Introduction

This layer contains recipes/classes/etc. for building Slint's C++ API, as well as the Rust based demos.

For a Rust based application using Slint, use meta-rust directly,

For a C++ based application, the recipes in this layer assume that your application is built using CMake and uses find_package(Slint) to locate Slint, and then uses slint_target_sources to compile .slint files to C++ as well as links against Slint::Slint. For more details, check out our C++ Getting Started. When creating a Bitbake recipe for, use this layer, and in your application's recipe inherit from cmake and slint.

Prerequisites

Meta-slint requires:

meta-openembedded/meta-oe
meta-slint

Check the layer.conf LAYERSERIES_COMPAT_meta for yocto version compatibility

For local version locking just copy the slint-cpp_x.x.x.bb and modify the SLINT_REV and set PREFERRED_VERSION_slint-cpp = "x.x.x" and PREFERRED_VERSION_slint-cpp-native = "x.x.x" in your conf/local.conf`.

Features

For git builds and builds from Slint version 1.3 onwards, certain features are configurable via PACKAGECONFIG.

Feature Name	Description	Enabled by Default
renderer-skia	Skia OpenGL renderer	No
renderer-femtovg	Lightweight FemtoVG OpenGL renderer	Yes
backend-linuxkms	Backend for rendering via KMS/DRM	No
interpreter	C++ API for Slint Interpreter	Yes

Set the PACKAGECONFIG:pn-slint-cpp variable in your conf/local.conf to tweak. For example, to disable the FemtoVG renderer, enable Skia, and the linuxkms backend, set them like this:

PACKAGECONFIG:append:pn-slint-cpp = " backend-linuxkms renderer-skia "
PACKAGECONFIG:remove:pn-slint-cpp = " renderer-femtovg "

Yocto Release Specific Notes

Kirkstone

For compiling against Kirkstone, you need to upgrade Rust to match the minimum required Rust version required by the Slint release you're compiling.

This means that you may have to either backport the rust recipes or add meta-rust to your project.

Mickledore

For compiling against Kirkstone, you need to upgrade Rust to match the minimum required Rust version required by the Slint release you're compiling.

Unfortunately meta-rust does not work with Mickledore at the moment because bitbake's classes directory was split up into classes-global, classes-recipe, and classes. The rust recipes in openembedded-core are in classes-recipe and are thus always found before the rust recipes in meta-rust that are supposed to override them, as they are there located in classes.

A workaround is to cherry-pick a series of commits from upstream oe/master:

• 39e05f9b0fdc3f76f8b80a12989f78614bc9ea5c
• d1af583c290eb0cff5e36363f7531832a863a1a8
• c3eba94ee44adcd3a0aa61f6b087c15c02e4697f
• ad4369d7901c1239e5f07473b1f2517edc4a23ea
• 30637cdeb31fae02544fdc643a455d0ebb126ee6
• d1386bbf2211c7616527e62f2f7b069a935b0d68
• 728c40b939c6af6358a483237298ca834cbb8993

into your local openembedded-core layer.

Compiling the Skia Renderer

The Skia renderer requires clang to compile. The meta-clang layer provides current versions of clang that work with the recipes in this layer.

Building an SDK that contains Slint

With Slint version 1.3 or newer, the nativesdk-slint-cpp package allows for including Slint in your SDK, so that CMake based applications that use Slint and the Slint C++ compiler can be used.

Either add the package to your corresponding package groups or add the following to your conf/local.conf:

TOOLCHAIN_HOST_TASK:append = " nativesdk-slint-cpp"

Building an SDK for external Slint builds

A regular Yocto SDK should be suitable for building Slint against, out of the box. Make sure to source your environment-setup before invoking cmake on the Slint build, and pass -DRust_CARGO_TARGET=<your triplet>.

If your build of Slint enables the Skia renderer (SLINT_FEATURE_RENDERER_SKIA), make sure to include the meta-clang layer in your project and set CLANGSDK = "1" in your conf/local.conf before running the populate_sdk task on your image.

Demo Images

STM32 MPU OpenSTLinux

When building for STM32 MPU OpenSTLinux, adding this meta-slint layer to your environment enables an additional st-example-image-slint image target. In your conf/local.conf set DISTRO = "openstlinux-eglfs" and run bitbake st-example-image-slint to build an image that ships various Slint demos in a minimal image. The demos run directly on the framebuffer with the LinuxKMS backend.

(Tested on stm32mp157-disco)

F&S Elektronik Systeme

When building for F&S Elektronik meta-fus, adding this meta-slint layer to your environment enables an additional fus-image-slint-demos image target.

Steps:

• Add meta-slint
• Add meta-clang
• Add meta-rust
• Edit your conf/local.conf:
  • Make sure DISTRO is set to "fus-imx-wayland"
  • Select the Rust version from meta-rust by adding this line (adjust path to layer accordingly): include ../../sources/meta-rust/conf/distro/include/rust_versions.inc
• Run bitbake fus-image-slint-demos to build an image that ships various Slint demos in a minimal image. The demos run directly on the framebuffer with the LinuxKMS backend.