[OSX] fix pasting from clipboard

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

@@ -175,8 +175,8 @@ public:
 
 AVNCOM(IAvnString, 17) : IUnknown
 {
-    virtual HRESULT GetPointer(void**retOut) = 0;
+    virtual HRESULT Pointer(void**retOut) = 0;
-    virtual HRESULT GetLength(int*ret) = 0;
+    virtual HRESULT Length(int*ret) = 0;
 };
 
 AVNCOM(IAvnWindowBase, 02) : IUnknown
@@ -321,7 +321,7 @@ AVNCOM(IAvnScreens, 0e) : IUnknown
 
 AVNCOM(IAvnClipboard, 0f) : IUnknown
 {
-    virtual HRESULT GetText (IAvnString** ppv   ) = 0;
+    virtual IAvnString* GetText () = 0;
     virtual HRESULT SetText (char* text) = 0;
     virtual HRESULT Clear() = 0;
 };

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

@@ -21,7 +21,7 @@ public:
         _string = string;
     }
     
-    virtual HRESULT GetPointer(void**retOut) override
+    virtual HRESULT Pointer(void**retOut) override
     {
         @autoreleasepool
         {
@@ -36,7 +36,7 @@ public:
         }
     }
     
-    virtual HRESULT GetLength(int*retOut) override
+    virtual HRESULT Length(int*retOut) override
     {
         if(retOut == nullptr)
         {

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

@@ -8,18 +8,11 @@ class Clipboard : public ComSingleObject<IAvnClipboard, &IID_IAvnClipboard>
 {
 public:
     FORWARD_IUNKNOWN()
-    virtual HRESULT GetText (IAvnString** retOut) override
+    virtual IAvnString* GetText () override
     {
         @autoreleasepool
         {
-            if(retOut == nullptr)
+            return CreateAvnString([[NSPasteboard generalPasteboard] stringForType:NSPasteboardTypeString]);
-            {
-                return E_POINTER;
-            }
-            
-            *retOut = CreateAvnString([[NSPasteboard generalPasteboard] stringForType:NSPasteboardTypeString]);
-        
-            return S_OK;
         }
     }
     

src/Avalonia.Native/ClipboardImpl.cs

@@ -26,11 +26,12 @@ namespace Avalonia.Native
 
         public unsafe Task<string> GetTextAsync()
         {
-            var text = _native.GetText();
+            using (var text = _native.GetText())
-
+            {
-            var result = System.Text.Encoding.UTF8.GetString((byte*)text.GetPointer(), text.GetLength());
+                var result = System.Text.Encoding.UTF8.GetString((byte*)text.Pointer(), text.Length());
 
-            return Task.FromResult(result);
+                return Task.FromResult(result);
+            }
         }
 
         public Task SetTextAsync(string text)