Add default ctors and Create() to wxDirDialog and wxFileDialog in wxOSX.

Allow two-step creation of these classes.

Closes #15316.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74476 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/osx/filedlg.h

@@ -31,7 +31,23 @@ protected:
     wxArrayString m_paths;
 
 public:
+    wxFileDialog() { Init(); }
     wxFileDialog(wxWindow *parent,
+                 const wxString& message = wxFileSelectorPromptStr,
+                 const wxString& defaultDir = wxEmptyString,
+                 const wxString& defaultFile = wxEmptyString,
+                 const wxString& wildCard = wxFileSelectorDefaultWildcardStr,
+                 long style = wxFD_DEFAULT_STYLE,
+                 const wxPoint& pos = wxDefaultPosition,
+                 const wxSize& sz = wxDefaultSize,
+                 const wxString& name = wxFileDialogNameStr)
+    {
+        Init();
+
+        Create(parent,message,defaultDir,defaultFile,wildCard,style,pos,sz,name);
+    }
+
+    void Create(wxWindow *parent,
                  const wxString& message = wxFileSelectorPromptStr,
                  const wxString& defaultDir = wxEmptyString,
                  const wxString& defaultFile = wxEmptyString,
@@ -87,6 +103,10 @@ protected:
     WX_NSObject m_delegate;
     WX_NSObject m_sheetDelegate;
 #endif
+
+private:
+    // Common part of all ctors.
+    void Init();
 };
 
 #endif // _WX_FILEDLG_H_