Fix Entry/SearchBar color issues (#306)

* Fix disappearing Entry text on UWP Anniversary Edition
Fix background color reversion bug in UWP Phone
Move SearchBar styling on UWP to its own file
Make foreground/background color changes on UWP SearchBar/Entry consistent
Fix SearchBar color toggle bug on WP8

* Temporarily moving SDK target to previous version

* Fix build error on OSX

1 files changed, 37 insertions, 0 deletions

diff --git a/Xamarin.Forms.Platform.WP8/BrushHelpers.cs b/Xamarin.Forms.Platform.WP8/BrushHelpers.cs
new file mode 100644
index 00000000..993b23f4
--- /dev/null
+++ b/Xamarin.Forms.Platform.WP8/BrushHelpers.cs
@@ -0,0 +1,37 @@
+using System;
+using System.Windows.Media;
+
+namespace Xamarin.Forms.Platform.WinPhone
+{
+	internal static class BrushHelpers
+	{
+		/// <summary>
+		/// Handles the logic for setting a Xamarin.Forms Color for a Brush
+		/// while caching the original default brush
+		/// </summary>
+		/// <param name="color">The target Xamarin.Forms.Color</param>
+		/// <param name="defaultbrush">The renderer's cache for the default brush</param>
+		/// <param name="getter">Delegate for retrieving the Control's current Brush</param>
+		/// <param name="setter">Delegate for setting the Control's Brush</param>
+		public static void UpdateColor(Color color, ref Brush defaultbrush, Func<Brush> getter, Action<Brush> setter)
+		{
+			if (color.IsDefault)
+			{
+				if (defaultbrush == null)
+				{
+					return;
+				}
+
+				setter(defaultbrush);
+				return;
+			}
+
+			if (defaultbrush == null)
+			{
+				defaultbrush = getter();
+			}
+
+			setter(color.ToBrush());
+		}
+	}
+}