[Win] Will arrange native children of custom renderers (opt-in) (#322)

* Add repro for 42602

* [Win] Add option to arrange native children

* [Win] Don't allocate arrangedChildren unless required

1 files changed, 57 insertions, 0 deletions

diff --git a/Xamarin.Forms.ControlGallery.WindowsPhone/CustomRenderers.cs b/Xamarin.Forms.ControlGallery.WindowsPhone/CustomRenderers.cs
new file mode 100644
index 00000000..2f6cae90
--- /dev/null
+++ b/Xamarin.Forms.ControlGallery.WindowsPhone/CustomRenderers.cs
@@ -0,0 +1,57 @@
+using Windows.UI.Xaml.Controls;
+using Windows.UI.Xaml.Media;
+using Windows.UI.Xaml.Shapes;
+using Xamarin.Forms.Platform.WinRT;
+
+[assembly: ExportRenderer(typeof(Xamarin.Forms.Controls.Bugzilla42602.TextBoxView), typeof(Xamarin.Forms.ControlGallery.WindowsPhone.TextBoxViewRenderer))]
+namespace Xamarin.Forms.ControlGallery.WindowsPhone
+{
+	public class TextBoxViewRenderer : BoxViewRenderer
+	{
+		Canvas m_Canvas;
+
+		protected override void OnElementChanged(ElementChangedEventArgs<BoxView> e)
+		{
+			base.OnElementChanged(e);
+
+			ArrangeNativeChildren = true;
+
+			if (m_Canvas != null)
+				Children.Remove(m_Canvas);
+
+			m_Canvas = new Canvas()
+			{
+				Width = 200,
+				Height = 200,
+				Background = new SolidColorBrush(global::Windows.UI.Color.FromArgb(0, 255, 255, 255)),
+				IsHitTestVisible = false
+			};
+
+			Children.Add(m_Canvas);
+
+			//ellipse
+			Shape ellipse = new Ellipse()
+			{
+				Width = 100,
+				Height = 100,
+				Fill = new SolidColorBrush(global::Windows.UI.Color.FromArgb(255, 255, 0, 0)),
+
+			};
+			Canvas.SetLeft(ellipse, 0);
+			Canvas.SetTop(ellipse, 0);
+			m_Canvas.Children.Add(ellipse);
+
+			//text
+			TextBlock text = new TextBlock()
+			{
+				FontSize = 50,
+				FontWeight = global::Windows.UI.Text.FontWeights.Normal,
+				Text = "hello world",
+				Foreground = new SolidColorBrush(global::Windows.UI.Color.FromArgb(255, 255, 0, 0))
+			};
+			Canvas.SetLeft(text, 0);
+			Canvas.SetTop(text, 150);
+			m_Canvas.Children.Add(text);
+		}
+	}
+}