made it possible to customize wxGenericDirCtrl, such as using checked wxTreeCtrl (patch #1019699)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@30249 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/dirctrlg.cpp

@@ -519,7 +519,7 @@ bool wxGenericDirCtrl::Create(wxWindow *parent,
     else
         filterStyle |= wxBORDER_SUNKEN;
 
-    m_treeCtrl = new wxTreeCtrl(this, wxID_TREECTRL,
+    m_treeCtrl = CreateTreeCtrl(this, wxID_TREECTRL,
                                 wxPoint(0,0), GetClientSize(), treeStyle);
 
     if (!filter.IsEmpty() && (style & wxDIRCTRL_SHOW_FILTERS))
@@ -584,6 +584,11 @@ void wxGenericDirCtrl::Init()
     m_filterListCtrl = NULL;
 }
 
+wxTreeCtrl* wxGenericDirCtrl::CreateTreeCtrl(wxWindow *parent, wxWindowID id, const wxPoint& pos, const wxSize& size, long treeStyle)
+{
+    return new wxTreeCtrl(parent, id, pos, size, treeStyle);
+}
+
 void wxGenericDirCtrl::ShowHidden( bool show )
 {
     m_showHidden = show;