third_party/WebKit/Source/core/layout/line/InlineBox.h

/*
 * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2009, 2010, 2011 Apple Inc.
 *               All rights reserved.
 *
 * 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 InlineBox_h
#define InlineBox_h

#include "core/CoreExport.h"
#include "core/layout/api/LineLayoutBoxModel.h"
#include "core/layout/api/LineLayoutItem.h"
#include "core/layout/api/SelectionState.h"
#include "platform/graphics/paint/DisplayItemClient.h"
#include "platform/text/TextDirection.h"

namespace blink {

class HitTestRequest;
class HitTestResult;
class LayoutObject;
class RootInlineBox;

enum MarkLineBoxes { MarkLineBoxesDirty, DontMarkLineBoxes };

// InlineBox represents a rectangle that occurs on a line.  It corresponds to
// some LayoutObject (i.e., it represents a portion of that LayoutObject).
class CORE_EXPORT InlineBox : public DisplayItemClient {
  WTF_MAKE_NONCOPYABLE(InlineBox);

 public:
  InlineBox(LineLayoutItem obj)
      : m_next(nullptr),
        m_prev(nullptr),
        m_parent(nullptr),
        m_lineLayoutItem(obj),
        m_logicalWidth()
#if ENABLE(ASSERT)
        ,
        m_hasBadParent(false)
#endif
  {
  }

  InlineBox(LineLayoutItem item,
            LayoutPoint topLeft,
            LayoutUnit logicalWidth,
            bool firstLine,
            bool constructed,
            bool dirty,
            bool extracted,
            bool isHorizontal,
            InlineBox* next,
            InlineBox* prev,
            InlineFlowBox* parent)
      : m_bitfields(firstLine, constructed, dirty, extracted, isHorizontal),
        m_next(next),
        m_prev(prev),
        m_parent(parent),
        m_lineLayoutItem(item),
        m_topLeft(topLeft),
        m_logicalWidth(logicalWidth)
#if ENABLE(ASSERT)
        ,
        m_hasBadParent(false)
#endif
  {
  }

  virtual ~InlineBox();

  virtual void destroy();

  virtual void deleteLine();
  virtual void extractLine();
  virtual void attachLine();

  virtual bool isLineBreak() const { return false; }

  // These methods are called when the caller wants to move the position of
  // InlineBox without full layout of it. The implementation should update the
  // position of the whole subtree (e.g. position of descendants and overflow
  // etc. should also be moved accordingly).
  virtual void move(const LayoutSize& delta);
  DISABLE_CFI_PERF void moveInLogicalDirection(
      const LayoutSize& deltaInLogicalDirection) {
    move(isHorizontal() ? deltaInLogicalDirection
                        : deltaInLogicalDirection.transposedSize());
  }
  void moveInInlineDirection(LayoutUnit delta) {
    moveInLogicalDirection(LayoutSize(delta, LayoutUnit()));
  }
  void moveInBlockDirection(LayoutUnit delta) {
    moveInLogicalDirection(LayoutSize(LayoutUnit(), delta));
  }

  virtual void paint(const PaintInfo&,
                     const LayoutPoint&,
                     LayoutUnit lineTop,
                     LayoutUnit lineBottom) const;
  virtual bool nodeAtPoint(HitTestResult&,
                           const HitTestLocation& locationInContainer,
                           const LayoutPoint& accumulatedOffset,
                           LayoutUnit lineTop,
                           LayoutUnit lineBottom);

  // InlineBoxes are allocated out of the rendering partition.
  void* operator new(size_t);
  void operator delete(void*);

#ifndef NDEBUG
  void showTreeForThis() const;
  void showLineTreeForThis() const;

  virtual void showBox(int = 0) const;
  virtual void showLineTreeAndMark(const InlineBox* = nullptr,
                                   const char* = nullptr,
                                   const InlineBox* = nullptr,
                                   const char* = nullptr,
                                   const LayoutObject* = nullptr,
                                   int = 0) const;
#endif

  virtual const char* boxName() const;

  // DisplayItemClient methods
  String debugName() const override;
  LayoutRect visualRect() const override;

  bool isText() const { return m_bitfields.isText(); }
  void setIsText(bool isText) { m_bitfields.setIsText(isText); }

  virtual bool isInlineFlowBox() const { return false; }
  virtual bool isInlineTextBox() const { return false; }
  virtual bool isRootInlineBox() const { return false; }

  virtual bool isSVGInlineTextBox() const { return false; }
  virtual bool isSVGInlineFlowBox() const { return false; }
  virtual bool isSVGRootInlineBox() const { return false; }

  bool hasVirtualLogicalHeight() const {
    return m_bitfields.hasVirtualLogicalHeight();
  }
  void setHasVirtualLogicalHeight() {
    m_bitfields.setHasVirtualLogicalHeight(true);
  }
  virtual LayoutUnit virtualLogicalHeight() const {
    ASSERT_NOT_REACHED();
    return LayoutUnit();
  }

  bool isHorizontal() const { return m_bitfields.isHorizontal(); }
  void setIsHorizontal(bool isHorizontal) {
    m_bitfields.setIsHorizontal(isHorizontal);
  }

  virtual LayoutRect calculateBoundaries() const {
    ASSERT_NOT_REACHED();
    return LayoutRect();
  }

  bool isConstructed() { return m_bitfields.constructed(); }
  virtual void setConstructed() { m_bitfields.setConstructed(true); }

  void setExtracted(bool extracted = true) {
    m_bitfields.setExtracted(extracted);
  }

  void setFirstLineStyleBit(bool firstLine) {
    m_bitfields.setFirstLine(firstLine);
  }
  bool isFirstLineStyle() const { return m_bitfields.firstLine(); }

  void remove(MarkLineBoxes = MarkLineBoxesDirty);

  InlineBox* nextOnLine() const { return m_next; }
  InlineBox* prevOnLine() const { return m_prev; }
  void setNextOnLine(InlineBox* next) {
    ASSERT(m_parent || !next);
    m_next = next;
  }
  void setPrevOnLine(InlineBox* prev) {
    ASSERT(m_parent || !prev);
    m_prev = prev;
  }
  bool nextOnLineExists() const;

  virtual bool isLeaf() const { return true; }

  InlineBox* nextLeafChild() const;
  InlineBox* prevLeafChild() const;

  // Helper functions for editing and hit-testing code.
  // FIXME: These two functions should be moved to RenderedPosition once the
  // code to convert between Position and inline box, offset pair is moved to
  // RenderedPosition.
  InlineBox* nextLeafChildIgnoringLineBreak() const;
  InlineBox* prevLeafChildIgnoringLineBreak() const;

  LineLayoutItem getLineLayoutItem() const { return m_lineLayoutItem; }

  InlineFlowBox* parent() const {
    ASSERT(!m_hasBadParent);
    return m_parent;
  }
  void setParent(InlineFlowBox* par) { m_parent = par; }

  const RootInlineBox& root() const;
  RootInlineBox& root();

  // x() is the left side of the box in the containing block's coordinate
  // system.
  void setX(LayoutUnit x) { m_topLeft.setX(x); }
  LayoutUnit x() const { return m_topLeft.x(); }
  LayoutUnit left() const { return m_topLeft.x(); }

  // y() is the top side of the box in the containing block's coordinate system.
  void setY(LayoutUnit y) { m_topLeft.setY(y); }
  LayoutUnit y() const { return m_topLeft.y(); }
  LayoutUnit top() const { return m_topLeft.y(); }

  const LayoutPoint& topLeft() const { return m_topLeft; }

  LayoutUnit width() const {
    return isHorizontal() ? logicalWidth() : logicalHeight();
  }
  LayoutUnit height() const {
    return isHorizontal() ? logicalHeight() : logicalWidth();
  }
  LayoutSize size() const { return LayoutSize(width(), height()); }
  LayoutUnit right() const { return left() + width(); }
  LayoutUnit bottom() const { return top() + height(); }

  // The logicalLeft position is the left edge of the line box in a horizontal
  // line and the top edge in a vertical line.
  LayoutUnit logicalLeft() const {
    return isHorizontal() ? m_topLeft.x() : m_topLeft.y();
  }
  LayoutUnit logicalRight() const { return logicalLeft() + logicalWidth(); }
  void setLogicalLeft(LayoutUnit left) {
    if (isHorizontal())
      setX(left);
    else
      setY(left);
  }
  int pixelSnappedLogicalLeft() const { return logicalLeft().toInt(); }
  int pixelSnappedLogicalRight() const { return logicalRight().ceil(); }
  int pixelSnappedLogicalTop() const { return logicalTop().toInt(); }
  int pixelSnappedLogicalBottom() const { return logicalBottom().ceil(); }

  // The logicalTop[ position is the top edge of the line box in a horizontal
  // line and the left edge in a vertical line.
  LayoutUnit logicalTop() const {
    return isHorizontal() ? m_topLeft.y() : m_topLeft.x();
  }
  LayoutUnit logicalBottom() const { return logicalTop() + logicalHeight(); }
  void setLogicalTop(LayoutUnit top) {
    if (isHorizontal())
      setY(top);
    else
      setX(top);
  }

  // The logical width is our extent in the line's overall inline direction,
  // i.e., width for horizontal text and height for vertical text.
  void setLogicalWidth(LayoutUnit w) { m_logicalWidth = w; }
  LayoutUnit logicalWidth() const { return m_logicalWidth; }

  // The logical height is our extent in the block flow direction, i.e., height
  // for horizontal text and width for vertical text.
  LayoutUnit logicalHeight() const;

  LayoutRect logicalFrameRect() const {
    return isHorizontal() ? LayoutRect(m_topLeft.x(), m_topLeft.y(),
                                       m_logicalWidth, logicalHeight())
                          : LayoutRect(m_topLeft.y(), m_topLeft.x(),
                                       m_logicalWidth, logicalHeight());
  }

  virtual int baselinePosition(FontBaseline baselineType) const;
  virtual LayoutUnit lineHeight() const;

  virtual int caretMinOffset() const;
  virtual int caretMaxOffset() const;

  unsigned char bidiLevel() const { return m_bitfields.bidiEmbeddingLevel(); }
  void setBidiLevel(unsigned char level) {
    m_bitfields.setBidiEmbeddingLevel(level);
  }
  TextDirection direction() const { return bidiLevel() % 2 ? RTL : LTR; }
  bool isLeftToRightDirection() const { return direction() == LTR; }
  int caretLeftmostOffset() const {
    return isLeftToRightDirection() ? caretMinOffset() : caretMaxOffset();
  }
  int caretRightmostOffset() const {
    return isLeftToRightDirection() ? caretMaxOffset() : caretMinOffset();
  }

  virtual void clearTruncation() {}

  bool isDirty() const { return m_bitfields.dirty(); }
  virtual void markDirty() { m_bitfields.setDirty(true); }

  virtual void dirtyLineBoxes();

  virtual SelectionState getSelectionState() const;

  virtual bool canAccommodateEllipsis(bool ltr,
                                      int blockEdge,
                                      int ellipsisWidth) const;
  // visibleLeftEdge, visibleRightEdge are in the parent's coordinate system.
  virtual LayoutUnit placeEllipsisBox(bool ltr,
                                      LayoutUnit visibleLeftEdge,
                                      LayoutUnit visibleRightEdge,
                                      LayoutUnit ellipsisWidth,
                                      LayoutUnit& truncatedWidth,
                                      bool&);

#if ENABLE(ASSERT)
  void setHasBadParent();
#endif

  int expansion() const { return m_bitfields.expansion(); }

  bool visibleToHitTestRequest(const HitTestRequest& request) const {
    return getLineLayoutItem().visibleToHitTestRequest(request);
  }

  // Anonymous inline: https://drafts.csswg.org/css2/visuren.html#anonymous
  bool isAnonymousInline() const {
    return getLineLayoutItem().isText() && getLineLayoutItem().parent() &&
           getLineLayoutItem().parent().isBox();
  }
  EVerticalAlign verticalAlign() const {
    return isAnonymousInline() ? ComputedStyle::initialVerticalAlign()
                               : getLineLayoutItem()
                                     .style(m_bitfields.firstLine())
                                     ->verticalAlign();
  }

  // Use with caution! The type is not checked!
  LineLayoutBoxModel boxModelObject() const {
    if (!getLineLayoutItem().isText())
      return LineLayoutBoxModel(m_lineLayoutItem);
    return LineLayoutBoxModel(nullptr);
  }

  LayoutPoint locationIncludingFlipping() const;

  // Converts from a rect in the logical space of the InlineBox to one in the
  // physical space of the containing block. The logical space of an InlineBox
  // may be transposed for vertical text and flipped for right-to-left text.
  void logicalRectToPhysicalRect(LayoutRect&) const;

  // TODO(szager): The Rect versions should return a rect, not modify the
  // argument.
  void flipForWritingMode(FloatRect&) const;
  FloatPoint flipForWritingMode(const FloatPoint&) const;
  void flipForWritingMode(LayoutRect&) const;
  LayoutPoint flipForWritingMode(const LayoutPoint&) const;

  bool knownToHaveNoOverflow() const {
    return m_bitfields.knownToHaveNoOverflow();
  }
  void clearKnownToHaveNoOverflow();

  bool dirOverride() const { return m_bitfields.dirOverride(); }
  void setDirOverride(bool dirOverride) {
    m_bitfields.setDirOverride(dirOverride);
  }

  // Set all LineLayoutItems in the inline box subtree should do full paint
  // invalidation.
  void setShouldDoFullPaintInvalidationRecursively();

#define ADD_BOOLEAN_BITFIELD(name, Name) \
 private:                                \
  unsigned m_##name : 1;                 \
                                         \
 public:                                 \
  bool name() const { return m_##name; } \
  void set##Name(bool name) { m_##name = name; }

  class InlineBoxBitfields {
    DISALLOW_NEW();

   public:
    InlineBoxBitfields(bool firstLine = false,
                       bool constructed = false,
                       bool dirty = false,
                       bool extracted = false,
                       bool isHorizontal = true)
        : m_firstLine(firstLine),
          m_constructed(constructed),
          m_bidiEmbeddingLevel(0),
          m_dirty(dirty),
          m_extracted(extracted),
          m_hasVirtualLogicalHeight(false),
          m_isHorizontal(isHorizontal),
          m_endsWithBreak(false),
          m_hasSelectedChildrenOrCanHaveLeadingExpansion(false),
          m_knownToHaveNoOverflow(true),
          m_hasEllipsisBoxOrHyphen(false),
          m_dirOverride(false),
          m_isText(false),
          m_determinedIfNextOnLineExists(false),
          m_nextOnLineExists(false),
          m_expansion(0) {}

    // Some of these bits are actually for subclasses and moved here to compact
    // the structures.
    // for this class
    ADD_BOOLEAN_BITFIELD(firstLine, FirstLine);
    ADD_BOOLEAN_BITFIELD(constructed, Constructed);

   private:
    // The maximium bidi level is 62:
    // http://unicode.org/reports/tr9/#Explicit_Levels_and_Directions
    unsigned m_bidiEmbeddingLevel : 6;

   public:
    unsigned char bidiEmbeddingLevel() const { return m_bidiEmbeddingLevel; }
    void setBidiEmbeddingLevel(unsigned char bidiEmbeddingLevel) {
      m_bidiEmbeddingLevel = bidiEmbeddingLevel;
    }

    ADD_BOOLEAN_BITFIELD(dirty, Dirty);
    ADD_BOOLEAN_BITFIELD(extracted, Extracted);
    ADD_BOOLEAN_BITFIELD(hasVirtualLogicalHeight, HasVirtualLogicalHeight);
    ADD_BOOLEAN_BITFIELD(isHorizontal, IsHorizontal);
    // for RootInlineBox
    ADD_BOOLEAN_BITFIELD(endsWithBreak,
                         EndsWithBreak);  // Whether the line ends with a <br>.
    // shared between RootInlineBox and InlineTextBox
    ADD_BOOLEAN_BITFIELD(hasSelectedChildrenOrCanHaveLeadingExpansion,
                         HasSelectedChildrenOrCanHaveLeadingExpansion);

    // This boolean will never be set if there is potential for overflow, but it
    // will be eagerly cleared in the opposite case. As such, it's a
    // conservative tracking of the absence of overflow.
    //
    // For whether we have overflow, callers should use m_overflow on
    // InlineFlowBox.
    ADD_BOOLEAN_BITFIELD(knownToHaveNoOverflow, KnownToHaveNoOverflow);
    ADD_BOOLEAN_BITFIELD(hasEllipsisBoxOrHyphen, HasEllipsisBoxOrHyphen);
    // for InlineTextBox
    ADD_BOOLEAN_BITFIELD(dirOverride, DirOverride);
    // Whether or not this object represents text with a non-zero height.
    // Includes non-image list markers, text boxes.
    ADD_BOOLEAN_BITFIELD(isText, IsText);

   private:
    mutable unsigned m_determinedIfNextOnLineExists : 1;

   public:
    bool determinedIfNextOnLineExists() const {
      return m_determinedIfNextOnLineExists;
    }
    void setDeterminedIfNextOnLineExists(
        bool determinedIfNextOnLineExists) const {
      m_determinedIfNextOnLineExists = determinedIfNextOnLineExists;
    }

   private:
    mutable unsigned m_nextOnLineExists : 1;

   public:
    bool nextOnLineExists() const { return m_nextOnLineExists; }
    void setNextOnLineExists(bool nextOnLineExists) const {
      m_nextOnLineExists = nextOnLineExists;
    }

   private:
    unsigned m_expansion : 12;  // for justified text

   public:
    signed expansion() const { return m_expansion; }
    void setExpansion(signed expansion) { m_expansion = expansion; }
  };
#undef ADD_BOOLEAN_BITFIELD

 private:
  // Converts the given (top-left) position from the logical space of the
  // InlineBox to the physical space of the containing block. The size indicates
  // the size of the box whose point is being flipped.
  LayoutPoint logicalPositionToPhysicalPoint(const LayoutPoint&,
                                             const LayoutSize&) const;

  void setLineLayoutItemShouldDoFullPaintInvalidationIfNeeded();

  InlineBoxBitfields m_bitfields;

  InlineBox* m_next;  // The next element on the same line as us.
  InlineBox* m_prev;  // The previous element on the same line as us.

  InlineFlowBox* m_parent;  // The box that contains us.
  LineLayoutItem m_lineLayoutItem;

 protected:
  // For RootInlineBox
  bool endsWithBreak() const { return m_bitfields.endsWithBreak(); }
  void setEndsWithBreak(bool endsWithBreak) {
    m_bitfields.setEndsWithBreak(endsWithBreak);
  }
  bool hasEllipsisBox() const { return m_bitfields.hasEllipsisBoxOrHyphen(); }
  bool hasSelectedChildren() const {
    return m_bitfields.hasSelectedChildrenOrCanHaveLeadingExpansion();
  }
  void setHasSelectedChildren(bool hasSelectedChildren) {
    m_bitfields.setHasSelectedChildrenOrCanHaveLeadingExpansion(
        hasSelectedChildren);
  }
  void setHasEllipsisBox(bool hasEllipsisBox) {
    m_bitfields.setHasEllipsisBoxOrHyphen(hasEllipsisBox);
  }

  // For InlineTextBox
  bool hasHyphen() const { return m_bitfields.hasEllipsisBoxOrHyphen(); }
  void setHasHyphen(bool hasHyphen) {
    m_bitfields.setHasEllipsisBoxOrHyphen(hasHyphen);
  }
  bool canHaveLeadingExpansion() const {
    return m_bitfields.hasSelectedChildrenOrCanHaveLeadingExpansion();
  }
  void setCanHaveLeadingExpansion(bool canHaveLeadingExpansion) {
    m_bitfields.setHasSelectedChildrenOrCanHaveLeadingExpansion(
        canHaveLeadingExpansion);
  }
  signed expansion() { return m_bitfields.expansion(); }
  void setExpansion(signed expansion) { m_bitfields.setExpansion(expansion); }

  // For InlineFlowBox and InlineTextBox
  bool extracted() const { return m_bitfields.extracted(); }

  LayoutPoint m_topLeft;
  LayoutUnit m_logicalWidth;

 private:
#if ENABLE(ASSERT)
  bool m_hasBadParent;
#endif
};

#if !ENABLE(ASSERT)
inline InlineBox::~InlineBox() {}
#endif

#if ENABLE(ASSERT)
inline void InlineBox::setHasBadParent() {
  m_hasBadParent = true;
}
#endif

#define DEFINE_INLINE_BOX_TYPE_CASTS(typeName)                     \
  DEFINE_TYPE_CASTS(typeName, InlineBox, box, box->is##typeName(), \
                    box.is##typeName())

// Allow equality comparisons of InlineBox's by reference or pointer,
// interchangeably.
DEFINE_COMPARISON_OPERATORS_WITH_REFERENCES(InlineBox)

}  // namespace blink

#ifndef NDEBUG
// Outside the WebCore namespace for ease of invocation from gdb.
void showTree(const blink::InlineBox*);
void showLineTree(const blink::InlineBox*);
#endif

#endif  // InlineBox_h