tearing down event handlers on page disappears

src/App/App.csproj

@@ -58,6 +58,7 @@
     <Compile Include="Abstractions\Services\ISecureStorageService.cs" />
     <Compile Include="Abstractions\Services\ISqlService.cs" />
     <Compile Include="Constants.cs" />
+    <Compile Include="Controls\ExtendedToolbarItem.cs" />
     <Compile Include="Controls\DismissModalToolBarItem.cs" />
     <Compile Include="Controls\ExtendedEditor.cs" />
     <Compile Include="Controls\ExtendedButton.cs" />

src/App/Controls/DismissModalToolBarItem.cs

@@ -4,14 +4,13 @@ using Xamarin.Forms;
 
 namespace Bit.App.Controls
 {
-    public class DismissModalToolBarItem : ToolbarItem, IDisposable
+    public class DismissModalToolBarItem : ExtendedToolbarItem, IDisposable
     {
         private readonly ContentPage _page;
-        private readonly Action _cancelClickedAction;
 
         public DismissModalToolBarItem(ContentPage page, string text = null, Action cancelClickedAction = null)
+            : base(cancelClickedAction)
         {
-            _cancelClickedAction = cancelClickedAction;
             _page = page;
             // TODO: init and dispose events from pages
             InitEvents();
@@ -19,20 +18,10 @@ namespace Bit.App.Controls
             Priority = -1;
         }
 
-        private async void ClickedItem(object sender, EventArgs e)
+        protected async override void ClickedItem(object sender, EventArgs e)
         {
-            _cancelClickedAction?.Invoke();
+            base.ClickedItem(sender, e);
             await _page.Navigation.PopModalAsync();
         }
-
-        public void InitEvents()
-        {
-            Clicked += ClickedItem;
-        }
-
-        public void Dispose()
-        {
-            Clicked -= ClickedItem;
-        }
     }
 }

src/App/Controls/ExtendedToolbarItem.cs

@@ -0,0 +1,30 @@
+using System;
+using Xamarin.Forms;
+
+namespace Bit.App.Controls
+{
+    public class ExtendedToolbarItem : ToolbarItem, IDisposable
+    {
+        public ExtendedToolbarItem(Action clickAction = null)
+        {
+            ClickAction = clickAction;
+        }
+
+        public Action ClickAction { get; set; }
+
+        protected virtual void ClickedItem(object sender, EventArgs e)
+        {
+            ClickAction?.Invoke();
+        }
+
+        public void InitEvents()
+        {
+            Clicked += ClickedItem;
+        }
+
+        public void Dispose()
+        {
+            Clicked -= ClickedItem;
+        }
+    }
+}

src/App/Controls/VaultListViewCell.cs

@@ -6,21 +6,17 @@ namespace Bit.App.Controls
 {
     public class VaultListViewCell : LabeledDetailCell
     {
-        private Action<VaultListPageModel.Login> _moreClickedAction;
-
         public static readonly BindableProperty LoginParameterProperty = BindableProperty.Create(nameof(LoginParameter),
             typeof(VaultListPageModel.Login), typeof(VaultListViewCell), null);
 
         public VaultListViewCell(Action<VaultListPageModel.Login> moreClickedAction)
         {
-            _moreClickedAction = moreClickedAction;
-
             SetBinding(LoginParameterProperty, new Binding("."));
             Label.SetBinding<VaultListPageModel.Login>(Label.TextProperty, s => s.Name);
             Detail.SetBinding<VaultListPageModel.Login>(Label.TextProperty, s => s.Username);
 
             Button.Image = "more";
-            Button.Command = new Command(() => ShowMore());
+            Button.Command = new Command(() => moreClickedAction?.Invoke(LoginParameter));
             Button.BackgroundColor = Color.Transparent;
 
             BackgroundColor = Color.White;
@@ -31,10 +27,5 @@ namespace Bit.App.Controls
             get { return GetValue(LoginParameterProperty) as VaultListPageModel.Login; }
             set { SetValue(LoginParameterProperty, value); }
         }
-
-        private void ShowMore()
-        {
-            _moreClickedAction?.Invoke(LoginParameter);
-        }
     }
 }

src/App/Pages/RegisterPage.cs

@@ -35,6 +35,9 @@ namespace Bit.App.Pages
         public FormEntryCell PasswordCell { get; set; }
         public FormEntryCell ConfirmPasswordCell { get; set; }
         public FormEntryCell PasswordHintCell { get; set; }
+        public StackLayout StackLayout { get; set; }
+        public Label PasswordLabel { get; set; }
+        public Label HintLabel { get; set; }
 
         private void Init()
         {
@@ -71,7 +74,7 @@ namespace Bit.App.Pages
                 }
             };
 
-            var passwordLabel = new Label
+            PasswordLabel = new Label
             {
                 Text = AppResources.MasterPasswordDescription,
                 LineBreakMode = LineBreakMode.WordWrap,
@@ -93,7 +96,7 @@ namespace Bit.App.Pages
                 }
             };
 
-            var hintLabel = new Label
+            HintLabel = new Label
             {
                 Text = AppResources.MasterPasswordHintDescription,
                 LineBreakMode = LineBreakMode.WordWrap,
@@ -102,21 +105,15 @@ namespace Bit.App.Pages
                 Margin = new Thickness(15, (this.IsLandscape() ? 5 : 0), 15, 25)
             };
 
-            var layout = new StackLayout
+            StackLayout = new StackLayout
             {
-                Children = { table, passwordLabel, table2, hintLabel },
+                Children = { table, PasswordLabel, table2, HintLabel },
                 Spacing = 0
             };
 
-            layout.LayoutChanged += (sender, args) =>
-            {
-                passwordLabel.WidthRequest = layout.Bounds.Width - passwordLabel.Bounds.Left * 2;
-                hintLabel.WidthRequest = layout.Bounds.Width - hintLabel.Bounds.Left * 2;
-            };
-
             var scrollView = new ScrollView
             {
-                Content = layout
+                Content = StackLayout
             };
 
             var loginToolbarItem = new ToolbarItem(AppResources.Submit, null, async () =>
@@ -148,6 +145,7 @@ namespace Bit.App.Pages
             PasswordHintCell.InitEvents();
             ConfirmPasswordCell.InitEvents();
             PasswordHintCell.Entry.Completed += Entry_Completed;
+            StackLayout.LayoutChanged += Layout_LayoutChanged;
             EmailCell.Entry.FocusWithDelay();
         }
         protected override void OnDisappearing()
@@ -158,6 +156,13 @@ namespace Bit.App.Pages
             PasswordHintCell.Dispose();
             ConfirmPasswordCell.Dispose();
             PasswordHintCell.Entry.Completed -= Entry_Completed;
+            StackLayout.LayoutChanged -= Layout_LayoutChanged;
+        }
+
+        private void Layout_LayoutChanged(object sender, EventArgs e)
+        {
+            PasswordLabel.WidthRequest = StackLayout.Bounds.Width - PasswordLabel.Bounds.Left * 2;
+            HintLabel.WidthRequest = StackLayout.Bounds.Width - HintLabel.Bounds.Left * 2;
         }
 
         private async void Entry_Completed(object sender, EventArgs e)

src/App/Pages/Tools/ToolsPage.cs

@@ -23,42 +23,37 @@ namespace Bit.App.Pages
             Init();
         }
 
+        public ToolsViewCell GeneratorCell { get; set; }
+        public ToolsViewCell WebCell { get; set; }
+        public ToolsViewCell ImportCell { get; set; }
+        public ToolsViewCell ExtensionCell { get; set; }
+        public ToolsViewCell AutofillCell { get; set; }
+
         public void Init()
         {
-            var generatorCell = new ToolsViewCell(AppResources.PasswordGenerator, AppResources.PasswordGeneratorDescription,
+            GeneratorCell = new ToolsViewCell(AppResources.PasswordGenerator, AppResources.PasswordGeneratorDescription,
                 "refresh");
-            generatorCell.Tapped += GeneratorCell_Tapped;
+            WebCell = new ToolsViewCell(AppResources.WebVault, AppResources.WebVaultDescription, "globe");
-            var webCell = new ToolsViewCell(AppResources.WebVault, AppResources.WebVaultDescription, "globe");
+            ImportCell = new ToolsViewCell(AppResources.ImportLogins, AppResources.ImportLoginsDescription, "cloudup");
-            webCell.Tapped += WebCell_Tapped;
-            var importCell = new ToolsViewCell(AppResources.ImportLogins, AppResources.ImportLoginsDescription, "cloudup");
-            importCell.Tapped += ImportCell_Tapped;
 
-            var section = new TableSection { generatorCell };
+            var section = new TableSection { GeneratorCell };
 
             if(Device.OS == TargetPlatform.iOS)
             {
-                var extensionCell = new ToolsViewCell(AppResources.BitwardenAppExtension,
+                ExtensionCell = new ToolsViewCell(AppResources.BitwardenAppExtension,
                     AppResources.BitwardenAppExtensionDescription, "upload");
-                extensionCell.Tapped += (object sender, EventArgs e) =>
+                section.Add(ExtensionCell);
-                {
-                    Navigation.PushModalAsync(new ExtendedNavigationPage(new ToolsExtensionPage()));
-                };
-                section.Add(extensionCell);
             }
             else
             {
-                var autofillServiceCell = new ToolsViewCell(
+                AutofillCell = new ToolsViewCell(
                     string.Format("{0} ({1})", AppResources.BitwardenAutofillService, AppResources.Beta),
                     AppResources.BitwardenAutofillServiceDescription, "upload");
-                autofillServiceCell.Tapped += (object sender, EventArgs e) =>
+                section.Add(AutofillCell);
-                {
-                    Navigation.PushModalAsync(new ExtendedNavigationPage(new ToolsAutofillServicePage()));
-                };
-                section.Add(autofillServiceCell);
             }
 
-            section.Add(webCell);
+            section.Add(WebCell);
-            section.Add(importCell);
+            section.Add(ImportCell);
 
             var table = new ExtendedTableView
             {
@@ -81,6 +76,37 @@ namespace Bit.App.Pages
             Content = table;
         }
 
+        protected override void OnAppearing()
+        {
+            base.OnAppearing();
+            GeneratorCell.Tapped += GeneratorCell_Tapped;
+            WebCell.Tapped += WebCell_Tapped;
+            ImportCell.Tapped += ImportCell_Tapped;
+            ExtensionCell.Tapped += ExtensionCell_Tapped;
+            AutofillCell.Tapped += AutofillCell_Tapped;
+        }
+
+        protected override void OnDisappearing()
+        {
+            base.OnDisappearing();
+            GeneratorCell.Tapped -= GeneratorCell_Tapped;
+            WebCell.Tapped -= WebCell_Tapped;
+            ImportCell.Tapped -= ImportCell_Tapped;
+            ExtensionCell.Tapped -= ExtensionCell_Tapped;
+            AutofillCell.Tapped -= AutofillCell_Tapped;
+
+        }
+
+        private void AutofillCell_Tapped(object sender, EventArgs e)
+        {
+            Navigation.PushModalAsync(new ExtendedNavigationPage(new ToolsAutofillServicePage()));
+        }
+
+        private void ExtensionCell_Tapped(object sender, EventArgs e)
+        {
+            Navigation.PushModalAsync(new ExtendedNavigationPage(new ToolsExtensionPage()));
+        }
+
         private async void GeneratorCell_Tapped(object sender, EventArgs e)
         {
             await Navigation.PushForDeviceAsync(new ToolsPasswordGeneratorPage());

src/App/Pages/Vault/VaultAutofillListLoginsPage.cs

@@ -59,6 +59,8 @@ namespace Bit.App.Pages
         public StackLayout NoDataStackLayout { get; set; }
         public ListView ListView { get; set; }
         public ActivityIndicator LoadingIndicator { get; set; }
+        private SearchToolBarItem SearchItem { get; set; }
+        private AddLoginToolBarItem AddLoginItem { get; set; }
         private IGoogleAnalyticsService GoogleAnalyticsService { get; set; }
         private IUserDialogs UserDialogs { get; set; }
         private string Uri { get; set; }
@@ -88,8 +90,10 @@ namespace Bit.App.Pages
                 Spacing = 20
             };
 
-            ToolbarItems.Add(new AddLoginToolBarItem(this));
+            AddLoginItem = new AddLoginToolBarItem(this);
-            ToolbarItems.Add(new SearchToolBarItem(this));
+            ToolbarItems.Add(AddLoginItem);
+            SearchItem = new SearchToolBarItem(this);
+            ToolbarItems.Add(SearchItem);
 
             ListView = new ListView(ListViewCachingStrategy.RecycleElement)
             {
@@ -106,8 +110,6 @@ namespace Bit.App.Pages
                 ListView.RowHeight = -1;
             }
 
-            ListView.ItemSelected += LoginSelected;
-
             Title = string.Format(AppResources.LoginsForUri, _name ?? "--");
 
             LoadingIndicator = new ActivityIndicator
@@ -123,9 +125,20 @@ namespace Bit.App.Pages
         protected override void OnAppearing()
         {
             base.OnAppearing();
+            ListView.ItemSelected += LoginSelected;
+            AddLoginItem.InitEvents();
+            SearchItem.InitEvents();
             _filterResultsCancellationTokenSource = FetchAndLoadVault();
         }
 
+        protected override void OnDisappearing()
+        {
+            base.OnDisappearing();
+            ListView.ItemSelected -= LoginSelected;
+            AddLoginItem.Dispose();
+            SearchItem.Dispose();
+        }
+
         protected override bool OnBackButtonPressed()
         {
             GoogleAnalyticsService.TrackExtensionEvent("BackClosed", Uri.StartsWith("http") ? "Website" : "App");
@@ -266,26 +279,18 @@ namespace Bit.App.Pages
             UserDialogs.Toast(string.Format(AppResources.ValueHasBeenCopied, alertLabel));
         }
 
-        private class AddLoginToolBarItem : ToolbarItem
+        private class AddLoginToolBarItem : ExtendedToolbarItem
         {
-            private readonly VaultAutofillListLoginsPage _page;
-
             public AddLoginToolBarItem(VaultAutofillListLoginsPage page)
+                : base(() => page.AddLoginAsync())
             {
-                _page = page;
                 Text = AppResources.Add;
                 Icon = "plus";
-                Clicked += ClickedItem;
                 Priority = 2;
             }
-
-            private void ClickedItem(object sender, EventArgs e)
-            {
-                _page.AddLoginAsync();
-            }
         }
 
-        private class SearchToolBarItem : ToolbarItem
+        private class SearchToolBarItem : ExtendedToolbarItem
         {
             private readonly VaultAutofillListLoginsPage _page;
 
@@ -294,11 +299,11 @@ namespace Bit.App.Pages
                 _page = page;
                 Text = AppResources.Search;
                 Icon = "search";
-                Clicked += ClickedItem;
                 Priority = 1;
+                ClickAction = () => DoClick();
             }
 
-            private void ClickedItem(object sender, EventArgs e)
+            private void DoClick()
             {
                 _page.GoogleAnalyticsService.TrackExtensionEvent("CloseToSearch",
                     _page.Uri.StartsWith("http") ? "Website" : "App");

src/App/Pages/Vault/VaultListLoginsPage.cs

@@ -66,6 +66,7 @@ namespace Bit.App.Pages
         public StackLayout NoDataStackLayout { get; set; }
         public StackLayout ResultsStackLayout { get; set; }
         public ActivityIndicator LoadingIndicator { get; set; }
+        private AddLoginToolBarItem AddLoginItem { get; set; }
         public string Uri { get; set; }
 
         private void Init()
@@ -80,7 +81,8 @@ namespace Bit.App.Pages
 
             if(!_favorites)
             {
-                ToolbarItems.Add(new AddLoginToolBarItem(this));
+                AddLoginItem = new AddLoginToolBarItem(this);
+                ToolbarItems.Add(AddLoginItem);
             }
 
             ListView = new ListView(ListViewCachingStrategy.RecycleElement)
@@ -98,16 +100,12 @@ namespace Bit.App.Pages
                 ListView.RowHeight = -1;
             }
 
-            ListView.ItemSelected += LoginSelected;
-
             Search = new SearchBar
             {
                 Placeholder = AppResources.SearchVault,
                 FontSize = Device.GetNamedSize(NamedSize.Small, typeof(Button)),
                 CancelButtonColor = Color.FromHex("3c8dbc")
             };
-            Search.TextChanged += SearchBar_TextChanged;
-            Search.SearchButtonPressed += SearchBar_SearchButtonPressed;
             // Bug with searchbar on android 7, ref https://bugzilla.xamarin.com/show_bug.cgi?id=43975
             if(Device.OS == TargetPlatform.Android && _deviceInfoService.Version >= 24)
             {
@@ -231,6 +229,11 @@ namespace Bit.App.Pages
         protected override void OnAppearing()
         {
             base.OnAppearing();
+            ListView.ItemSelected += LoginSelected;
+            Search.TextChanged += SearchBar_TextChanged;
+            Search.SearchButtonPressed += SearchBar_SearchButtonPressed;
+            AddLoginItem?.InitEvents();
+
             if(_loadExistingData)
             {
                 _filterResultsCancellationTokenSource = FetchAndLoadVault();
@@ -268,6 +271,15 @@ namespace Bit.App.Pages
             }
         }
 
+        protected override void OnDisappearing()
+        {
+            base.OnDisappearing();
+            ListView.ItemSelected -= LoginSelected;
+            Search.TextChanged -= SearchBar_TextChanged;
+            Search.SearchButtonPressed -= SearchBar_SearchButtonPressed;
+            AddLoginItem.Dispose();
+        }
+
         protected override bool OnBackButtonPressed()
         {
             if(string.IsNullOrWhiteSpace(Uri))
@@ -469,21 +481,16 @@ namespace Bit.App.Pages
             await Navigation.PushForDeviceAsync(page);
         }
 
-        private class AddLoginToolBarItem : ToolbarItem
+        private class AddLoginToolBarItem : ExtendedToolbarItem
         {
             private readonly VaultListLoginsPage _page;
 
             public AddLoginToolBarItem(VaultListLoginsPage page)
+                : base(() => page.AddLogin())
             {
                 _page = page;
                 Text = AppResources.Add;
                 Icon = "plus";
-                Clicked += ClickedItem;
-            }
-
-            private void ClickedItem(object sender, EventArgs e)
-            {
-                _page.AddLogin();
             }
         }
 

src/App/Pages/Vault/VaultViewLoginPage.cs

@@ -6,6 +6,7 @@ using Bit.App.Models.Page;
 using Bit.App.Resources;
 using Xamarin.Forms;
 using XLabs.Ioc;
+using System.Threading.Tasks;
 
 namespace Bit.App.Pages
 {
@@ -33,10 +34,12 @@ namespace Bit.App.Pages
         public LabeledValueCell UsernameCell { get; set; }
         public LabeledValueCell PasswordCell { get; set; }
         public LabeledValueCell UriCell { get; set; }
+        private EditLoginToolBarItem EditItem { get; set; }
 
         private void Init()
         {
-            ToolbarItems.Add(new EditLoginToolBarItem(this, _loginId));
+            EditItem = new EditLoginToolBarItem(this, _loginId);
+            ToolbarItems.Add(EditItem);
             if(Device.OS == TargetPlatform.iOS)
             {
                 ToolbarItems.Add(new DismissModalToolBarItem(this));
@@ -121,6 +124,8 @@ namespace Bit.App.Pages
 
         protected async override void OnAppearing()
         {
+            EditItem.InitEvents();
+
             var login = await _loginService.GetByIdAsync(_loginId);
             if(login == null)
             {
@@ -169,13 +174,18 @@ namespace Bit.App.Pages
             base.OnAppearing();
         }
 
+        protected override void OnDisappearing()
+        {
+            EditItem.Dispose();
+        }
+
         private void Copy(string copyText, string alertLabel)
         {
             _clipboardService.CopyToClipboard(copyText);
             _userDialogs.Toast(string.Format(AppResources.ValueHasBeenCopied, alertLabel));
         }
 
-        private class EditLoginToolBarItem : ToolbarItem
+        private class EditLoginToolBarItem : ExtendedToolbarItem
         {
             private readonly VaultViewLoginPage _page;
             private readonly string _loginId;
@@ -185,10 +195,10 @@ namespace Bit.App.Pages
                 _page = page;
                 _loginId = loginId;
                 Text = AppResources.Edit;
-                Clicked += ClickedItem;
+                ClickAction = async () => await ClickedItem();
             }
 
-            private async void ClickedItem(object sender, EventArgs e)
+            private async Task ClickedItem()
             {
                 var page = new VaultEditLoginPage(_loginId);
                 await _page.Navigation.PushForDeviceAsync(page);