I am using WidgetsBindingObserver to check the platform brightness, it works well when the app is up and running. The app can detect the platform brightness changes by user. However when the app is closed and reopen again. The initial startup the method "didChangePlatformBrightness()" did not run at all for Android but it was executed for IOS. Why is this so?
Below is my code:
class _MyAppState extends State<MyApp> with WidgetsBindingObserver{
ScaffoldDataBloc bloc;
ScaffoldDataState state;
var systemBrightness;
#override
void initState() {
WidgetsBinding.instance.addObserver(this);
bloc = ScaffoldDataBloc();
}
void dispose() {
super.dispose();
WidgetsBinding.instance.removeObserver(this);
}
#override
void didChangePlatformBrightness() {
super.didChangePlatformBrightness();
final Brightness brightness = WidgetsBinding.instance.window.platformBrightness;
//inform listeners and rebuild widget tree
systemBrightness = brightness;
print('didchange: ' + systemBrightness.toString());
setState(() {});
}
....
On Android, the print statement 'didchange' was not printout. For IOS this is the result:
flutter: didchange: Brightness.dark
Is it a bug?
Thanks.
Related
how to store starting and ending time of a timer using shared preference in flutter and when i close the app and reopen app should start from ending timer time
if anyone knows anything regarding this issue please share
By using WidgetsBindingObserver you can listen to your application state.
class MyPage extends StatefulWidget {
#override
_MyPageState createState() => _MyPageState();
}
class _MyPageState extends State<MyPage> with WidgetsBindingObserver {
#override
void initState() {
super.initState();
WidgetsBinding.instance!.addObserver(this);
}
#override
void dispose() {
WidgetsBinding.instance!.removeObserver(this);
super.dispose();
}
#override
void didChangeAppLifecycleState(AppLifecycleState state) {
super.didChangeAppLifecycleState(state);
// Here you will get your application state like resumed, inactive, paused, detached
// when the application will close `detached` state will come, and store the latest timer data in your shared preferences
if(state == AppLifecycleState.detached){
// store last timer data into shared preferences
}
print('Current state = $state');
}
#override
Widget build(BuildContext context) => Scaffold();
}
and when your application starts :
Get the data from Shared preferences and Start the timer from there
Do this thing after initializing the shared preferences in main.dart or in your root widget.
I am using this plugin to update my location in firebase. When the app is in foreground everything works perfectly but as soon as my app goes in background then the location update service stops,I tried using didChangeAppLifecycleState but I can't seem to get it to work,
This is my implementaion so far..
class HomeTabPage extends StatefulWidget {
#override
_HomeTabPageState createState() => _HomeTabPageState();
}
class _HomeTabPageState extends State < HomeTabPage >
with AutomaticKeepAliveClientMixin, WidgetsBindingObserver {
#override
void initState() {
super.initState();
WidgetsBinding.instance.addObserver(this);
}
#override
void dispose() {
super.dispose();
WidgetsBinding.instance.removeObserver(this);
}
#override
void didChangeAppLifecycleState(AppLifecycleState state) async {
super.didChangeAppLifecycleState(state);
if (state == AppLifecycleState.inactive ||
state == AppLifecycleState.detached) return;
final isBackground = state == AppLifecycleState.paused;
if (isBackground) {
print("### paused");
StreamSubscription < Position > backgroundStreamSubscription =
Geolocator.getPositionStream().listen((Position position) {
initPositionPoint = position;
Geofire.setLocation(
currentFirebaseUser.uid, position.latitude, position.longitude);
});
}
}
From Github issues #53 and #444 of the flutter-geolocator repo it seems that it doesn't support background location tracking. It seems that some folks have been using background_locator as an alternative, so you might want to look at that.
I am using Flutter with hooks and I am trying to get the App Life Cycle State. I followed documentation and created new hook (code shown below) which works ok for all situations with one exception. When the application state becomes "paused", the hook does not return the value back to the widget. I am not clear what to do at this point. Someone suggested using Isolates but I don't see how that can help. Updating App Life Cycle is not compute expensive.
Please let me know what else I could do make this work.
Thanks
import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart';
AppLifecycleState useAppLifecycleState() {
return use(const _LifeCycleState());
}
class _LifeCycleState extends Hook<AppLifecycleState> {
const _LifeCycleState();
#override
__LifeCycleState createState() => __LifeCycleState();
}
class __LifeCycleState extends HookState<AppLifecycleState, _LifeCycleState>
with WidgetsBindingObserver {
AppLifecycleState _state;
#override
void initHook() {
super.initHook();
WidgetsBinding.instance.addObserver(this);
}
#override
void dispose() {
super.dispose();
WidgetsBinding.instance.removeObserver(this);
}
#override
AppLifecycleState build(BuildContext context) {
return _state;
}
#override
void didChangeAppLifecycleState(AppLifecycleState state) {
setState(() {
_state = state;
});
super.didChangeAppLifecycleState(state);
}
}
Thanks for your help.
In my app, I am playing music (local) in a loop, which plays continuously unless the user stops it. I am using audioplayers package.
Future playLoop(String filePath) async {
player.stop();
player = await cache.loop(filePath);
}
Currently, when app is minimised, the music is not getting stoped. The feature I want to implement is that when the app is minimised, it should stop playing music in the background.
Thanks in advance.
Solutions :
#override
void didChangeAppLifecycleState(AppLifecycleState state) {
if (state == AppLifecycleState.paused) {
//stop your audio player
}else{
print(state.toString());
}
}
#override
void initState() {
super.initState();
WidgetsBinding.instance.addObserver(this);
}
There are mainly 4 states for it:
resumed: The application is visible and responding to user input.
inactive: The application is in an inactive state and is not receiving
user input.
paused: The application is not currently visible to the user, not
responding user input, and running in the background.
detached: The application is still hosted on a flutter engine but is
detached from any host views.
The solution above is correct, but some steps are needed before to get it
1 add WidgetsBindingObserver to your class
class AnyClass extends StatefulWidgets {
_AnyClassState createState() => _AnyClassState();
}
class _AnyClassState extends State<AnyClass> with
WidgetsBindingObserver {
Widget build(BuildContext context) {
return ...
}
}
2 Now it will work, we can added the methods inside class
class _AnyClassState extends State<AnyClass> with
WidgetsBindingObserver {
// ADD THIS AppLifecycleState VARIABLE
late AppLifecycleState appLifecycle;
// ADD THIS FUNCTION WITH A AppLifecycleState PARAMETER
didChangeAppLifecycleState(AppLifecycleState state) {
appLifecycle = state;
setStae(() {});
if(state == AppLifecycle.paused) {
// IF YOUT APP IS IN BACKGROUND...
// YOU CAN ADDED THE ACTION HERE
print('My app is in background');
}
}
// CREATE INITSTATE AND DISPOSE METHODS
initState() {
super.initState();
WidgetsBinding.instance.addObserver(this);
}
dispose() {
WidgetsBinding.instance.removeObserver(this);
super.dispose();
}
Widget build(BuildContext context) {
return ...
}
}
NOW IT WILL WORK FINE!
I am trying to pull off some basic stuff here. Scenario: I am checking for GPS status on init() using isLocationServiceEnabled. If the GPS is off, I'm showing a popup that redirects to Location settings using AndroidIntent. If hit back without turning on the GPS, I want to capture the event when my app comes to foreground. I guessed it has to do with the lifecycle and tried like below, nothing gets print on the console
AppLifecycleState _notification;
#override
void didChangeAppLifecycleState(AppLifecycleState state) {
setState(() {
_notification = state;
print('onResumed called 1');
print(_notification);
});
if( state == AppLifecycleState.resumed){
print('onResumed called 2');
}
}
Am I missing something here?
Did you extend class with WidgetsBindingObserver like so:
class _WhateverWidget extends State<WhateverWidget> with WidgetsBindingObserver
and then initialize an instance like so:
#override void initState() {
WidgetsBinding.instance.addObserver(this);
super.initState();
}
#override void dispose() {
WidgetsBinding.instance.removeObserver(this);
super.dispose();
}