Make it more obvious that there are no named ranges

and thus the selected doc can't be used as the source of external
data for this sheet. In other words, help the user figure out
why is OK button disabled

Change-Id: Ie1b999c9c3640397e9f6f6ee321d3a5a5d63fa3b
Reviewed-on: https://gerrit.libreoffice.org/72075
Tested-by: Jenkins
Reviewed-by: Katarina Behrens <Katarina.Behrens@cib.de>

sc/inc/strings.hrc

@@ -370,6 +370,7 @@
 
 #define STR_NO_USER_DATA_AVAILABLE                  NC_("sharedocumentdlg|nouserdata", "No user data available.")
 #define STR_EXCLUSIVE_ACCESS                        NC_("sharedocumentdlg|exclusive", "(exclusive access)")
+#define STR_NO_NAMED_RANGES_AVAILABLE               NC_("STR_NO_NAMED_RANGES_AVAILABLE", "No named ranges available in the selected document")
 
 #endif
 

sc/source/ui/miscdlgs/linkarea.cxx

@@ -32,6 +32,8 @@
 #include <rangeutl.hxx>
 #include <docsh.hxx>
 #include <tablink.hxx>
+#include <scresid.hxx>
+#include <strings.hrc>
 
 ScLinkedAreaDlg::ScLinkedAreaDlg(weld::Window* pParent)
     : GenericDialogController(pParent, "modules/scalc/ui/externaldata.ui", "ExternalDataDialog")
@@ -260,8 +262,13 @@ void ScLinkedAreaDlg::UpdateSourceRanges()
 
     m_xLbRanges->thaw();
 
-    if (m_xLbRanges->n_children() == 1)
+    if (m_xLbRanges->n_children() >= 1)
         m_xLbRanges->select(0);
+    else
+    {
+        m_xLbRanges->append_text(ScResId(STR_NO_NAMED_RANGES_AVAILABLE));
+        m_xLbRanges->set_sensitive(false);
+    }
 }
 
 void ScLinkedAreaDlg::UpdateEnable()