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* Copyright (C) 1997 Martin Jones (
* (C) 1997 Torben Weis (
* (C) 1998 Waldo Bastian (
* (C) 1999 Lars Knoll (
* (C) 1999 Antti Koivisto (
* Copyright (C) 2003, 2004, 2005, 2006, 2009 Apple Inc. All rights reserved.
* Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* Library General Public License for more details.
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
#include "third_party/blink/renderer/core/layout/layout_table_box_component.h"
namespace blink {
class LayoutTable;
// LayoutTableCol is used to represent table column or column groups
// (display: table-column and display: table-column-group).
// The reason to use the same LayoutObject is that both objects behave in a very
// similar way. The main difference between the 2 is that table-column-group
// allows table-column children, when table-column don't.
// Note that this matches how <col> and <colgroup> map to the same class:
// HTMLTableColElement.
// In HTML and CSS, table columns and colgroups don't own the cells, they are
// descendants of the rows.
// As such table columns and colgroups have a very limited scope in the table:
// - column / cell sizing (the 'width' property)
// - background painting (the 'background' property).
// - border collapse resolution
// (
// See for the standard.
// Note that we don't implement the "visibility: collapse" inheritance to the
// cells.
// Because table columns and column groups are placeholder elements (see
// previous paragraph), they are never laid out and layout() should not be
// called on them.
class LayoutTableCol final : public LayoutTableBoxComponent {
explicit LayoutTableCol(Element*);
void ClearPreferredLogicalWidthsDirtyBits();
// The 'span' attribute in HTML.
// For CSS table columns or colgroups, this is always 1.
unsigned Span() const { return span_; }
bool IsTableColumnGroupWithColumnChildren() { return FirstChild(); }
bool IsTableColumn() const {
return StyleRef().Display() == EDisplay::kTableColumn;
bool IsTableColumnGroup() const {
return StyleRef().Display() == EDisplay::kTableColumnGroup;
LayoutTableCol* EnclosingColumnGroup() const;
// Returns the next column or column-group.
LayoutTableCol* NextColumn() const;
const char* GetName() const override { return "LayoutTableCol"; }
bool IsOfType(LayoutObjectType type) const override {
return type == kLayoutObjectLayoutTableCol || LayoutBox::IsOfType(type);
void UpdateFromElement() override;
void ComputePreferredLogicalWidths() override { NOTREACHED(); }
void InsertedIntoTree() override;
void WillBeRemovedFromTree() override;
bool IsChildAllowed(LayoutObject*, const ComputedStyle&) const override;
bool CanHaveChildren() const override;
PaintLayerType LayerTypeRequired() const override { return kNoPaintLayer; }
bool PaintedOutputOfObjectHasNoEffectRegardlessOfSize() const final;
void StyleDidChange(StyleDifference, const ComputedStyle* old_style) override;
LayoutTable* Table() const final;
unsigned span_;
DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutTableCol, IsLayoutTableCol());
} // namespace blink