Make Editor focused background color behavior consistent with Entry on Windows (#456)

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla44584.cs

@@ -0,0 +1,44 @@
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+
+namespace Xamarin.Forms.Controls
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Bugzilla, 44584,
+		"UWP - Editor: changing the background color will only take effect after the entry gained focus")]
+	public class Bugzilla44584 : TestContentPage
+	{
+		protected override void Init()
+		{
+			var instructions = new Label
+			{
+				Text = @"
+Tap the first button once to turn the Entry background color to Green. Tap the Entry to focus it; the background should remain green; if it does not, the test has failed. 
+Tap the second button once to turn the Editor background color to Green. Tap the Editor to focus it; the background should remain green; if it does not, the test has failed." 
+			};
+
+			var entryButton = new Button { Text = "Toggle Entry Background (Green/Default)" };
+			var entry = new Entry();
+
+			entryButton.Clicked +=
+				(sender, args) => { entry.BackgroundColor = entry.BackgroundColor != Color.Green ? Color.Green : Color.Default; };
+
+			var editorButton = new Button { Text = "Toggle Editor Background (Green/Default)" };
+			var editor = new Editor()
+			{
+				HeightRequest = 80
+			};
+
+			editorButton.Clicked +=
+				(sender, args) => { editor.BackgroundColor = editor.BackgroundColor != Color.Green ? Color.Green : Color.Default; };
+
+			var layout = new StackLayout
+			{
+				VerticalOptions = LayoutOptions.Center,
+				Children = { instructions, entryButton, entry, editorButton, editor }
+			};
+
+			Content = layout;
+		}
+	}
+}

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems

@@ -128,6 +128,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla43516.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla44166.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla44461.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Bugzilla44584.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla42832.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla44044.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)CarouselAsync.cs" />

Xamarin.Forms.Platform.WinRT/EditorRenderer.cs

@@ -1,6 +1,7 @@
 using System.ComponentModel;
 using Windows.UI.Xaml;
 using Windows.UI.Xaml.Controls;
+using Windows.UI.Xaml.Media;
 
 #if WINDOWS_UWP
 
@@ -10,9 +11,10 @@ namespace Xamarin.Forms.Platform.UWP
 namespace Xamarin.Forms.Platform.WinRT
 #endif
 {
-	public class EditorRenderer : ViewRenderer<Editor, TextBox>
+	public class EditorRenderer : ViewRenderer<Editor, FormsTextBox>
 	{
 		bool _fontApplied;
+		Brush _backgroundColorFocusedDefaultBrush;
 
 		protected override void OnElementChanged(ElementChangedEventArgs<Editor> e)
 		{
@@ -20,7 +22,12 @@ namespace Xamarin.Forms.Platform.WinRT
 			{
 				if (Control == null)
 				{
-					var textBox = new TextBox { AcceptsReturn = true, TextWrapping = TextWrapping.Wrap };
+					var textBox = new FormsTextBox
+					{
+						AcceptsReturn = true,
+						TextWrapping = TextWrapping.Wrap,
+						Style = Windows.UI.Xaml.Application.Current.Resources["FormsTextBoxStyle"] as Windows.UI.Xaml.Style
+					};
 
 					SetNativeControl(textBox);
 
@@ -50,6 +57,8 @@ namespace Xamarin.Forms.Platform.WinRT
 
 		protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
 		{
+			base.OnElementPropertyChanged(sender, e);
+
 			if (e.PropertyName == Editor.TextColorProperty.PropertyName)
 			{
 				UpdateTextColor();
@@ -70,8 +79,6 @@ namespace Xamarin.Forms.Platform.WinRT
 			{
 				UpdateText();
 			}
-
-			base.OnElementPropertyChanged(sender, e);
 		}
 
 		void OnLostFocus(object sender, RoutedEventArgs e)
@@ -79,6 +86,20 @@ namespace Xamarin.Forms.Platform.WinRT
 			Element.SendCompleted();
 		}
 
+		protected override void UpdateBackgroundColor()
+		{
+			base.UpdateBackgroundColor();
+
+			if (Control == null)
+			{
+				return;
+			}
+
+			// By default some platforms have alternate default background colors when focused
+			BrushHelpers.UpdateColor(Element.BackgroundColor, ref _backgroundColorFocusedDefaultBrush,
+				() => Control.BackgroundFocusBrush, brush => Control.BackgroundFocusBrush = brush);
+		}
+
 		void OnNativeTextChanged(object sender, Windows.UI.Xaml.Controls.TextChangedEventArgs args)
 		{
 			Element.SetValueCore(Editor.TextProperty, Control.Text);

Xamarin.Forms.Platform.WinRT/FormsTextBox.cs

@@ -111,7 +111,7 @@ namespace Xamarin.Forms.Platform.WinRT
 			if (Device.Idiom == TargetIdiom.Phone)
 			{
 				// If we're on the phone, we need to grab this from the template
-				// so we can manually handle it's background when focused
+				// so we can manually handle its background when focused
 				_borderElement = (Border)GetTemplateChild("BorderElement");
 			}
 		}