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

/*
 * (C) 1999 Lars Knoll (knoll@kde.org)
 * (C) 2000 Dirk Mueller (mueller@kde.org)
 * Copyright (C) 2004, 2005, 2006, 2007 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 LayoutTextFragment_h
#define LayoutTextFragment_h

#include "core/editing/EditingUtilities.h"
#include "core/layout/LayoutText.h"
#include "platform/heap/Handle.h"

namespace blink {

class FirstLetterPseudoElement;

// Used to represent a text substring of an element, e.g., for text runs that
// are split because of first letter and that must therefore have different
// styles (and positions in the layout tree).
// We cache offsets so that text transformations can be applied in such a way
// that we can recover the original unaltered string from our corresponding DOM
// node.
class LayoutTextFragment final : public LayoutText {
 public:
  LayoutTextFragment(Node*, StringImpl*, int startOffset, int length);
  LayoutTextFragment(Node*, StringImpl*);
  ~LayoutTextFragment() override;

  bool isTextFragment() const override { return true; }

  bool canBeSelectionLeaf() const override {
    return node() && hasEditableStyle(*node());
  }

  unsigned start() const { return m_start; }
  unsigned fragmentLength() const { return m_fragmentLength; }

  unsigned textStartOffset() const override { return start(); }

  void setContentString(StringImpl*);
  StringImpl* contentString() const { return m_contentString.get(); }
  // The complete text is all of the text in the associated DOM text node.
  PassRefPtr<StringImpl> completeText() const;
  // The fragment text is the text which will be used by this
  // LayoutTextFragment. For things like first-letter this may differ from the
  // completeText as we maybe using only a portion of the text nodes content.

  PassRefPtr<StringImpl> originalText() const override;

  void setText(PassRefPtr<StringImpl>, bool force = false) override;
  void setTextFragment(PassRefPtr<StringImpl>, unsigned start, unsigned length);

  void transformText() override;

  // FIXME: Rename to LayoutTextFragment
  const char* name() const override { return "LayoutTextFragment"; }

  void setFirstLetterPseudoElement(FirstLetterPseudoElement* element) {
    m_firstLetterPseudoElement = element;
  }
  FirstLetterPseudoElement* firstLetterPseudoElement() const {
    return m_firstLetterPseudoElement;
  }

  void setIsRemainingTextLayoutObject(bool isRemainingText) {
    m_isRemainingTextLayoutObject = isRemainingText;
  }
  bool isRemainingTextLayoutObject() const {
    return m_isRemainingTextLayoutObject;
  }

 protected:
  void willBeDestroyed() override;

 private:
  LayoutBlock* blockForAccompanyingFirstLetter() const;
  UChar previousCharacter() const override;

  Text* associatedTextNode() const;
  void updateHitTestResult(HitTestResult&, const LayoutPoint&) override;

  unsigned m_start;
  unsigned m_fragmentLength;
  bool m_isRemainingTextLayoutObject;
  RefPtr<StringImpl> m_contentString;
  // Reference back to FirstLetterPseudoElement; cleared by
  // FirstLetterPseudoElement::detachLayoutTree() if it goes away first.
  UntracedMember<FirstLetterPseudoElement> m_firstLetterPseudoElement;
};

DEFINE_TYPE_CASTS(LayoutTextFragment,
                  LayoutObject,
                  object,
                  toLayoutText(object)->isTextFragment(),
                  toLayoutText(object).isTextFragment());

}  // namespace blink

#endif  // LayoutTextFragment_h