macos: Provide fallback pasteboard for gtype Dnd

The Drag data should pass through the macos pasteboard system.
We need to provide some pasteboard type. Let's make it a "URL",
which is a pretty generic type anyway.

1 files changed, 20 insertions, 1 deletions

diff --git a/gdk/macos/gdkmacospasteboard.c b/gdk/macos/gdkmacospasteboard.c
index f74f9818cd..66b3c9f03b 100644
--- a/gdk/macos/gdkmacospasteboard.c
+++ b/gdk/macos/gdkmacospasteboard.c
@@ -372,7 +372,7 @@ _gdk_macos_pasteboard_register_drag_types (NSWindow *window)
   serializable = gdk_content_formats_union_serialize_mime_types (serializable);
   mime_types = gdk_content_formats_get_mime_types (serializable, &n_mime_types);
 
-  for (guint i = 0; mime_types[i]; i++)
+  for (gsize i = 0; i < n_mime_types; i++)
     {
       const char *mime_type = mime_types[i];
       NSPasteboardType type;
@@ -386,6 +386,25 @@ _gdk_macos_pasteboard_register_drag_types (NSWindow *window)
         }
     }
 
+  gdk_content_formats_unref (serializable);
+
+  /* Default to an url type (think gobject://internal)
+   * to support internal, GType-based DnD.
+   */
+  if (n_mime_types == 0)
+    {
+      GdkContentFormats *formats;
+      gsize n_gtypes;
+
+      formats = gdk_content_provider_ref_formats (self->_contentProvider);
+      gdk_content_formats_get_gtypes (formats, &n_gtypes);
+
+      if (n_gtypes)
+        [ret addObject:NSPasteboardTypeURL];
+
+      gdk_content_formats_unref (formats);
+    }
+
   return g_steal_pointer (&ret);
 }