CMake: How do I add files to application target using multiple CMakeLists.txt files?

[Toppler]

When I add a QML_ELEMENT class (cpp and h) files to cmake variable CPP_AND_H_PROJECT_FILES and then use it in qt_add_executable, everything works fine.

But when I add the same two files in that same variable in a CMakeLists.txt that is located in the same directory where the files are, Qt Creator and QQmlApplicationEngine do not recognize the class/files anymore. Everything still compiles correctly and I can even use a static member of that class in main.

Qt Creator Projects tree does not show the files and QQmlApplicationEngine runtime error says:

QQmlApplicationEngine failed to load component
qrc:/d230404b_project_test/Main.qml:12:5: TestValue is not a type

How do I tell QT Creator and QQmlApplicationEngine that the files are added?

github.com/T0pp1er/d230404b_project_test

cmake_minimum_required(VERSION 3.16)

project(d230404b_project_test VERSION 0.1 LANGUAGES CXX)

set(CMAKE_CXX_STANDARD_REQUIRED ON)

find_package(Qt6 6.4 REQUIRED COMPONENTS Quick)

qt_standard_project_setup()

set(CPP_AND_H_PROJECT_FILES main.cpp)


### THIS WORKS ##########################################

# set(CPP_AND_H_PROJECT_FILES ${CPP_AND_H_PROJECT_FILES}
#     values/testvalue.h
#     values/testvalue.cpp
# )
# include_directories(values)

### THIS DOES NOT WORK (but compiles correctly) #########

set(VALUES_DIR values)
add_subdirectory(${VALUES_DIR})

        # #values/CMakeLists.txt
        #
        # set(CPP_AND_H_PROJECT_FILES ${CPP_AND_H_PROJECT_FILES}
        #     ${VALUES_DIR}/testvalue.h
        #     ${VALUES_DIR}/testvalue.cpp
        # )
        # include_directories(${VALUES_DIR})

#########################################################


qt_add_executable(appd230404b_project_test
    ${CPP_AND_H_PROJECT_FILES}
)

qt_add_qml_module(appd230404b_project_test
    URI d230404b_project_test
    VERSION 1.0
    QML_FILES Main.qml
)

set_target_properties(appd230404b_project_test PROPERTIES
    MACOSX_BUNDLE_GUI_IDENTIFIER my.example.com
    MACOSX_BUNDLE_BUNDLE_VERSION ${PROJECT_VERSION}
    MACOSX_BUNDLE_SHORT_VERSION_STRING ${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}
    MACOSX_BUNDLE TRUE
    WIN32_EXECUTABLE TRUE
)

target_link_libraries(appd230404b_project_test
    PRIVATE Qt6::Quick
)

install(TARGETS appd230404b_project_test
    BUNDLE DESTINATION .
    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})

[Toppler]

The magical entity that creates ".qmltypes" file and registers components seems to only see one CMakeLists.txt file, despite add_subdirectory. You need to manually tell in the same CMakeLists.txt where qt_add_qml_module is where the source files are using SOURCES parameter.

I just tried to have something similar to qmake project include (.pri) files.

Seems like one CMakeLists.txt file per target is the simplest way to.

Here is something that works:

# CMakeLists.txt

cmake_minimum_required(VERSION 3.16)

project(d230406a_project_test_b VERSION 0.1 LANGUAGES CXX)

set(CMAKE_CXX_STANDARD_REQUIRED ON)

find_package(Qt6 6.4 REQUIRED COMPONENTS Quick)

qt_standard_project_setup()

set(CPP_AND_H_PROJECT_FILES)

set(VALUES_DIR values)

add_subdirectory(${VALUES_DIR})
        # values/CMakeLists.txt:
        # set(CPP_AND_H_PROJECT_FILES ${CPP_AND_H_PROJECT_FILES}
        #     ${VALUES_DIR}/testvalue.h
        #     ${VALUES_DIR}/testvalue.cpp
        # )
include_directories(${VALUES_DIR})

qt_add_executable(appd230406a_project_test_b
    main.cpp ${CPP_AND_H_PROJECT_FILES}
)

qt_add_qml_module(appd230406a_project_test_b
    URI d230406a_project_test_b
    VERSION 1.0
    QML_FILES Main.qml
    SOURCES values/testvalue.h values/testvalue.cpp
    #SOURCES ${CPP_AND_H_PROJECT_FILES} # THIS DOES NOT WORK
)

set_target_properties(appd230406a_project_test_b PROPERTIES
    MACOSX_BUNDLE_GUI_IDENTIFIER my.example.com
    MACOSX_BUNDLE_BUNDLE_VERSION ${PROJECT_VERSION}
    MACOSX_BUNDLE_SHORT_VERSION_STRING ${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}
    MACOSX_BUNDLE TRUE
    WIN32_EXECUTABLE TRUE
)

target_link_libraries(appd230406a_project_test_b
    PRIVATE Qt6::Quick
)

install(TARGETS appd230406a_project_test_b
    BUNDLE DESTINATION .
    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})

# values/CmakeLists.txt

set(CPP_AND_H_PROJECT_FILES ${CPP_AND_H_PROJECT_FILES}
    ${VALUES_DIR}/testvalue.h
    ${VALUES_DIR}/testvalue.cpp
)

#include_directories(${VALUES_DIR}) # THIS DOES NOT WORK