flutter/packages/flutter_tools/templates/package_ffi

# {{projectName}}

{{description}}

## Getting Started

This project is a starting point for a Flutter
[FFI package](https://docs.flutter.dev/development/platform-integration/c-interop),
a specialized package that includes native code directly invoked with Dart FFI.

## Project structure

This template uses the following structure:

* `src`: Contains the native source code, and a CmakeFile.txt file for building
  that source code into a dynamic library.

* `lib`: Contains the Dart code that defines the API of the plugin, and which
  calls into the native code using `dart:ffi`.

* `bin`: Contains the `build.dart` that performs the external native builds.

## Building and bundling native code

`build.dart` does the building of native components.

Bundling is done by Flutter based on the output from `build.dart`.

## Binding to native code

To use the native code, bindings in Dart are needed.
To avoid writing these by hand, they are generated from the header file
(`src/{{projectName}}.h`) by `package:ffigen`.
Regenerate the bindings by running `flutter pub run ffigen --config ffigen.yaml`.

## Invoking native code

Very short-running native functions can be directly invoked from any isolate.
For example, see `sum` in `lib/{{projectName}}.dart`.

Longer-running functions should be invoked on a helper isolate to avoid
dropping frames in Flutter applications.
For example, see `sumAsync` in `lib/{{projectName}}.dart`.

## Flutter help

For help getting started with Flutter, view our
[online documentation](https://flutter.dev/docs), which offers tutorials,
samples, guidance on mobile development, and a full API reference.