flutter_flutter/sky/engine/core/rendering/InlineTextBox.h

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

#include "flutter/sky/engine/core/editing/CompositionUnderline.h"
#include "flutter/sky/engine/core/rendering/InlineBox.h"
#include "flutter/sky/engine/core/rendering/RenderText.h"
#include "flutter/sky/engine/platform/text/TextRun.h"
#include "flutter/sky/engine/platform/transforms/AffineTransform.h"
#include "flutter/sky/engine/wtf/Forward.h"

namespace blink {

struct CompositionUnderline;
class DocumentMarker;
class GraphicsContext;

const unsigned short cNoTruncation = USHRT_MAX;
const unsigned short cFullTruncation = USHRT_MAX - 1;

class InlineTextBox : public InlineBox {
 public:
  InlineTextBox(RenderObject& obj)
      : InlineBox(obj),
        m_prevTextBox(0),
        m_nextTextBox(0),
        m_start(0),
        m_len(0),
        m_truncation(cNoTruncation) {}

  RenderText& renderer() const { return toRenderText(InlineBox::renderer()); }

  virtual void destroy() override final;

  InlineTextBox* prevTextBox() const { return m_prevTextBox; }
  InlineTextBox* nextTextBox() const { return m_nextTextBox; }
  void setNextTextBox(InlineTextBox* n) { m_nextTextBox = n; }
  void setPreviousTextBox(InlineTextBox* p) { m_prevTextBox = p; }

  // FIXME: These accessors should ASSERT(!isDirty()). See
  // https://bugs.webkit.org/show_bug.cgi?id=97264
  unsigned start() const { return m_start; }
  unsigned end() const { return m_len ? m_start + m_len - 1 : m_start; }
  unsigned len() const { return m_len; }

  void setStart(unsigned start) { m_start = start; }
  void setLen(unsigned len) { m_len = len; }

  void offsetRun(int d) {
    ASSERT(!isDirty());
    m_start += d;
  }

  unsigned short truncation() { return m_truncation; }

  virtual void markDirty() override final;

  using InlineBox::canHaveLeadingExpansion;
  using InlineBox::hasHyphen;
  using InlineBox::setCanHaveLeadingExpansion;
  using InlineBox::setHasAddedEllipsis;
  using InlineBox::setHasHyphen;

  static inline bool compareByStart(const InlineTextBox* first,
                                    const InlineTextBox* second) {
    return first->start() < second->start();
  }

  virtual int baselinePosition(FontBaseline) const override final;
  virtual LayoutUnit lineHeight() const override final;

  bool getEmphasisMarkPosition(RenderStyle*, TextEmphasisPosition&) const;

  LayoutRect logicalOverflowRect() const;
  void setLogicalOverflowRect(const LayoutRect&);
  LayoutUnit logicalTopVisualOverflow() const {
    return logicalOverflowRect().y();
  }
  LayoutUnit logicalBottomVisualOverflow() const {
    return logicalOverflowRect().maxY();
  }

#ifndef NDEBUG
  virtual void showBox(int = 0) const override;
  virtual const char* boxName() const override;
#endif

  enum RotationDirection { Counterclockwise, Clockwise };
  static AffineTransform rotation(const FloatRect& boxRect, RotationDirection);

 private:
  LayoutUnit selectionTop();
  LayoutUnit selectionBottom();
  LayoutUnit selectionHeight();

  // charactersWithHyphen, if provided, must not be destroyed before the
  // TextRun.
  TextRun constructTextRun(RenderStyle*,
                           const Font&,
                           StringBuilder* charactersWithHyphen = 0) const;
  TextRun constructTextRun(RenderStyle*,
                           const Font&,
                           StringView,
                           int maximumLength,
                           StringBuilder* charactersWithHyphen = 0) const;

 public:
  TextRun constructTextRunForInspector(RenderStyle*, const Font&) const;
  virtual FloatRect calculateBoundaries() const override {
    return FloatRect(x(), y(), width(), height());
  }

  virtual LayoutRect localSelectionRect(int startPos, int endPos);
  bool isSelected(int startPos, int endPos) const;
  void selectionStartEnd(int& sPos, int& ePos);

 protected:
  virtual void paint(PaintInfo&,
                     const LayoutPoint&,
                     LayoutUnit lineTop,
                     LayoutUnit lineBottom,
                     Vector<RenderBox*>& layers) override;
  virtual bool nodeAtPoint(const HitTestRequest&,
                           HitTestResult&,
                           const HitTestLocation& locationInContainer,
                           const LayoutPoint& accumulatedOffset,
                           LayoutUnit lineTop,
                           LayoutUnit lineBottom) override;

 private:
  virtual void deleteLine() override final;
  virtual void extractLine() override final;
  virtual void attachLine() override final;

 public:
  virtual RenderObject::SelectionState selectionState() override final;

 private:
  virtual void clearTruncation() override final {
    m_truncation = cNoTruncation;
  }

 public:
  virtual bool isLineBreak() const override final;

  void setExpansion(int newExpansion) {
    m_logicalWidth -= expansion();
    InlineBox::setExpansion(newExpansion);
    m_logicalWidth += newExpansion;
  }

 private:
  virtual bool isInlineTextBox() const override final { return true; }

 public:
  virtual int caretMinOffset() const override final;
  virtual int caretMaxOffset() const override final;

 private:
  float textPos() const;  // returns the x position relative to the left start
                          // of the text line.

 public:
  virtual int offsetForPosition(float x,
                                bool includePartialGlyphs = true) const;
  virtual float positionForOffset(int offset) const;

  bool containsCaretOffset(
      int offset) const;  // false for offset after line break

  // Fills a vector with the pixel width of each character.
  void characterWidths(Vector<float>&) const;

 private:
  InlineTextBox*
      m_prevTextBox;  // The previous box that also uses our RenderObject
  InlineTextBox* m_nextTextBox;  // The next box that also uses our RenderObject
  TextBlobPtr m_cachedTextBlob;

  int m_start;
  unsigned short m_len;

  unsigned short m_truncation;  // Where to truncate when text overflow is
                                // applied.  We use special constants to denote
                                // no truncation (the whole run paints) and full
                                // truncation (nothing paints at all).

  unsigned underlinePaintStart(const CompositionUnderline&);
  unsigned underlinePaintEnd(const CompositionUnderline&);

 protected:
  void paintSingleCompositionBackgroundRun(GraphicsContext*,
                                           const FloatPoint& boxOrigin,
                                           RenderStyle*,
                                           const Font&,
                                           Color backgroundColor,
                                           int startPos,
                                           int endPos);
  void paintCompositionBackgrounds(GraphicsContext*,
                                   const FloatPoint& boxOrigin,
                                   RenderStyle*,
                                   const Font&,
                                   bool useCustomUnderlines);
  void paintCompositionUnderline(GraphicsContext*,
                                 const FloatPoint& boxOrigin,
                                 const CompositionUnderline&);

 private:
  void paintDecoration(GraphicsContext*,
                       const FloatPoint& boxOrigin,
                       TextDecoration);
  void paintSelection(GraphicsContext*,
                      const FloatPoint& boxOrigin,
                      RenderStyle*,
                      const Font&,
                      Color textColor);

  TextRun::ExpansionBehavior expansionBehavior() const {
    return (canHaveLeadingExpansion() ? TextRun::AllowLeadingExpansion
                                      : TextRun::ForbidLeadingExpansion) |
           (expansion() && nextLeafChild() ? TextRun::AllowTrailingExpansion
                                           : TextRun::ForbidTrailingExpansion);
  }
};

DEFINE_INLINE_BOX_TYPE_CASTS(InlineTextBox);

void alignSelectionRectToDevicePixels(FloatRect&);

inline AffineTransform InlineTextBox::rotation(
    const FloatRect& boxRect,
    RotationDirection rotationDirection) {
  return rotationDirection == Clockwise
             ? AffineTransform(0, 1, -1, 0, boxRect.x() + boxRect.maxY(),
                               boxRect.maxY() - boxRect.x())
             : AffineTransform(0, -1, 1, 0, boxRect.x() - boxRect.maxY(),
                               boxRect.x() + boxRect.maxY());
}

}  // namespace blink

#endif  // SKY_ENGINE_CORE_RENDERING_INLINETEXTBOX_H_