expander some code refactoring

src/Perspex.Controls/Expander.cs

@@ -13,57 +13,62 @@ namespace Perspex.Controls
 
     public class Expander : HeaderedContentControl
     {
+        public static readonly PerspexProperty<bool> IsExpandedProperty =
+            PerspexProperty.Register<Expander, bool>(nameof(IsExpanded), true);
+
+        public static readonly PerspexProperty<ExpandDirection> ExpandDirectionProperty =
+            PerspexProperty.Register<Expander, ExpandDirection>(nameof(ExpandDirection), ExpandDirection.Down);
+
+        public static readonly PerspexProperty<IPageTransition> ContentTransitionProperty =
+            PerspexProperty.Register<Expander, IPageTransition>(nameof(ContentTransition));
+
         static Expander()
         {
-            PseudoClass(ExpandDirectionProperty, d => d == ExpandDirection.Down, ":ExpandDirectionDown");
-            PseudoClass(ExpandDirectionProperty, d => d == ExpandDirection.Up, ":ExpandDirectionUp");
-            PseudoClass(ExpandDirectionProperty, d => d == ExpandDirection.Left, ":ExpandDirectionLeft");
-            PseudoClass(ExpandDirectionProperty, d => d == ExpandDirection.Right, ":ExpandDirectionRight");
+            PseudoClass(ExpandDirectionProperty, d => d == ExpandDirection.Down, ":down");
+            PseudoClass(ExpandDirectionProperty, d => d == ExpandDirection.Up, ":up");
+            PseudoClass(ExpandDirectionProperty, d => d == ExpandDirection.Left, ":left");
+            PseudoClass(ExpandDirectionProperty, d => d == ExpandDirection.Right, ":right");
 
             PseudoClass(IsExpandedProperty, ":expanded");
 
             IsExpandedProperty.Changed.AddClassHandler<Expander>(x => x.OnIsExpandedChanged);
         }
 
-        protected virtual void OnIsExpandedChanged(PerspexPropertyChangedEventArgs e)
-        {
-            IVisual visualContent = Presenter;
-            if (Content != null && ContentTransition != null && visualContent != null)
-            {
-                bool forward = ExpandDirection == ExpandDirection.Left || ExpandDirection == ExpandDirection.Up;
-                if (IsExpanded)
-                {
-                    ContentTransition.Start(null, visualContent, forward);
-                }
-                else
-                {
-                    ContentTransition.Start(visualContent, null, !forward);
-                }
-            }
-        }
-
-        public static readonly PerspexProperty<bool> IsExpandedProperty = PerspexProperty.Register<Expander, bool>(nameof(IsExpanded), true);
-
         public bool IsExpanded
         {
             get { return GetValue(IsExpandedProperty); }
             set { SetValue(IsExpandedProperty, value); }
         }
 
-        public static readonly PerspexProperty<ExpandDirection> ExpandDirectionProperty = PerspexProperty.Register<Expander, ExpandDirection>(nameof(ExpandDirection), ExpandDirection.Down);
-
         public ExpandDirection ExpandDirection
         {
             get { return GetValue(ExpandDirectionProperty); }
             set { SetValue(ExpandDirectionProperty, value); }
         }
 
-        public static readonly PerspexProperty<IPageTransition> ContentTransitionProperty = PerspexProperty.Register<Expander, IPageTransition>(nameof(ContentTransition));
-
         public IPageTransition ContentTransition
         {
             get { return GetValue(ContentTransitionProperty); }
             set { SetValue(ContentTransitionProperty, value); }
         }
+
+        protected virtual void OnIsExpandedChanged(PerspexPropertyChangedEventArgs e)
+        {
+            IVisual visualContent = Presenter;
+
+            if (Content != null && ContentTransition != null && visualContent != null)
+            {
+                bool forward = ExpandDirection == ExpandDirection.Left ||
+                                ExpandDirection == ExpandDirection.Up;
+                if (IsExpanded)
+                {
+                    ContentTransition.Start(null, visualContent, forward);
+                }
+                else
+                {
+                    ContentTransition.Start(visualContent, null, !forward);
+                }
+            }
+        }
     }
 }

src/Perspex.Themes.Default/Expander.paml

@@ -95,27 +95,27 @@
   <Style Selector="Expander /template/ ToggleButton#PART_toggle:pointerover /template/ Border">
     <Setter Property="BorderBrush" Value="#ffaaaaaa" />
   </Style>
-  <Style Selector="Expander:ExpandDirectionDown:expanded /template/ ToggleButton#PART_toggle /template/ Path">
+  <Style Selector="Expander:down:expanded /template/ ToggleButton#PART_toggle /template/ Path">
     <Setter Property="RenderTransform">
       <RotateTransform Angle="90" />
     </Setter>
   </Style>
-  <Style Selector="Expander:ExpandDirectionUp:expanded /template/ ToggleButton#PART_toggle /template/ Path">
+  <Style Selector="Expander:up:expanded /template/ ToggleButton#PART_toggle /template/ Path">
     <Setter Property="RenderTransform">
       <RotateTransform Angle="-90" />
     </Setter>
   </Style>
-  <Style Selector="Expander:ExpandDirectionLeft:expanded /template/ ToggleButton#PART_toggle /template/ Path">
+  <Style Selector="Expander:left:expanded /template/ ToggleButton#PART_toggle /template/ Path">
     <Setter Property="RenderTransform">
       <RotateTransform Angle="180" />
     </Setter>
   </Style>
-  <Style Selector="Expander:ExpandDirectionRight /template/ ToggleButton#PART_toggle /template/ Path">
+  <Style Selector="Expander:right /template/ ToggleButton#PART_toggle /template/ Path">
     <Setter Property="RenderTransform">
       <RotateTransform Angle="180" />
     </Setter>
   </Style>
-  <Style Selector="Expander:ExpandDirectionRight:expanded /template/ ToggleButton#PART_toggle /template/ Path">
+  <Style Selector="Expander:right:expanded /template/ ToggleButton#PART_toggle /template/ Path">
     <Setter Property="RenderTransform">
       <RotateTransform Angle="0" />
     </Setter>