flutter-embedder.git

The Flutter Embedder for Fuchsia is a new in-progress runtime for Flutter apps on Fuchsia. This runtime is built on top of Flutter's embedder platform.

This repository is a work in progress and should be considered experimental.

Requirements

  1. Set $FUCHSIA_EMBEDDER_DIR to your flutter-embedder.git checkout location, for example ~/flutter-embedder.

    export FUCHSIA_EMBEDDER_DIR=$HOME/flutter-embedder

  2. Bootstrap the repository's dependencies:

    $FUCHSIA_EMBEDDER_DIR/scripts/bootstrap.sh

    This script initializes tools (including bazel and ffx), installs some Git hooks and downloads the workstation_eng.qemu-x64 product bundle, which you can use to run the examples below.

Run an example app

  1. Start the emulator.

    If running in a graphical environment:

    $FUCHSIA_EMBEDDER_DIR/tools/ffx emu start workstation_eng.qemu-x64

    If running in a terminal environment:

    $FUCHSIA_EMBEDDER_DIR/tools/ffx emu start --headless workstation_eng.qemu-x64

  2. (optional) Watch the device log in a separate window:

    $FUCHSIA_EMBEDDER_DIR/tools/ffx log

  3. Run an example app:

    $FUCHSIA_EMBEDDER_DIR/scripts/build_and_run_example.sh hello_flutter

TODO(akbiggs): The app occasionally gets stuck on a loading screen instead of rendering. Re-running the app usually fixes it. We need to fix this.

Syncing engine artifacts

Occasionally you will need to update the Flutter Engine artifacts (embedder.h and libengine_flutter.so) that are used by the embedder to run Flutter apps. A script is provided for this workflow.

Requirements

  1. You will need to get the Flutter Engine source code. Note that this is not just cloning https://github.com/flutter/engine.
  2. Set $ENGINE_DIR to the src folder of your Flutter Engine checkout location, for example ~/engine/src.
  3. $DEPOT_TOOLS should be set to your depot_tools location, for example ~/depot_tools.
  4. You will need to git stash or git commit any local changes to the Flutter Engine or the script will fail.

Running the script

You can run the script with a flutter/engine Git commit to sync the Engine artifacts to that revision.

$FUCHSIA_EMBEDDER_DIR/scripts/sync_engine_artifacts_to_revision.sh <ENGINE_COMMIT_SHA>

A common workflow is to sync your Engine commit to the Flutter tool in this repository, for example when updating the Flutter tool to a new version. To do this:

$FUCHSIA_EMBEDDER_DIR/scripts/sync_engine_artifacts_to_revision.sh $(cat $FUCHSIA_EMBEDDER_DIR/third_party/dart-pkg/internal/flutter/flutter/bin/internal/engine.version)