Merge branch 'master' into dev/suess/Prism.Avalonia

.gitignore

@@ -208,3 +208,9 @@ FakesAssemblies/
 
 # Binlog
 *.binlog
+
+# macOS
+.DS_Store
+
+# VSCode
+.mono

src/Maui/Prism.Maui/Common/MvvmHelpers.cs

@@ -1,4 +1,6 @@
+#nullable enable
 using System.ComponentModel;
+using System.Diagnostics.CodeAnalysis;
 using System.Reflection;
 using Prism.Dialogs;
 using Prism.Navigation;
@@ -11,14 +13,14 @@ namespace Prism.Common;
 
 public static class MvvmHelpers
 {
-    public static void InvokeViewAndViewModelAction<T>(object view, Action<T> action) where T : class
+    public static void InvokeViewAndViewModelAction<T>(object? view, Action<T> action) where T : class
     {
         if (view is T viewAsT)
         {
             action(viewAsT);
         }
 
-        if (view is BindableObject element && element.BindingContext is T viewModelAsT)
+        if (view is BindableObject { BindingContext: T viewModelAsT })
         {
             action(viewModelAsT);
         }
@@ -32,14 +34,14 @@ public static void InvokeViewAndViewModelAction<T>(object view, Action<T> action
         }
     }
 
-    public static async Task InvokeViewAndViewModelActionAsync<T>(object view, Func<T, Task> action) where T : class
+    public static async Task InvokeViewAndViewModelActionAsync<T>(object? view, Func<T, Task> action) where T : class
     {
         if (view is T viewAsT)
         {
             await action(viewAsT);
         }
 
-        if (view is BindableObject element && element.BindingContext is T viewModelAsT)
+        if (view is BindableObject { BindingContext: T viewModelAsT })
         {
             await action(viewModelAsT);
         }
@@ -49,11 +51,11 @@ public static async Task InvokeViewAndViewModelActionAsync<T>(object view, Func<
             var children = page.GetChildRegions();
             if (children is not null)
                 foreach (var child in children)
-                    await InvokeViewAndViewModelActionAsync<T>(child, action);
+                    await InvokeViewAndViewModelActionAsync(child, action);
         }
     }
 
-    public static void DestroyPage(IView view)
+    public static void DestroyPage(IView? view)
     {
         try
         {
@@ -96,7 +98,7 @@ private static void DestroyChildren(IView page)
         }
     }
 
-    public static void DestroyWithModalStack(Page page, IList<Page> modalStack)
+    public static void DestroyWithModalStack(Page? page, IList<Page?> modalStack)
     {
         foreach (var childPage in modalStack.Reverse())
         {
@@ -105,15 +107,15 @@ public static void DestroyWithModalStack(Page page, IList<Page> modalStack)
         DestroyPage(page);
     }
 
-    public static T GetImplementerFromViewOrViewModel<T>(object view)
+    public static T? GetImplementerFromViewOrViewModel<T>(object view)
             where T : class
     {
         if (view is T viewAsT)
         {
             return viewAsT;
         }
 
-        if (view is VisualElement element && element.BindingContext is T vmAsT)
+        if (view is VisualElement { BindingContext: T vmAsT })
         {
             return vmAsT;
         }
@@ -136,12 +138,12 @@ public static bool IsNavigationTarget(object view, NavigationContext navigationC
         return path == viewType.Name || path == viewType.FullName;
     }
 
-    public static void OnNavigatedFrom(object view, NavigationContext navigationContext)
+    public static void OnNavigatedFrom(object? view, NavigationContext navigationContext)
     {
         InvokeViewAndViewModelAction<IRegionAware>(view, x => x.OnNavigatedFrom(navigationContext));
     }
 
-    public static void OnNavigatedTo(object view, NavigationContext navigationContext)
+    public static void OnNavigatedTo(object? view, NavigationContext navigationContext)
     {
         InvokeViewAndViewModelAction<IRegionAware>(view, x => x.OnNavigatedTo(navigationContext));
     }
@@ -161,35 +163,35 @@ private static bool CanNavigate(object page, INavigationParameters parameters)
         return implementer?.CanNavigate(parameters) ?? true;
     }
 
-    public static void OnNavigatedFrom(object page, INavigationParameters parameters)
+    public static void OnNavigatedFrom(object? page, INavigationParameters parameters)
     {
         if (page != null)
             InvokeViewAndViewModelAction<INavigatedAware>(page, v => v.OnNavigatedFrom(parameters));
     }
 
-    public static async Task OnInitializedAsync(object page, INavigationParameters parameters)
+    public static async Task OnInitializedAsync(object? page, INavigationParameters parameters)
     {
         if (page is null) return;
 
         InvokeViewAndViewModelAction<IInitialize>(page, v => v.Initialize(parameters));
         await InvokeViewAndViewModelActionAsync<IInitializeAsync>(page, async v => await v.InitializeAsync(parameters));
     }
 
-    private static bool HasKey(this IEnumerable<KeyValuePair<string, object>> parameters, string name, out string key)
+    private static bool HasKey(this IEnumerable<KeyValuePair<string, object>> parameters, string name, [MaybeNullWhen(returnValue: false)] out string key)
     {
         key = parameters.Select(x => x.Key).FirstOrDefault(k => k.Equals(name, StringComparison.InvariantCultureIgnoreCase));
         return !string.IsNullOrEmpty(key);
     }
 
-    public static void OnNavigatedTo(object page, INavigationParameters parameters)
+    public static void OnNavigatedTo(object? page, INavigationParameters parameters)
     {
         if (page != null)
             InvokeViewAndViewModelAction<INavigatedAware>(page, v => v.OnNavigatedTo(parameters));
     }
 
-    public static Page GetOnNavigatedToTarget(Page page, IView mainPage, bool useModalNavigation)
+    public static Page? GetOnNavigatedToTarget(Page page, IView? mainPage, bool useModalNavigation)
     {
-        Page target;
+        Page? target;
         if (useModalNavigation)
         {
             var previousPage = GetPreviousPage(page, page.Navigation.ModalStack);
@@ -210,9 +212,9 @@ public static Page GetOnNavigatedToTarget(Page page, IView mainPage, bool useMod
         return target;
     }
 
-    public static Page GetOnNavigatedToTargetFromChild(IView target)
+    public static Page? GetOnNavigatedToTargetFromChild(IView? target)
     {
-        Page child = null;
+        Page? child = null;
 
         if (target is FlyoutPage flyout)
             child = flyout.Detail;
@@ -230,9 +232,9 @@ public static Page GetOnNavigatedToTargetFromChild(IView target)
         return null;
     }
 
-    public static Page GetPreviousPage(Page currentPage, System.Collections.Generic.IReadOnlyList<Page> navStack)
+    public static Page? GetPreviousPage(Page currentPage, IReadOnlyList<Page?> navStack)
     {
-        Page previousPage = null;
+        Page? previousPage = null;
 
         int currentPageIndex = GetCurrentPageIndex(currentPage, navStack);
         int previousPageIndex = currentPageIndex - 1;
@@ -242,7 +244,7 @@ public static Page GetPreviousPage(Page currentPage, System.Collections.Generic.
         return previousPage;
     }
 
-    public static int GetCurrentPageIndex(Page currentPage, System.Collections.Generic.IReadOnlyList<Page> navStack)
+    public static int GetCurrentPageIndex(Page currentPage, IReadOnlyList<Page?> navStack)
     {
         int stackCount = navStack.Count;
         for (int x = 0; x < stackCount; x++)
@@ -255,14 +257,14 @@ public static int GetCurrentPageIndex(Page currentPage, System.Collections.Gener
         return stackCount - 1;
     }
 
-    public static Page GetCurrentPage(Page mainPage) =>
+    public static Page? GetCurrentPage(Page mainPage) =>
         _getCurrentPage(mainPage);
 
     [EditorBrowsable(EditorBrowsableState.Never)]
-    public static void SetCurrentPageDelegate(Func<Page, Page> getCurrentPageDelegate) =>
+    public static void SetCurrentPageDelegate(Func<Page, Page?> getCurrentPageDelegate) =>
         _getCurrentPage = getCurrentPageDelegate;
 
-    private static Func<Page, Page> _getCurrentPage = mainPage =>
+    private static Func<Page, Page?> _getCurrentPage = mainPage =>
     {
         var page = mainPage;
 
@@ -273,7 +275,7 @@ public static void SetCurrentPageDelegate(Func<Page, Page> getCurrentPageDelegat
         return EvaluateCurrentPage(page);
     };
 
-    private static Page GetTarget(Page target)
+    private static Page? GetTarget(Page? target)
     {
         return target switch
         {
@@ -285,14 +287,14 @@ private static Page GetTarget(Page target)
         };
     }
 
-    private static Page EvaluateCurrentPage(Page target)
+    private static Page? EvaluateCurrentPage(Page? target)
     {
-        Page child = GetTarget(target);
+        Page? child = GetTarget(target);
 
         if (child is not null)
             target = GetOnNavigatedToTargetFromChild(child);
 
-        if (target is Page page)
+        if (target is { } page)
         {
             if (target is IDialogContainer)
             {
@@ -319,9 +321,9 @@ public static async Task HandleNavigationPageGoBack(NavigationPage navigationPag
     {
         var navigationService = Navigation.Xaml.Navigation.GetNavigationService(navigationPage.CurrentPage);
         var result = await navigationService.GoBackAsync();
-        if (result.Exception is NavigationException navEx && navEx.Message == NavigationException.CannotPopApplicationMainPage)
+        if (result.Exception is NavigationException { Message: NavigationException.CannotPopApplicationMainPage })
         {
-            Application.Current.Quit();
+            Application.Current?.Quit();
         }
     }
 
@@ -335,13 +337,13 @@ public static async Task HandleNavigationPageSwipedAway(NavigationPage navigatio
             },
         };
         var result = await navigationService.GoBackAsync(navParams);
-        if (result.Exception is NavigationException navEx && navEx.Message == NavigationException.CannotPopApplicationMainPage)
+        if (result.Exception is NavigationException { Message: NavigationException.CannotPopApplicationMainPage })
         {
-            Application.Current.Quit();
+            Application.Current?.Quit();
         }
     }
 
-    public static void HandleSystemGoBack(IView previousPage, IView currentPage)
+    public static void HandleSystemGoBack(IView? previousPage, IView? currentPage)
     {
         var parameters = new NavigationParameters();
         parameters.GetNavigationParametersInternal().Add(KnownInternalParameters.NavigationMode, NavigationMode.Back);
@@ -352,22 +354,22 @@ public static void HandleSystemGoBack(IView previousPage, IView currentPage)
 
     internal static bool HasDirectNavigationPageParent(Page page)
     {
-        return page?.Parent != null && page?.Parent is NavigationPage;
+        return page.Parent is NavigationPage;
     }
 
     internal static bool HasNavigationPageParent(Page page) =>
         HasNavigationPageParent(page, out var _);
 
-    internal static bool HasNavigationPageParent(Page page, out NavigationPage navigationPage)
+    internal static bool HasNavigationPageParent(Page page, out NavigationPage? navigationPage)
     {
-        if (page?.Parent != null)
+        if (page.Parent != null)
         {
             if (page.Parent is NavigationPage navParent)
             {
                 navigationPage = navParent;
                 return true;
             }
-            else if ((page.Parent is TabbedPage) && page.Parent?.Parent is NavigationPage navigationParent)
+            else if (page.Parent is TabbedPage && page.Parent?.Parent is NavigationPage navigationParent)
             {
                 navigationPage = navigationParent;
                 return true;

src/Prism.Core/Common/IParameters.cs

@@ -1,6 +1,6 @@
-using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 
+#nullable enable
 namespace Prism.Common
 {
     /// <summary>
@@ -65,6 +65,6 @@ public interface IParameters : IEnumerable<KeyValuePair<string, object>>
         /// </summary>
         /// <param name="key">The key of the parameter to get.</param>
         /// <returns>A matching value if it exists.</returns>
-        object this[string key] { get; }
+        object? this[string key] { get; }
     }
 }

src/Prism.Core/Common/ListDictionary.cs

@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-
 namespace Prism.Common
 {
     /// <summary>

src/Prism.Core/Common/ParametersBase.cs

@@ -1,19 +1,16 @@
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.ComponentModel;
 using System.Diagnostics.CodeAnalysis;
-using System.Linq;
 using System.Text;
-
+#nullable enable
 namespace Prism.Common
 {
     /// <summary>
     /// This is a generic parameters base class used for Dialog Parameters and Navigation Parameters.
     /// </summary>
     public abstract class ParametersBase : IParameters
     {
-        private readonly List<KeyValuePair<string, object>> _entries = [];
+        private readonly List<KeyValuePair<string, object?>> _entries = [];
 
         /// <summary>
         /// Default constructor.
@@ -51,7 +48,7 @@ protected ParametersBase(string query)
                         }
                         i++;
                     }
-                    string key = null;
+                    string? key = null;
                     string value;
                     if (num4 >= 0)
                     {
@@ -75,7 +72,7 @@ protected ParametersBase(string query)
         /// </summary>
         /// <param name="key">The key for the value to be returned.</param>
         /// <returns>The value of the parameter referenced by the key; otherwise <c>null</c>.</returns>
-        public object this[string key]
+        public object? this[string key]
         {
             get
             {
@@ -108,7 +105,7 @@ public object this[string key]
         /// <param name="key">The key to reference this value in the parameters collection.</param>
         /// <param name="value">The value of the parameter to store.</param>
         public void Add(string key, object value) =>
-            _entries.Add(new KeyValuePair<string, object>(key, value));
+            _entries.Add(new KeyValuePair<string, object?>(key, value));
 
         /// <summary>
         /// Checks collection for presence of key.
@@ -122,7 +119,7 @@ public bool ContainsKey(string key) =>
         /// Gets an enumerator for the KeyValuePairs in parameter collection.
         /// </summary>
         /// <returns>Enumerator.</returns>
-        public IEnumerator<KeyValuePair<string, object>> GetEnumerator() =>
+        public IEnumerator<KeyValuePair<string, object?>> GetEnumerator() =>
             _entries.GetEnumerator();
 
         /// <summary>
@@ -181,7 +178,7 @@ public override string ToString()
 
                     queryBuilder.Append(Uri.EscapeDataString(kvp.Key));
                     queryBuilder.Append('=');
-                    queryBuilder.Append(Uri.EscapeDataString(kvp.Value?.ToString() is string str ? str : string.Empty));
+                    queryBuilder.Append(Uri.EscapeDataString(kvp.Value?.ToString() ?? string.Empty));
                 }
             }
 
@@ -193,7 +190,7 @@ public override string ToString()
         /// </summary>
         /// <param name="parameters">An IEnumerable of KeyValuePairs to add to the current parameter list.</param>
         [EditorBrowsable(EditorBrowsableState.Never)]
-        public void FromParameters(IEnumerable<KeyValuePair<string, object>> parameters) =>
+        public void FromParameters(IEnumerable<KeyValuePair<string, object?>> parameters) =>
             _entries.AddRange(parameters);
     }
 }