text: /*
   * (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.
   *
   */
  
  #pragma once
  
  #include "RenderText.h"
  
  namespace WebCore {
  
  // 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 render 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 RenderTextFragment final : public RenderText {
      WTF_MAKE_ISO_ALLOCATED(RenderTextFragment);
  public:
      RenderTextFragment(Text&, const String&, int startOffset, int length);
      RenderTextFragment(Document&, const String&, int startOffset, int length);
      RenderTextFragment(Document&, const String&);
  
      virtual ~RenderTextFragment();
  
      bool canBeSelectionLeaf() const override;
  
      unsigned start() const { return m_start; }
      unsigned end() const { return m_end; }
  
      RenderBoxModelObject* firstLetter() const { return m_firstLetter.get(); }
      void setFirstLetter(RenderBoxModelObject& firstLetter) { m_firstLetter = makeWeakPtr(firstLetter); }
      
      RenderBlock* blockForAccompanyingFirstLetter();
  
      void setContentString(const String& text);
      StringImpl* contentString() const { return m_contentString.impl(); }
  
      void setText(const String&, bool force = false) override;
  
      const String& altText() const { return m_altText; }
      void setAltText(const String& altText) { m_altText = altText; }
      
  private:
      bool isTextFragment() const override { return true; }
      void styleDidChange(StyleDifference, const RenderStyle* oldStyle) override;
  
      UChar previousCharacter() const override;
  
      unsigned m_start;
      unsigned m_end;
      // Alternative description that can be used for accessibility instead of the native text.
      String m_altText;
      String m_contentString;
      WeakPtr<RenderBoxModelObject> m_firstLetter;
  };
  
  } // namespace WebCore
  
  SPECIALIZE_TYPE_TRAITS_BEGIN(WebCore::RenderTextFragment)
      static bool isType(const WebCore::RenderText& renderer) { return renderer.isTextFragment(); }
      static bool isType(const WebCore::RenderObject& renderer) { return is<WebCore::RenderText>(renderer) && isType(downcast<WebCore::RenderText>(renderer)); }
  SPECIALIZE_TYPE_TRAITS_END()
  