Replace Locator.Current with AppLocator.Current (#4217)

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**What kind of change does this PR introduce?**
<!-- Bug fix, feature, docs update, ... -->

update

**What is the new behavior?**
<!-- If this is a feature change -->

Updated all usages of Locator.Current and Locator.CurrentMutable to
AppLocator.Current and AppLocator.CurrentMutable across the codebase.
This change standardizes dependency resolution and improves clarity
regarding the application's service locator.

**What might this PR break?**

Locator usage replaced with underlying AppLocator, not expecting
breaking change

**Please check if the PR fulfills these requirements**
- [ ] Tests for the changes have been added (for bug fixes / features)
- [ ] Docs have been added / updated (for bug fixes / features)

**Other information**:

Author: ChrisPulman

src/ReactiveUI.Maui/Common/RoutedViewHost.cs

@@ -49,7 +49,7 @@ public RoutedViewHost()
         HorizontalContentAlignment = HorizontalAlignment.Stretch;
         VerticalContentAlignment = VerticalAlignment.Stretch;
 
-        var platform = Locator.Current.GetService<IPlatformOperations>();
+        var platform = AppLocator.Current.GetService<IPlatformOperations>();
         Func<string?> platformGetter = () => default;
 
         if (platform is null)

src/ReactiveUI.Maui/Common/ViewModelViewHost.cs

@@ -49,7 +49,7 @@ public partial class ViewModelViewHost : TransitioningContentControl, IViewFor,
 #endif
     public ViewModelViewHost()
     {
-        var platform = Locator.Current.GetService<IPlatformOperations>();
+        var platform = AppLocator.Current.GetService<IPlatformOperations>();
         Func<string?> platformGetter = () => default;
 
         if (platform is null)

src/ReactiveUI.Maui/ReactiveShellContent.cs

@@ -47,7 +47,7 @@ public partial class ReactiveShellContent<TViewModel> : ShellContent, IActivatab
     /// </summary>
     public ReactiveShellContent()
     {
-        var view = Locator.Current.GetService<IViewFor<TViewModel>>(Contract);
+        var view = AppLocator.Current.GetService<IViewFor<TViewModel>>(Contract);
         if (view is not null)
         {
             ContentTemplate = new DataTemplate(() => view);
@@ -80,14 +80,14 @@ public string? Contract
 
     private static void ViewModelChanged(BindableObject bindable, object oldValue, object newValue)
     {
-        if (Locator.Current is null)
+        if (AppLocator.Current is null)
         {
-            throw new NullReferenceException(nameof(Locator.Current));
+            throw new NullReferenceException(nameof(AppLocator.Current));
         }
 
         if (bindable is ReactiveShellContent<TViewModel> svm)
         {
-            var view = Locator.Current.GetService<IViewFor<TViewModel>>(svm.Contract);
+            var view = AppLocator.Current.GetService<IViewFor<TViewModel>>(svm.Contract);
             if (view is not null)
             {
                 svm.ContentTemplate = new DataTemplate(() => view);

src/ReactiveUI.Maui/RoutedViewHost.cs

@@ -161,7 +161,7 @@ public RoutedViewHost()
             await SyncNavigationStacksAsync();
         });
 
-        var screen = Locator.Current.GetService<IScreen>() ?? throw new Exception("You *must* register an IScreen class representing your App's main Screen");
+        var screen = AppLocator.Current.GetService<IScreen>() ?? throw new Exception("You *must* register an IScreen class representing your App's main Screen");
         Router = screen.Router;
     }
 

src/ReactiveUI.Winforms/ReactiveUI.Winforms.csproj

@@ -20,7 +20,7 @@
     <Compile Include="..\ReactiveUI.Wpf\Rx\**\*.cs" LinkBase="Rx" Exclude="..\ReactiveUI.Wpf\Rx\**\Dispatcher*.cs;..\ReactiveUI.Wpf\Rx\Internal\*.cs;..\ReactiveUI.Wpf\Rx\Concurrency\*.cs;..\ReactiveUI.Wpf\Rx\Linq\ControlObservable.cs" />
   </ItemGroup>
 
-  <ItemGroup Condition="$(TargetFramework.StartsWith('net4')) or $(TargetFramework.EndsWith('-windows10.0.17763.0'))">
+  <ItemGroup Condition="$(TargetFramework.StartsWith('net4'))">
     <Compile Include="..\ReactiveUI.Wpf\Rx\Concurrency\ControlScheduler.cs" LinkBase="Rx\Concurrency" />
   </ItemGroup>
 </Project>

src/ReactiveUI.Wpf/Common/RoutedViewHost.cs

@@ -71,7 +71,7 @@ public RoutedViewHost()
         HorizontalContentAlignment = HorizontalAlignment.Stretch;
         VerticalContentAlignment = VerticalAlignment.Stretch;
 
-        var platform = Locator.Current.GetService<IPlatformOperations>();
+        var platform = AppLocator.Current.GetService<IPlatformOperations>();
         Func<string?> platformGetter = () => default;
 
         if (platform is null)

src/ReactiveUI.Wpf/Common/ViewModelViewHost.cs

@@ -78,7 +78,7 @@ public ViewModelViewHost()
         DefaultStyleKey = typeof(ViewModelViewHost);
 #endif
 
-        var platform = Locator.Current.GetService<IPlatformOperations>();
+        var platform = AppLocator.Current.GetService<IPlatformOperations>();
         Func<string?> platformGetter = () => default;
 
         if (platform is null)

src/ReactiveUI.Wpf/ReactiveUI.Wpf.csproj

@@ -17,7 +17,7 @@
     <Compile Remove="Rx\Internal\Constants.cs;Rx\**\Dispatcher*.cs;Rx\**\Control*.cs" />
   </ItemGroup>
 
-  <ItemGroup Condition="$(TargetFramework.StartsWith('net46')) or $(TargetFramework.EndsWith('-windows10.0.17763.0'))">
+  <ItemGroup Condition="$(TargetFramework.StartsWith('net46'))">
     <Compile Include="Rx\Internal\Constants.cs;Rx\**\Dispatcher*.cs" />
   </ItemGroup>
 </Project>

src/ReactiveUI.Wpf/Rx/Concurrency/DispatcherScheduler.cs

@@ -6,11 +6,10 @@
 namespace System.Reactive.Concurrency;
 
 /// <summary>
-/// Represents an object that schedules units of work on a <see cref="System.Windows.Threading.Dispatcher"/>.
+/// The <see cref="DispatcherScheduler"/> schedules units of work on a <see cref="System.Windows.Threading.Dispatcher"/>.
 /// </summary>
-/// <remarks>
-/// This scheduler type is typically used indirectly through the <see cref="Linq.DispatcherObservable.ObserveOnDispatcher{TSource}(IObservable{TSource})"/> and <see cref="Linq.DispatcherObservable.SubscribeOnDispatcher{TSource}(IObservable{TSource})"/> methods that use the Dispatcher on the calling thread.
-/// </remarks>
+/// <seealso cref="System.Reactive.Concurrency.LocalScheduler" />
+/// <seealso cref="System.Reactive.Concurrency.ISchedulerPeriodic" />
 public class DispatcherScheduler : LocalScheduler, ISchedulerPeriodic
 {
     /// <summary>

src/ReactiveUI/Activation/ViewForMixins.cs

@@ -15,7 +15,7 @@ public static class ViewForMixins
     private static readonly MemoizingMRUCache<Type, IActivationForViewFetcher?> _activationFetcherCache =
         new(
             (t, _) =>
-                Locator.Current
+                AppLocator.Current
                        .GetServices<IActivationForViewFetcher?>()
                        .Aggregate((count: 0, viewFetcher: default(IActivationForViewFetcher?)), (acc, x) =>
                        {