Add methods for aligning view edges to the center of other views.

Cirrious.FluentLayout/AdvancedFluentLayoutExtensions.cs

@@ -110,7 +110,19 @@ public static FluentLayout ToTopMargin(this UIView view, UIView previous) =>
 			view.Top().EqualTo().TopMarginOf(previous);
 
 		public static FluentLayout ToBottomMargin(this UIView view, UIView previous) =>
-			view.Bottom().EqualTo().BottomMarginOf(previous);			
+			view.Bottom().EqualTo().BottomMarginOf(previous);
+
+	public static FluentLayout ToLeftOfCenterOf(this UIView view, UIView previous, nfloat? margin = null) =>
+		view.Right().EqualTo().CenterXOf(previous).Minus(margin.GetValueOrDefault(0));
+
+	public static FluentLayout ToRightOfCenterOf(this UIView view, UIView previous, nfloat? margin = null) =>
+		view.Left().EqualTo().CenterXOf(previous).Plus(margin.GetValueOrDefault(0));
+
+	public static FluentLayout AboveCenterOf(this UIView view, UIView previous, nfloat? margin = null) =>
+		view.Bottom().EqualTo().CenterYOf(previous).Minus(margin.GetValueOrDefault(0));
+
+	public static FluentLayout BelowCenterOf(this UIView view, UIView previous, nfloat? margin = null) =>
+		view.Top().EqualTo().CenterYOf(previous).Plus(margin.GetValueOrDefault(0));
 
         public static IEnumerable<FluentLayout> FullWidthOf(this UIView view, UIView parent, nfloat? margin = null)
         {

QuickLayout.Core/QuickLayout.Core.csproj

@@ -45,6 +45,7 @@
     <Compile Include="ViewModels\FullSizeViewModel.cs" />
     <Compile Include="ViewModels\SearchViewModel.cs" />
     <Compile Include="ViewModels\TipViewModel.cs" />
+    <Compile Include="ViewModels\ToCenterConstraintsViewModel.cs" />
     <Compile Include="ViewModels\UpdateConstraintsViewModel.cs" />
     <Compile Include="ViewModels\AdvancedVerticalStackViewModel.cs" />
     <Compile Include="ViewModels\DirectionFormViewModel.cs" />

QuickLayout.Core/ViewModels/FirstViewModel.cs

@@ -26,5 +26,7 @@ public class FirstViewModel
         public void GoRightToLeft() => ShowViewModel<RightToLeftViewModel>();
 
         public void GoViewWithSafeArea() => ShowViewModel<ViewWithSafeAreaViewModel>();
+
+        public void GoCenterConstraints() => ShowViewModel<ToCenterConstraintsViewModel>();
     }
 }

QuickLayout.Core/ViewModels/ToCenterConstraintsViewModel.cs

@@ -0,0 +1,8 @@
+using MvvmCross.Core.ViewModels;
+
+namespace QuickLayout.Core.ViewModels
+{
+    public class ToCenterConstraintsViewModel : MvxViewModel
+    {
+    }
+}

QuickLayout.Touch/QuickLayout.Touch.csproj

@@ -90,6 +90,7 @@
     <Compile Include="Main.cs" />
     <Compile Include="AppDelegate.cs" />
     <Compile Include="Setup.cs" />
+    <Compile Include="Views\ToCenterConstraintsView.cs" />
     <Compile Include="Views\DetailsView.cs" />
     <Compile Include="Views\FirstView.cs" />
     <Compile Include="Views\FormGridView.cs" />
@@ -159,11 +160,21 @@
     <InterfaceDefinition Include="Resources\LaunchScreen.storyboard" />
   </ItemGroup>
   <ItemGroup>
-    <ImageAsset Include="Assets.xcassets\LaunchImage.launchimage\Contents.json" />
-    <ImageAsset Include="Assets.xcassets\LaunchImage.launchimage\Default.png" />
-    <ImageAsset Include="Assets.xcassets\LaunchImage.launchimage\Default%402x.png" />
-    <ImageAsset Include="Assets.xcassets\LaunchImage.launchimage\Default-568h%402x.png" />
-    <ImageAsset Include="Assets.xcassets\AppIcon.appiconset\Contents.json" />
+    <ImageAsset Include="Assets.xcassets\LaunchImage.launchimage\Contents.json">
+      <Visible>false</Visible>
+    </ImageAsset>
+    <ImageAsset Include="Assets.xcassets\LaunchImage.launchimage\Default.png">
+      <Visible>false</Visible>
+    </ImageAsset>
+    <ImageAsset Include="Assets.xcassets\LaunchImage.launchimage\Default%402x.png">
+      <Visible>false</Visible>
+    </ImageAsset>
+    <ImageAsset Include="Assets.xcassets\LaunchImage.launchimage\Default-568h%402x.png">
+      <Visible>false</Visible>
+    </ImageAsset>
+    <ImageAsset Include="Assets.xcassets\AppIcon.appiconset\Contents.json">
+      <Visible>false</Visible>
+    </ImageAsset>
   </ItemGroup>
   <Import Project="$(MSBuildExtensionsPath)\Xamarin\iOS\Xamarin.iOS.CSharp.targets" />
 </Project>

QuickLayout.Touch/Views/FirstView.cs

@@ -11,7 +11,7 @@ namespace QuickLayout.Touch.Views
 	[Register("FirstView")]
     public class FirstView : MvxViewController
     {
-		private UIButton _viewForm, _viewFormGrid, _viewDetails, _viewSearch, _viewTip, _viewUpdateConstaints, _viewAdvancedVerticalStack, _fullSize, _directionFormView, _rightToLeft, _viewSafeArea;
+		private UIButton _viewForm, _viewFormGrid, _viewDetails, _viewSearch, _viewTip, _viewUpdateConstaints, _viewAdvancedVerticalStack, _fullSize, _directionFormView, _rightToLeft, _viewSafeArea, _viewCenterConstraints;
 
         public override void ViewDidLoad()
         {
@@ -66,6 +66,10 @@ public override void ViewDidLoad()
             _viewSafeArea.SetTitle("View with Safe Area", UIControlState.Normal);
             Add(_viewSafeArea);
 
+            _viewCenterConstraints = new UIButton(UIButtonType.RoundedRect);
+            _viewCenterConstraints.SetTitle("View Contraining to centers", UIControlState.Normal);
+            Add(_viewCenterConstraints);
+
 			View.SubviewsDoNotTranslateAutoresizingMaskIntoConstraints();
 
             var set = this.CreateBindingSet<FirstView, FirstViewModel>();
@@ -80,6 +84,7 @@ public override void ViewDidLoad()
 			set.Bind(_directionFormView).To("GoDirectionForm");
             set.Bind(_rightToLeft).To("GoRightToLeft");
             set.Bind(_viewSafeArea).To("GoViewWithSafeArea");
+            set.Bind(_viewCenterConstraints).To("GoCenterConstraints");
             set.Apply();
 
             var constraints = View.VerticalStackPanelConstraints(

QuickLayout.Touch/Views/ToCenterConstraintsView.cs

@@ -0,0 +1,55 @@
+using Cirrious.FluentLayouts.Touch;
+using Foundation;
+using MvvmCross.iOS.Views;
+using QuickLayout.Core.ViewModels;
+using UIKit;
+
+namespace QuickLayout.Touch.Views
+{
+    [Register("ToCenterConstraintsView")]
+    public class ToCenterConstraintsView : MvxViewController<ToCenterConstraintsViewModel>
+    {
+        public override void ViewDidLoad()
+        {
+
+            UIView firstContainer = new UIView
+            {
+                TranslatesAutoresizingMaskIntoConstraints = false,
+                BackgroundColor = UIColor.Blue
+            },
+
+            secondContainer = new UIView
+            {
+                TranslatesAutoresizingMaskIntoConstraints = false,
+                BackgroundColor = UIColor.Red
+            },
+
+            thirdContainer = new UIView
+            {
+                TranslatesAutoresizingMaskIntoConstraints = false,
+                BackgroundColor = UIColor.Yellow,
+                Alpha = .5f
+            };
+
+            View.AddSubviews(firstContainer, secondContainer, thirdContainer);
+
+            View.AddConstraints(new FluentLayout[]
+            {
+                firstContainer.AtTopOf(View),
+                firstContainer.AtLeftOf(View),
+                firstContainer.AboveCenterOf(View, 10f),
+                firstContainer.ToLeftOfCenterOf(View, 10f),
+
+                secondContainer.AtBottomOf(View),
+                secondContainer.AtRightOf(View),
+                secondContainer.ToRightOfCenterOf(View, 10f),
+                secondContainer.BelowCenterOf(View, 10f),
+
+                thirdContainer.ToRightOfCenterOf(firstContainer),
+                thirdContainer.ToLeftOfCenterOf(secondContainer),
+                thirdContainer.AboveCenterOf(secondContainer),
+                thirdContainer.BelowCenterOf(firstContainer)
+            });
+        }
+    }
+}