Switchcell oncolor (#4036) fixes #4027

* Added OnColor property for changing switchcell color

* Added logic to apply color to Switch

* Used nameof on the OnColor property

* [UWP] support for UWP

Xamarin.Forms.Controls/GalleryPages/CellsGalleries/SwitchCellListPage.cs

@@ -8,6 +8,7 @@ namespace Xamarin.Forms.Controls
 	{
 		public string Label { get; set; }
 		public bool SwitchOn { get; set; }
+		public Color OnColor { get; set; }
 	}
 
 	public class SwitchCellListPage : ContentPage
@@ -23,6 +24,7 @@ namespace Xamarin.Forms.Controls
 				Bindings = {
 					{SwitchCell.TextProperty, new Binding ("Label")},
 					{SwitchCell.OnProperty, new Binding ("SwitchOn")},
+					{SwitchCell.OnColorProperty, new Binding ("OnColor")},
 				}
 			};
 
@@ -33,6 +35,7 @@ namespace Xamarin.Forms.Controls
 				ItemsSource = Enumerable.Range (0, 100).Select (i => new SwitchCellItem {
 					Label = "Label " + i,
 					SwitchOn =  i % 2 == 0 ? false : true,
+					OnColor = i % 2 == 0 ? Color.Firebrick : Color.GreenYellow
 				}),
 				ItemTemplate = dataTemplate
 			};

Xamarin.Forms.Core/Cells/SwitchCell.cs

@@ -12,6 +12,14 @@ namespace Xamarin.Forms
 
 		public static readonly BindableProperty TextProperty = BindableProperty.Create("Text", typeof(string), typeof(SwitchCell), default(string));
 
+		public static readonly BindableProperty OnColorProperty = BindableProperty.Create(nameof(OnColor), typeof(Color), typeof(SwitchCell), Color.Default);
+
+		public Color OnColor
+		{
+			get { return (Color)GetValue(OnColorProperty); }
+			set { SetValue(OnColorProperty, value); }
+		}
+
 		public bool On
 		{
 			get { return (bool)GetValue(OnProperty); }

Xamarin.Forms.Platform.Android/Cells/SwitchCellRenderer.cs

@@ -3,12 +3,16 @@ using Android.Content;
 using Android.Views;
 using AView = Android.Views.View;
 using ASwitch = Android.Widget.Switch;
+using Android.OS;
+using Android.Graphics;
+using Android.Graphics.Drawables;
 
 namespace Xamarin.Forms.Platform.Android
 {
 	public class SwitchCellRenderer : CellRenderer
 	{
 		SwitchCellView _view;
+		Drawable _defaultTrackDrawable;
 
 		protected override AView GetCellCore(Cell item, AView convertView, ViewGroup parent, Context context)
 		{
@@ -19,11 +23,16 @@ namespace Xamarin.Forms.Platform.Android
 
 			_view.Cell = cell;
 
+			var aSwitch = _view.AccessoryView as ASwitch;
+			if (aSwitch != null)
+				_defaultTrackDrawable = aSwitch.TrackDrawable;
+
 			UpdateText();
 			UpdateChecked();
 			UpdateHeight();
 			UpdateIsEnabled(_view, cell);
 			UpdateFlowDirection();
+			UpdateOnColor(_view, cell);
 
 			return _view;
 		}
@@ -33,13 +42,18 @@ namespace Xamarin.Forms.Platform.Android
 			if (args.PropertyName == SwitchCell.TextProperty.PropertyName)
 				UpdateText();
 			else if (args.PropertyName == SwitchCell.OnProperty.PropertyName)
+			{
 				UpdateChecked();
+				UpdateOnColor(_view, (SwitchCell)sender);
+			}
 			else if (args.PropertyName == "RenderHeight")
 				UpdateHeight();
 			else if (args.PropertyName == Cell.IsEnabledProperty.PropertyName)
 				UpdateIsEnabled(_view, (SwitchCell)sender);
 			else if (args.PropertyName == VisualElement.FlowDirectionProperty.PropertyName)
 				UpdateFlowDirection();
+			else if (args.PropertyName == SwitchCell.OnColorProperty.PropertyName)
+				UpdateOnColor(_view, (SwitchCell)sender);
 		}
 
 		void UpdateChecked()
@@ -69,5 +83,31 @@ namespace Xamarin.Forms.Platform.Android
 		{
 			_view.MainText = ((SwitchCell)Cell).Text;
 		}
+
+		void UpdateOnColor(SwitchCellView cell, SwitchCell switchCell)
+		{
+			var aSwitch = cell.AccessoryView as ASwitch;
+			if (aSwitch != null)
+			{
+				if (switchCell.On)
+				{
+					if (switchCell.OnColor == Color.Default)
+					{
+						aSwitch.TrackDrawable = _defaultTrackDrawable;
+					}
+					else
+					{
+						if (Build.VERSION.SdkInt >= BuildVersionCodes.JellyBean)
+						{
+							aSwitch.TrackDrawable.SetColorFilter(switchCell.OnColor.ToAndroid(), PorterDuff.Mode.Multiply);
+						}
+					}
+				}
+				else
+				{
+					aSwitch.TrackDrawable.ClearColorFilter();
+				}
+			}
+		}
 	}
 }

Xamarin.Forms.Platform.UAP/CellControl.cs

@@ -9,6 +9,7 @@ using Windows.UI.Xaml.Controls;
 using Windows.UI.Xaml.Controls.Primitives;
 using Windows.UI.Xaml.Input;
 using Windows.UI.Xaml.Media;
+using Windows.UI.Xaml.Media.Animation;
 using Xamarin.Forms.Internals;
 
 namespace Xamarin.Forms.Platform.UWP
@@ -23,6 +24,7 @@ namespace Xamarin.Forms.Platform.UWP
 		internal static readonly BindableProperty MeasuredEstimateProperty = BindableProperty.Create("MeasuredEstimate", typeof(double), typeof(ListView), -1d);
 		readonly Lazy<ListView> _listView;
 		readonly PropertyChangedEventHandler _propertyChangedHandler;
+		Brush _defaultOnColor;
 
 		IList<MenuItem> _contextActions;
 		Windows.UI.Xaml.DataTemplate _currentTemplate;
@@ -101,6 +103,7 @@ namespace Xamarin.Forms.Platform.UWP
 			if (lv != null)
 			{
 				lv.SetValue(MeasuredEstimateProperty, result.Height);
+				SetDafaultColor();
 			}
 
 			return result;
@@ -138,6 +141,77 @@ namespace Xamarin.Forms.Platform.UWP
 			}
 			else if (e.PropertyName == VisualElement.FlowDirectionProperty.PropertyName)
 				UpdateFlowDirection(Cell);
+			else if (e.PropertyName == SwitchCell.OnProperty.PropertyName ||
+				e.PropertyName == SwitchCell.OnColorProperty.PropertyName)
+			{
+				UpdateOnColor();
+			}
+		}
+
+		void UpdateOnColor()
+		{
+			if (!(Cell is SwitchCell switchCell))
+				return;
+
+			var color = switchCell.OnColor == Color.Default
+				? _defaultOnColor
+				: new SolidColorBrush(switchCell.OnColor.ToWindowsColor());
+
+			var nativeSwitch = FrameworkElementExtensions.GetFirstDescendant<ToggleSwitch>(this);
+
+			// change fill color in switch rectangle
+			var rects = nativeSwitch.GetDescendantsByName<Windows.UI.Xaml.Shapes.Rectangle>("SwitchKnobBounds");
+			foreach (var rect in rects)
+				rect.Fill = color;
+
+			// change color in animation on PointerOver
+			var grid = nativeSwitch.GetFirstDescendant<Windows.UI.Xaml.Controls.Grid>();
+			var gridVisualStateGroups = Windows.UI.Xaml.VisualStateManager.GetVisualStateGroups(grid);
+			Windows.UI.Xaml.VisualStateGroup vsGroup = null;
+			foreach (var visualGroup in gridVisualStateGroups)
+			{
+				if (visualGroup.Name == "CommonStates")
+				{
+					vsGroup = visualGroup;
+					break;
+				}
+			}
+			if (vsGroup == null)
+				return;
+
+			Windows.UI.Xaml.VisualState vState = null;
+			foreach (var visualState in vsGroup.States)
+			{
+				if (visualState.Name == "PointerOver")
+				{
+					vState = visualState;
+					break;
+				}
+			}
+			if (vState == null)
+				return;
+
+			var visualStates = vState.Storyboard.Children;
+			foreach (ObjectAnimationUsingKeyFrames item in visualStates)
+			{
+				if ((string)item.GetValue(Storyboard.TargetNameProperty) == "SwitchKnobBounds")
+				{
+					item.KeyFrames[0].Value = color;
+					break;
+				}
+			}
+		}
+
+		void SetDafaultColor()
+		{
+			if (_defaultOnColor == null && Cell is SwitchCell)
+			{
+				var nativeSwitch = FrameworkElementExtensions.GetFirstDescendant<ToggleSwitch>(this);
+				var rects = nativeSwitch.GetDescendantsByName<Windows.UI.Xaml.Shapes.Rectangle>("SwitchKnobBounds");
+				foreach (var rect in rects)
+					_defaultOnColor = rect.Fill;
+				UpdateOnColor();
+			}
 		}
 
 		void OnClick(object sender, PointerRoutedEventArgs e)

Xamarin.Forms.Platform.iOS/Cells/SwitchCellRenderer.cs

@@ -9,6 +9,8 @@ namespace Xamarin.Forms.Platform.iOS
 	{
 		const string CellName = "Xamarin.SwitchCell";
 
+		UIColor _defaultOnColor;
+
 		public override UITableViewCell GetCell(Cell item, UITableViewCell reusableCell, UITableView tv)
 		{
 			var tvc = reusableCell as CellTableViewCell;
@@ -32,6 +34,8 @@ namespace Xamarin.Forms.Platform.iOS
 
 			var boolCell = (SwitchCell)item;
 
+			_defaultOnColor = UISwitch.Appearance.OnTintColor;
+
 			tvc.Cell = item;
 			tvc.PropertyChanged += HandlePropertyChanged;
 			tvc.AccessoryView = uiSwitch;
@@ -44,6 +48,7 @@ namespace Xamarin.Forms.Platform.iOS
 			UpdateBackground(tvc, item);
 			UpdateIsEnabled(tvc, boolCell);
 			UpdateFlowDirection(tvc, boolCell);
+			UpdateOnColor(tvc, boolCell);
 
 			return tvc;
 		}
@@ -54,13 +59,18 @@ namespace Xamarin.Forms.Platform.iOS
 			var realCell = (CellTableViewCell)GetRealCell(boolCell);
 
 			if (e.PropertyName == SwitchCell.OnProperty.PropertyName)
+			{
 				((UISwitch)realCell.AccessoryView).SetState(boolCell.On, true);
+				UpdateOnColor(realCell, boolCell);
+			}
 			else if (e.PropertyName == SwitchCell.TextProperty.PropertyName)
 				realCell.TextLabel.Text = boolCell.Text;
 			else if (e.PropertyName == Cell.IsEnabledProperty.PropertyName)
 				UpdateIsEnabled(realCell, boolCell);
 			else if (e.PropertyName == VisualElement.FlowDirectionProperty.PropertyName)
 				UpdateFlowDirection(realCell, boolCell);
+			else if (e.PropertyName == SwitchCell.OnColorProperty.PropertyName)
+				UpdateOnColor(realCell, boolCell);
 		}
 
 		void OnSwitchValueChanged(object sender, EventArgs eventArgs)
@@ -97,5 +107,17 @@ namespace Xamarin.Forms.Platform.iOS
 			if (uiSwitch != null)
 				uiSwitch.Enabled = switchCell.IsEnabled;
 		}
+
+		void UpdateOnColor(CellTableViewCell cell, SwitchCell switchCell)
+		{
+			var uiSwitch = cell.AccessoryView as UISwitch;
+			if (uiSwitch != null)
+			{
+				if (switchCell.OnColor == Color.Default)
+					uiSwitch.OnTintColor = _defaultOnColor;
+				else
+					uiSwitch.OnTintColor = switchCell.OnColor.ToUIColor();
+			}
+		}
 	}
 }