Repeat footers in paginated context

third_party/WebKit/Source/core/layout/LayoutTable.h

 /*
  * Copyright (C) 1997 Martin Jones (mjones@kde.org)
  *           (C) 1997 Torben Weis (weis@kde.org)
  *           (C) 1998 Waldo Bastian (bastian@kde.org)
  *           (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2009, 2010 Apple Inc.
  *               All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 235 matching lines @@
   }
   void SetEffectiveColumnPosition(unsigned index, int position) {
     // Note that if our horizontal border-spacing changed, our position will
     // change but not our column's width. In practice, horizontal border-spacing
     // won't change often.
     column_logical_width_changed_ |=
         effective_column_positions_[index] != position;
     effective_column_positions_[index] = position;
   }
 
+  void SetPositionOfRepeatingFooterGroupOnPage(int page, LayoutUnit position) {

[mstensho (USE GERRIT), 2017/05/08 13:55:59]

Could you document here that |page| is the page number relatively to the page
where the table starts - NOT the overall page number?

[rhogan, 2017/05/09 19:57:15]

Done.

+    position_of_repeating_footer_group_on_page_.Grow(page + 1);

[mstensho (USE GERRIT), 2017/05/08 13:55:59]

Grow() requires that you're actually requesting growth, and it seems that
there's no guarantee that page+1 is larger than the current size of the vector,
since nobody resets it at the beginning of layout, so that a subsequent layout
is bound to hit the DCHECK_GE failure in Vector::Grow().

[rhogan, 2017/05/09 19:57:15]

Done.

+    position_of_repeating_footer_group_on_page_[page] = position;
+  }
+  const LayoutUnit GetPositionOfRepeatingFooterGroupOnPage(int page) const {
+    return position_of_repeating_footer_group_on_page_[page];
+  }
+  const Vector<LayoutUnit>& PositionOfRepeatingFooterGroupOnPage() const {
+    return position_of_repeating_footer_group_on_page_;
+  }
+
   LayoutTableSection* Header() const {
     // TODO(mstensho): We should ideally DCHECK(!needsSectionRecalc()) here, but
     // we currently cannot, due to crbug.com/693212
     return head_;
   }
   LayoutTableSection* Footer() const {
     DCHECK(!NeedsSectionRecalc());
     return foot_;
   }
   LayoutTableSection* FirstBody() const {
@@ skipping 172 matching lines @@
   void AddCaption(const LayoutTableCaption*);
   void RemoveCaption(const LayoutTableCaption*);
   void AddColumn(const LayoutTableCol*);
   void RemoveColumn(const LayoutTableCol*);
 
   void PaintBoxDecorationBackground(const PaintInfo&,
                                     const LayoutPoint&) const final;
 
   void PaintMask(const PaintInfo&, const LayoutPoint&) const final;
 
-  void SubtractCaptionRect(LayoutRect&) const;
+  void SubtractCaptionRect(LayoutRect&, bool after_only = false) const;
 
   bool IsLogicalWidthAuto() const;
 
   // When table headers are repeated, we need to know the offset from the block
   // start of the fragmentation context to the first occurrence of the table
   // header.
   LayoutUnit BlockOffsetToFirstRepeatableHeader() const {
     return block_offset_to_first_repeatable_header_;
   }
 
@@ skipping 89 matching lines @@
   // LayoutTable.
   mutable Vector<ColumnStruct> effective_columns_;
 
   // Holds the logical layout positions of effective columns, and the last item
   // (whose index is numEffectiveColumns()) holds the position of the imaginary
   // column after the last column.
   // Because of the last item, m_effectiveColumnPositions.size() is always
   // numEffectiveColumns() + 1.
   mutable Vector<int> effective_column_positions_;
 
+  mutable Vector<LayoutUnit> position_of_repeating_footer_group_on_page_;

[mstensho (USE GERRIT), 2017/05/08 13:55:59]

Are you sure you shouldn't use <int> here? Tables don't really deal a lot with
subpixels. Also, this should probably be a typedef, since you need it for
PositionOfRepeatingFooterGroupOnPage() as well.

[rhogan, 2017/05/09 19:57:15]

The row's logical top is stored as a LayoutUnit so it makes sense to me to store
it without converting it.

+
   // The captions associated with this object.
   mutable Vector<LayoutTableCaption*> captions_;
 
   // Holds pointers to LayoutTableCol objects for <col>s and <colgroup>s under
   // this table.
   // There is no direct relationship between the size of and index into this
   // vector and those of m_effectiveColumns because they hold different things.
   mutable Vector<LayoutTableCol*> column_layout_objects_;
 
   mutable LayoutTableSection* head_;
@@ skipping 54 matching lines @@
   if (first_body_)
     return first_body_;
   return foot_;
 }
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutTable, IsTable());
 
 }  // namespace blink
 
 #endif  // LayoutTable_h