third_party/WebKit/Source/core/paint/BoxBorderPainter.h

// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BoxBorderPainter_h
#define BoxBorderPainter_h

#include "core/layout/BackgroundBleedAvoidance.h"
#include "core/style/BorderEdge.h"
#include "platform/geometry/FloatRoundedRect.h"

namespace blink {

class ComputedStyle;
class GraphicsContext;
class LayoutRect;
struct PaintInfo;
class Path;

typedef unsigned BorderEdgeFlags;

class BoxBorderPainter {
  STACK_ALLOCATED();

 public:
  BoxBorderPainter(const LayoutRect& borderRect,
                   const ComputedStyle&,
                   BackgroundBleedAvoidance,
                   bool includeLogicalLeftEdge,
                   bool includeLogicalRightEdge);

  BoxBorderPainter(const ComputedStyle&,
                   const LayoutRect& outer,
                   const LayoutRect& inner,
                   const BorderEdge& uniformEdgeInfo);

  void paintBorder(const PaintInfo&, const LayoutRect& borderRect) const;

 private:
  struct ComplexBorderInfo;
  enum MiterType {
    NoMiter,
    SoftMiter,  // Anti-aliased
    HardMiter,  // Not anti-aliased
  };

  void computeBorderProperties();

  BorderEdgeFlags paintOpacityGroup(GraphicsContext&,
                                    const ComplexBorderInfo&,
                                    unsigned index,
                                    float accumulatedOpacity) const;
  void paintSide(GraphicsContext&,
                 const ComplexBorderInfo&,
                 BoxSide,
                 unsigned alpha,
                 BorderEdgeFlags) const;
  void paintOneBorderSide(GraphicsContext&,
                          const FloatRect& sideRect,
                          BoxSide,
                          BoxSide adjacentSide1,
                          BoxSide adjacentSide2,
                          const Path*,
                          bool antialias,
                          Color,
                          BorderEdgeFlags) const;
  bool paintBorderFastPath(GraphicsContext&,
                           const LayoutRect& borderRect) const;
  void drawDoubleBorder(GraphicsContext&, const LayoutRect& borderRect) const;

  void drawBoxSideFromPath(GraphicsContext&,
                           const LayoutRect&,
                           const Path&,
                           float thickness,
                           float drawThickness,
                           BoxSide,
                           Color,
                           EBorderStyle) const;
  void clipBorderSidePolygon(GraphicsContext&,
                             BoxSide,
                             MiterType miter1,
                             MiterType miter2) const;
  void clipBorderSideForComplexInnerPath(GraphicsContext&, BoxSide) const;

  MiterType computeMiter(BoxSide,
                         BoxSide adjacentSide,
                         BorderEdgeFlags,
                         bool antialias) const;
  static bool mitersRequireClipping(MiterType miter1,
                                    MiterType miter2,
                                    EBorderStyle,
                                    bool antialias);

  const BorderEdge& firstEdge() const {
    ASSERT(m_visibleEdgeSet);
    return m_edges[m_firstVisibleEdge];
  }

  // const inputs
  const ComputedStyle& m_style;
  const BackgroundBleedAvoidance m_bleedAvoidance;
  const bool m_includeLogicalLeftEdge;
  const bool m_includeLogicalRightEdge;

  // computed attributes
  FloatRoundedRect m_outer;
  FloatRoundedRect m_inner;
  BorderEdge m_edges[4];

  unsigned m_visibleEdgeCount;
  unsigned m_firstVisibleEdge;
  BorderEdgeFlags m_visibleEdgeSet;

  bool m_isUniformStyle;
  bool m_isUniformWidth;
  bool m_isUniformColor;
  bool m_isRounded;
  bool m_hasAlpha;
};

}  // namespace blink

#endif