Enable Nullable annotations

Related to #4

Directory.Build.props

@@ -1,6 +1,7 @@
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 
   <PropertyGroup>
+    <Nullable>enable</Nullable>
     <LangVersion>latest</LangVersion>
     <ImplicitUsings>enable</ImplicitUsings>
   </PropertyGroup>

Mopups/Mopups.Maui/Pages/PopupPage.cs

@@ -5,7 +5,6 @@ namespace Mopups.Pages;
 
 public partial class PopupPage : ContentPage
 {
-
     public event EventHandler? BackgroundClicked;
 
     public static readonly BindableProperty CloseWhenBackgroundIsClickedProperty = BindableProperty.Create(nameof(CloseWhenBackgroundIsClicked), typeof(bool), typeof(PopupPage), true);
@@ -40,8 +39,6 @@ public partial class PopupPage : ContentPage
         private set { SetValue(KeyboardOffsetProperty, value); }
     }
 
-
-
     public PopupPage()
     {
         BackgroundColor = Color.FromArgb("#80000000");
@@ -52,20 +49,17 @@ public partial class PopupPage : ContentPage
         return false;
     }
 
-
     protected override void LayoutChildren(double x, double y, double width, double height)
     {
         height -= KeyboardOffset;
         base.LayoutChildren(x, y, width, height);
     }
 
-
     protected virtual bool OnBackgroundClicked()
     {
         return CloseWhenBackgroundIsClicked;
     }
 
-
     internal void SendBackgroundClick()
     {
         BackgroundClicked?.Invoke(this, EventArgs.Empty);

Mopups/Mopups.Maui/Platforms/Android/Renderers/PopupPageRenderer.cs

@@ -12,7 +12,7 @@ public class PopupPageHandler : ContentViewHandler
     private readonly MopupGestureDetectorListener _gestureDetectorListener;
     private readonly GestureDetector _gestureDetector;
     private DateTime _downTime;
-    private Microsoft.Maui.Graphics.Point _downPosition;
+    private Point _downPosition;
     private bool _disposed;
 
     public PopupPageHandler()
@@ -57,7 +57,7 @@ public class PopupPageHandler : ContentViewHandler
     }
 
 
-    private bool OnTouchEvent(object? sender, MotionEvent e)
+    private bool OnTouchEvent(object? sender, MotionEvent? e)
     {
         if (_disposed)
         {
@@ -78,7 +78,6 @@ public class PopupPageHandler : ContentViewHandler
 
     private void OnBackgroundClick(object? sender, MotionEvent e)
     {
-
         var isInRegion = IsInRegion(e.RawX, e.RawY, (sender as Android.Views.View)!);
 
         if (!isInRegion)
@@ -101,7 +100,6 @@ public class PopupPageHandler : ContentViewHandler
     {
         try
         {
-
             DispatchTouchEvent(e.Event);
 
             void DispatchTouchEvent(MotionEvent e)
@@ -142,7 +140,6 @@ public class PopupPageHandler : ContentViewHandler
         }
         catch (Exception)
         {
-
             throw;
         }
     }
@@ -151,9 +148,9 @@ public class PopupPageHandler : ContentViewHandler
     {
         try
         {
-            var activity = Microsoft.Maui.Essentials.Platform.CurrentActivity;
+            var activity = Platform.CurrentActivity;
 
-            Microsoft.Maui.Thickness systemPadding;
+            Thickness systemPadding;
             var keyboardOffset = 0d;
 
             var decoreView = activity.Window.DecorView;
@@ -189,8 +186,6 @@ public class PopupPageHandler : ContentViewHandler
             }
             else
             {
-
-
                 var keyboardHeight = 0d;
 
                 if (visibleRect.Bottom < screenSize.Y)
@@ -218,7 +213,6 @@ public class PopupPageHandler : ContentViewHandler
         }
         catch (Exception)
         {
-
             throw;
         }
     }

Mopups/Mopups.Maui/Services/PopupNavigation.cs

@@ -11,13 +11,13 @@ public class PopupNavigation : IPopupNavigation
     public IReadOnlyList<PopupPage> PopupStack => _popupStack;
     private readonly List<PopupPage> _popupStack = new();
 
-    public event EventHandler<PopupPage> Pushing;
+    public event EventHandler<PopupPage>? Pushing;
 
-    public event EventHandler<PopupPage> Pushed;
+    public event EventHandler<PopupPage>? Pushed;
 
-    public event EventHandler<PopupPage> Popping;
+    public event EventHandler<PopupPage>? Popping;
 
-    public event EventHandler<PopupPage> Popped;
+    public event EventHandler<PopupPage>? Popped;
 
 
     private static readonly Lazy<IPopupPlatform> lazyImplementation = new(() => GeneratePopupPlatform(), System.Threading.LazyThreadSafetyMode.PublicationOnly);
@@ -80,7 +80,6 @@ public class PopupNavigation : IPopupNavigation
 
     public Task RemovePageAsync(PopupPage page)
     {
-
         if (page == null)
             throw new InvalidOperationException("Page can not be null");
 

SampleMaui/CSharpMarkup/LoginPage.cs

@@ -1,5 +1,6 @@
 using Mopups.Pages;
 using Mopups.Services;
+using System.Diagnostics.CodeAnalysis;
 using ScrollView = Microsoft.Maui.Controls.ScrollView;
 
 namespace SampleMaui.CSharpMarkup;
@@ -7,12 +8,17 @@ namespace SampleMaui.CSharpMarkup;
 public partial class LoginPage : PopupPage
 {
     public Frame FrameContainer { get; set; }
-    public Image DotNetBotImage { get; set; }
+    public Image? DotNetBotImage { get; set; }
 
     public Entry UsernameEntry { get; set; }
     public Entry PasswordEntry { get; set; }
 
     public Button LoginButton { get; set; }
+
+    [MemberNotNull(nameof(UsernameEntry))]
+    [MemberNotNull(nameof(PasswordEntry))]
+    [MemberNotNull(nameof(LoginButton))]
+    [MemberNotNull(nameof(FrameContainer))]
     protected void BuildContent()
     {
         try
@@ -23,7 +29,6 @@ public partial class LoginPage : PopupPage
                 VerticalOptions = LayoutOptions.Center,
                 BackgroundColor = Color.FromRgb(200.00, 0.00, 0.00),
                 Content = GenerateLoginView()
-
             };
         }
         catch (Exception)
@@ -32,13 +37,17 @@ public partial class LoginPage : PopupPage
         }
     }
 
+    [MemberNotNull(nameof(UsernameEntry))]
+    [MemberNotNull(nameof(PasswordEntry))]
+    [MemberNotNull(nameof(LoginButton))]
+    [MemberNotNull(nameof(FrameContainer))]
     private Frame GenerateLoginView()
     {
         FrameContainer = new Frame
         {
-            Margin = new Microsoft.Maui.Thickness(1),
+            Margin = new Thickness(1),
-            Padding = new Microsoft.Maui.Thickness(0),
+            Padding = new Thickness(0),
-            BackgroundColor = Microsoft.Maui.Graphics.Colors.Gray,
+            BackgroundColor = Colors.Gray,
             HorizontalOptions = LayoutOptions.Center,
             VerticalOptions = LayoutOptions.Center,
             Content = GenerateFrameContainerContent()
@@ -46,15 +55,17 @@ public partial class LoginPage : PopupPage
         return FrameContainer;
     }
 
+    [MemberNotNull(nameof(UsernameEntry))]
+    [MemberNotNull(nameof(PasswordEntry))]
+    [MemberNotNull(nameof(LoginButton))]
     private StackLayout GenerateFrameContainerContent()
     {
         var frameContainerContent = new StackLayout
         {
-            Margin = new Microsoft.Maui.Thickness(1),
+            Margin = new Thickness(1),
-            Padding = new Microsoft.Maui.Thickness(1, 1),
+            Padding = new Thickness(1, 1),
             HorizontalOptions = LayoutOptions.Center,
             VerticalOptions = LayoutOptions.Center
-
         };
         /*
         DotNetBotImage = new Image