[iOS] Use UIButtonType.System for Button and utilize UIButton.Appearance (#554)

* Change button style and use UIButton appearance

* added sample code

* change references

* setting other properties

* add comment

* refactor proxy setter

* made control states array static

* remove category declaration

* changes

* add sample code

* changes

* Fix identation

* Update ButtonRenderer.cs

3 files changed, 64 insertions, 3 deletions

diff --git a/Xamarin.Forms.ControlGallery.iOS/AppDelegate.cs b/Xamarin.Forms.ControlGallery.iOS/AppDelegate.cs
index d3107735..1aed7738 100644
--- a/Xamarin.Forms.ControlGallery.iOS/AppDelegate.cs
+++ b/Xamarin.Forms.ControlGallery.iOS/AppDelegate.cs
@@ -205,7 +205,7 @@ namespace Xamarin.Forms.ControlGallery.iOS
 			sl?.Children.Add(uilabel);
 
 			// Create and add a native Button 
-			var uibutton = new UIButton(UIButtonType.RoundedRect);
+			var uibutton = new UIButton(UIButtonType.System);
 			uibutton.SetTitle("Toggle Text Amount", UIControlState.Normal);
 			uibutton.Font = UIFont.FromName("Helvetica", 14f);
 
@@ -304,7 +304,7 @@ namespace Xamarin.Forms.ControlGallery.iOS
 				Text = "DefaultText"
 			};
 
-			var uibuttonColor = new UIButton(UIButtonType.RoundedRect);
+			var uibuttonColor = new UIButton(UIButtonType.System);
 			uibuttonColor.SetTitle("Toggle Text Color Binding", UIControlState.Normal);
 			uibuttonColor.Font = UIFont.FromName("Helvetica", 14f);
 			uibuttonColor.TouchUpInside += (sender, args) => uilabel.TextColor = UIColor.Blue;
@@ -347,7 +347,7 @@ namespace Xamarin.Forms.ControlGallery.iOS
 		public void StartPressed40911()
 		{
 			var loginViewController = new UIViewController { View = { BackgroundColor = UIColor.White } };
-			var button = UIButton.FromType(UIButtonType.RoundedRect);
+			var button = UIButton.FromType(UIButtonType.System);
 			button.SetTitle("Login", UIControlState.Normal);
 			button.Frame = new CGRect(20, 100, 200, 44);
 			loginViewController.View.AddSubview(button);
diff --git a/Xamarin.Forms.ControlGallery.iOS/CustomRenderer40251.cs b/Xamarin.Forms.ControlGallery.iOS/CustomRenderer40251.cs
new file mode 100644
index 00000000..19ebbb76
--- /dev/null
+++ b/Xamarin.Forms.ControlGallery.iOS/CustomRenderer40251.cs
@@ -0,0 +1,60 @@
+using UIKit;
+using Xamarin.Forms.Platform.iOS;
+using Xamarin.Forms;
+using System.Collections.Generic;
+using Xamarin.Forms.ControlGallery.iOS;
+using Xamarin.Forms.Controls.Issues;
+
+[assembly: ExportRenderer(typeof(Button), typeof(CustomRenderer40251))]
+namespace Xamarin.Forms.ControlGallery.iOS
+{
+	public class CustomRenderer40251 : ButtonRenderer
+	{
+		Dictionary<string, object> originalValues = new Dictionary<string, object>();
+
+		public CustomRenderer40251()
+		{
+			if (TestPage40251.Arg == "TitleColor")
+			{
+				originalValues.Add("TitleColor", UIButton.Appearance.TitleColor(UIControlState.Normal));
+				UIButton.Appearance.SetTitleColor(UIColor.Red, UIControlState.Normal);
+			}
+			else if (TestPage40251.Arg == "TitleShadowColor")
+			{
+				originalValues.Add("TitleShadowColor", UIButton.Appearance.TitleShadowColor(UIControlState.Normal));
+				UIButton.Appearance.SetTitleShadowColor(UIColor.White, UIControlState.Normal);
+			}
+			else if (TestPage40251.Arg == "BackgroundImage")
+			{
+				originalValues.Add("BackgroundImage", UIButton.Appearance.BackgroundImageForState(UIControlState.Normal));
+				UIButton.Appearance.SetBackgroundImage(new UIImage("Intranet-icon.png"), UIControlState.Normal);
+			}
+		}
+
+		protected override void OnElementChanged(ElementChangedEventArgs<Button> e)
+		{
+			base.OnElementChanged(e);
+
+			if (e.NewElement != null)
+			{
+				if (Control != null)
+					Control.TitleShadowOffset = new CoreGraphics.CGSize(2, 2);
+			}
+		}
+
+		protected override void Dispose(bool disposing)
+		{
+			if (disposing)
+			{
+				if (TestPage40251.Arg == "TitleColor")
+					UIButton.Appearance.SetTitleColor(originalValues["TitleColor"] as UIColor, UIControlState.Normal);
+				else if (TestPage40251.Arg == "TitleShadowColor")
+					UIButton.Appearance.SetTitleShadowColor(originalValues["TitleShadowColor"] as UIColor, UIControlState.Normal);
+				else if (TestPage40251.Arg == "BackgroundImage")
+					UIButton.Appearance.SetBackgroundImage(originalValues["BackgroundImage"] as UIImage, UIControlState.Normal);
+			}
+
+			base.Dispose(disposing);
+		}
+	}
+}
\ No newline at end of file
diff --git a/Xamarin.Forms.ControlGallery.iOS/Xamarin.Forms.ControlGallery.iOS.csproj b/Xamarin.Forms.ControlGallery.iOS/Xamarin.Forms.ControlGallery.iOS.csproj
index a601b513..0810383a 100644
--- a/Xamarin.Forms.ControlGallery.iOS/Xamarin.Forms.ControlGallery.iOS.csproj
+++ b/Xamarin.Forms.ControlGallery.iOS/Xamarin.Forms.ControlGallery.iOS.csproj
@@ -160,6 +160,7 @@
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="BrokenNativeControl.cs" />
+    <Compile Include="CustomRenderer40251.cs" />
     <Compile Include="Main.cs" />
     <Compile Include="AppDelegate.cs" />
     <None Include="app.config" />