more grid folding: got rid of duplicate version of methods for finding the closest row/column edge, appending/inserting/deleting rows/columns, and moving cursor vertically/horizontally

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@55663 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/grid.h

@@ -101,6 +101,14 @@ public:
     /// Must be overridden to implement testing for empty cells.
     virtual bool IsEmptyCell(int row, int col) = 0;
 
+    /**
+        Same as IsEmptyCell() but taking wxGridCellCoords.
+
+        Notice that this method is not virtual, only IsEmptyCell() should be
+        overridden.
+     */
+    bool IsEmpty(const wxGridCellCoords& coords);
+
     /// Must be overridden to implement accessing the table values as text.
     virtual wxString GetValue(int row, int col) = 0;