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

3 files changed, 77 insertions, 10 deletions

diff --git a/Xamarin.Forms.Platform.WP8/DatePickerRenderer.cs b/Xamarin.Forms.Platform.WP8/DatePickerRenderer.cs
index 9553171b..5685310d 100644
--- a/Xamarin.Forms.Platform.WP8/DatePickerRenderer.cs
+++ b/Xamarin.Forms.Platform.WP8/DatePickerRenderer.cs
@@ -1,17 +1,28 @@
 using System;
 using System.ComponentModel;
 using System.Reflection;
+using System.Windows.Media;
 using Microsoft.Phone.Controls;
 
 namespace Xamarin.Forms.Platform.WinPhone
 {
 	public class DatePickerRenderer : ViewRenderer<DatePicker, Microsoft.Phone.Controls.DatePicker>
 	{
+		Brush _defaultBrush;
+
 		protected override void OnElementChanged(ElementChangedEventArgs<DatePicker> e)
 		{
 			base.OnElementChanged(e);
 
 			var datePicker = new Microsoft.Phone.Controls.DatePicker { Value = Element.Date };
+
+			datePicker.Loaded += (sender, args) => {
+				// The defaults from the control template won't be available
+				// right away; we have to wait until after the template has been applied
+				_defaultBrush = datePicker.Foreground;
+				UpdateTextColor();
+			};
+
 			datePicker.ValueChanged += DatePickerOnValueChanged;
 			SetNativeControl(datePicker);
 
@@ -20,11 +31,14 @@ namespace Xamarin.Forms.Platform.WinPhone
 
 		protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
 		{
-			if (e.PropertyName == "Date")
+			base.OnElementPropertyChanged(sender, e);
+
+			if (e.PropertyName == DatePicker.DateProperty.PropertyName)
 				Control.Value = Element.Date;
 			else if (e.PropertyName == DatePicker.FormatProperty.PropertyName)
 				UpdateFormatString();
-			base.OnElementPropertyChanged(sender, e);
+			else if (e.PropertyName == DatePicker.TextColorProperty.PropertyName)
+				UpdateTextColor();
 		}
 
 		internal override void OnModelFocusChangeRequested(object sender, VisualElement.FocusRequestArgs args)
@@ -55,5 +69,11 @@ namespace Xamarin.Forms.Platform.WinPhone
 		{
 			Control.ValueStringFormat = "{0:" + Element.Format + "}";
 		}
+
+		void UpdateTextColor()
+		{
+			Color color = Element.TextColor;
+			Control.Foreground = color.IsDefault ? (_defaultBrush ?? color.ToBrush()) : color.ToBrush();
+		}
 	}
 }
\ No newline at end of file
diff --git a/Xamarin.Forms.Platform.WP8/PickerRenderer.cs b/Xamarin.Forms.Platform.WP8/PickerRenderer.cs
index f9cd2d81..d52f7314 100644
--- a/Xamarin.Forms.Platform.WP8/PickerRenderer.cs
+++ b/Xamarin.Forms.Platform.WP8/PickerRenderer.cs
@@ -4,6 +4,7 @@ using System.ComponentModel;
 using System.Reflection;
 using System.Windows;
 using System.Windows.Controls;
+using System.Windows.Media;
 using Microsoft.Phone.Controls;
 
 namespace Xamarin.Forms.Platform.WinPhone
@@ -11,8 +12,8 @@ namespace Xamarin.Forms.Platform.WinPhone
 	public class PickerRenderer : ViewRenderer<Picker, FrameworkElement>
 	{
 		bool _isChanging;
-
 		FormsListPicker _listPicker;
+		Brush _defaultBrush;
 
 		protected override void OnElementChanged(ElementChangedEventArgs<Picker> e)
 		{
@@ -34,6 +35,12 @@ namespace Xamarin.Forms.Platform.WinPhone
 			_listPicker.Items.Add(new ItemViewModel(" ") { MaxHeight = 0 });
 
 			_listPicker.ListPickerModeChanged += ListPickerModeChanged;
+			_listPicker.Loaded += (sender, args) => {
+				// The defaults from the control template won't be available
+				// right away; we have to wait until after the template has been applied
+				_defaultBrush = _listPicker.Foreground;
+				UpdateTextColor();
+			};
 
 			var grid = new System.Windows.Controls.Grid { Children = { _listPicker }, MaxWidth = Device.Info.PixelScreenSize.Width };
 			SetNativeControl(grid);
@@ -45,20 +52,29 @@ namespace Xamarin.Forms.Platform.WinPhone
 		protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
 		{
 			base.OnElementPropertyChanged(sender, e);
+
 			if (e.PropertyName == Picker.TitleProperty.PropertyName)
+			{
 				_listPicker.FullModeHeader = Element.Title;
-
-			if (e.PropertyName == VisualElement.IsEnabledProperty.PropertyName)
+			}
+			else if (e.PropertyName == VisualElement.IsEnabledProperty.PropertyName)
+			{
 				UpdateIsEnabled();
-
-			if (e.PropertyName == Picker.SelectedIndexProperty.PropertyName)
+				UpdateTextColor();
+			}
+			else if (e.PropertyName == Picker.SelectedIndexProperty.PropertyName)
 			{
 				if (Element.SelectedIndex >= 0 && Element.SelectedIndex < Element.Items.Count)
 					_listPicker.SelectedIndex = Element.SelectedIndex + 1;
 			}
-
-			if (e.PropertyName == View.HorizontalOptionsProperty.PropertyName)
+			else if (e.PropertyName == View.HorizontalOptionsProperty.PropertyName)
+			{
 				UpdateAlignment();
+			}
+			else if (e.PropertyName == Picker.TextColorProperty.PropertyName)
+			{
+				UpdateTextColor();
+			}
 		}
 
 		protected override void OnGotFocus(object sender, RoutedEventArgs args)
@@ -198,6 +214,17 @@ namespace Xamarin.Forms.Platform.WinPhone
 			_listPicker.SelectedIndex = Element.SelectedIndex + 1;
 		}
 
+		void UpdateTextColor()
+		{
+			if (!_listPicker.IsEnabled)
+			{
+				return;
+			}
+
+			Color color = Element.TextColor;
+			_listPicker.Foreground = color.IsDefault ? (_defaultBrush ?? color.ToBrush()) : color.ToBrush();
+		}
+
 		class ItemViewModel : INotifyPropertyChanged
 		{
 			string _data;
diff --git a/Xamarin.Forms.Platform.WP8/TimePickerRenderer.cs b/Xamarin.Forms.Platform.WP8/TimePickerRenderer.cs
index 70841d7a..542bddfc 100644
--- a/Xamarin.Forms.Platform.WP8/TimePickerRenderer.cs
+++ b/Xamarin.Forms.Platform.WP8/TimePickerRenderer.cs
@@ -1,17 +1,29 @@
 using System;
 using System.ComponentModel;
 using System.Reflection;
+using System.Windows.Media;
 using Microsoft.Phone.Controls;
 
 namespace Xamarin.Forms.Platform.WinPhone
 {
 	public class TimePickerRenderer : ViewRenderer<TimePicker, Microsoft.Phone.Controls.TimePicker>
 	{
+		Brush _defaultBrush;
+
 		protected override void OnElementChanged(ElementChangedEventArgs<TimePicker> e)
 		{
 			base.OnElementChanged(e);
 
 			var timePicker = new Microsoft.Phone.Controls.TimePicker { Value = DateTime.Today.Add(Element.Time) };
+
+			timePicker.Loaded += (sender, args) =>
+			{
+				// The defaults from the control template won't be available
+				// right away; we have to wait until after the template has been applied
+				_defaultBrush = timePicker.Foreground;
+				UpdateTextColor();
+			};
+
 			timePicker.ValueChanged += TimePickerOnValueChanged;
 
 			SetNativeControl(timePicker);
@@ -22,10 +34,12 @@ namespace Xamarin.Forms.Platform.WinPhone
 		{
 			base.OnElementPropertyChanged(sender, e);
 
-			if (e.PropertyName == "Time")
+			if (e.PropertyName == TimePicker.TimeProperty.PropertyName)
 				Control.Value = DateTime.Today.Add(Element.Time);
 			else if (e.PropertyName == TimePicker.FormatProperty.PropertyName)
 				UpdateFormatString();
+			else if (e.PropertyName == TimePicker.TextColorProperty.PropertyName)
+				UpdateTextColor();
 		}
 
 		internal override void OnModelFocusChangeRequested(object sender, VisualElement.FocusRequestArgs args)
@@ -56,5 +70,11 @@ namespace Xamarin.Forms.Platform.WinPhone
 		{
 			Control.ValueStringFormat = "{0:" + Element.Format + "}";
 		}
+
+		void UpdateTextColor()
+		{
+			Color color = Element.TextColor;
+			Control.Foreground = color.IsDefault ? (_defaultBrush ?? color.ToBrush()) : color.ToBrush();
+		}
 	}
 }
\ No newline at end of file