public interface FlutterPlugin
A Flutter plugin allows Flutter developers to interact with a host platform, e.g., Android and
iOS, via Dart code. It includes platform code, as well as Dart code. A plugin author is
responsible for setting up an appropriate MethodChannel
to communicate between platform code and Dart code.
A Flutter plugin has a lifecycle. First, a developer must add a FlutterPlugin to an
instance of FlutterEngine. To do this, obtain a PluginRegistry with
FlutterEngine.getPlugins(), then call PluginRegistry.add(FlutterPlugin),
passing the instance of the Flutter plugin. During the call to
PluginRegistry.add(FlutterPlugin), the FlutterEngine will invoke
onAttachedToEngine(FlutterPluginBinding) on the given FlutterPlugin. If the
FlutterPlugin is removed from the FlutterEngine via
PluginRegistry.remove(Class), or if the FlutterEngine is destroyed, the
FlutterEngine will invoke onDetachedFromEngine(FlutterPluginBinding)
on the given FlutterPlugin.
Once a FlutterPlugin is attached to a FlutterEngine, the plugin's code is
permitted to access and invoke methods on resources within the FlutterPlugin.FlutterPluginBinding that
the FlutterEngine gave to the FlutterPlugin in
onAttachedToEngine(FlutterPluginBinding). This includes, for example, the application
Context for the running app.
The FlutterPlugin.FlutterPluginBinding provided in onAttachedToEngine(FlutterPluginBinding)
is no longer valid after the execution of onDetachedFromEngine(FlutterPluginBinding).
Do not access any properties of the FlutterPlugin.FlutterPluginBinding after the completion of
onDetachedFromEngine(FlutterPluginBinding).
To register a MethodChannel, obtain a BinaryMessenger
via the FlutterPlugin.FlutterPluginBinding.
An Android Flutter plugin may require access to app resources or other artifacts that can only
be retrieved through a Context. Developers can access the application context via
FlutterPlugin.FlutterPluginBinding.getApplicationContext().
Some plugins may require access to the Activity that is displaying a Flutter experience,
or may need to react to Activity lifecycle events, e.g., onCreate(),
onStart(), onResume(), onPause(), onStop(), onDestroy().
Any such plugin should implement
ActivityAware in addition to implementing
FlutterPlugin. ActivityAware provides callback hooks that expose access to an
associated Activity and its Lifecycle. All plugins must respect the possibility
that a Flutter experience may never be associated with an Activity, e.g., when Flutter
is used for background behavior. Additionally, all plugins must respect that a Activitys
may come and go over time, thus requiring plugins to cleanup resources and recreate those
resources as the Activity comes and goes.
| Modifier and Type | Interface and Description |
|---|---|
static interface |
FlutterPlugin.FlutterAssets
Provides Flutter plugins with access to Flutter asset information.
|
static class |
FlutterPlugin.FlutterPluginBinding
Resources made available to all plugins registered with a given
FlutterEngine. |
| Modifier and Type | Method and Description |
|---|---|
void |
onAttachedToEngine(FlutterPlugin.FlutterPluginBinding binding)
This
FlutterPlugin has been associated with a FlutterEngine instance. |
void |
onDetachedFromEngine(FlutterPlugin.FlutterPluginBinding binding)
This
FlutterPlugin has been removed from a FlutterEngine instance. |
void onAttachedToEngine(@NonNull FlutterPlugin.FlutterPluginBinding binding)
FlutterPlugin has been associated with a FlutterEngine instance.
Relevant resources that this FlutterPlugin may need are provided via the binding.
The binding may be cached and referenced until
onDetachedFromEngine(FlutterPluginBinding) is invoked and returns.
void onDetachedFromEngine(@NonNull FlutterPlugin.FlutterPluginBinding binding)
FlutterPlugin has been removed from a FlutterEngine instance.
The binding passed to this method is the same instance that was passed in
onAttachedToEngine(FlutterPluginBinding). It is provided again in this method as a
convenience. The binding may be referenced during the execution of this method, but
it must not be cached or referenced after this method returns.
FlutterPlugins should release all resources in this method.