[OSX] dont allow disabled windows to resize.

Author: danwalmsley

native/Avalonia.Native/src/OSX/WindowImpl.h

@@ -13,6 +13,7 @@
 class WindowImpl : public virtual WindowBaseImpl, public virtual IAvnWindow, public IWindowStateChanged
 {
 private:
+    bool _isEnabled;
     bool _canResize;
     bool _fullScreenActive;
     SystemDecorations _decorations;

native/Avalonia.Native/src/OSX/WindowImpl.mm

@@ -9,6 +9,7 @@
 #include "WindowProtocol.h"
 
 WindowImpl::WindowImpl(IAvnWindowEvents *events, IAvnGlContext *gl) : WindowBaseImpl(events, gl) {
+    _isEnabled = true;
     _children = std::list<WindowImpl*>();
     _isClientAreaExtended = false;
     _extendClientHints = AvnDefaultChrome;
@@ -75,7 +76,9 @@
     START_COM_CALL;
 
     @autoreleasepool {
+        _isEnabled = enable;
         [GetWindowProtocol() setEnabled:enable];
+        UpdateStyle();
         return S_OK;
     }
 }
@@ -573,7 +576,7 @@
         case SystemDecorationsFull:
             s = s | NSWindowStyleMaskTitled | NSWindowStyleMaskClosable;
 
-            if (_canResize) {
+            if (_canResize && _isEnabled) {
                 s = s | NSWindowStyleMaskResizable;
             }
             break;