document GetPickerCtrl() method and provide an example of how to use it to change the default 'Browse' label for wxFilePickerCtrl

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@57159 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/pickerbase.h

@@ -50,15 +50,35 @@ public:
         @c wxPB_USE_TEXTCTRL style was not specified when this control was created.
 
         @remarks
-        The contents of the text control could be containing an invalid
+        The contents of the text control could be an invalid representation of
-        representation of the entity which can be chosen through the picker
+        the entity which can be chosen through the picker
-        (e.g. the user entered an invalid colour syntax because of a typo).
+        (e.g. when the user enters an invalid colour syntax because of a typo).
         Thus you should never parse the content of the textctrl to get the
         user's input; rather use the derived-class getter
         (e.g. wxColourPickerCtrl::GetColour(), wxFilePickerCtrl::GetPath(), etc).
     */
     wxTextCtrl* GetTextCtrl();
 
+    /**
+        Returns the native implementation of the real picker control.
+
+        @note
+        The returned control in the generic implementation of wxFilePickerCtrl,
+        wxDirPickerCtrl, wxFontPickerCtrl and wxColourPickerCtrl is a specialized
+        wxButton class so that you can change its label doing, e.g.:
+        @code
+            #ifdef __WXMSW__
+                // wxMSW is one of the platforms where the generic implementation
+                // of wxFilePickerCtrl is used...
+
+                wxButton *pButt = wx_static_cast(wxButton*, myFilePickerCtrl->GetPickerCtrl());
+                if (pButt)
+                    pButt->SetLabel("Custom browse string");
+            #endif
+        @endcode
+    */
+    wxControl* GetPickerCtrl();
+
     /**
         Returns the proportion value of the text control.