Qt6 running an example from the documentation

Ivelin

Hello, I am trying to run an example from the documentation

Unfortunately it doesn't come up with any instructions on how to run it with CMake.

I see that there is a CMakeLists.txt file and the only thing I have added is a line, so I can point to where my Qt6 installation is.

That's the changed CMakeLists.txt file:

cmake_minimum_required(VERSION 3.16)
project(androidnotifier LANGUAGES CXX)

set(CMAKE_INCLUDE_CURRENT_DIR ON)

set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)
set(CMAKE_AUTOUIC ON)

if(NOT DEFINED INSTALL_EXAMPLESDIR)
  set(INSTALL_EXAMPLESDIR "examples")
endif()


set(CMAKE_PREFIX_PATH "/home/ivelin/Qt/6.2.4/android_x86_64/lib/cmake") # THAT'S WHAT I HAVE ADDED
find_package(Qt6 COMPONENTS Widgets REQUIRED)

set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/corelib/platform/androidnotifier")

set(PROJECT_SOURCES
        main.cpp
        notificationclient.cpp
        notificationclient.h
)

if(ANDROID)
    qt_add_executable(androidnotifier
        MANUAL_FINALIZATION
        ${PROJECT_SOURCES})
    target_link_libraries(androidnotifier PRIVATE Qt6::Widgets)

    set_property(TARGET androidnotifier APPEND PROPERTY QT_ANDROID_PACKAGE_SOURCE_DIR
                 ${CMAKE_CURRENT_SOURCE_DIR}/android)

    qt_finalize_executable(androidnotifier)

    set(qml_resource_files
        "images/happy.png"
        "images/sad.png"
    )

    qt6_add_resources(androidnotifier "main"
        PREFIX
            "/"
        FILES
            ${qml_resource_files}
    )

    install(TARGETS androidnotifier
        RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
        BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
        LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
    )
endif()

However, after running

cmake .

I get

-- Could NOT find Qt6WidgetsTools (missing: Qt6WidgetsTools_DIR)
CMake Warning at /home/ivelin/Qt/6.2.4/android_x86_64/lib/cmake/Qt6/Qt6Config.cmake:209 (find_package):
  Found package configuration file:

    /home/ivelin/Qt/6.2.4/android_x86_64/lib/cmake/Qt6Widgets/Qt6WidgetsConfig.cmake

  but it set Qt6Widgets_FOUND to FALSE so package "Qt6Widgets" is considered
  to be NOT FOUND.  Reason given by package:

  Target "Qt6::Widgets" was not found.

Call Stack (most recent call first):
  CMakeLists.txt:15 (find_package)


CMake Error at CMakeLists.txt:15 (find_package):
  Found package configuration file:

    /home/ivelin/Qt/6.2.4/android_x86_64/lib/cmake/Qt6/Qt6Config.cmake

  but it set Qt6_FOUND to FALSE so package "Qt6" is considered to be NOT
  FOUND.  Reason given by package:

  Failed to find Qt component "Widgets".

  Expected Config file at
  "/home/ivelin/Qt/6.2.4/android_x86_64/lib/cmake/Qt6Widgets/Qt6WidgetsConfig.cmake"
  exists

I'd basically would want to build the example and run it on my mobile phone.

I have been running through forums, including this one, but I haven't found anything to help me out.

Could someone explain me what's wrong and try to guide me through how to fix it please ?

JoeCFD

@Ivelin Qt 6.2.4 is kind of old. Try to install Qt6.6.1. I tested your Android example with Qt 6.6.1 and got errors. Will check it out later.
Run the example in Qt Creator like
qtcreator(comes with 6.6.1) CMakeLists.ext

cmake alone will not work because NDK, SDK and JDK paths are not set.

Ivelin

@JoeCFD, I do not have problem setting it I am pretty sure so I will try to do that because I have a lot of problems setting my Android kit in Qt Creator and I can't just set it because I am getting weird TLS errors

Ivelin

@JoeCFD, I think I found a way to make that work

I have changed 2 lines in Qt6Config.cmake from

set(Qt6_FOUND FALSE)

to

set(Qt6_FOUND TRUE)

I ran

cmake .

and I got CMakeFiles forder with a notificaitonclient.cpp, CMakeCache.txt and cmake_install.cmake

but now what ? Even though the command output is


-- Configuring done
-- Generating done
-- Build files have been written to: /home/ivelin/Qt/Examples/Qt-6.2.4/corelib/platform/androidnotifier

I find no executable apk file ? Why is that?

What else do I have to do ?

JoeCFD

@Ivelin run
locate .apk
to find where your apk is located and copy it into your device.

Ivelin

@JoeCFD, I tried.

I can't find an apk file anywhere in the current directory.

JoeCFD

@Ivelin did you build? run
make -j4

Ivelin

@JoeCFD

That's what I get after make -j4

JoeCFD

@Ivelin I am not sure if your app is built. I have a dir android-build which you do not have.

run
locate .apk

normally better to
mkdir build
cd build
cmake ..
make

cmake has messy stuff which you do not want it in your project dir.

JoeCFD

@Ivelin take a look at how to pass Android settings to cmake file.
https://developer.android.com/ndk/guides/cmake
What you did will not build.

Ivelin

@JoeCFD, thank you for providing this information. I have clearer picture right now, but I got another problem

At the moment after I do

cmake -DCMAKE_TOOLCHAIN_FILE=/opt/android-ndk/build/cmake/android.toolchain.cmake -DANDROID_ABI=armeabi-v7a -DANDROID_PLATFORM=26 .

I get

-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /opt/android-ndk/toolchains/llvm/prebuilt/linux-x86_64/bin/clang++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
CMake Error at CMakeLists.txt:16 (find_package):
  By not providing "FindQt6.cmake" in CMAKE_MODULE_PATH this project has
  asked CMake to find a package configuration file provided by "Qt6", but
  CMake did not find one.

  Could not find a package configuration file provided by "Qt6" with any of
  the following names:

    Qt6Config.cmake
    qt6-config.cmake

  Add the installation prefix of "Qt6" to CMAKE_PREFIX_PATH or set "Qt6_DIR"
  to a directory containing one of the above files.  If "Qt6" provides a
  separate development package or SDK, be sure it has been installed.


-- Configuring incomplete, errors occurred!
See also "/home/ivelin/Qt/Examples/Qt-6.2.4/corelib/platform/androidnotifier/CMakeFiles/CMakeOutput.log".

which is weird because when I do

cmake .

only

I get

-- The CXX compiler identification is GNU 9.4.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Looking for C++ include pthread.h
-- Looking for C++ include pthread.h - found
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Failed
-- Check if compiler accepts -pthread
-- Check if compiler accepts -pthread - yes
-- Found Threads: TRUE  
-- Could NOT find Qt6WidgetsTools (missing: Qt6WidgetsTools_DIR)
CMake Warning at /home/ivelin/Qt/6.2.4/android_x86_64/lib/cmake/Qt6/Qt6Config.cmake:209 (find_package):
  Found package configuration file:

    /home/ivelin/Qt/6.2.4/android_x86_64/lib/cmake/Qt6Widgets/Qt6WidgetsConfig.cmake

  but it set Qt6Widgets_FOUND to FALSE so package "Qt6Widgets" is considered
  to be NOT FOUND.  Reason given by package:

  Target "Qt6::Widgets" was not found.

Call Stack (most recent call first):
  CMakeLists.txt:16 (find_package)


-- Configuring done
-- Generating done
-- Build files have been written to: /home/ivelin/Qt/Examples/Qt-6.2.4/corelib/platform/androidnotifier

Why is that ? Could you help me out ?

JoeCFD

@Ivelin Can you try?
CMAKE_PREFIX_PATH "/home/ivelin/Qt/6.2.4/android_x86_64/lib/cmake/Qt6"

Ivelin

@JoeCFD said in Qt6 running an example from the documentation:

/home/ivelin/Qt/6.2.4/android_x86_64/lib/cmake/Qt6"

I have set it in the CMakeLists.txt file as

set(CMAKE_PREFIX_PATH "/home/ivelin/Qt/6.2.4/android_x86_64/lib/cmake/Qt6")

Now I get

-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /opt/android-ndk/toolchains/llvm/prebuilt/linux-x86_64/bin/clang++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
CMake Warning at CMakeLists.txt:15 (find_package):
  By not providing "FindQt6.cmake" in CMAKE_MODULE_PATH this project has
  asked CMake to find a package configuration file provided by "Qt6", but
  CMake did not find one.

  Could not find a package configuration file provided by "Qt6" with any of
  the following names:

    Qt6Config.cmake
    qt6-config.cmake

  Add the installation prefix of "Qt6" to CMAKE_PREFIX_PATH or set "Qt6_DIR"
  to a directory containing one of the above files.  If "Qt6" provides a
  separate development package or SDK, be sure it has been installed.


CMake Error at CMakeLists.txt:26 (qt_add_executable):
  Unknown CMake command "qt_add_executable".


-- Configuring incomplete, errors occurred!
See also "/home/ivelin/Qt/Examples/Qt-6.2.4/corelib/platform/androidnotifier/CMakeFiles/CMakeOutput.log".

Ivelin

@JoeCFD, perhaps something is wrong with my toolchain file?

I have downloaded this Qt from Qt creator and I got my ndk, sdk and toolchain file ask from the Android Studio

JoeCFD

@Ivelin Try to upgrade your Qt to 6.6.1 and show your command here. I can test it for you. I guess lower Qt6 versions have more bugs.

Ivelin

@JoeCFD, I have made some progress.

As I said I have downloaded Qt6 from the Qt Maintenance. I looked in the Qt/6.2.4 folder and saw there there is a qt.toolchain.cmake file in Qt/6.2.4/android_x86_64/lib/cmake/Qt6/qt.toolchain.cmake, so I used that one.

It gave me an error that it is searching for /opt/android/android-ndk-r22b, but I hadn't had /opt/android, so I created a folder and downloaded the anroid-ndk-r22b file from the official android ndk downloads. It was also searching for an sdk, but I already had one ( Don't remember where I got it from )

After that I ran this command:

cmake -DCMAKE_TOOLCHAIN_FILE=/home/ivelin/Qt/6.2.4/android_x86_64/lib/cmake/Qt6/qt.toolchain.cmake .

I got

-- The CXX compiler identification is Clang 11.0.5
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /opt/android/android-ndk-r22b/toolchains/llvm/prebuilt/linux-x86_64/bin/clang++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Looking for C++ include pthread.h
-- Looking for C++ include pthread.h - found
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Failed
-- Check if compiler accepts -pthread
-- Check if compiler accepts -pthread - yes
-- Found Threads: TRUE  
-- Performing Test HAVE_STDATOMIC
-- Performing Test HAVE_STDATOMIC - Success
-- Found WrapAtomic: TRUE  
-- Performing Test HAVE_EGL
-- Performing Test HAVE_EGL - Success
-- Found EGL: /opt/android/android-ndk-r22b/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/include (found version "1.5") 
-- Performing Test HAVE_GLESv2
-- Performing Test HAVE_GLESv2 - Success
-- Found GLESv2: /opt/android/android-ndk-r22b/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/include  
-- Found WrapVulkanHeaders: /opt/android/android-ndk-r22b/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/include  
-- Found android platform plugin at: /home/ivelin/Qt/6.2.4/android_x86_64/./plugins/platforms/libplugins_platforms_qtforandroid_x86_64.so
-- Configuring done
-- Generating done
-- Build files have been written to: /home/ivelin/Qt/Examples/Qt-6.2.4/corelib/platform/androidnotifier

which seems like a successful build. Then I ran make and got

Why is that ? Any ideas on how to fix it ?

JoeCFD

@Ivelin Read the error messages. Install Android studio and then use it to install SDK build tool 30.0.2.

Ivelin

@JoeCFD, sorry that was a stupid mistake from mine.

I have installed the corresponding SDK from Android Studio and moved the file from where the Android Studio was configured to download it to where qt6 cmake is searching for it - /opt/android and now it is working.

Thank you for your patience and support. I wouldn't make it without your patience and guidance.

Cheers.