[Chat] update for iPhone X

Chat/Chat/ChatViewController.cs

@@ -53,7 +53,7 @@ namespace Chat
 				new Message { Type = MessageType.Incoming, Text = "And what do you think?" },
 				new Message { Type = MessageType.Outgoing, Text = "I think it is the best way to develop mobile applications." },
 				new Message { Type = MessageType.Incoming, Text = "Wow :-)" },
-				new Message { Type = MessageType.Outgoing, Text = "Yep. Check it out\nhttp://Xamarin.com" },
+				new Message { Type = MessageType.Outgoing, Text = "Yep. Check it out\nhttp://xamarin.com" },
 				new Message { Type = MessageType.Incoming, Text = "Will do. Thanks" }
 			};
 		}
@@ -105,6 +105,16 @@ namespace Chat
 			tableView.RegisterClassForCellReuse (typeof(OutgoingCell), OutgoingCell.CellId);
 			View.AddSubview (tableView);
 
+            if (UIDevice.CurrentDevice.CheckSystemVersion(11, 0))
+            {   // iPhone X layout
+                var safeGuide = View.SafeAreaLayoutGuide;
+                tableView.TopAnchor.ConstraintEqualTo(safeGuide.TopAnchor).Active = true;
+				tableView.LeadingAnchor.ConstraintEqualTo(safeGuide.LeadingAnchor).Active = true;
+				tableView.TrailingAnchor.ConstraintEqualTo(safeGuide.TrailingAnchor).Active = true;
+				tableView.BottomAnchor.ConstraintEqualTo(safeGuide.BottomAnchor, -44).Active = true;
+            }
+            else
+            {
                 var pinLeft = NSLayoutConstraint.Create(tableView, NSLayoutAttribute.Leading, NSLayoutRelation.Equal, View, NSLayoutAttribute.Leading, 1f, 0f);
                 View.AddConstraint(pinLeft);
 
@@ -116,23 +126,36 @@ namespace Chat
 
                 var pinBottom = NSLayoutConstraint.Create(tableView, NSLayoutAttribute.Bottom, NSLayoutRelation.Equal, View, NSLayoutAttribute.Bottom, 1f, 0f);
                 View.AddConstraint(pinBottom);
-
+            }
 			chatSource = new ChatSource (messages);
 			tableView.Source = chatSource;
 		}
 
         void SetUpToolbar()
         {
-			toolbar = new UIToolbar {
+            toolbar = new UIToolbar
+            {
                 TranslatesAutoresizingMaskIntoConstraints = false
             };
-			chatInputView = new ChatInputView {
+            chatInputView = new ChatInputView
+            {
                 TranslatesAutoresizingMaskIntoConstraints = false
             };
 
             toolbar.LayoutIfNeeded();
             View.AddSubview(toolbar);
 
+
+            if (UIDevice.CurrentDevice.CheckSystemVersion(11, 0))
+            {   // iPhone X layout
+				var safeGuide = View.SafeAreaLayoutGuide;
+                toolbar.HeightAnchor.ConstraintEqualTo(44).Active = true;
+                toolbar.LeadingAnchor.ConstraintEqualTo(safeGuide.LeadingAnchor).Active = true;
+                toolbar.TrailingAnchor.ConstraintEqualTo(safeGuide.TrailingAnchor).Active = true;
+                toolbar.BottomAnchor.ConstraintEqualTo(safeGuide.BottomAnchor).Active = true;
+            }
+            else
+            {
                 var pinLeft = NSLayoutConstraint.Create (toolbar, NSLayoutAttribute.Leading, NSLayoutRelation.Equal, View, NSLayoutAttribute.Leading, 1f, 0f);
                 View.AddConstraint (pinLeft);
 
@@ -144,6 +167,7 @@ namespace Chat
 
                 toolbarHeightConstraint = NSLayoutConstraint.Create (toolbar, NSLayoutAttribute.Height, NSLayoutRelation.Equal, null, NSLayoutAttribute.NoAttribute, 0f, 44f);
                 View.AddConstraint (toolbarHeightConstraint);
+            }
 
 			toolbar.AddSubview (chatInputView);
 
@@ -223,11 +247,24 @@ namespace Chat
 		void UpdateButtomLayoutConstraint (UIKeyboardEventArgs e)
 		{
 			UIViewAnimationCurve curve = e.AnimationCurve;
-			UIView.Animate (e.AnimationDuration, 0, ConvertToAnimationOptions (e.AnimationCurve), () => {
+            if (UIDevice.CurrentDevice.CheckSystemVersion(11, 0))
+            {
+				UIView.Animate(e.AnimationDuration, 0, ConvertToAnimationOptions(e.AnimationCurve), () =>
+				{
+					nfloat offsetFromBottom = tableView.Frame.GetMaxY() - e.FrameEnd.GetMinY();
+					offsetFromBottom = NMath.Max(0, offsetFromBottom);
+					
+				}, null);
+            }
+            else
+            {
+                UIView.Animate(e.AnimationDuration, 0, ConvertToAnimationOptions(e.AnimationCurve), () =>
+                {
                     nfloat offsetFromBottom = tableView.Frame.GetMaxY() - e.FrameEnd.GetMinY();
                     offsetFromBottom = NMath.Max(0, offsetFromBottom);
                     SetToolbarContstraint(offsetFromBottom);
                 }, null);
+            }
 		}
 
 		void SetToolbarContstraint (nfloat constant)