Cleaned up wxArtProvider:

1. Move platform-specific code for both GetSizeHint() and GetBitmap()
   into platform-specific files.
2. Introduced GetNativeSizeHint() to make native sizes better accessible,
   without having to understand weird GetSizeHint() semantics.
3. Fixed GetNativeSizeHint() to return sensible values in non-GTK ports;
   it returns wxDefaultSize if it can't make a good guess instead of
   returning arbitrary value.
4. Use 16x16 icons on MSW instead of 16x15: it works and is more
   'natural' size.



git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@56372 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/osx/artmac.cpp

@@ -19,14 +19,13 @@
     #pragma hdrstop
 #endif
 
+#include "wx/artprov.h"
+
 #ifndef WX_PRECOMP
     #include "wx/image.h"
 #endif
 
-#if !defined(__WXUNIVERSAL__) && wxOSX_USE_CARBON
-
-#include "wx/artprov.h"
-#include "wx/image.h"
+#if wxOSX_USE_CARBON
 
 // ----------------------------------------------------------------------------
 // wxMacArtProvider
@@ -109,6 +108,22 @@ wxBitmap wxMacArtProvider::CreateBitmap(const wxArtID& id,
     return wxNullBitmap;
 }
 
-#endif // !defined(__WXUNIVERSAL__)
 
+// ----------------------------------------------------------------------------
+// wxArtProvider::GetNativeSizeHint()
+// ----------------------------------------------------------------------------
 
+/*static*/
+wxSize wxArtProvider::GetNativeSizeHint(const wxArtClient& client)
+{
+    if ( client == wxART_TOOLBAR )
+    {
+        // See http://developer.apple.com/documentation/UserExperience/Conceptual/AppleHIGuidelines/XHIGIcons/chapter_15_section_9.html:
+        // "32 x 32 pixels is the recommended size"
+        return wxSize(32, 32);
+    }
+
+    return wxDefaultSize;
+}
+
+#endif // wxOSX_USE_CARBON