# Package io.flutter.embedding.engine

- Interface Summary
  Interface | Description
  --- | ---
  FlutterEngine.EngineLifecycleListener | Lifecycle callbacks for Flutter engine lifecycle events.
  FlutterJNI.AccessibilityDelegate | Delegate responsible for creating and updating Android-side caches of Flutter's semantics tree and custom accessibility actions.
  FlutterJNI.AsyncWaitForVsyncDelegate |

- Class Summary
  Class | Description
  --- | ---
  FlutterEngine | A single Flutter execution environment.
  FlutterEngineCache | Static singleton cache that holds `FlutterEngine` instances identified by `String`s.
  FlutterEngineGroup | Represents a collection of `FlutterEngine`s who share resources to allow them to be created faster and with less memory than calling the `FlutterEngine`'s constructor multiple times.
  FlutterEngineGroup.Options | Options that control how a FlutterEngine should be created.
  FlutterEngineGroupCache | Static singleton cache that holds `FlutterEngineGroup` instances identified by `String`s.
  FlutterJNI | Interface between Flutter embedding's Java code and Flutter engine's C/C++ code.
  FlutterJNI.Factory | A factory for creating `FlutterJNI` instances.
  FlutterOverlaySurface |
  FlutterShellArgs | Arguments that can be delivered to the Flutter shell when it is created.