flutter_system_events

中文文档

One Flutter API for system events: listen to typed changes, or read the current system state on demand.

Use it when your app needs to react to keyboard, lifecycle, network, memory, battery, orientation, time, screen, or brightness changes without wiring several platform listeners yourself.

Installation

dependencies:
  flutter_system_events: ^0.8.0

API

Listen to all events, or subscribe to one typed event group:

SystemEvents.events.listen((event) {});
SystemEvents.keyboard.listen((event) {});
SystemEvents.lifecycle.listen((event) {});
SystemEvents.network.listen((event) {});
SystemEvents.memory.listen((event) {});
SystemEvents.battery.listen((event) {});
SystemEvents.orientation.listen((event) {});
SystemEvents.time.listen((event) {});
SystemEvents.screen.listen((event) {});

Read current values without waiting for the next event:

await SystemEvents.currentNetwork();
await SystemEvents.currentBattery();
await SystemEvents.currentOrientation();
await SystemEvents.currentScreenBrightness();

Usage

Initialize once, then listen to the stream that matches the state your UI cares about.

import 'dart:async';

import 'package:flutter_system_events/flutter_system_events.dart';

StreamSubscription<NetworkEvent>? networkSubscription;

Future<void> startSystemEvents() async {
  await SystemEvents.initialize();

  networkSubscription = SystemEvents.network.listen((event) {
    print('network online=${event.online} type=${event.networkType.name}');
  });

  final battery = await SystemEvents.currentBattery();
  print('battery level=${battery.level} state=${battery.state.name}');
}

Future<void> stopSystemEvents() async {
  await networkSubscription?.cancel();
  await SystemEvents.dispose();
}

You can also handle every event from one stream:

SystemEvents.events.listen((event) {
  switch (event) {
    case KeyboardEvent(:final visible, :final height):
      print('keyboard visible=$visible height=$height');
    case LifecycleEvent(:final state):
      if (state == LifecycleState.resumed) print('refresh data');
    case NetworkEvent(:final online, :final networkType):
      print('network online=$online type=${networkType.name}');
    case MemoryEvent():
      print('memory pressure');
    case BatteryEvent(:final level, :final charging, :final state):
      print('battery level=$level charging=$charging state=${state.name}');
    case OrientationEvent(:final orientation):
      print('orientation=${orientation.name}');
    case TimeEvent(:final reason):
      print('time reason=${reason.name}');
    case ScreenEvent(:final change, :final brightness):
      print('screen change=${change.name} brightness=$brightness');
    case UnknownSystemEvent(:final rawType, :final reason):
      print('unknown event type=$rawType reason=$reason');
  }
});

Event payloads

Event	Field	Meaning
KeyboardEvent	visible	Whether the keyboard is visible.
KeyboardEvent	height	Keyboard height in logical pixels.
LifecycleEvent	state	Current app lifecycle state.
NetworkEvent	online	Whether a network connection is available.
NetworkEvent	networkType	Current network connection type.
MemoryEvent	state	Current memory pressure state.
MemoryEvent	level	Platform-specific memory pressure level.
BatteryEvent	level	Battery level from 0 to 100, or -1 when unavailable.
BatteryEvent	charging	Whether the device is charging or full.
BatteryEvent	state	Current battery state.
OrientationEvent	orientation	Current screen orientation.
TimeEvent	reason	Why a time event was emitted.
ScreenEvent	change	off, on, unlocked, or brightness.
ScreenEvent	brightness	Screen brightness from 0.0 to 1.0 when change is brightness.

Memory events are hints. The plugin reports pressure; your app decides what can be released safely.

Android screen events include off, on, unlocked, and brightness changes. iOS supports unlocked and brightness changes; iOS does not expose reliable public screen off/on notifications for apps.

Platform support

Event	Android	iOS	macOS	Windows	Linux	Web
KeyboardEvent	Yes	Yes	Yes	In progress	In progress	Yes
LifecycleEvent	Yes	Yes	In progress	In progress	In progress	Yes
NetworkEvent	Yes	Yes	In progress	In progress	In progress	Yes
MemoryEvent	Yes	Yes	In progress	In progress	In progress	In progress
BatteryEvent	Yes	Yes	In progress	In progress	In progress	In progress
OrientationEvent	Yes	Yes	In progress	In progress	In progress	In progress
TimeEvent	Yes	Yes	In progress	In progress	In progress	In progress
ScreenEvent	Yes	Partial	In progress	In progress	In progress	In progress

Libraries

flutter_system_events

Listens to selected system-level events from Flutter apps.

flutter_system_events_method_channel

flutter_system_events_platform_interface

flutter_system_events_web