Flutter Linux CPP Embedder

• Desktop Plugin Registry
  • Flutter Pigeon CPP compatible
  • Plugins modeled after Window CPP
  • Plugins enabled/disabled via CMake
  • Firestore first party compatible
• Desktop Texture Registry
  • Camera first party compatible
  • Video Player first party compatible
• Platform View Framework
  • AndroidView widget compatible
• Backend Support
  • EGL
  • Vulkan (first Flutter embedder to support this)
  • Wayland Leased DRM (coming soon)
  • DRM/KMS (coming soon)
• Same source code runs on Desktop and embedded Linux image
  • Ubuntu 18+
  • Fedora 33+
  • Yocto Dunfell/Kirkstone/Scarthgap

ivi-homescreen plugins are located at https://github.com/toyota-connected/ivi-homescreen-plugins

There are two ways to reference this repo:

1. Clone plugins repo to root of ivi-homescreen folder
2. Set PLUGIN_DIR to repo path. -DPLUGIN_DIR=

Logging level support

• trace
• debug
• info
• warn
• error
• critical
• off

If environmental variable SPDLOG_LEVEL is not set, logging defaults to info.

To set logging to trace use

SPDLOG_LEVEL=trace

To set logging to debug use

SPDLOG_LEVEL=debug

To test DLT logging on desktop use the following

Ubuntu packages

sudo apt-get install libdlt-dev dlt-viewer dlt-daemon dlt-tools

Fedora packages

sudo dnf install dlt-libs-devel dlt-daemon dlt-tools

Start new terminal

dlt-daemon

Start new terminal

dlt-receive -a localhost

You can enable the sanitizers with SANITIZE_ADDRESS, SANITIZE_MEMORY, SANITIZE_THREAD or SANITIZE_UNDEFINED options in your CMake configuration. You can do this by passing e.g. -DSANITIZE_ADDRESS=On on your command line.

If sanitizers are supported by your compiler, the specified targets will be built with sanitizer support. If your compiler has no sanitizing capabilities you'll get a warning but CMake will continue processing and sanitizing will simply just be ignored.

This is the default build configuration. To manually build EGL Backend use

-DBUILD_BACKEND_WAYLAND_EGL=ON -DBUILD_BACKEND_WAYLAND_VULKAN=OFF

To build Vulkan Backend use

-DBUILD_BACKEND_WAYLAND_EGL=OFF -DBUILD_BACKEND_WAYLAND_VULKAN=ON

Running Vulkan requires an engine version that supports Vulkan. Stable does not yet support Vulkan.

If an override file is not present, it gets loaded from a default location.

Bundle Override

{bundle path}/data/icudtl.dat

Yocto Default

/usr/share/flutter/icudtl.dat

Desktop Default

/usr/local/share/flutter/icudtl.dat

Bundle Override

{bundle path}/lib/libflutter_engine.so

Yocto/Desktop Default - https://tldp.org/HOWTO/Program-Library-HOWTO/shared-libraries.html

help - Prints all command line options and exits

-b {path to bundle folder} - Sets the Bundle Path. A bundle path expects the following folder structure:

  Flutter Application (bundle folder)
    data/flutter_assets
    data/icudtl.dat (optional - overrides system path)
    lib/libapp.so
    lib/libflutter_engine.so (optional - overrides system path)

If there are multiple references to this option, it will associate a new view per bundle. This example will open two windows sized 1280x1024 both running the Gallery app:

homescreen -b $HOME/workspace-automation/app/gallery/.desktop-homescreen -b $HOME/workspace-automation/app/gallery/.desktop-homescreen -w 1280 -h 1024

-a {int value} - Sets the Engine's initial state of Accessibility Feature support. Requires an integer value.

-disable-cursor - Disables the cursor.

-d - Outputs backend debug information. If Vulkan and Validation Layer are available, it will be loaded.

-f - Sets the window to fullscreen.

-w {int value} - Sets View width. Requires an integer value.

-h {int value} - Sets View height. Requires an integer value.

-i {int value} - Sets ivi-shell surface ID. Requires an integer value.

-p {int value} - Sets Pixel Ratio. Requires a double value.

-t {String} - Sets cursor theme to load. e.g. -t DMZ-White

• -wayland-event-mask - Sets events to ignore. e.g. -wayland-event-mask pointer-axis, or --wayland-event-mask="pointer-axis, touch"

  • Available parameters are: pointer, pointer-axis, pointer-buttons, pointer-motion, keyboard, touch

• Dart VM arguments - any additional command line arguments not handled get directly passed to the Dart VM instance.

app_id - Sets Application ID. Currently only the primary index app_id value is used.

cursor_theme - Sets cursor theme to use. This only applies to command line, and global parameter options.

disable_cursor - Disables the cursor. This only applies to command line, and global parameter options.

debug_backend - Enables Backend Debug logic.

wayland_event_mask - See command line option --wayland-event-mask

debug_backed - Prints out debug information relevant to the backend

vm_args - Array of strings which get passed to the VM instance as command line arguments.

window_type - Currently used for AGL Compositor Window Types. If not running on AGL compositor, it will create borderless windows in no particular position.

width - sets View width. Requires an integer value.

height - sets View height. Requires an integer value.

output_index - select logical index of Wayland output to display on

pixel_ratio - sets the pixel ratio for Flutter engine instance

accessibility_features - Bitmask of Engine Accessibility Features. Requires an integer. See flutter_embedder.h for valid values.

fullscreen - Sets window to fullscreen.

ivi_surface_id - Sets ivi-shell surface ID.

fps_output_console - Setting to 1 FPS count is output to stdout.

fps_output_overlay - If "fps_output_console"=1 and "fps_output_overlay"=1 the screen overlay is enabled.

fps_output_frequency - Optional for FPS. Changing value controls the update interval.

x - x position of activation area

y - y position of activation area

width - width of activation area

height - height of activation area

• Locate config.toml file in the root of your bundle folder
• Comments work
• Any combination of values can be defined.
• Any empty file is valid

[global]
app_id = 'gallery'                 # Application name
cursor_theme = 'Coolbeans'         # Cursor theme used to load cursor icons from
disable_cursor = true              # used to disable cursor
wayland_event_mask = 'keyboard'    # mask the keyboard event
debug_backend = false              # do not print backend debug info

[view]
width = 1920
height = 1080
vm_args = ['--enable-asserts', '--verbose-logging']  # pass parameters to the Dart VM
window_type = 'NORMAL'                               # set window type to Normal
output_index = 2                                     # use second logical occuring wayland output
pixel_ratio = 4.5                                    # set flutter engine pixel ratio
ivi_surface_id = 5002                                # set ivi-shell surface id
accessibility_features = 52                          # set flutter engine accessibility feature flags
fullscreen = false                                   # do not start in fullscreen
fps_output_console = 1
fps_output_overlay = 1
fps_output_frequency = 3

[window_activation_area]
x = 10        # x location
y = 10        # y location
width = 1024
height = 768

Only VM Command Line arguments are additive. Meaning all instances of VM command line references will get added together; JSON view + JSON global + CLI args.

All other parameters get assigned using the following ordering:

1. TOML Configuration View parameters
2. TOML Configuration Global (non-view) parameters
3. Command Line parameters (Overrides anything set in TOML file)

ENABLE_XDG_CLIENT - Enable XDG Client. Defaults to ON

ENABLE_AGL_SHELL_CLIENT - Enable AGL Client. Defaults to OFF

ENABLE_IVI_SHELL_CLIENT - Enable ivi-shell Client. Defaults to OFF

ENABLE_DRM_LEASE_CLIENT - Enable drm lease Client. Defaults to OFF

ENABLE_LTO - Enable Link Time Optimization. Defaults to OFF

ENABLE_DLT - Enable DLT logging. Defaults to OFF

BUILD_BACKEND_WAYLAND_EGL - Build Backend for EGL. Defaults to ON

BUILD_EGL_TRANSPARENCY - Build with EGL Transparency Enabled. Defaults to ON

BUILD_EGL_ENABLE_3D - Build with EGL Stencil, Depth, and Stencil config Enabled. Defaults to ON

BUILD_EGL_ENABLE_MULTISAMPLE - Build with EGL Sample set to 4. Defaults to ON

BUILD_BACKEND_WAYLAND_VULKAN - Build Backed for Vulkan. Defaults to OFF

BUILD_BACKEND_HEADLESS_EGL - Build Headless backend for EGL (OSMesa). Defaults to OFF

DEBUG_PLATFORM_MESSAGES - Dump Platform Channel Messages. Defaults to OFF

BUILD_CRASH_HANDLER - Build Sentry IO Crash Handler Support. Defaults to OFF

BUILD_DOCS - Builds Docs. Defaults to OFF

BUILD_UNIT_TESTS - Build Unit Tests. Defaults to OFF

UNIT_TEST_SAVE_GOLDENS - Update test goldens. Defaults to OFF

EXE_OUTPUT_NAME - Set executable output name. Defaults to homescreen

DISABLE_PLUGINS - Disables all plugins located in the plugins folder. Defaults to OFF

BUILD_PLUGIN_AUDIOPLAYERS_LINUX - Include Audioplayers Linux plugin. Defaults to OFF

BUILD_PLUGIN_CAMERA - Include Camera plugin. Defaults to OFF

BUILD_PLUGIN_CLOUD_FIRESTORE - Plugin Cloud Firestore. Defaults to OFF

BUILD_PLUGIN_DESKTOP_WINDOW_LINUX - Includes Desktop Window Linux Plugin. Defaults to OFF

BUILD_PLUGIN_FILE_SELECTOR - Include File Selector plugin. Defaults to OFF

BUILD_PLUGIN_FIREBASE_AUTH - Plugin Firebase Auth. Defaults to OFF

BUILD_PLUGIN_FIREBASE_STORAGE - Plugin Firebase Storage. Defaults to OFF

BUILD_PLUGIN_GO_ROUTER - Includes Go Router Plugin. Defaults to ON

BUILD_PLUGIN_GOOGLE_SIGN_IN - Include Google Sign In manager. Defaults to OFF

BUILD_PLUGIN_INTEGRATION_TEST - Included Flutter Integration Test support. Defaults to OFF

BUILD_PLUGIN_PDF - Include PDF plugin. Defaults to OFF

BUILD_PLUGIN_SECURE_STORAGE - Includes Flutter Secure Storage. Defaults to OFF

BUILD_PLUGIN_URL_LAUNCHER - Includes URL Launcher Plugin. Defaults to OFF

BUILD_PLUGIN_VIDEO_PLAYER_LINUX - Include Video Player plugin. Defaults to OFF

BUILD_PLUGIN_FILAMENT_VIEW - Include Filament View plugin. Defaults to OFF

BUILD_PLUGIN_LAYER_PLAYGROUND_VIEW - Include Layer Playground View plugin. Defaults to OFF

BUILD_PLUGIN_NAV_RENDER_VIEW - Include Navigation Render View plugin. Defaults to OFF

BUILD_PLUGIN_WEBIVEW_FLUTTER_VIEW - Includes WebView View Plugin. Defaults to OFF

Backend selections (Vulkan, EGL/GLESv2) are mutually exclusive by design.

Running EGL backend on a Lenovo Thinkpad with NVidia drivers may generate many GL runtime errors. This should resolve it:

export __EGL_VENDOR_LIBRARY_FILENAMES=/usr/share/glvnd/egl_vendor.d/50_mesa.json

Log out if logged in Login screen Click on username field Right-click on the gear icon below username field, and select "Ubuntu on Wayland" Enter password and login

Defaults to Wayland, no need to do anything special

sudo add-apt-repository ppa:kisak/kisak-mesa
sudo apt-get update -y
sudo apt-get -y install libwayland-dev wayland-protocols \
mesa-common-dev libegl1-mesa-dev libgles2-mesa-dev mesa-utils \
libxkbcommon-dev

# To build doxygen documentation
sudo apt-get -y install doxygen

git clone https://github.com/toyota-connected-na/ivi-homescreen.git
mkdir build && cd build
cmake .. -DCMAKE_STAGING_PREFIX=`pwd`/out/usr/local
make install -j

git clone https://github.com/toyota-connected-na/ivi-homescreen.git
mkdir build && cd build
CC=/usr/lib/llvm-12/bin/clang CXX=/usr/lib/llvm-12/bin/clang++ cmake .. -DCMAKE_STAGING_PREFIX=`pwd`/out/usr/local
make install -j

wget https://apt.llvm.org/llvm.sh
chmod +x llvm.sh
sudo ./llvm.sh 14
sudo apt-get install -y libc++-14-dev libc++abi-14-dev libunwind-dev

https://github.com/toyota-connected-na/ivi-homescreen/blob/main/.github/workflows/ivi-homescreen-linux.yml

make package -j
sudo apt install ./ivi-homescreen-1.0.0-Release-beta-Linux-x86_64.deb

Release Bundle Folder layout

.desktop-homescreen/
├── data
│ ├── flutter_assets
│ │   └── ... 
│ └── icudtl.dat
├── default_config.json (optional)
└── lib
    ├── libapp.so
    └── libflutter_engine.so

Running the bundle above would be

homescreen --b=`pwd`/.desktop-homescreen --w=1024 --h=768

https://github.com/meta-flutter/workspace-automation

Example usage to run gallery application on Linux desktop

Run once

git clone https://github.com/meta-flutter/workspace-automation
cd workspace_automation
sudo ./flutter_workspace.py

Run for each development session, or new terminal window opened

source ./setup_env.sh
cd app/gallery
flutter run -d desktop-homescreen

flutter_workspace.py installs runtime packages, patches source files, compiles projects, etc.

Note: sudo is required to install runtime packages

Path prefix used to determine required files is determined at build.

For desktop CMAKE_INSTALL_PREFIX defaults to /usr/local For target Yocto builds CMAKE_INSTALL_PREFIX defaults to /usr

Sentry-native support is available for Crash Handling. This pushes a mini-dump to the cloud for triage and tracking.

To create user account and get DNS See https://sentry.io/welcome/

Required CMake Variables

-DBUILD_CRASH_HANDLER=ON
-DCRASH_HANDLER_DSN="dsn from your account"

Required source repo: https://github.com/getsentry/sentry-native

sentry build

git clone https://github.com/getsentry/sentry-native
mkdir build && cd build
cmake .. -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_STAGING_PREFIX=`pwd`/out/usr
make install

ivi-homescreen build

git clone https://github.com/toyota-connected/ivi-homescreen
mkdir build && cd build
cmake .. -DBUILD_CRASH_HANDLER=ON -DCRASH_HANDLER_DSN="dsn from your account"
make -j
LD_LIBRARY_PATH=<sentry staged sysroot install path>/lib homescreen --b=<your bundle folder> --f

https://github.com/meta-flutter/meta-flutter/tree/scarthgap/recipes-graphics/toyota

https://github.com/meta-flutter/meta-flutter/tree/kirkstone/recipes-graphics/toyota

https://github.com/meta-flutter/meta-flutter/tree/dunfell/recipes-graphics/toyota