doc update

doc/userdefinedmethods.md

@@ -1,39 +1,73 @@
 # User defined extension methods
 
-In __CodeMarkup.Maui__, you can create your own extension methods by defining a static method within a static class.
+In `Sharp.UI`, you can create your own extension methods by defining a static method within a static class.
 
-Here's an example of extension methods that set an entry font size:
+Here's an example of extension methods that set a label font size:
 
 ```cs
 public static T FontSize<T>(this T self,
     double fontSize)
-    where T : Microsoft.Maui.Controls.Entry
+    where T : Microsoft.Maui.Controls.Label
 {
-    self.SetValue(Microsoft.Maui.Controls.Entry.FontSizeProperty, fontSize);
+    self.SetValue(Microsoft.Maui.Controls.Label.FontSizeProperty, fontSize);
     return self;
 }
 
 public static T FontSize<T>(this T self, Func<PropertyContext<double>, IPropertyBuilder<double>> configure)
-    where T : Microsoft.Maui.Controls.Entry
+    where T : Microsoft.Maui.Controls.Label
 {
-    var context = new PropertyContext<double>(self, Microsoft.Maui.Controls.Entry.FontSizeProperty);
+    var context = new PropertyContext<double>(self, Microsoft.Maui.Controls.Label.FontSizeProperty);
     configure(context).Build();
     return self;
 }
 
 public static SettersContext<T> FontSize<T>(this SettersContext<T> self,
     double fontSize)
-    where T : Microsoft.Maui.Controls.Entry
+    where T : Microsoft.Maui.Controls.Label
 {
-    self.XamlSetters.Add(new Setter { Property = Microsoft.Maui.Controls.Entry.FontSizeProperty, Value = fontSize });
+    self.XamlSetters.Add(new Setter { Property = Microsoft.Maui.Controls.Label.FontSizeProperty, Value = fontSize });
     return self;
 }
 
 public static SettersContext<T> FontSize<T>(this SettersContext<T> self, Func<PropertySettersContext<double>, IPropertySettersBuilder<double>> configure)
-    where T : Microsoft.Maui.Controls.Entry
+    where T : Microsoft.Maui.Controls.Label
 {
-    var context = new PropertySettersContext<double>(self.XamlSetters, Microsoft.Maui.Controls.Entry.FontSizeProperty);
+    var context = new PropertySettersContext<double>(self.XamlSetters, Microsoft.Maui.Controls.Label.FontSizeProperty);
     configure(context).Build();
     return self;
 }
+
+public static Task<bool> AnimateFontSizeTo<T>(this T self, double value, uint length = 250, Easing? easing = null)
+    where T : Microsoft.Maui.Controls.Label
+{
+    double fromValue = self.FontSize;
+    var transform = (double t) => Transformations.DoubleTransform(fromValue, value, t);
+    var callback = (double actValue) => { self.FontSize = actValue; };
+    return Transformations.AnimateAsync<double>(self, "AnimateFontSizeTo", transform, callback, length, easing);
+}
 ```
+
+it allows you the following usage:
+
+```cs
+new Label().FontSize(28)
+```
+
+or:
+
+```cs
+new Label().FontSize(e => e.Path("MyFontSize").Source(myModel))
+new Label().FontSize(e => e.OnPhone(30).OnTablet(50).Default(40))
+```
+
+or use it in a style context:
+
+```cs
+new Style<Label>(e => e
+    .FontSize(20)
+    .CenterVertically()
+    .CenterHorizontally())
+```
+
+
+or use in an animation context.