Modal window flag for OSX

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

@@ -19,6 +19,8 @@ class WindowBaseImpl;
 -(void) pollModalSession: (NSModalSession _Nonnull) session;
 -(void) restoreParentWindow;
 -(bool) shouldTryToHandleEvents;
+-(bool) isModal;
+-(void) setModal: (bool) isModal;
 -(void) showAppMenuOnly;
 -(void) showWindowMenuWithAppMenu;
 -(void) applyMenu:(NSMenu* _Nullable)menu;

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

@@ -433,6 +433,9 @@ private:
         {
             if([Window parentWindow] != nil)
                 [[Window parentWindow] removeChildWindow:Window];
+            
+            [Window setModal:FALSE];
+            
             WindowBaseImpl::Show();
             
             return SetWindowState(_lastWindowState);
@@ -450,6 +453,8 @@ private:
             if(cparent == nullptr)
                 return E_INVALIDARG;
             
+            [Window setModal:TRUE];
+            
             [cparent->Window addChildWindow:Window ordered:NSWindowAbove];
             WindowBaseImpl::Show();
             
@@ -1144,6 +1149,7 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
     ComPtr<WindowBaseImpl> _parent;
     bool _canBecomeKeyAndMain;
     bool _closed;
+    bool _isModal;
     AvnMenu* _menu;
     double _lastScaling;
 }
@@ -1322,11 +1328,25 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
         auto ch = objc_cast<AvnWindow>(uch);
         if(ch == nil)
             continue;
+        
+        if(![ch isModal])
+            continue;
+        
         return FALSE;
     }
     return TRUE;
 }
 
+-(bool) isModal
+{
+    return _isModal;
+}
+
+-(void) setModal: (bool) isModal
+{
+    _isModal = isModal;
+}
+
 -(void)makeKeyWindow
 {
     if([self activateAppropriateChild: true])