From e4902ec3cfbf46a694aa4eefb5cf413b2eeea641 Mon Sep 17 00:00:00 2001
From: Vladislav Antonyuk <vlad.antonyuk@gmail.com>
Date: Tue, 28 Jan 2025 19:01:02 +0200
Subject: [PATCH] Fix exception on constraint, fix modal navigation

---
 .../Pages/Alerts/SnackbarPage.xaml            |  8 +---
 .../Pages/Alerts/SnackbarPage.xaml.cs         | 37 +++++++++----------
 .../Views/Alert/AlertView.macios.cs           |  8 ++--
 3 files changed, 22 insertions(+), 31 deletions(-)

diff --git a/samples/CommunityToolkit.Maui.Sample/Pages/Alerts/SnackbarPage.xaml b/samples/CommunityToolkit.Maui.Sample/Pages/Alerts/SnackbarPage.xaml
index 6ae99f7cb..f5f6e30b2 100644
--- a/samples/CommunityToolkit.Maui.Sample/Pages/Alerts/SnackbarPage.xaml
+++ b/samples/CommunityToolkit.Maui.Sample/Pages/Alerts/SnackbarPage.xaml
@@ -16,7 +16,7 @@
     </pages:BasePage.Resources>
     
     <Grid RowSpacing="12"
-          RowDefinitions="70,20,40,40,40,20,*">
+          RowDefinitions="70,20,40,40,40,20">
         <Label Grid.Row="0"
                Text="The Snackbar is a timed alert that appears at the bottom of the screen by default. It is dismissed after a configurable duration of time. Snackbar is fully customizable and can be anchored to any IView."
                HorizontalTextAlignment="Justify"
@@ -43,12 +43,6 @@
 
         <Label Grid.Row="5"
                x:Name="SnackbarShownStatus" />
-        
-        <Button Grid.Row="6"
-                x:Name="DisplaySnackbarButtonAnchoredToButtonOnBottom"
-                VerticalOptions="End"
-                Text="Display Snackbar Anchored to this Button"
-                Clicked="DisplaySnackbarButtonAnchoredToButtonOnBottomClicked"/>
     </Grid>
     
 </pages:BasePage>
\ No newline at end of file
diff --git a/samples/CommunityToolkit.Maui.Sample/Pages/Alerts/SnackbarPage.xaml.cs b/samples/CommunityToolkit.Maui.Sample/Pages/Alerts/SnackbarPage.xaml.cs
index eb70c5455..91ee16327 100644
--- a/samples/CommunityToolkit.Maui.Sample/Pages/Alerts/SnackbarPage.xaml.cs
+++ b/samples/CommunityToolkit.Maui.Sample/Pages/Alerts/SnackbarPage.xaml.cs
@@ -83,15 +83,6 @@ async void DisplayCustomSnackbarAnchoredToButtonClicked(object? sender, EventArg
 			throw new NotSupportedException($"{nameof(DisplayCustomSnackbarButtonAnchoredToButton)}.{nameof(ITextButton.Text)} Not Recognized");
 		}
 	}
-	
-	async void DisplaySnackbarButtonAnchoredToButtonOnBottomClicked(object sender, EventArgs e)
-	{
-		await DisplaySnackbarButtonAnchoredToButtonOnBottom.DisplaySnackbar(
-			"This Snackbar is anchored to the button on the bottom of a page. This Snackbar appears above the button to avoid clipping the Snackbar on the bottom of the Page.",
-			() => DisplaySnackbarButtonAnchoredToButtonOnBottom.BackgroundColor = Colors.Blue,
-			"Close",
-			TimeSpan.FromSeconds(5));
-	}
 
 	void Snackbar_Dismissed(object? sender, EventArgs e)
 	{
@@ -107,6 +98,20 @@ async void DisplaySnackbarInModalButtonClicked(object? sender, EventArgs e)
 	{
 		if (Application.Current?.Windows[0].Page is Page mainPage)
 		{
+			var button = new Button()
+				.CenterHorizontal()
+				.Text("Display Snackbar");
+			button.Command = new AsyncRelayCommand(token => button.DisplaySnackbar(
+				"This Snackbar is anchored to the button on the bottom to avoid clipping the Snackbar on the top of the Page.",
+				() => { },
+				"Close",
+				TimeSpan.FromSeconds(5), token: token));
+
+			var backButton = new Button()
+				.CenterHorizontal()
+				.Text("Back to Snackbar MainPage");
+			backButton.Command = new AsyncRelayCommand(mainPage.Navigation.PopModalAsync);
+			
 			await mainPage.Navigation.PushModalAsync(new ContentPage
 			{
 				Content = new VerticalStackLayout
@@ -115,19 +120,11 @@ await mainPage.Navigation.PushModalAsync(new ContentPage
 
 					Children =
 					{
-						new Button { Command = new AsyncRelayCommand(static token => Snackbar.Make("Snackbar in a Modal MainPage").Show(token)) }
-							.Top().CenterHorizontal()
-							.Text("Display Snackbar"),
-
-						new Label()
-							.Center().TextCenter()
-							.Text("This is a Modal MainPage"),
+						button,
 
-						new Button { Command = new AsyncRelayCommand(mainPage.Navigation.PopModalAsync) }
-							.Bottom().CenterHorizontal()
-							.Text("Back to Snackbar MainPage")
+						backButton
 					}
-				}.Center()
+				}
 			}.Padding(12));
 		}
 	}
diff --git a/src/CommunityToolkit.Maui.Core/Views/Alert/AlertView.macios.cs b/src/CommunityToolkit.Maui.Core/Views/Alert/AlertView.macios.cs
index 22c0fda9b..1f729e2b5 100644
--- a/src/CommunityToolkit.Maui.Core/Views/Alert/AlertView.macios.cs
+++ b/src/CommunityToolkit.Maui.Core/Views/Alert/AlertView.macios.cs
@@ -10,7 +10,6 @@ public class AlertView(bool shouldFillAndExpandHorizontally) : UIView
 {
 	const int defaultSpacing = 10;
 	readonly List<UIView> children = [];
-	readonly bool shouldFillAndExpandHorizontally = shouldFillAndExpandHorizontally;
 
 	/// <summary>
 	/// Parent UIView
@@ -71,7 +70,7 @@ public void Setup()
 	public override void LayoutSubviews()
 	{
 		base.LayoutSubviews();
-
+		
 		if (AnchorView is null)
 		{
 			this.SafeBottomAnchor().ConstraintEqualTo(ParentView.SafeBottomAnchor(), -defaultSpacing).Active = true;
@@ -80,11 +79,12 @@ public override void LayoutSubviews()
 		else if (AnchorView.Superview is not null
 		         && AnchorView.Superview.ConvertRectToView(AnchorView.Frame, null).Top < Container.Frame.Height + SafeAreaLayoutGuide.LayoutFrame.Bottom)
 		{
-			this.SafeTopAnchor().ConstraintEqualTo(AnchorView.SafeBottomAnchor(), defaultSpacing).Active = true;
+			var top = AnchorView.Superview.Frame.Top + AnchorView.Frame.Height + defaultSpacing;
+			this.SafeTopAnchor().ConstraintEqualTo(ParentView.TopAnchor, top).Active = true;
 		}
 		else
 		{
-			this.SafeBottomAnchor().ConstraintEqualTo(AnchorView.SafeTopAnchor(), -defaultSpacing).Active = true;
+			this.SafeBottomAnchor().ConstraintEqualTo(AnchorView.SafeTopAnchor(), 0).Active = true;
 		}
 	}