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

src/generic/grid.cpp

@@ -5346,6 +5346,67 @@ void wxGrid::DrawHighlight(wxDC& dc, const wxGridCellCoordsArray& cells)
     }
 }
 
+// Used by wxGrid::Render() to draw the grid lines only for the cells in the
+// specified range.
+void
+wxGrid::DrawRangeGridLines(wxDC& dc,
+                           const wxRegion& reg,
+                           const wxGridCellCoords& topLeft,
+                           const wxGridCellCoords& bottomRight)
+{
+    if ( !m_gridLinesEnabled )
+         return;
+
+    int top, left, width, height;
+    reg.GetBox( left, top, width, height );
+
+    // create a clipping region
+    wxRegion clippedcells( dc.LogicalToDeviceX( left ),
+                           dc.LogicalToDeviceY( top ),
+                           dc.LogicalToDeviceXRel( width ),
+                           dc.LogicalToDeviceYRel( height ) );
+
+    // subtract multi cell span area from clipping region for lines
+    wxRect rect;
+    for ( int row = topLeft.GetRow(); row <= bottomRight.GetRow(); row++ )
+    {
+        for ( int col = topLeft.GetCol(); col <= bottomRight.GetCol(); col++ )
+        {
+            int cell_rows, cell_cols;
+            GetCellSize( row, col, &cell_rows, &cell_cols );
+            if ( cell_rows > 1 || cell_cols > 1 ) // multi cell
+            {
+                rect = CellToRect( row, col );
+                // cater for scaling
+                // device origin already set in ::Render() for x, y
+                rect.x = dc.LogicalToDeviceX( rect.x );
+                rect.y = dc.LogicalToDeviceY( rect.y );
+                rect.width = dc.LogicalToDeviceXRel( rect.width );
+                rect.height = dc.LogicalToDeviceYRel( rect.height ) - 1;
+                clippedcells.Subtract( rect );
+            }
+            else if ( cell_rows < 0 || cell_cols < 0 ) // part of multicell
+            {
+                rect = CellToRect( row + cell_rows, col + cell_cols );
+                rect.x = dc.LogicalToDeviceX( rect.x );
+                rect.y = dc.LogicalToDeviceY( rect.y );
+                rect.width = dc.LogicalToDeviceXRel( rect.width );
+                rect.height = dc.LogicalToDeviceYRel( rect.height ) - 1;
+                clippedcells.Subtract( rect );
+            }
+        }
+    }
+
+    dc.SetDeviceClippingRegion( clippedcells );
+
+    DoDrawGridLines(dc,
+                    top, left, top + height, left + width,
+                    topLeft.GetRow(), topLeft.GetCol(),
+                    bottomRight.GetRow(), bottomRight.GetCol());
+
+    dc.DestroyClippingRegion();
+}
+
 // This is used to redraw all grid lines e.g. when the grid line colour
 // has been changed
 //