Struct qt_build_utils::QtBuild

pub struct QtBuild { /* private fields */ }

Helper for build.rs scripts using Qt

let qt_modules = vec!["Core", "Gui"]
    .iter()
    .map(|m| String::from(*m))
    .collect();
let qtbuild = qt_build_utils::QtBuild::new(qt_modules).expect("Could not find Qt installation");

Implementations

impl QtBuild

pub fn new(qt_modules: Vec<String>) -> Result<Self, QtBuildError>

Search for where Qt is installed using qmake. Specify the Qt modules you are linking with the qt_modules parameter, ommitting the Qt prefix ("Core" rather than "QtCore"). After construction, use the QtBuild::qmake_query method to get information about the Qt installation.

The directories specified by the PATH environment variable are where qmake is searched for. Alternatively, the QMAKE environment variable may be set to specify an explicit path to qmake.

If multiple major versions (for example, 5 and 6) of Qt could be installed, set the QT_VERSION_MAJOR environment variable to force which one to use. When using Cargo as the build system for the whole build, prefer using QT_VERSION_MAJOR over the QMAKE environment variable because it will account for different names for the qmake executable that some Linux distributions use.

However, when building a Rust staticlib that gets linked to C++ code by a C++ build system, it is best to use the QMAKE environment variable to ensure that the Rust staticlib is linked to the same installation of Qt that the C++ build system has detected. With CMake, you can get this from the Qt::qmake target’s IMPORTED_LOCATION property, for example:

find_package(Qt6 COMPONENTS Core)
if(NOT Qt6_FOUND)
    find_package(Qt5 5.15 COMPONENTS Core REQUIRED)
endif()
get_target_property(QMAKE Qt::qmake IMPORTED_LOCATION)

execute_process(
    COMMAND cmake -E env
        "CARGO_TARGET_DIR=${CMAKE_CURRENT_BINARY_DIR}/cargo"
        "QMAKE=${QMAKE}"
        cargo build
    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
)

pub fn qmake_query(&self, var_name: &str) -> String

Get the output of running qmake -query var_name

pub fn cargo_link_libraries(&self)

Tell Cargo to link each Qt module.

pub fn include_paths(&self) -> Vec<PathBuf>

Get the include paths for Qt, including Qt module subdirectories. This is intended to be passed to whichever tool you are using to invoke the C++ compiler.

pub fn version(&self) -> &SemVer

Version of the detected Qt installation

pub fn moc(&mut self, input_file: impl AsRef<Path>) -> MocProducts

Run moc on a C++ header file and save the output into cargo’s OUT_DIR. The return value contains the path to the generated C++ file, which can then be passed to cc::Build::files, as well as the path to the generated metatypes.json file, which can be passed to register_qml_types.

pub fn register_qml_types( &mut self, metatypes_json: &[impl AsRef<Path>], major_version: usize, minor_version: usize, import_name: &str ) -> QmlTypeRegistrationFiles

Generate C++ files to automatically register a QML element at build time using the JSON output from moc

pub fn qrc(&mut self, input_file: &impl AsRef<Path>) -> PathBuf

Run rcc on a .qrc file and save the output into cargo’s OUT_DIR. The path to the generated C++ file is returned, which can then be passed to cc::Build::files. The compiled static library must be linked with +whole-archive or the linker will discard the generated static variables because they are not referenced from main.