Fixed layout issues on Mac.

src/HotUI.Mac/Handlers/AbstractLayoutHandler.cs

@@ -15,12 +15,10 @@ namespace HotUI.Mac.Handlers
 
         protected AbstractLayoutHandler(CGRect rect) : base(rect)
         {
-            InitializeDefaults();
         }
 
         protected AbstractLayoutHandler()
         {
-            InitializeDefaults();
         }
         
         public override bool IsFlipped => true;
@@ -44,7 +42,7 @@ namespace HotUI.Mac.Handlers
 
         public void SetFrame(RectangleF frame)
         {
-            View.Frame = frame.ToCGRect();
+            Frame = frame.ToCGRect();
         }
 
         public void SetView(View view)
@@ -52,6 +50,7 @@ namespace HotUI.Mac.Handlers
             _view = view as AbstractLayout;
             if (_view != null)
             {
+                _view.NeedsLayout += HandleNeedsLayout;
                 _view.ChildrenChanged += HandleChildrenChanged;
                 _view.ChildrenAdded += HandleChildrenAdded;
                 _view.ChildrenRemoved += ViewOnChildrenRemoved;
@@ -70,6 +69,11 @@ namespace HotUI.Mac.Handlers
             }
         }
 
+        private void HandleNeedsLayout(object sender, EventArgs e)
+        {
+            SetNeedsLayout();
+        }
+
         public void Remove(View view)
         {
             foreach (var subview in _view)
@@ -84,6 +88,7 @@ namespace HotUI.Mac.Handlers
 
             if (view != null)
             {
+                _view.NeedsLayout -= HandleNeedsLayout;
                 _view.ChildrenChanged -= HandleChildrenChanged;
                 _view.ChildrenAdded -= HandleChildrenAdded;
                 _view.ChildrenRemoved -= ViewOnChildrenRemoved;
@@ -110,11 +115,6 @@ namespace HotUI.Mac.Handlers
         {
         }
 
-        private void InitializeDefaults()
-        {
-            TranslatesAutoresizingMaskIntoConstraints = false;
-        }
-
         private void HandleChildrenAdded(object sender, LayoutEventArgs e)
         {
             for (var i = 0; i < e.Count; i++)
@@ -199,7 +199,11 @@ namespace HotUI.Mac.Handlers
 
         public void SizeToFit()
         {
-            _measured = _view.Measure(Superview?.Bounds.Size.ToSizeF() ?? NSScreen.MainScreen.Frame.Size.ToSizeF());
+            var size = Superview?.Bounds.Size;
+            if (size == null || ((CGSize)size).IsEmpty)
+                size = NSScreen.MainScreen.Frame.Size;
+
+            _measured = _view.Measure(((CGSize)size).ToSizeF());
             base.Frame = new CGRect(new CGPoint(0, 0), _measured.ToCGSize());
         }
 
@@ -229,7 +233,10 @@ namespace HotUI.Mac.Handlers
         
         public override void Layout()
         {
-            if (Superview == null || Bounds.Size.IsEmpty)
+            if (Superview == null)
+                return;
+
+            if (Bounds.Size.IsEmpty)
                 return;
 
             _view.Frame = Frame.ToRectangleF();

src/HotUI.Mac/HotUIView.cs

@@ -2,6 +2,7 @@
 using AppKit;
 using HotUI.Mac.Extensions;
 using HotUI.Mac.Handlers;
+using System;
 
 namespace HotUI.Mac
 {
@@ -13,16 +14,11 @@ namespace HotUI.Mac
         
         public HotUIView()
         {
-            TranslatesAutoresizingMaskIntoConstraints = false;
-            AutoresizesSubviews = true;
-            AutoresizingMask = NSViewResizingMask.HeightSizable | NSViewResizingMask.WidthSizable;
         }
 
         public HotUIView(CGRect rect) : base(rect)
         {
-            TranslatesAutoresizingMaskIntoConstraints = false;
-            AutoresizesSubviews = true;
-            AutoresizingMask = NSViewResizingMask.HeightSizable | NSViewResizingMask.WidthSizable;
+
         }
 
         public View CurrentView
@@ -33,12 +29,52 @@ namespace HotUI.Mac
                 if (value == _virtualView)
                     return;
 
-                _virtualView = value;
-                _handler = _virtualView.GetOrCreateViewHandler();
-                if (_handler is ViewHandler viewHandler)
-                    viewHandler.NativeViewChanged += HandleNativeViewChanged;
+                if (_virtualView != null)
+                {
+                    _virtualView.ViewHandlerChanged -= HandleViewHandlerChanged;
+                    _virtualView.NeedsLayout -= HandleNeedsLayout;
+                    if (_handler is MacViewHandler viewHandler)
+                        viewHandler.NativeViewChanged -= HandleNativeViewChanged;
+                }
 
-                HandleNativeViewChanged(this, null);
+                _virtualView = value;
+
+                if (_virtualView != null)
+                {
+                    _handler = _virtualView.GetOrCreateViewHandler();
+
+                    _virtualView.ViewHandlerChanged += HandleViewHandlerChanged;
+                    _virtualView.NeedsLayout += HandleNeedsLayout;
+                    if (_handler is MacViewHandler viewHandler)
+                        viewHandler.NativeViewChanged += HandleNativeViewChanged;
+
+                    HandleNativeViewChanged(this, new ViewChangedEventArgs(_virtualView, null, (NSView)_handler.NativeView));
+                }
+            }
+        }
+
+        private void HandleNeedsLayout(object sender, EventArgs e)
+        {
+            SetNeedsLayout();
+        }
+
+        private void HandleViewHandlerChanged(object sender, ViewHandlerChangedEventArgs e)
+        {
+            Console.WriteLine($"[{GetType().Name}] HandleViewHandlerChanged: [{sender.GetType()}] From:[{e.OldViewHandler?.GetType()}] To:[{e.NewViewHandler?.GetType()}]");
+
+            if (e.OldViewHandler is MacViewHandler oldHandler)
+            {
+                oldHandler.NativeViewChanged -= HandleNativeViewChanged;
+                _nativeView?.RemoveFromSuperview();
+                _nativeView = null;
+            }
+
+            if (e.NewViewHandler is MacViewHandler newHandler)
+            {
+                newHandler.NativeViewChanged += HandleNativeViewChanged;
+                _nativeView = newHandler.View ?? new NSView();
+                AddSubview(_nativeView);
+                SetNeedsLayout();
             }
         }
 
@@ -110,19 +146,13 @@ namespace HotUI.Mac
                     bounds.Height -= padding.VerticalThickness;
                 }
 
-                if (_nativeView is NSTableView || _nativeView is ListViewHandler)
-                    _nativeView.Frame = bounds;
-                else
-                {
-                    CGSize sizeThatFits;
-                    if (_nativeView is AbstractLayoutHandler layout)
-                        sizeThatFits = layout.SizeThatFits(bounds.Size);
-                    else
-                        sizeThatFits = bounds.Size;
-                    var x = ((bounds.Width - sizeThatFits.Width) / 2) + padding.Left;
-                    var y = ((bounds.Height - sizeThatFits.Height) / 2) + padding.Top;
-                    _nativeView.Frame = new CGRect(x, y, sizeThatFits.Width, sizeThatFits.Height);
-                }
+                var sizeThatFits = _virtualView.Measure(bounds.Size.ToSizeF());
+                _virtualView.MeasuredSize = sizeThatFits;
+                _virtualView.MeasurementValid = true;
+
+                var x = ((bounds.Width - sizeThatFits.Width) / 2) + padding.Left;
+                var y = ((bounds.Height - sizeThatFits.Height) / 2) + padding.Top;
+                _virtualView.Frame = new RectangleF((float)x, (float)y, sizeThatFits.Width, sizeThatFits.Height);
             }
         }
     }

src/HotUI.iOS/Handlers/AbstractLayoutHandler.cs

@@ -1,8 +1,6 @@
 using System;
-using System.Collections.Generic;
 using CoreGraphics;
 using HotUI.iOS.Controls;
-using HotUI.Layout;
 using UIKit;
 
 namespace HotUI.iOS.Handlers

src/HotUI.iOS/HotUIView.cs

@@ -13,7 +13,6 @@ namespace HotUI.iOS
         public HotUIView()
         {
             BackgroundColor = UIColor.White;
-            AutosizesSubviews = false;
         }
 
         public HotUIView(CGRect rect) : base(rect)