Qt 6.2 support

Miguel Angel — Fri, 28 Oct 2022 13:51:15 -0000

Hi, sorry for asking as the question may be stupid, but I did not find any information around.
Is there any support available or planned for Qt 6.2?

thanks in advance!

Read QByteArray data from cpp to python list

foghua — Sat, 19 Dec 2020 05:25:07 -0000

Suppose there is a QByteArray object transfered from cpp to python script, how can I read it's data to a python list object? Use while loop to read data byte by byte? Any elegant solution?

Read QByteArray data from cpp to python list

foghua — Sat, 19 Dec 2020 05:25:07 -0000

Suppose there is a QByteArray object transfered from cpp to python script, how can I read it's data to a python list object? Use while loop to read data byte by byte? Any elegant solution?

passing python byte array to C++ function

foghua — Sat, 19 Dec 2020 02:58:36 -0000

you need use a python string as the input parameter

Trying to build with cmake, getting "No Module named PythonQt" error when trying to run Python code

Flower lady — Thu, 03 Dec 2020 04:00:14 -0000

I've done a bit of digging, and noticed that PythonQt simply isn't initializing at all, which is upsetting. I'm reexamining my library paths and seeing if there's a way to figure this out.

Trying to build with cmake, getting "No Module named PythonQt" error when trying to run Python code

Flower lady — Wed, 02 Dec 2020 04:37:22 -0000

So, I will say that I have PythonQt working beautifully with a qmake build. However, times are changing, and so must I. I've ported pretty much everything over into CMake. However, Python is the one thing that is not working quite right. As I said, I'm getting the ModuleNotFoundError: No module named \PythonQt\. So, something is not quite right. I would very much appreciate help in either 1) figuring out what is wrong with my cmake, or 2) figuring out where PythonQt actually defines itself on the Python side so I can debug the code at runtime.

I'm honestly surprised to be running into a bug right this, since it seems like Python and everything linked correctly (I'm not getting any library errors), but I may have lost some dependency that would make PythonQt unhappy (but not raise a compile error? It's weird).

# Project-level setup ====================================================
project( project_name )
cmake_minimum_required( VERSION 3.10 )
set(TARGET_NAME "project_name")


# Find includes in corresponding build directories
set(CMAKE_INCLUDE_CURRENT_DIR ON)

# Instruct CMake to run moc automatically when needed.
set(CMAKE_AUTOMOC ON) # Saves having to usue QT5_WRAP_CPP
set(CMAKE_AUTORCC ON) # Saves having to use QT5_ADD_RESOURCES
set(CMAKE_AUTOUIC ON) # Saves having to use QT5_WRAP_UI


# Set compiler flags =====================================================
# Use C++20
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

# Multiprocess compiler
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /MP")

# Set paths to find Qt ===================================================
# Find Qt itself
if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
    set(CMAKE_PREFIX_PATH "C:\\Qt\\5.12.2\\msvc2017")
else()
    message (WARNING "-------- System not supported ---------")
endif()

# Find UI files
set(CMAKE_AUTOUIC_SEARCH_PATHS "${CMAKE_CURRENT_SOURCE_DIR}/ui")

# Find Required Qt Libraries =============================================
find_package(Qt5 COMPONENTS Core REQUIRED)# Core stuff
find_package(Qt5 COMPONENTS Concurrent REQUIRED) # For threading
find_package(Qt5 COMPONENTS Gamepad REQUIRED) # Controller support
find_package(Qt5 COMPONENTS Gui REQUIRED) # For OpenGL integration
find_package(Qt5 COMPONENTS OpenGLExtensions REQUIRED)
find_package(Qt5 COMPONENTS Multimedia REQUIRED) # Multimedia capabilities
find_package(Qt5 COMPONENTS MultimediaWidgets REQUIRED)
find_package(Qt5 COMPONENTS Widgets REQUIRED) # For widgets

# Set build mode directory options ========================================
# add_definitions(-DAPPLETTUTORIAL1_LIBRARY)
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY_DEBUG ${CMAKE_BINARY_DIR}/debug)
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY_RELEASE ${CMAKE_BINARY_DIR}/release)

# Set directories to find libraries, need to do this before add_executable for desired target
file(TO_CMAKE_PATH "$ENV{PYTHON_LIB}" ENV_PYTHON_LIB)
message(STATUS "Setting link directory ${ENV_PYTHON_LIB}")
link_directories(${ENV_PYTHON_LIB})

# Build EXE ===============================================================
message (STATUS "-------- Finding source, header, resource, UI files relative to  ${CMAKE_SOURCE_DIR} ---------")
file(GLOB_RECURSE MY_SOURCES RELATIVE ${CMAKE_SOURCE_DIR} "src/*.cpp"  "src/*.h"
"resources/*.qrc" "ui/*.ui")

message (STATUS "=========== FOUND FILES =============")
message (STATUS "${MY_SOURCES}")
message (STATUS "=========== END FILES ===============")

# Add an executable to be built from sources variable
add_executable(${TARGET_NAME} ${MY_SOURCES})

# Add compile definitions to the target ===================================
set(DEBUG_DEFINITIONS "DEBUG_MODE")
set(RELEASE_DEFINITIONS "QT_NO_DEBUG_OUTPUT")
target_compile_definitions(${TARGET_NAME} PUBLIC
    $<$<CONFIG:DEBUG>:${DEBUG_DEFINITIONS}>
    $<$<CONFIG:RELEASE>:${RELEASE_DEFINITIONS}>
)

# Pre-processor Defines ===================================================
add_definitions(-D_UNICODE -D_ENABLE_EXTENDED_ALIGNED_STORAGE -DWIN64 -DQT_DLL -DQT_OPENGL_LIB)
add_definitions(-DDEVELOP_MODE)
add_definitions(-DLINALG_USE_EIGEN)

# Disable warnings about deprecated things, like using strcpy (sorry, not sorry)
if(MSVC)
    add_definitions(-D_CRT_SECURE_NO_WARNINGS)
endif()

# Add compile options to the target =======================================
target_link_libraries(${TARGET_NAME} opengl32 glu32)
target_link_libraries(${TARGET_NAME} Qt5::Core)
target_link_libraries(${TARGET_NAME} Qt5::Concurrent) 
target_link_libraries(${TARGET_NAME} Qt5::Gamepad)
target_link_libraries(${TARGET_NAME} Qt5::Gui)
target_link_libraries(${TARGET_NAME} Qt5::OpenGLExtensions) # TODO: Probably unnecessary, remove
target_link_libraries(${TARGET_NAME} Qt5::Multimedia)
target_link_libraries(${TARGET_NAME} Qt5::MultimediaWidgets)
target_link_libraries(${TARGET_NAME} Qt5::Widgets)

# Add additional libraries ================================================
message(STATUS "Default library search directories: ${CMAKE_SOURCE_DIR}/lib ${CMAKE_SOURCE_DIR}/lib/assimp")

# PythonQt
message (STATUS "=========== Including PythonQt =============")
# add_definitions(-DPYTHONQT_USE_RELEASE_PYTHON_FALLBACK)

# For system versions, see: 
# https://stackoverflow.com/questions/9160335/os-specific-instructions-in-cmake-how-to
if(DEFINED ENV{PYTHON_VERSION})
    set(PYTHON_VERSION $ENV{PYTHON_VERSION})
else()
    if(WIN32)
        # for Windows operating system in general
        # if(MSVC OR MSYS OR MINGW) # for detecting Windows compilers
        set(PYTHON_VERSION 38)
    elseif(APPLE)
        # for MacOS X or iOS, watchOS, tvOS (since 3.10.3)
    elseif(UNIX AND NOT APPLE)
        # For Linux, BSD, Solaris, Minix
        set(PYTHON_VERSION 3.8)
    else()
        message( WARNING "Unrecognized operating system")
    endif()
endif()
message (STATUS "PYTHON VERSION $ENV{PYTHON_VERSION}")

# Set up include paths and libraries for Python itself
if(WIN32)
    # for Windows operating system in general
    # if(MSVC OR MSYS OR MINGW) # for detecting Windows compilers

    # Convert paths to CMAKE-friendly versions
    file(TO_CMAKE_PATH "$ENV{PYTHON_PATH}" ENV_PYTHON_PATH)

    # Link Python
    target_include_directories(${TARGET_NAME} PRIVATE "${ENV_PYTHON_PATH}/include")
    message(STATUS "Python include path for windows is ${ENV_PYTHON_PATH}/include")
    message(STATUS "Python path is ${ENV_PYTHON_PATH}")
    find_library(PYTHON_DEBUG_LIB NAMES "python${PYTHON_VERSION}_d" HINTS ${ENV_PYTHON_LIB})
    find_library(PYTHON_RELEASE_LIB NAMES "python${PYTHON_VERSION}" HINTS ${ENV_PYTHON_LIB})
    message(STATUS "Linking Python with debug path ${PYTHON_DEBUG_LIB} and release path ${PYTHON_RELEASE_LIB}")
    target_link_libraries(${TARGET_NAME}
        debug ${PYTHON_DEBUG_LIB} optimized ${PYTHON_RELEASE_LIB}
    )
elseif(APPLE)
    # for MacOS X or iOS, watchOS, tvOS (since 3.10.3)
    message (STATUS "BUILDING FOR APPLE")
    # Include library directory
    target_include_directories(${TARGET_NAME} PRIVATE "/System/Library/Frameworks/Python.framework/Headers")

    # Find library with name Python, and link
    find_library(PYTHON_LIBRARY_PATH NAMES "Python")
    target_link_libraries(${TARGET_NAME}
        ${PYTHON_LIBRARY_PATH}
    )
elseif(UNIX AND NOT APPLE)
    # For Linux, BSD, Solaris, Minix
    message (STATUS "BUILDING FOR UNIX")
    execute_process(COMMAND python${PYTHON_VERSION}-config --embed --libs
        OUTPUT_VARIABLE PYTHON_LIBRARY_PATH
        RESULT_VARIABLE FAILED_TO_DETECT_PYTHON
    )
    if(FAILED_TO_DETECT_PYTHON)
        message (WARNING "Failed to detect Python")
    else()
        # Set library path
        target_link_libraries(${TARGET_NAME} ${PYTHON_LIBRARY_PATH})
    endif()
else()
    message( WARNING "Unrecognized operating system")
endif()

# Include and link PythonQt
set(PYTHON_QT_PATH "${CMAKE_SOURCE_DIR}/../third_party/PythonQt")
set(PYTHON_QT_LIB_PATH "${PYTHON_QT_PATH}/lib")
set(PYTHON_QT_DEBUG_LIB_PATH ${PYTHON_QT_LIB_PATH}/PythonQt-Qt5-Python${PYTHON_VERSION}_d.lib)
set(PYTHON_QT_RELEASE_LIB_PATH ${PYTHON_QT_LIB_PATH}/PythonQt-Qt5-Python${PYTHON_VERSION}.lib)
message(STATUS "Linking PythonQt with debug path ${PYTHON_QT_DEBUG_LIB_PATH} and release path ${PYTHON_QT_RELEASE_LIB_PATH}")
target_include_directories(${TARGET_NAME} PRIVATE "${PYTHON_QT_PATH}/src")
target_link_libraries(${TARGET_NAME} 
    debug "${PYTHON_QT_DEBUG_LIB_PATH}" optimized "${PYTHON_QT_RELEASE_LIB_PATH}")

Is there support for the negation operator using PythonQt::TypeSlots?

Flower lady — Wed, 18 Nov 2020 00:26:18 -0000

I ask because I am trying to get a slot working for getitem, but no dice for me, so I might be using the wrong types. I attempted with :

public slots:
...
    double __getitem__(MyVectorType* v, int idx) const;

Is there support for the negation operator using PythonQt::TypeSlots?

Flower lady — Tue, 17 Nov 2020 02:35:15 -0000

Wonderful, thanks Florian! Any tips on where to go to look up these sorts of things? The documentation is a bit sparse. I can also dig into the code, but there is a LOT of code, and it's hard to tell where the meat of the C++ to Python conversion is happening.

Is there support for the negation operator using PythonQt::TypeSlots?

Florian Link — Mon, 16 Nov 2020 07:36:21 -0000

I looked this up, you actually need an overloaded __sub__ slot without second object, which returns a negated object. This is due to the code generator and c++, where negation and subtraction is the same -operator

Is there support for the negation operator using PythonQt::TypeSlots?

Flower lady — Mon, 16 Nov 2020 01:24:32 -0000

Hey folks, is there a way to support negation for my custom types, e.g., something = -my_type_instance? I have in-place subtraction implemented using the correct flags and overriding iadd in my C++ wrapper for my class, but it seems like negation is a bit different.

Recent posts to Discussion

Qt 6.2 support

Read QByteArray data from cpp to python list

Read QByteArray data from cpp to python list

passing python byte array to C++ function

Trying to build with cmake, getting "No Module named PythonQt" error when trying to run Python code

Trying to build with cmake, getting "No Module named PythonQt" error when trying to run Python code

Is there support for the negation operator using PythonQt::TypeSlots?

Is there support for the negation operator using PythonQt::TypeSlots?

Is there support for the negation operator using PythonQt::TypeSlots?

Is there support for the negation operator using PythonQt::TypeSlots?