[Chat] setup toolbar with code. It is imposible to setup autolayout on uibarbuttonitems via XCoder or XS designer, so the code is the only way

Xamarin.iOS 8.10.0.255

Chat/Chat/ChatInput/ChatInputView.cs

@@ -7,24 +7,35 @@ namespace Chat
 {
 	public partial class ChatInputView : UIView
 	{
+		static readonly UIColor ButtonTextColorNormal = UIColor.FromRGB (1, 122, 255);
+		static readonly UIColor ButtonTextColorDisabled = UIColor.FromRGB (142, 142, 147);
+		static readonly UIFont ButtonFont = UIFont.SystemFontOfSize (17, UIFontWeight.Bold);
+
+		static readonly UIColor InputBackgroundColor =  UIColor.FromWhiteAlpha (250, 1);
+		static readonly UIColor InputBorderColor = UIColor.FromRGB (200, 200, 205);
+		const float BorderWidth = 0.5f;
+		const float CornerRadius = 5;
+
+		const float ToolbarMinHeight = 44;
+
 		public UITextView TextView { get; private set; }
 		public UIButton SendButton { get; private set; }
 
 		public ChatInputView()
 		{
 			TextView = new UITextView ();
-			TextView.Layer.BorderColor = UIColor.FromRGB (200, 200, 205).CGColor;
+			TextView.Layer.BorderColor = InputBorderColor.CGColor;
-			TextView.Layer.BorderWidth = (float)0.5;
+			TextView.Layer.BorderWidth = BorderWidth;
-			TextView.Layer.CornerRadius = 5;
+			TextView.Layer.CornerRadius = CornerRadius;
-			TextView.BackgroundColor = UIColor.FromWhiteAlpha (250, 1);
+			TextView.BackgroundColor = InputBackgroundColor;
 			TextView.TranslatesAutoresizingMaskIntoConstraints = false;
 
 			SendButton = new UIButton ();
 			SendButton.SetTitle ("Send", UIControlState.Normal);
-			SendButton.Font = UIFont.SystemFontOfSize (15, UIFontWeight.Bold);
+			SendButton.Font = ButtonFont;
+			SendButton.SetTitleColor (ButtonTextColorNormal, UIControlState.Normal);
+			SendButton.SetTitleColor (ButtonTextColorDisabled, UIControlState.Disabled);
 			SendButton.TranslatesAutoresizingMaskIntoConstraints = false;
-			SendButton.SetTitleColor (UIColor.FromRGB (142, 142, 147), UIControlState.Disabled);
-			SendButton.SetTitleColor (UIColor.FromRGB (1, 122, 255), UIControlState.Normal);
 
 			AddSubviews (TextView, SendButton);
 
@@ -37,13 +48,11 @@ namespace Chat
 				NSLayoutFormatOptions.DirectionLeadingToTrailing,
 				"input", TextView
 			);
-			var c3 = NSLayoutConstraint.FromVisualFormat ("V:[button]-|",
+			// We want Send button was centered when Toolbar has MinHeight (pin button in this state)
-				NSLayoutFormatOptions.DirectionLeadingToTrailing,
+			var c3 = NSLayoutConstraint.Create(SendButton, NSLayoutAttribute.CenterY, NSLayoutRelation.Equal, this, NSLayoutAttribute.Bottom, 1, -ToolbarMinHeight / 2);
-				"button", SendButton
-			);
 			AddConstraints (c1);
 			AddConstraints (c2);
-			AddConstraints (c3);
+			AddConstraint (c3);
 		}
 	}
 }

Chat/Chat/ChatViewController.cs

@@ -68,12 +68,7 @@ namespace Chat
 			chatInputView = new ChatInputView ();
 
 			SendButton.TouchUpInside += OnSendClicked;
-
 			TextView.Changed += OnTextChanged;
-			TextView.Layer.BorderColor = UIColor.FromRGB (200, 200, 205).CGColor;
-			TextView.Layer.BorderWidth = (float)0.5;
-			TextView.Layer.CornerRadius = 5;
-			TextView.BackgroundColor = UIColor.FromWhiteAlpha (250, 1);
 
 			chatSrc = new ChatSource (messages, ShowMenu);
 			TableView.Source = chatSrc;
@@ -137,8 +132,7 @@ namespace Chat
 
 				var offset = TableView.ContentOffset;
 				offset.Y += newOverlap - oldOverlap;
-				if(offset.Y < 0)
+				offset.Y = NMath.Max(offset.Y, 0);
-					offset.Y = 0;
 				TableView.ContentOffset = offset;
 			}, null);
 		}
@@ -160,7 +154,6 @@ namespace Chat
 			return NMath.Min (TableView.ContentSize.Height - TableView.ContentOffset.Y, TableView.Frame.Height);
 		}
 
-		// returns changes in ContentInsetY and ContentOffsetY values
 		void UpdateTableInsets()
 		{
 			UIEdgeInsets oldInset = TableView.ContentInset;
@@ -206,7 +199,7 @@ namespace Chat
 
 			var indexPaths = new NSIndexPath[] { LastIndexPath };
 			TableView.InsertRows(indexPaths, UITableViewRowAnimation.None);
-			TableView.ScrollToRow (indexPaths [0], UITableViewScrollPosition.Bottom, true);
+			TableView.ScrollToRow (LastIndexPath, UITableViewScrollPosition.Bottom, true);
 		}
 
 		void OnTextChanged (object sender, EventArgs e)