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

This embedder can currently only be built on Linux, not Mac or Windows (native).

If you're using WSL2 (Windows Subsystem for Linux), see SETUP_WINDOWS.md first.

Clone this repository.

git clone https://fuchsia.googlesource.com/flutter-embedder

Set $FUCHSIA_EMBEDDER_DIR to your flutter-embedder.git checkout location, for example ~/flutter-embedder.
```
export FUCHSIA_EMBEDDER_DIR=$HOME/flutter-embedder
```
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

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
```
If you want to use your own build of Fuchsia instead of a prebuilt image, see testing_fuchsia_sdk_changes.md.

Set the default target in ffx to be fuchsia-emulator:

$FUCHSIA_EMBEDDER_DIR/tools/ffx target default set fuchsia-emulator

Run an example component:
```
$FUCHSIA_EMBEDDER_DIR/scripts/build_and_run_example.sh hello_flutter
```
This can also be done from VSCode by following this guide.
- For an arm64 device, run:
```
$FUCHSIA_EMBEDDER_DIR/scripts/build_and_run_example.sh hello_flutter --cpu arm64
```
- To watch logs for the example component, run:
```
$FUCHSIA_EMBEDDER_DIR/scripts/build_and_run_example.sh hello_flutter --log
```
  If you want to watch all logs, run $FUCHSIA_EMBEDDER_DIR/tools/ffx log in a separate terminal.
- To watch FIDL calls for the example component, run:
```
$FUCHSIA_EMBEDDER_DIR/scripts/build_and_run_example.sh hello_flutter --fidl
```
  Caveats:
  - --fidl currently requires using a local Fuchsia SDK instead of the prebuilt Fuchsia SDK. See this guide for setup instructions.
  - --fidl attaches after the component has been run, so it does not pick up FIDL calls made when the component starts.
  TODO(akbiggs): Work with Bazel SDK team to get proper support for --fidl.
- To attach a debugger to the example component, see debugging.md

Running unit tests

To run unit tests for this repository locally, first execute steps 1 & 2 from the previos section, then run the following command:

$FUCHSIA_EMBEDDER_DIR/scripts/tests/run_unittests.sh

There is no CQ for this repository yet.

Uploading changes for review.

See git_workflow.md.

Making Flutter Engine changes

Running the Flutter app is handled by the Flutter Engine's embedder platform code. This code is compiled into a shared library called libflutter_engine.so, which we can interact with using the embedder.h header.

If you need to make changes to this Flutter Engine code (for example for testing a new API in embedder.h with this embedder) see making_engine_changes.md for instructions.

This isn‘t required for changes to only flutter-embedder.git’s source code.

Testing Fuchsia SDK changes

You may want to test changes to the Fuchsia platform (fuchsia.git) against the flutter-embedder repository locally (for example, to validate a WIP API using a Flutter component). To do so, see testing_fuchsia_sdk_changes.md for instructions.

This isn‘t required for changes to only flutter-embedder.git’s source code (in which case you can follow “Run an example app”) or changes to only fuchsia.git's non-SDK code (in which case you can run the example component on an emulator from fuchsia.git). It is only necessary if you have an unsubmitted API in the Fuchsia SDK that you want to test in flutter-embedder.