Add wxGrid::DrawRangeGridLines().

This method draws only the grid lines for the cells in the specified range and
not for all of them.

It is not used yet but will be by the upcoming wxGrid::Render(), see #14294.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@71576 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/generic/grid.h

@@ -2133,6 +2133,12 @@ private:
     // redraw the grid lines, should be called after changing their attributes
     void RedrawGridLines();
 
+    // draw all grid lines in the given cell region (unlike the public
+    // DrawAllGridLines() which just draws all of them)
+    void DrawRangeGridLines(wxDC& dc, const wxRegion& reg,
+                            const wxGridCellCoords& topLeft,
+                            const wxGridCellCoords& bottomRight);
+
     // draw all lines from top to bottom row and left to right column in the
     // rectangle determined by (top, left)-(bottom, right) -- but notice that
     // the caller must have set up the clipping correctly, this rectangle is