/.../ros_workspace_test/devel
Install space: /home/.../ros_workspace_test/install
####
#### Running command: "cmake /home/.../ros_workspace_test/src -DCMAKE_PREFIX_PATH=/opt/Qt5.9.1/5.9.1/gcc_64/lib/ -DWITH_QT:BOOL=ON -DCATKIN_DEVEL_PREFIX=/home/.../ros_workspace_test/devel -DCMAKE_INSTALL_PREFIX=/home/.../ros_workspace_test/install -G Unix Makefiles" in "/home/.../ros_workspace_test/build"
####
-- Using CATKIN_DEVEL_PREFIX: /home/.../ros_workspace_test/devel
-- Using CMAKE_PREFIX_PATH: /opt/Qt5.9.1/5.9.1/gcc_64/lib/
-- Using PYTHON_EXECUTABLE: /usr/bin/python
-- Using Debian Python package layout
-- Using empy: /usr/bin/empy
-- Using CATKIN_ENABLE_TESTING: ON
-- Call enable_testing()
-- Using CATKIN_TEST_RESULTS_DIR: /home/.../ros_workspace_test/build/test_results
-- Found gtest sources under '/usr/src/gtest': gtests will be built
-- Using Python nosetests: /usr/bin/nosetests-2.7
-- catkin 0.6.19
-- BUILD_SHARED_LIBS is on
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- ~~ traversing 1 packages in topological order:
-- ~~ - draw_on_images
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- +++ processing catkin package: 'draw_on_images'
-- ==> add_subdirectory(draw_on_images)
-- Configuring done
-- Generating done
CMake Warning:
Manually-specified variables were not used by the project:
WITH_QT
-- Build files have been written to: /home/.../ros_workspace_test/build
####
#### Running command: "make -j4 -l4" in "/home/.../ros_workspace_test/build"
####
[ 14%] Automoc for target draw_on_images
[ 14%] Built target draw_on_images_automoc
Linking CXX executable /home/.../ros_workspace_test/devel/lib/draw_on_images/draw_on_images
CMakeFiles/draw_on_images.dir/src/main.cpp.o: In function `int qmlRegisterType<Draw_on_qimage>(char const*, int, int, char const*)':
main.cpp:(.text._Z15qmlRegisterTypeI14Draw_on_qimageEiPKciiS2_[_Z15qmlRegisterTypeI14Draw_on_qimageEiPKciiS2_]+0x38): undefined reference to `Draw_on_qimage::staticMetaObject'
main.cpp:(.text._Z15qmlRegisterTypeI14Draw_on_qimageEiPKciiS2_[_Z15qmlRegisterTypeI14Draw_on_qimageEiPKciiS2_]+0x1b6): undefined reference to `Draw_on_qimage::staticMetaObject'
CMakeFiles/draw_on_images.dir/src/main.cpp.o: In function `Draw_on_qimage::~Draw_on_qimage()':
main.cpp:(.text._ZN14Draw_on_qimageD2Ev[_ZN14Draw_on_qimageD5Ev]+0x13): undefined reference to `vtable for Draw_on_qimage'
main.cpp:(.text._ZN14Draw_on_qimageD2Ev[_ZN14Draw_on_qimageD5Ev]+0x25): undefined reference to `vtable for Draw_on_qimage'
CMakeFiles/draw_on_images.dir/src/main.cpp.o: In function `QMetaTypeIdQObject<Draw_on_qimage*, true>::qt_metatype_id()':
main.cpp:(.text._ZN18QMetaTypeIdQObjectIP14Draw_on_qimageLb1EE14qt_metatype_idEv[_ZN18QMetaTypeIdQObjectIP14Draw_on_qimageLb1EE14qt_metatype_idEv]+0x2c): undefined reference to `Draw_on_qimage::staticMetaObject'
CMakeFiles/draw_on_images.dir/src/main.cpp.o: In function `QtPrivate::MetaObjectForType<Draw_on_qimage*, true>::value()':
main.cpp:(.text._ZN9QtPrivate17MetaObjectForTypeIP14Draw_on_qimageLb1EE5valueEv[_ZN9QtPrivate17MetaObjectForTypeIP14Draw_on_qimageLb1EE5valueEv]+0x7): undefined reference to `Draw_on_qimage::staticMetaObject'
CMakeFiles/draw_on_images.dir/src/main.cpp.o:(.data.rel.ro._ZTVN11QQmlPrivate11QQmlElementI14Draw_on_qimageEE[_ZTVN11QQmlPrivate11QQmlElementI14Draw_on_qimageEE]+0x10): undefined reference to `Draw_on_qimage::metaObject() const'
CMakeFiles/draw_on_images.dir/src/main.cpp.o:(.data.rel.ro._ZTVN11QQmlPrivate11QQmlElementI14Draw_on_qimageEE[_ZTVN11QQmlPrivate11QQmlElementI14Draw_on_qimageEE]+0x18): undefined reference to `Draw_on_qimage::qt_metacast(char const*)'
CMakeFiles/draw_on_images.dir/src/main.cpp.o:(.data.rel.ro._ZTVN11QQmlPrivate11QQmlElementI14Draw_on_qimageEE[_ZTVN11QQmlPrivate11QQmlElementI14Draw_on_qimageEE]+0x20): undefined reference to `Draw_on_qimage::qt_metacall(QMetaObject::Call, int, void**)'
CMakeFiles/draw_on_images.dir/src/main.cpp.o:(.data.rel.ro._ZTIN11QQmlPrivate11QQmlElementI14Draw_on_qimageEE[_ZTIN11QQmlPrivate11QQmlElementI14Draw_on_qimageEE]+0x10): undefined reference to `typeinfo for Draw_on_qimage'
CMakeFiles/draw_on_images.dir/src/main.cpp.o: In function `Provide_QPixmap_to_QML::~Provide_QPixmap_to_QML()':
main.cpp:(.text._ZN22Provide_QPixmap_to_QMLD2Ev[_ZN22Provide_QPixmap_to_QMLD5Ev]+0x13): undefined reference to `vtable for Provide_QPixmap_to_QML'
main.cpp:(.text._ZN22Provide_QPixmap_to_QMLD2Ev[_ZN22Provide_QPixmap_to_QMLD5Ev]+0x25): undefined reference to `vtable for Provide_QPixmap_to_QML'
CMakeFiles/draw_on_images.dir/src/draw_on_qimage.cpp.o: In function `Draw_on_qimage::Draw_on_qimage(QQuickPaintedItem*)':
draw_on_qimage.cpp:(.text+0x4b): undefined reference to `vtable for Draw_on_qimage'
draw_on_qimage.cpp:(.text+0x5d): undefined reference to `vtable for Draw_on_qimage'
CMakeFiles/draw_on_images.dir/src/provide_qpixmap_to_qml.cpp.o: In function `Provide_QPixmap_to_QML::Provide_QPixmap_to_QML()':
provide_qpixmap_to_qml.cpp:(.text+0x52): undefined reference to `vtable for Provide_QPixmap_to_QML'
provide_qpixmap_to_qml.cpp:(.text+0x64): undefined reference to `vtable for Provide_QPixmap_to_QML'
collect2: error: ld returned 1 exit status
make[2]: *** [/home/.../ros_workspace_test/devel/lib/draw_on_images/draw_on_images] Error 1
make[1]: *** [draw_on_images/CMakeFiles/draw_on_images.dir/all] Error 2
make: *** [all] Error 2
Invoking "make -j4 -l4" failed
How to link Qt 5.9 in ROS?
I am using Ubuntu 14.

Answer 1

Solution was to add the header files to add_executable in CMakelists.txt:
add_executable(${PROJECT_NAME} ${RESOURCES}
src/main.cpp
include/draw_on_images/draw_on_qimage.h src/draw_on_qimage.cpp
include/draw_on_images/provide_qpixmap_to_qml.h src/provide_qpixmap_to_qml.cpp)

Answer 2

My guess is that CMake's AUTOMOC fails in this case. See the documentation here https://cmake.org/cmake/help/v3.0/prop_tgt/AUTOMOC.html
It asserts, that the header file of your class Draw_on_qimage is similarly named as the source file and is locatable by CMake.
You can avoid AUTOMOC by manually running moc on your header for your QObject-derived class like this
QT5_WRAP_CPP(MOC_SOURCES <path of header file of your class Draw_on_qimage>)
add_executable(${PROJECT_NAME} ${RESOURCES} src/main.cpp src/draw_on_qimage.cpp ${MOC_SOURCES} src/provide_qpixmap_to_qml.cpp