Removed functionality implemented by #1190.

src/Avalonia.Controls/Window.cs

@@ -148,9 +148,6 @@ namespace Avalonia.Controls
             impl.WindowStateChanged = HandleWindowStateChanged;
             _maxPlatformClientSize = PlatformImpl?.MaxClientSize ?? default(Size);
             Screens = new Screens(PlatformImpl?.Screen);
-
-            if (PlatformImpl != null)
-                PlatformImpl.WindowStateChanged = s => WindowState = s;
         }
         
         /// <inheritdoc/>
@@ -321,11 +318,13 @@ namespace Avalonia.Controls
 
         protected virtual void HandleWindowStateChanged(WindowState state)
         {
+            WindowState = state;
+
             if (state == WindowState.Minimized)
             {
                 Renderer.Stop();
             }
-            else if (state == WindowState.Normal)
+            else
             {
                 Renderer.Start();
             }

src/Avalonia.DesignerSupport/Remote/Stubs.cs

@@ -33,7 +33,6 @@ namespace Avalonia.DesignerSupport.Remote
         public Action<Point> PositionChanged { get; set; }
         public WindowState WindowState { get; set; }
         public Action<WindowState> WindowStateChanged { get; set; }
-
         public IRenderer CreateRenderer(IRenderRoot root) => new ImmediateRenderer(root);
         public void Dispose()
         {

src/Windows/Avalonia.Win32/Interop/UnmanagedMethods.cs

@@ -104,30 +104,6 @@ namespace Avalonia.Win32.Interop
             ForceMinimize = 11
         }
 
-        public enum SysCommands
-        {
-            SC_SIZE = 0xF000,
-            SC_MOVE = 0xF010,
-            SC_MINIMIZE = 0xF020,
-            SC_MAXIMIZE = 0xF030,
-            SC_NEXTWINDOW = 0xF040,
-            SC_PREVWINDOW = 0xF050,
-            SC_CLOSE = 0xF060,
-            SC_VSCROLL = 0xF070,
-            SC_HSCROLL = 0xF080,
-            SC_MOUSEMENU = 0xF090,
-            SC_KEYMENU = 0xF100,
-            SC_ARRANGE = 0xF110,
-            SC_RESTORE = 0xF120,
-            SC_TASKLIST = 0xF130,
-            SC_SCREENSAVE = 0xF140,
-            SC_HOTKEY = 0xF150,
-            SC_DEFAULT = 0xF160,
-            SC_MONITORPOWER = 0xF170,
-            SC_CONTEXTHELP = 0xF180,
-            SC_SEPARATOR = 0xF00F,
-        }
-
         public enum SystemMetric
         {
             SM_CXSCREEN = 0,  // 0x00

src/Windows/Avalonia.Win32/WindowImpl.cs

@@ -650,25 +650,6 @@ namespace Avalonia.Win32
 
                     return IntPtr.Zero;
 
-                case UnmanagedMethods.WindowsMessage.WM_SYSCOMMAND:
-                    if (WindowStateChanged != null)
-                    {
-                        switch ((SysCommands)wParam)
-                        {
-                            case SysCommands.SC_MINIMIZE:
-                                WindowStateChanged(WindowState.Minimized);
-                                break;
-                            case SysCommands.SC_MAXIMIZE:
-                                WindowStateChanged(WindowState.Maximized);
-                                break;
-                            case SysCommands.SC_RESTORE:
-                                WindowStateChanged(WindowState.Normal);
-                                break;
-                        }
-                    }
-
-                    break;
-
                 case UnmanagedMethods.WindowsMessage.WM_MOVE:
                     PositionChanged?.Invoke(new Point((short)(ToInt32(lParam) & 0xffff), (short)(ToInt32(lParam) >> 16)));
                     return IntPtr.Zero;