From c25ee046580e9944230e2a19bda6df606ec657ba Mon Sep 17 00:00:00 2001
From: Vishnu Mohandas <vishnumohandas@gmail.com>
Date: Tue, 5 May 2020 18:26:24 +0530
Subject: [PATCH] Cancel subscriptions on dispose

---
 lib/ui/gallery.dart                |  9 ++++++++-
 lib/ui/gallery_app_bar_widget.dart | 10 +++++++++-
 lib/ui/home_widget.dart            |  8 +++++---
 3 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/lib/ui/gallery.dart b/lib/ui/gallery.dart
index 968203069..466266a86 100644
--- a/lib/ui/gallery.dart
+++ b/lib/ui/gallery.dart
@@ -1,3 +1,4 @@
+import 'dart:async';
 import 'dart:collection';
 
 import 'package:flutter/cupertino.dart';
@@ -29,10 +30,11 @@ class _GalleryState extends State<Gallery> {
   final List<List<Photo>> _collatedPhotos = List<List<Photo>>();
   Set<Photo> _selectedPhotos = HashSet<Photo>();
   List<Photo> _photos;
+  StreamSubscription<LocalPhotosUpdatedEvent> _subscription;
 
   @override
   void initState() {
-    Bus.instance.on<LocalPhotosUpdatedEvent>().listen((event) {
+    _subscription = Bus.instance.on<LocalPhotosUpdatedEvent>().listen((event) {
       setState(() {});
     });
     super.initState();
@@ -179,4 +181,9 @@ class _GalleryState extends State<Gallery> {
         firstDate.month == secondDate.month &&
         firstDate.day == secondDate.day;
   }
+
+  void dispose() {
+    _subscription.cancel();
+    super.dispose();
+  }
 }
diff --git a/lib/ui/gallery_app_bar_widget.dart b/lib/ui/gallery_app_bar_widget.dart
index 7e2da660c..915707537 100644
--- a/lib/ui/gallery_app_bar_widget.dart
+++ b/lib/ui/gallery_app_bar_widget.dart
@@ -1,3 +1,5 @@
+import 'dart:async';
+
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:photos/core/event_bus.dart';
@@ -28,10 +30,11 @@ class GalleryAppBarWidget extends StatefulWidget
 
 class _GalleryAppBarWidgetState extends State<GalleryAppBarWidget> {
   bool _hasSyncErrors = false;
+  StreamSubscription<RemoteSyncEvent> _subscription;
 
   @override
   void initState() {
-    Bus.instance.on<RemoteSyncEvent>().listen((event) {
+    _subscription = Bus.instance.on<RemoteSyncEvent>().listen((event) {
       setState(() {
         _hasSyncErrors = !event.success;
       });
@@ -162,4 +165,9 @@ class _GalleryAppBarWidgetState extends State<GalleryAppBarWidget> {
       ),
     );
   }
+
+  void dispose() {
+    _subscription.cancel();
+    super.dispose();
+  }
 }
diff --git a/lib/ui/home_widget.dart b/lib/ui/home_widget.dart
index 3fdaa0342..f65be0a4e 100644
--- a/lib/ui/home_widget.dart
+++ b/lib/ui/home_widget.dart
@@ -1,3 +1,4 @@
+import 'dart:async';
 import 'dart:collection';
 
 import 'package:flutter/cupertino.dart';
@@ -28,13 +29,14 @@ class _HomeWidgetState extends State<HomeWidget> {
   ShakeDetector _detector;
   int _selectedNavBarItem = 0;
   Set<Photo> _selectedPhotos = HashSet<Photo>();
+  StreamSubscription<LocalPhotosUpdatedEvent> _subscription;
 
   @override
   void initState() {
-    Bus.instance.on<LocalPhotosUpdatedEvent>().listen((event) {
+    _subscription = Bus.instance.on<LocalPhotosUpdatedEvent>().listen((event) {
       setState(() {});
     });
-    _detector = ShakeDetector.waitForStart(
+    _detector = ShakeDetector.autoStart(
         shakeThresholdGravity: 3,
         onPhoneShake: () {
           _logger.info("Emailing logs");
@@ -45,7 +47,6 @@ class _HomeWidgetState extends State<HomeWidget> {
 
   @override
   Widget build(BuildContext context) {
-    _detector.startListening();
     return Scaffold(
       appBar: GalleryAppBarWidget(
         widget.title,
@@ -104,6 +105,7 @@ class _HomeWidgetState extends State<HomeWidget> {
   @override
   void dispose() {
     _detector.stopListening();
+    _subscription.cancel();
     super.dispose();
   }
 }