[WinRT/UWP] Make TextBox better respect background color changes via behaviors (#749)

2 files changed, 82 insertions, 0 deletions

diff --git a/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla44955.cs b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla44955.cs
new file mode 100644
index 00000000..a30a65bd
--- /dev/null
+++ b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla44955.cs
@@ -0,0 +1,81 @@
+using System.Diagnostics;
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+
+#if UITEST
+using Xamarin.UITest;
+using NUnit.Framework;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Bugzilla, 44955, "[WinRT/UWP] Setting Entry BackgroundColor via Behavior results in sticky unfocused background color", PlatformAffected.WinRT)]
+	public class Bugzilla44955 : TestContentPage
+	{
+		Entry _validationEntry;
+		protected override void Init()
+		{
+			_validationEntry = new Entry();
+			_validationEntry.Behaviors.Add(new NonEmptyStringValidator());
+			Content = new StackLayout
+			{
+				Children =
+				{
+					new Label
+					{
+						Text = "The first entry should have a red background only when it is empty, regardless of focus (due to an attached behavior). The second has a set background color, the third is default, and the last is default, but disabled."
+					},
+					_validationEntry,
+					new Entry
+					{
+						BackgroundColor = Color.MediumPurple
+					},
+					new Entry(),
+					new Entry
+					{
+						IsEnabled = false
+					},
+					new Button
+					{
+						Text = "Change background of first label to yellow",
+						Command = new Command(() => _validationEntry.BackgroundColor = Color.Yellow)
+					}
+				}
+			};
+		}
+
+		protected override void OnDisappearing()
+		{
+			base.OnDisappearing();
+			_validationEntry.Behaviors.Clear();
+		}
+
+		class NonEmptyStringValidator : Behavior<Entry>
+		{
+			protected override void OnAttachedTo(Entry bindable)
+			{
+				bindable.TextChanged += HandleTextChanged;
+				Validate(bindable, bindable.Text);
+			}
+
+			protected override void OnDetachingFrom(Entry bindable)
+			{
+				bindable.TextChanged -= HandleTextChanged;
+			}
+
+			void HandleTextChanged(object sender, TextChangedEventArgs e)
+			{
+				Validate((Entry)sender, e.NewTextValue);
+			}
+
+			void Validate(Entry entry, string text)
+			{
+				if (text == null)
+					entry.BackgroundColor = Color.Red;
+				else
+					entry.BackgroundColor = text.Trim() != "" ? Color.Default : Color.Red;
+			}
+		}
+	}
+}
diff --git a/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems
index 1093f1b0..0deca6b6 100644
--- a/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems
+++ b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems
@@ -164,6 +164,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla44338.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla45027.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla45330.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Bugzilla44955.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla45743.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla46494.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla44476.cs" />