Use [NSApp run] instead of a custom run loop

native/Avalonia.Native/inc/avalonia-native.h

@@ -280,7 +280,7 @@ AVNCOM(IAvnPlatformThreadingInterface, 0b) : IUnknown
     virtual bool GetCurrentThreadIsLoopThread() = 0;
     virtual void SetSignaledCallback(IAvnSignaledCallback* cb) = 0;
     virtual IAvnLoopCancellation* CreateLoopCancellation() = 0;
-    virtual void RunLoop(IAvnLoopCancellation* cancel) = 0;
+    virtual HRESULT RunLoop(IAvnLoopCancellation* cancel) = 0;
     // Can't pass int* to sharpgentools for some reason
     virtual void Signal(int priority) = 0;
     virtual IUnknown* StartTimer(int priority, int ms, IAvnActionCallback* callback) = 0;

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

@@ -0,0 +1,24 @@
+#include "common.h"
+@interface AvnAppDelegate : NSObject<NSApplicationDelegate>
+@end
+
+@implementation AvnAppDelegate
+- (void)applicationWillFinishLaunching:(NSNotification *)notification
+{
+    
+}
+
+- (void)applicationDidFinishLaunching:(NSNotification *)notification
+{
+    [NSApp activateIgnoringOtherApps:true];
+}
+
+@end
+
+extern void InitializeAvnApp()
+{
+    NSApplication* app = [NSApplication sharedApplication];
+    id delegate = [AvnAppDelegate new];
+    [app setDelegate:delegate];
+    
+}

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

@@ -19,7 +19,7 @@ extern IAvnClipboard* CreateClipboard();
 extern IAvnCursorFactory* CreateCursorFactory();
 extern IAvnGlFeature* GetGlFeature();
 extern IAvnGlSurfaceRenderTarget* CreateGlRenderTarget(NSWindow* window, NSView* view);
-
+extern void InitializeAvnApp();
 extern NSPoint ToNSPoint (AvnPoint p);
 extern AvnPoint ToAvnPoint (NSPoint p);
 extern AvnPoint ConvertPointY (AvnPoint p);

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

@@ -64,8 +64,9 @@ public:
     {
         @autoreleasepool{
             [[ThreadingInitializer new] do];
-            return S_OK;
         }
+        InitializeAvnApp();
+        return S_OK;
     };
     
     virtual IAvnMacOptions* GetMacOptions()  override

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

@@ -57,16 +57,36 @@ class PlatformThreadingInterface : public ComSingleObject<IAvnPlatformThreadingI
 {
 private:
     Signaler* _signaler;
+    bool _wasRunningAtLeastOnce = false;
     
     class LoopCancellation : public ComSingleObject<IAvnLoopCancellation, &IID_IAvnLoopCancellation>
     {
     public:
         FORWARD_IUNKNOWN()
-        bool Cancelled = 0;
-        virtual void Cancel() override
+        bool Running = false;
+        bool Cancelled = false;
+        virtual void Cancel()
         {
-            Cancelled = 1;
+            Cancelled = true;
+            if(Running)
+            {
+                Running = false;
+                dispatch_async(dispatch_get_main_queue(), ^{
+                    [[NSApplication sharedApplication] stop:nil];
+                    NSEvent* event = [NSEvent otherEventWithType:NSEventTypeApplicationDefined
+                                                        location:NSMakePoint(0, 0)
+                                                   modifierFlags:0
+                                                       timestamp:0
+                                                    windowNumber:0
+                                                         context:nil
+                                                         subtype:0
+                                                           data1:0
+                                                           data2:0];
+                    [NSApp postEvent:event atStart:YES];
+                });
+            }
         }
+
     };
     
 public:
@@ -99,30 +119,17 @@ public:
         return new LoopCancellation();
     }
     
-    virtual void RunLoop(IAvnLoopCancellation* cancel) override
+    virtual HRESULT RunLoop(IAvnLoopCancellation* cancel) override
     {
-        @autoreleasepool {
-            auto can = dynamic_cast<LoopCancellation*>(cancel);
-            [[NSApplication sharedApplication] activateIgnoringOtherApps:true];
-            while(true)
-            {
-                @autoreleasepool
-                {
-                    if(can != NULL && can->Cancelled)
-                        return;
-                    NSEvent* ev = [[NSApplication sharedApplication]
-                                   nextEventMatchingMask:NSEventMaskAny
-                                   untilDate: [NSDate dateWithTimeIntervalSinceNow:1]
-                                   inMode:NSDefaultRunLoopMode
-                                   dequeue:true];
-                    if(can != NULL && can->Cancelled)
-                        return;
-                    if(ev != NULL)
-                        [[NSApplication sharedApplication] sendEvent:ev];
-                }
-            }
-            NSDebugLog(@"RunLoop exited");
-        }
+        auto can = dynamic_cast<LoopCancellation*>(cancel);
+        if(can->Cancelled)
+            return S_OK;
+        if(_wasRunningAtLeastOnce)
+            return E_FAIL;
+        can->Running = true;
+        _wasRunningAtLeastOnce = true;
+        [NSApp run];
+        return S_OK;
     }
     
     virtual void Signal(int priority) override