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, 14 insertions, 3 deletions

diff --git a/Xamarin.Forms.Platform.Android/Renderers/DatePickerRenderer.cs b/Xamarin.Forms.Platform.Android/Renderers/DatePickerRenderer.cs
index 11d9a0d0..5b0e0994 100644
--- a/Xamarin.Forms.Platform.Android/Renderers/DatePickerRenderer.cs
+++ b/Xamarin.Forms.Platform.Android/Renderers/DatePickerRenderer.cs
@@ -1,6 +1,7 @@
 using System;
 using System.ComponentModel;
 using Android.App;
+using Android.Content.Res;
 using Android.Widget;
 using AView = Android.Views.View;
 using Object = Java.Lang.Object;
@@ -11,6 +12,7 @@ namespace Xamarin.Forms.Platform.Android
 	{
 		DatePickerDialog _dialog;
 		bool _disposed;
+		TextColorSwitcher _textColorSwitcher;
 
 		public DatePickerRenderer()
 		{
@@ -47,24 +49,28 @@ namespace Xamarin.Forms.Platform.Android
 
 				textField.SetOnClickListener(TextFieldClickHandler.Instance);
 				SetNativeControl(textField);
+				_textColorSwitcher = new TextColorSwitcher(textField.TextColors); 
 			}
 
 			SetDate(Element.Date);
 
 			UpdateMinimumDate();
 			UpdateMaximumDate();
+			UpdateTextColor();
 		}
 
 		protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
 		{
 			base.OnElementPropertyChanged(sender, e);
 
-			if (e.PropertyName == "Date" || e.PropertyName == DatePicker.FormatProperty.PropertyName)
+			if (e.PropertyName == DatePicker.DateProperty.PropertyName || e.PropertyName == DatePicker.FormatProperty.PropertyName)
 				SetDate(Element.Date);
-			else if (e.PropertyName == "MinimumDate")
+			else if (e.PropertyName == DatePicker.MinimumDateProperty.PropertyName)
 				UpdateMinimumDate();
-			else if (e.PropertyName == "MaximumDate")
+			else if (e.PropertyName == DatePicker.MaximumDateProperty.PropertyName)
 				UpdateMaximumDate();
+			if (e.PropertyName == DatePicker.TextColorProperty.PropertyName)
+				UpdateTextColor();
 		}
 
 		internal override void OnFocusChangeRequested(object sender, VisualElement.FocusRequestArgs e)
@@ -141,6 +147,11 @@ namespace Xamarin.Forms.Platform.Android
 			}
 		}
 
+		void UpdateTextColor()
+		{
+			_textColorSwitcher?.UpdateTextColor(Control, Element.TextColor);
+		}
+
 		class TextFieldClickHandler : Object, IOnClickListener
 		{
 			public static readonly TextFieldClickHandler Instance = new TextFieldClickHandler();