Added wxPropertyGrid::SetUnspecifiedValueAppearance(); Added wxPGEditor::SetControlAppearance() for applying wxPGCell attributes on a property editor.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62973 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/propgrid/propgrid.cpp

@@ -2156,6 +2156,13 @@ void FormMain::CreateGrid( int style, int extraStyle )
 
     m_pPropGridManager->GetGrid()->SetVerticalSpacing( 2 );
 
+    //
+    // Set somewhat different unspecified value appearance
+    wxPGCell cell;
+    cell.SetText("Unspecified");
+    cell.SetFgCol(*wxLIGHT_GREY);
+    m_propGrid->SetUnspecifiedValueAppearance(cell);
+
     PopulateGrid();
 
     // Change some attributes in all properties