Added QTextEdit and QPlainTextEdit sink

[mguludag]

Hello I've added custom sink for show logs in QTextEdit or QPlainTextEdit widget. Its only dependency is Qt.

[gabime]

Thanks. Could you please merge all to single file called “qt_sinks” ?

[gabime]

Is there a way to avoid the expensive creation of std string? maybe use a string view?

[mguludag]

Ok. I changed it to spdlog::string_view_t but widget's slots accepts QString so constructed QString and emit its signal.

[gabime]

same

[gabime]

Thanks @mguludag

[FlorianWolters]

It took me some time to figure out how-to use qtextedit_sink_mt in qt_sinks.h with CMake v3.21.0 and spdlog v1.9.0.

The following minimal CMake example demonstrates how-to create the MOC generated C++ source file required for qt_sinks.h without using CMAKE_AUTOMOC:BOOL=TRUE. Using CMAKE_AUTOMOC could work in case spdlog is part of the CMake project itself and not an external "installation" by the means of find_package is used.

cmake_minimum_required(VERSION 3.21)

project(spdlog_qt_usage LANGUAGES CXX)

find_package(Qt5 REQUIRED CONFIG COMPONENTS Widgets)
find_package(spdlog REQUIRED CONFIG)

get_target_property(spdlog_include_dir spdlog::spdlog INTERFACE_INCLUDE_DIRECTORIES)
qt5_wrap_cpp(spdlog_qt_moc_source_files "${spdlog_include_dir}/spdlog/sinks/qt_sinks.h")

add_executable(main)
target_link_libraries(main
  PRIVATE
    Qt::Widgets
    spdlog::spdlog
  )
target_sources(main
  PRIVATE
    main.cpp
    ${spdlog_qt_moc_source_files}
  )

Questions:

1. Are there any plans to simplify this?
2. Is it really required that the "private" classes in qt_sinks.h inherit from QObject and use Q_OBJECT? What are the actual use cases for this? Shouldn't it work without the direct dependency to moc?

I think it would be great to have a solution in spdlog that doesn't require to run moc on a spdlog header file (though I think I am missing something here), e.g. refer to a solution like #1898, which doesn't use the class and macro.

[gabime]

Are there any plans to simplify this?

A PR to simplify would be most welcome.

Is it really required that the "private" classes in qt_sinks.h inherit from QObject and use Q_OBJECT? What are the actual use cases for this? Shouldn't it work without the direct dependency to moc?

If you could find a way to simplify this as well, it would be great to get a PR.

[mguludag]

It took me some time to figure out how-to use qtextedit_sink_mt in qt_sinks.h with CMake v3.21.0 and spdlog v1.9.0.

The following minimal CMake example demonstrates how-to create the MOC generated C++ source file required for qt_sinks.h without using CMAKE_AUTOMOC:BOOL=TRUE. Using CMAKE_AUTOMOC could work in case spdlog is part of the CMake project itself and not an external "installation" by the means of find_package is used.

cmake_minimum_required(VERSION 3.21)

project(spdlog_qt_usage LANGUAGES CXX)

find_package(Qt5 REQUIRED CONFIG COMPONENTS Widgets)
find_package(spdlog REQUIRED CONFIG)

get_target_property(spdlog_include_dir spdlog::spdlog INTERFACE_INCLUDE_DIRECTORIES)
qt5_wrap_cpp(spdlog_qt_moc_source_files "${spdlog_include_dir}/spdlog/sinks/qt_sinks.h")

add_executable(main)
target_link_libraries(main
  PRIVATE
    Qt::Widgets
    spdlog::spdlog
  )
target_sources(main
  PRIVATE
    main.cpp
    ${spdlog_qt_moc_source_files}
  )

Questions:

1. Are there any plans to simplify this?
2. Is it really required that the "private" classes in qt_sinks.h inherit from QObject and use Q_OBJECT? What are the actual use cases for this? Shouldn't it work without the direct dependency to moc?

I think it would be great to have a solution in spdlog that doesn't require to run moc on a spdlog header file (though I think I am missing something here), e.g. refer to a solution like #1898, which doesn't use the class and macro.

Thanks for the idea. I will test a simple solution and PR :)

Status 7/2/21 :
I tried solutions and methods like #1898 and It works in GUI thread as expected. But due the Qt's design direct access GUI elements from different thread crashes the application even with mutex 🤔