Fixed layout again.

Last commit actually ruined layout. Added a tab to the test app to test
that shiz.

Perspex.Controls/Button.cs

@@ -48,5 +48,15 @@ namespace Perspex.Controls
             add { this.AddHandler(ClickEvent, value); }
             remove { this.RemoveHandler(ClickEvent, value); }
         }
+
+        protected override Size MeasureOverride(Size availableSize)
+        {
+            return base.MeasureOverride(availableSize);
+        }
+
+        protected override Size ArrangeOverride(Size finalSize)
+        {
+            return base.ArrangeOverride(finalSize);
+        }
     }
 }

Perspex.Layout/Layoutable.cs

@@ -197,7 +197,7 @@ namespace Perspex.Layout
                 size = size.WithHeight(Math.Min(size.Height, this.DesiredSize.Value.Height));
             }
 
-            size = LayoutHelper.ApplyLayoutConstraints(this, finalRect.Size);
+            size = LayoutHelper.ApplyLayoutConstraints(this, size);
             size = this.ArrangeOverride(size).Constrain(size);
 
             switch (this.HorizontalAlignment)

TestApplication/Program.cs

@@ -117,6 +117,7 @@ namespace TestApplication
                                 TextTab(),
                                 ListsTab(),
                                 SlidersTab(),
+                                LayoutTab(),
                             }
                         },
                         new TextBlock
@@ -127,7 +128,7 @@ namespace TestApplication
                             [Grid.RowProperty] = 1,
                         }
                     }
-                }
+                },
             };
 
             window.Show();
@@ -277,5 +278,50 @@ namespace TestApplication
             };
         }
 
+        private static TabItem LayoutTab()
+        {
+            return new TabItem
+            {
+                Header = "Layout",
+                Content = new Grid
+                {
+                    ColumnDefinitions = new ColumnDefinitions
+                    {
+                        new ColumnDefinition(1, GridUnitType.Star),
+                        new ColumnDefinition(1, GridUnitType.Star),
+                    },
+                    Margin = new Thickness(50),
+                    Children = new Controls
+                    {
+                        new StackPanel
+                        {
+                            Orientation = Orientation.Vertical,
+                            Gap = 8,
+                            Children = new Controls
+                            {
+                                new Button { HorizontalAlignment = HorizontalAlignment.Left, Content = "Left Aligned" },
+                                new Button { HorizontalAlignment = HorizontalAlignment.Center, Content = "Center Aligned" },
+                                new Button { HorizontalAlignment = HorizontalAlignment.Right, Content = "Right Aligned" },
+                                new Button { HorizontalAlignment = HorizontalAlignment.Stretch, Content = "Stretch" },
+                            },
+                            [Grid.ColumnProperty] = 0,
+                        },
+                        new StackPanel
+                        {
+                            Orientation = Orientation.Horizontal,
+                            Gap = 8,
+                            Children = new Controls
+                            {
+                                new Button { VerticalAlignment = VerticalAlignment.Top, Content = "Top Aligned" },
+                                new Button { VerticalAlignment = VerticalAlignment.Center, Content = "Center Aligned" },
+                                new Button { VerticalAlignment = VerticalAlignment.Bottom, Content = "Bottom Aligned" },
+                                new Button { VerticalAlignment = VerticalAlignment.Stretch, Content = "Stretch" },
+                            },
+                            [Grid.ColumnProperty] = 1,
+                        },
+                    },
+                }
+            };
+        }
     }
 }