meson/docs/markdown/Qt6-module.md

Qt6 module

New in Meson 0.57.0

The Qt6 module provides methods to automatically deal with the various tools and steps required for Qt.

Warning: before version 0.63.0 Meson would fail to find Qt 6.1 or later due to the Qt tools having moved to the libexec subdirectory, and tool names being suffixed with only the Qt major version number e.g. qmake6.

compile_resources

New in 0.59.0

Compiles Qt's resources collection files (.qrc) into c++ files for compilation.

It takes no positional arguments, and the following keyword arguments:

• name (string | empty): if provided a single .cpp file will be generated, and the output of all qrc files will be combined in this file, otherwise each qrc file be written to its own cpp file.
• sources (File | string | custom_target | custom_target index | generator_output)[]: A list of sources to be transpiled. Required, must have at least one source
  New in 0.60.0: support for custom_target, custom_target_index, and generator_output.
• extra_args string[]: Extra arguments to pass directly to qt-rcc
• method string: The method to use to detect Qt, see dependency

compile_ui

New in 0.59.0

Compiles Qt's ui files (.ui) into header files.

It takes no positional arguments, and the following keyword arguments:

• sources (File | string | custom_target | custom_target index | generator_output)[]: A list of sources to be transpiled. Required, must have at least one source
  New in 0.60.0: support for custom_target, custom_target_index, and generator_output.
• extra_args string[]: Extra arguments to pass directly to qt-uic
• method string: The method to use to detect Qt, see dependency
• preserve_paths bool: New in 1.4.0. If true, specifies that the output files need to maintain their directory structure inside the target temporary directory. For instance, when a file called subdir/one.input is processed it generates a file {target private directory}/subdir/one.out when true, and {target private directory}/one.out when false (default).

compile_moc

New in 0.59.0

Compiles Qt's moc files (.moc) into header and/or source files. At least one of the keyword arguments headers and sources must be provided.

It takes no positional arguments, and the following keyword arguments:

• sources (File | string | custom_target | custom_target index | generator_output)[]: A list of sources to be transpiled into .moc files for manual inclusion.
  New in 0.60.0: support for custom_target, custom_target_index, and generator_output.
• headers (File | string | custom_target | custom_target index | generator_output)[]: A list of headers to be transpiled into .cpp files
  New in 0.60.0: support for custom_target, custom_target_index, and generator_output.
• extra_args string[]: Extra arguments to pass directly to qt-moc
• method string: The method to use to detect Qt, see dependency
• dependencies: dependency objects whose include directories are used by moc.
• include_directories (string | IncludeDirectory)[]: A list of include_directory() objects used when transpiling the .moc files
• preserve_paths bool: New in 1.4.0. If true, specifies that the output files need to maintain their directory structure inside the target temporary directory. For instance, when a file called subdir/one.input is processed it generates a file {target private directory}/subdir/one.out when true, and {target private directory}/one.out when false (default).
• output_json bool: New in 1.7.0. If true, generates additionnaly a JSON representation which may be used by external tools such as qmltyperegistrar

preprocess

Consider using compile_resources, compile_ui, and compile_moc instead.

Takes sources for moc, uic, and rcc, and converts them into c++ files for compilation.

Has the following signature: qt.preprocess(name: str | None, *sources: str)

If the name parameter is passed then all of the rcc files will be written to a single output file

Deprecated in 0.59.0: Files given in the variadic sources arguments as well as the sources keyword argument, were passed unmodified through the preprocessor programs. Don't do this - just add the output of preprocess() to another sources list:

sources = files('a.cpp', 'main.cpp', 'bar.c')
sources += qt.preprocess(qresources : ['resources'])

This method takes the following keyword arguments:

• qresources (string | File)[]: Passed to the RCC compiler
• ui_files: (string | File | CustomTarget)[]: Passed the uic compiler
• moc_sources: (string | File | CustomTarget)[]: Passed the moc compiler. These are converted into .moc files meant to be #includeed
• moc_headers: (string | File | CustomTarget)[]: Passed the moc compiler. These will be converted into .cpp files
• include_directories (IncludeDirectories | string)[], the directories to add to header search path for moc
• moc_extra_arguments string[]: any additional arguments to moc.
• uic_extra_arguments string[]: any additional arguments to uic.
• rcc_extra_arguments string[]: any additional arguments to rcc.
• dependencies Dependency[]: dependency objects needed by moc.
• Deprecated in 0.59.0.: sources: a list of extra sources, which are added to the output unchanged.
• preserve_paths bool: Since 1.4.0. If true, specifies that the output files need to maintain their directory structure inside the target temporary directory. For instance, when a file called subdir/one.input is processed it generates a file {target private directory}/subdir/one.out when true, and {target private directory}/one.out when false (default).
• moc_output_json bool: New in 1.7.0. If true, generates additionally a JSON representation which may be used by external tools such as qmltyperegistrar

It returns an array of targets and sources to pass to a compilation target.

compile_translations

This method generates the necessary targets to build translation files with lrelease, it takes no positional arguments, and the following keyword arguments:

• ts_files (File | string | custom_target | custom_target index | generator_output)[]: the list of input translation files produced by Qt's lupdate tool.
  New in 0.60.0: support for custom_target, custom_target_index, and generator_output.
• install bool: when true, this target is installed during the install step (optional).
• install_dir string: directory to install to (optional).
• build_by_default bool: when set to true, to have this target be built by default, that is, when invoking meson compile; the default value is false (optional).
• qresource string: rcc source file to extract ts_files from; cannot be used with ts_files kwarg.
• rcc_extra_arguments string[]: any additional arguments to rcc (optional), when used with `qresource.

Returns either: a list of custom targets for the compiled translations, or, if using a qresource file, a single custom target containing the processed source file, which should be passed to a main build target.

has_tools

This method returns true if all tools used by this module are found, false otherwise.

It should be used to compile optional Qt code:

qt6 = import('qt6')
if qt6.has_tools(required: get_option('qt_feature'))
  moc_files = qt6.preprocess(...)
  ...
endif

This method takes the following keyword arguments:

• required bool | FeatureOption: by default, required is set to false. If required is set to true or an enabled feature and some tools are missing Meson will abort.
• method string: The method to use to detect Qt, see dependency
• tools: string[]: Since 1.6.0. List of tools to check. Testable tools are moc, uic, rcc and lrelease. By default tools is set to ['moc', 'uic', 'rcc', 'lrelease']

qml_module

New in 1.7.0

This function requires one positional argument: the URI of the module as dotted identifier string. For instance Foo.Bar

This method takes the following keyword arguments:

• version: string: the module version in the form Major.Minor with an optional .Patch. For instance 1.0
• qml_sources (File | string | custom_target | custom_target index | generator_output)[]: A list of qml to be embedded in the module
• qml_singletons (File | string | custom_target | custom_target index | generator_output)[]: A list of qml to be embedded in the module and marked as singletons
• qml_internals (File | string | custom_target | custom_target index | generator_output)[]: A list of qml to be embedded in the module and marked as internal files
• resources_prefix string: By default resources_prefix is set to qt/qml. Prefix resources in the generated QRC with the given prefix
• imports: string[]: List of other QML modules imported by this module. Version can be specified as Module/1.0 or Module/auto. See qmldir documentation
• optional_imports: string[]: List of other QML modules that may be imported by this module. See imports for expected format and qmldir documentation
• default_imports: string[]: List QML modules that may be loaded by tooling. See imports for expected format and qmldir documentation
• depends_imports: string[]: List of QML extra dependencies that may not be imported by QML, such as dependencies existing in C++ code. See imports for expected format and qmldir documentation
• designer_supported bool: If true specifies that the module supports Qt Quick Designer
• moc_headers (File | string | custom_target | custom_target index | generator_output)[]: A list of headers to be transpiled into .cpp files. See Qt documentation regarding how to register C++ class as Qml elements. Note: due to some limitations of qmltyperegistrar, all headers that declare QML types need to be accessible in the project's include path.
• namespace: str: optional C++ namespace for plugin and generation code
• typeinfo: str: optional name for the generated qmltype file, by default it will be generated as {target_name}.qmltype
• rcc_extra_arguments: string[]: Extra arguments to pass directly to qt-rcc
• moc_extra_arguments: string[]: Extra arguments to pass directly to qt-moc
• qmlcachegen_extra_arguments: string[]: Extra arguments to pass directly to qmlcachegen
• qmltyperegistrar_extra_arguments: string[]: Extra arguments to pass directly to qmltyperegistrar
• generate_qmldir: bool: If true (default) auto generate the qmldir file
• generate_qmltype: bool: If true (default) auto generate qmltype file
• cachegen: bool: If true (default) preprocess QML and JS files with qmlcachegen
• method string: The method to use to detect Qt, see dependency
• preserve_paths bool: If true, specifies that the output files need to maintain their directory structure inside the target temporary directory. For instance, when a file called subdir/one.input is processed it generates a file {target private directory}/subdir/one.out when true, and {target private directory}/one.out when false (default).
• dependencies: dependency objects whose include directories are used by moc.
• include_directories (string | IncludeDirectory)[]: A list of include_directory() objects used when transpiling the .moc files
• install bool: when true, this target is installed during the install step (optional).
• install_dir string: directory to install to (optional).

Note: Qt uses static initialization to register its resources, if you're building a static library you may need to call these entry points explicitly. For a module Foo.Bar42 the generated resources are Foo_Bar42 and qmlcache_Foo_Bar42 when qmlcache is used, they can be imported using Q_INIT_RESOURCE. All non-alphanumeric characters from the module name are replaced with _. Type registration may be invoked explicitly using extern void qml_register_types_Foo_Bar42().

See Qt documentation for more information

Dependencies

See Qt dependencies

The 'modules' argument is used to include Qt modules in the project. See the Qt documentation for the list of modules.

The 'private_headers' argument allows usage of Qt's modules private headers.

Example

A simple example would look like this:

qt6 = import('qt6')
qt6_dep = dependency('qt6', modules: ['Core', 'Gui'])
inc = include_directories('includes')
moc_files = qt6.compile_moc(headers : 'myclass.h',
                            extra_arguments: ['-DMAKES_MY_MOC_HEADER_COMPILE'],
                            include_directories: inc,
                            dependencies: qt6_dep)
translations = qt6.compile_translations(ts_files : 'myTranslation_fr.ts', build_by_default : true)
executable('myprog', 'main.cpp', 'myclass.cpp', moc_files,
           include_directories: inc,
           dependencies : qt6_dep)

Sometimes, translations are embedded inside the binary using qresource files. In this case the ts files do not need to be explicitly listed, but will be inferred from the built qm files listed in the qresource file. For example:

qt6 = import('qt6')
qt6_dep = dependency('qt6', modules: ['Core', 'Gui'])
lang_cpp = qt6.compile_translations(qresource: 'lang.qrc')
executable('myprog', 'main.cpp', lang_cpp,
           dependencies: qt6_dep)