diff -r 000000000000 -r 6474c204b198 layout/xul/grid/nsGrid.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/xul/grid/nsGrid.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,133 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsGrid_h___
+#define nsGrid_h___
+
+#include "nsStackLayout.h"
+#include "nsIGridPart.h"
+#include "nsCOMPtr.h"
+
+class nsGridRowGroupLayout;
+class nsGridRowLayout;
+class nsBoxLayoutState;
+class nsGridCell;
+
+//#define DEBUG_grid 1
+
+/**
+ * The grid data structure, i.e., the grid cellmap.
+ */
+class nsGrid
+{
+public:
+  nsGrid();
+  ~nsGrid();
+
+  nsGridRow* GetColumnAt(int32_t aIndex, bool aIsHorizontal = true);
+  nsGridRow* GetRowAt(int32_t aIndex, bool aIsHorizontal = true);
+  nsGridCell* GetCellAt(int32_t aX, int32_t aY);
+
+  void NeedsRebuild(nsBoxLayoutState& aBoxLayoutState);
+  void RebuildIfNeeded();
+
+  // For all the methods taking an aIsHorizontal parameter:
+  // * When aIsHorizontal is true, the words "rows" and (for
+  //   GetColumnCount) "columns" refer to their normal meanings.
+  // * When aIsHorizontal is false, the meanings are flipped.
+  // FIXME:  Maybe eliminate GetColumnCount and change aIsHorizontal to
+  // aIsRows?  (Calling it horizontal doesn't really make sense because
+  // row groups and columns have vertical orientation, whereas column
+  // groups and rows are horizontal.)
+
+  nsSize GetPrefRowSize(nsBoxLayoutState& aBoxLayoutState, int32_t aRowIndex, bool aIsHorizontal = true);
+  nsSize GetMinRowSize(nsBoxLayoutState& aBoxLayoutState, int32_t aRowIndex, bool aIsHorizontal = true);
+  nsSize GetMaxRowSize(nsBoxLayoutState& aBoxLayoutState, int32_t aRowIndex, bool aIsHorizontal = true);
+  nscoord GetRowFlex(nsBoxLayoutState& aBoxLayoutState, int32_t aRowIndex, bool aIsHorizontal = true);
+
+  nscoord GetPrefRowHeight(nsBoxLayoutState& aBoxLayoutState, int32_t aRowIndex, bool aIsHorizontal = true);
+  nscoord GetMinRowHeight(nsBoxLayoutState& aBoxLayoutState, int32_t aRowIndex, bool aIsHorizontal = true);
+  nscoord GetMaxRowHeight(nsBoxLayoutState& aBoxLayoutState, int32_t aRowIndex, bool aIsHorizontal = true);
+  void GetRowOffsets(nsBoxLayoutState& aState, int32_t aIndex, nscoord& aTop, nscoord& aBottom, bool aIsHorizontal = true);
+
+  void RowAddedOrRemoved(nsBoxLayoutState& aBoxLayoutState, int32_t aIndex, bool aIsHorizontal = true);
+  void CellAddedOrRemoved(nsBoxLayoutState& aBoxLayoutState, int32_t aIndex, bool aIsHorizontal = true);
+  void DirtyRows(nsIFrame* aRowBox, nsBoxLayoutState& aState);
+#ifdef DEBUG_grid
+  void PrintCellMap();
+#endif
+  int32_t GetExtraColumnCount(bool aIsHorizontal = true);
+  int32_t GetExtraRowCount(bool aIsHorizontal = true);
+
+// accessors
+  void SetBox(nsIFrame* aBox) { mBox = aBox; }
+  nsIFrame* GetBox() { return mBox; }
+  nsIFrame* GetRowsBox() { return mRowsBox; }
+  nsIFrame* GetColumnsBox() { return mColumnsBox; }
+  int32_t GetRowCount(int32_t aIsHorizontal = true);
+  int32_t GetColumnCount(int32_t aIsHorizontal = true);
+
+  static nsIFrame* GetScrolledBox(nsIFrame* aChild);
+  static nsIFrame* GetScrollBox(nsIFrame* aChild);
+  static nsIGridPart* GetPartFromBox(nsIFrame* aBox);
+  void GetFirstAndLastRow(nsBoxLayoutState& aState, 
+                          int32_t& aFirstIndex, 
+                          int32_t& aLastIndex, 
+                          nsGridRow*& aFirstRow,
+                          nsGridRow*& aLastRow,
+                          bool aIsHorizontal);
+
+private:
+
+  nsMargin GetBoxTotalMargin(nsIFrame* aBox, bool aIsHorizontal = true);
+
+  void FreeMap();
+  void FindRowsAndColumns(nsIFrame** aRows, nsIFrame** aColumns);
+  void BuildRows(nsIFrame* aBox, int32_t aSize, nsGridRow** aColumnsRows, bool aIsHorizontal = true);
+  nsGridCell* BuildCellMap(int32_t aRows, int32_t aColumns);
+  void PopulateCellMap(nsGridRow* aRows, nsGridRow* aColumns, int32_t aRowCount, int32_t aColumnCount, bool aIsHorizontal = true);
+  void CountRowsColumns(nsIFrame* aBox, int32_t& aRowCount, int32_t& aComputedColumnCount);
+  void SetLargestSize(nsSize& aSize, nscoord aHeight, bool aIsHorizontal = true);
+  void SetSmallestSize(nsSize& aSize, nscoord aHeight, bool aIsHorizontal = true);
+  bool IsGrid(nsIFrame* aBox);
+
+  // the box that implement the <grid> tag
+  nsIFrame* mBox;
+
+  // an array of row object
+  nsGridRow* mRows;
+
+  // an array of columns objects.
+  nsGridRow* mColumns;
+
+  // the first in the <grid> that implements the <rows> tag.
+  nsIFrame* mRowsBox;
+
+  // the first in the <grid> that implements the <columns> tag.
+  nsIFrame* mColumnsBox;
+
+  // a flag that is false tells us to rebuild the who grid
+  bool mNeedsRebuild;
+
+  // number of rows and columns as defined by the XUL
+  int32_t mRowCount;
+  int32_t mColumnCount;
+
+  // number of rows and columns that are implied but not 
+  // explicitly defined int he XUL
+  int32_t mExtraRowCount;
+  int32_t mExtraColumnCount;
+
+  // x,y array of cells in the rows and columns
+  nsGridCell* mCellMap;
+
+  // a flag that when true suppresses all other MarkDirties. This
+  // prevents lots of extra work being done.
+  bool mMarkingDirty;
+};
+
+#endif
+