[iOS] decoupling UpdateText() on LabelRenderer (#950)

* [iOS] decoupling UpdateText() on LabelRenderer

* [iOS] do not update font and color on formattedstrings

1 files changed, 52 insertions, 15 deletions

diff --git a/Xamarin.Forms.Platform.iOS/Renderers/LabelRenderer.cs b/Xamarin.Forms.Platform.iOS/Renderers/LabelRenderer.cs
index 5eef6915..0d016e50 100644
--- a/Xamarin.Forms.Platform.iOS/Renderers/LabelRenderer.cs
+++ b/Xamarin.Forms.Platform.iOS/Renderers/LabelRenderer.cs
@@ -6,12 +6,14 @@ using SizeF = CoreGraphics.CGSize;
 #if __MOBILE__
 using UIKit;
 using NativeLabel = UIKit.UILabel;
-
-namespace Xamarin.Forms.Platform.iOS
 #else
 using AppKit;
 using NativeLabel = AppKit.NSTextField;
+#endif
 
+#if __MOBILE__
+namespace Xamarin.Forms.Platform.iOS
+#else
 namespace Xamarin.Forms.Platform.MacOS
 #endif
 {
@@ -110,6 +112,9 @@ namespace Xamarin.Forms.Platform.MacOS
 				}
 
 				UpdateText();
+				UpdateTextColor();
+				UpdateFont();
+
 				UpdateLineBreakMode();
 				UpdateAlignment();
 			}
@@ -126,9 +131,9 @@ namespace Xamarin.Forms.Platform.MacOS
 			else if (e.PropertyName == Label.VerticalTextAlignmentProperty.PropertyName)
 				UpdateLayout();
 			else if (e.PropertyName == Label.TextColorProperty.PropertyName)
-				UpdateText();
+				UpdateTextColor();
 			else if (e.PropertyName == Label.FontProperty.PropertyName)
-				UpdateText();
+				UpdateFont();
 			else if (e.PropertyName == Label.TextProperty.PropertyName)
 				UpdateText();
 			else if (e.PropertyName == Label.FormattedTextProperty.PropertyName)
@@ -241,6 +246,7 @@ namespace Xamarin.Forms.Platform.MacOS
 #endif
 		}
 
+		bool isTextFormatted;
 		void UpdateText()
 		{
 			_perfectSizeValid = false;
@@ -251,26 +257,57 @@ namespace Xamarin.Forms.Platform.MacOS
 			{
 #if __MOBILE__
 				Control.AttributedText = formatted.ToAttributed(Element, (Color)values[2]);
-			}
-			else
-			{
-				Control.Text = (string)values[1];
-				// default value of color documented to be black in iOS docs
-				Control.Font = Element.ToUIFont();
-				Control.TextColor = ((Color)values[2]).ToUIColor(ColorExtensions.Black);
-			}
 #else
 				Control.AttributedStringValue = formatted.ToAttributed(Element, (Color)values[2]);
+#endif
+				isTextFormatted = true;
 			}
 			else
 			{
+				if (isTextFormatted)
+				{
+					UpdateFont();
+					UpdateTextColor();
+				}
+#if __MOBILE__
+				Control.Text = (string)values[1];
+#else
 				Control.StringValue = (string)values[1] ?? "";
-				// default value of color documented to be black in iOS docs
-				Control.Font = Element.ToNSFont();
-				Control.TextColor = ((Color)values[2]).ToNSColor(ColorExtensions.Black);
+#endif
+				isTextFormatted = false;
 			}
+			UpdateLayout();
+		}
+
+		void UpdateFont()
+		{
+			if(isTextFormatted)
+				return;
+			_perfectSizeValid = false;
+
+#if __MOBILE__
+			Control.Font = Element.ToUIFont();
+#else
+			Control.Font = Element.ToNSFont();
 #endif
+			UpdateLayout();
+		}
+
+		void UpdateTextColor()
+		{
+			if (isTextFormatted)
+				return;
+			
+			_perfectSizeValid = false;
+
+			var textColor = (Color)Element.GetValue(Label.TextColorProperty);
 
+			// default value of color documented to be black in iOS docs
+#if __MOBILE__
+			Control.TextColor = textColor.ToUIColor(ColorExtensions.Black);
+#else
+			Control.TextColor = textColor.ToNSColor(ColorExtensions.Black);
+#endif
 			UpdateLayout();
 		}