From: Stephane Delcroix <stephane@delcroix.org>
Date: Thu, 2 Mar 2017 22:36:25 +0000 (+0100)
Subject: Backport #793  (#796)
X-Git-Tag: beta-2.3.4-pre3~8
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=dbe0d4945da400a5b00599155d22cda78754294a;p=platform%2Fupstream%2Fxamarin-forms.git

Backport #793  (#796)

* [Xaml] Fallback to App.Current for DynResources (Previewer) (#793)

* [Xaml] Fallback to App.Current for DynResources (Previewer)

* [C] avoid NRE and ensure setting the style

* remove files committed by accident
---

diff --git a/Xamarin.Forms.Core.UnitTests/DynamicResourceTests.cs b/Xamarin.Forms.Core.UnitTests/DynamicResourceTests.cs
index faea996..25ae329 100644
--- a/Xamarin.Forms.Core.UnitTests/DynamicResourceTests.cs
+++ b/Xamarin.Forms.Core.UnitTests/DynamicResourceTests.cs
@@ -10,6 +10,13 @@ namespace Xamarin.Forms.Core.UnitTests
 		{
 			base.Setup ();
 			Device.PlatformServices = new MockPlatformServices ();
+			Application.Current = new MockApplication();
+		}
+
+		[TearDown]
+		public override void TearDown()
+		{
+			Application.Current = null;
 		}
 
 		[Test]
@@ -143,11 +150,24 @@ namespace Xamarin.Forms.Core.UnitTests
 			label.SetDynamicResource (Label.TextProperty, "foo");
 			label.Resources = new ResourceDictionary { {"foo","FOO"}};
 
-			Assert.AreEqual ("FOO", label.Text);
+			Assume.That(label.Text, Is.EqualTo("FOO"));
 
 			label.Resources ["foo"] = "BAR";
 
 			Assert.AreEqual ("BAR", label.Text);
 		}
+
+		[Test]
+		public void FallbackToApplicationCurrent()
+		{
+			Application.Current.Resources = new ResourceDictionary { { "foo", "FOO" } };
+
+			var label = new Label();
+			label.BindingContext = new MockViewModel();
+			label.SetBinding(Label.TextProperty, "Text", BindingMode.TwoWay);
+			label.SetDynamicResource(Label.TextProperty, "foo");
+
+			Assert.That(label.Text, Is.EqualTo("FOO"));
+		}
 	}
 }
\ No newline at end of file
diff --git a/Xamarin.Forms.Core/MergedStyle.cs b/Xamarin.Forms.Core/MergedStyle.cs
index 59a1dea..941ebbd 100644
--- a/Xamarin.Forms.Core/MergedStyle.cs
+++ b/Xamarin.Forms.Core/MergedStyle.cs
@@ -125,12 +125,11 @@ namespace Xamarin.Forms
 			void RegisterImplicitStyles()
 			{
 				Type type = TargetType;
-				while (true)
-				{
+				while (true) {
 					BindableProperty implicitStyleProperty = BindableProperty.Create("ImplicitStyle", typeof(Style), typeof(VisualElement), default(Style),
-						propertyChanged: (bindable, oldvalue, newvalue) => ((VisualElement)bindable)._mergedStyle.OnImplicitStyleChanged());
-					Target.SetDynamicResource(implicitStyleProperty, type.FullName);
+						 propertyChanged: (bindable, oldvalue, newvalue) => OnImplicitStyleChanged());
 					_implicitStyles.Add(implicitStyleProperty);
+					Target.SetDynamicResource(implicitStyleProperty, type.FullName);
 					type = type.GetTypeInfo().BaseType;
 					if (s_stopAtTypes.Contains(type))
 						return;
diff --git a/Xamarin.Forms.Core/ResourcesExtensions.cs b/Xamarin.Forms.Core/ResourcesExtensions.cs
index 8930abf..7d2f8d0 100644
--- a/Xamarin.Forms.Core/ResourcesExtensions.cs
+++ b/Xamarin.Forms.Core/ResourcesExtensions.cs
@@ -55,6 +55,11 @@ namespace Xamarin.Forms
 					return true;
 				element = element.Parent;
 			}
+
+			//Fallback for the XF previewer
+			if (Application.Current != null && Application.Current.Resources != null && Application.Current.Resources.TryGetValue(key, out value))
+				return true;
+
 			value = null;
 			return false;
 		}