Add TextColor Property to Picker, TimePicker, DatePicker (#84)

* Add TextColor property to TimePicker
Add TextColor page to TimePicker gallery
Add TimePicker color toggling to color toggle test page
Split color toggle tests up among tabs

* Implement TimePicker.TextColor in iOS

* Implement TimePicker.TextColor for WinRT tablet

* Add IsEnabled=false tests to DefaultColorToggleTest Button and TimePicker
Consolidate ColorStates array
Fix IsEnabled changing color bug on iOS

* Implement TimePicker.TextColor for WP8

* Add TextColor property to DatePicker
Add DatePicker section to DefaultColorToggleTest
Impement DatePicker.TextColor for WP8

* Implement DatePicker.TextColor for WinRT/UWP/Windows Phone 8.1

* Implement DatePicker.TextColor for iOS

* Add TextColor to DatePicker Gallery Page

* Implement DatePicker.TextColor for Android

* Add Picker Gallery page for TextColor
Implement Picker.TextColor on Android
Consolidate TextColor management for Button, Picker, DatePicker, TimePicker
Implement

* Add untracked TextColorSwitcher
Implement Picker.TextColor in iOS

* Implement Picker.TextColor in WinRT/UWP/Windows Phone 8.1
Remove Pioker Loaded handlers in Dispose

* Implement Picker.TextColor in WP8

* Removed unused field
Update ignored warnings

* Update docs

* Use nameof() for BindableProperties

* Cleanup

* Fix custom renderer crashes for classes using TextColorSwitcher

* Correct property name references

* Fix typo and 'if' formatting

* Add missing else

1 files changed, 23 insertions, 1 deletions

diff --git a/Xamarin.Forms.Platform.WinRT/DatePickerRenderer.cs b/Xamarin.Forms.Platform.WinRT/DatePickerRenderer.cs
index 23f134f2..88df5cbc 100644
--- a/Xamarin.Forms.Platform.WinRT/DatePickerRenderer.cs
+++ b/Xamarin.Forms.Platform.WinRT/DatePickerRenderer.cs
@@ -1,6 +1,8 @@
 using System;
 using System.ComponentModel;
+using Windows.UI.Xaml;
 using Windows.UI.Xaml.Controls;
+using Windows.UI.Xaml.Media;
 
 #if WINDOWS_UWP
 
@@ -12,6 +14,8 @@ namespace Xamarin.Forms.Platform.WinRT
 {
 	public class DatePickerRenderer : ViewRenderer<DatePicker, FormsDatePicker>, IWrapperAware
 	{
+		Brush _defaultBrush;
+
 		public void NotifyWrapped()
 		{
 			if (Control != null)
@@ -26,6 +30,7 @@ namespace Xamarin.Forms.Platform.WinRT
 			{
 				Control.ForceInvalidate -= PickerOnForceInvalidate;
 				Control.DateChanged -= OnControlDateChanged;
+				Control.Loaded -= ControlOnLoaded;
 			}
 
 			base.Dispose(disposing);
@@ -38,8 +43,9 @@ namespace Xamarin.Forms.Platform.WinRT
 				if (Control == null)
 				{
 					var picker = new FormsDatePicker();
-					picker.DateChanged += OnControlDateChanged;
 					SetNativeControl(picker);
+					Control.Loaded += ControlOnLoaded;
+					Control.DateChanged += OnControlDateChanged;
 				}
 
 				UpdateMinimumDate();
@@ -50,6 +56,14 @@ namespace Xamarin.Forms.Platform.WinRT
 			base.OnElementChanged(e);
 		}
 
+		void ControlOnLoaded(object sender, RoutedEventArgs routedEventArgs)
+		{
+			// The defaults from the control template won't be available
+			// right away; we have to wait until after the template has been applied
+			_defaultBrush = Control.Foreground;
+			UpdateTextColor();
+		}
+
 		protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
 		{
 			base.OnElementPropertyChanged(sender, e);
@@ -60,6 +74,8 @@ namespace Xamarin.Forms.Platform.WinRT
 				UpdateMaximumDate();
 			else if (e.PropertyName == DatePicker.MinimumDateProperty.PropertyName)
 				UpdateMinimumDate();
+			else if (e.PropertyName == DatePicker.TextColorProperty.PropertyName)
+				UpdateTextColor();
 		}
 
 		void OnControlDateChanged(object sender, DatePickerValueChangedEventArgs e)
@@ -93,5 +109,11 @@ namespace Xamarin.Forms.Platform.WinRT
 			DateTime mindate = Element.MinimumDate;
 			Control.MinYear = new DateTimeOffset(mindate);
 		}
+
+		void UpdateTextColor()
+		{
+			Color color = Element.TextColor;
+			Control.Foreground = color.IsDefault ? (_defaultBrush ?? color.ToBrush()) : color.ToBrush();
+		}
 	}
 }
\ No newline at end of file