chromium/third_party/blink/renderer/core/layout/layout_view.h

/*
 * Copyright (C) 1999 Lars Knoll ([email protected])
 * Copyright (C) 2006 Apple Computer, Inc.
 *
 * 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
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * 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.
 *
 */

#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_LAYOUT_VIEW_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_LAYOUT_VIEW_H_

#include "base/check_op.h"
#include "base/dcheck_is_on.h"
#include "third_party/blink/public/mojom/scroll/scrollbar_mode.mojom-blink.h"
#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/layout/layout_block_flow.h"
#include "third_party/blink/renderer/core/layout/layout_quote.h"
#include "third_party/blink/renderer/core/scroll/scrollable_area.h"
#include "third_party/blink/renderer/platform/graphics/overlay_scrollbar_clip_behavior.h"
#include "third_party/blink/renderer/platform/heap/collection_support/heap_hash_set.h"
#include "third_party/blink/renderer/platform/heap/garbage_collected.h"
#include "third_party/blink/renderer/platform/wtf/casting.h"
#include "third_party/blink/renderer/platform/wtf/text/text_offset_map.h"

namespace blink {

class HitTestCache;
class HitTestLocation;
class HitTestResult;
class LayoutText;
class LayoutViewTransitionRoot;
class LocalFrameView;

struct VariableLengthTransformResult { … };

// LayoutView is the root of the layout tree and the Document's LayoutObject.
//
// It corresponds to the CSS concept of 'initial containing block' (or ICB).
// http://www.w3.org/TR/CSS2/visudet.html#containing-block-details
//
// Its dimensions match that of the layout viewport. This viewport is used to
// size elements, in particular fixed positioned elements.
// LayoutView is always at position (0,0) relative to the document (and so isn't
// necessarily in view).
// See
// https://www.chromium.org/developers/design-documents/blink-coordinate-spaces
// about the different viewports.
//
// Because there is one LayoutView per rooted layout tree (or Frame), this class
// is used to add members shared by this tree (e.g. m_layoutState or
// m_layoutQuoteHead).
class CORE_EXPORT LayoutView : public LayoutBlockFlow { … };

template <>
struct DowncastTraits<LayoutView> { … };

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_LAYOUT_VIEW_H_