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is no longer valid after the execution of onDetachedFromEngine(FlutterPluginBinding).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.