ui/gfx/paint_vector_icon.cc

// 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.

#include "ui/gfx/paint_vector_icon.h"

#include <map>
#include <tuple>

#include "base/i18n/rtl.h"
#include "base/lazy_instance.h"
#include "base/macros.h"
#include "base/memory/ptr_util.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_split.h"
#include "cc/paint/paint_canvas.h"
#include "cc/paint/paint_flags.h"
#include "third_party/skia/include/core/SkPath.h"
#include "ui/gfx/canvas.h"
#include "ui/gfx/image/canvas_image_source.h"
#include "ui/gfx/scoped_canvas.h"
#include "ui/gfx/vector_icon_types.h"
#include "ui/gfx/vector_icons_public.h"

namespace gfx {

namespace {

// Translates a string such as "MOVE_TO" into a command such as MOVE_TO.
CommandType CommandFromString(const std::string& source) {
#define RETURN_IF_IS(command) \
  if (source == #command)     \
    return command;

  RETURN_IF_IS(NEW_PATH);
  RETURN_IF_IS(PATH_COLOR_ARGB);
  RETURN_IF_IS(PATH_MODE_CLEAR);
  RETURN_IF_IS(STROKE);
  RETURN_IF_IS(CAP_SQUARE);
  RETURN_IF_IS(MOVE_TO);
  RETURN_IF_IS(R_MOVE_TO);
  RETURN_IF_IS(ARC_TO);
  RETURN_IF_IS(R_ARC_TO);
  RETURN_IF_IS(LINE_TO);
  RETURN_IF_IS(R_LINE_TO);
  RETURN_IF_IS(H_LINE_TO);
  RETURN_IF_IS(R_H_LINE_TO);
  RETURN_IF_IS(V_LINE_TO);
  RETURN_IF_IS(R_V_LINE_TO);
  RETURN_IF_IS(CUBIC_TO);
  RETURN_IF_IS(R_CUBIC_TO);
  RETURN_IF_IS(CUBIC_TO_SHORTHAND);
  RETURN_IF_IS(CIRCLE);
  RETURN_IF_IS(ROUND_RECT);
  RETURN_IF_IS(CLOSE);
  RETURN_IF_IS(CANVAS_DIMENSIONS);
  RETURN_IF_IS(CLIP);
  RETURN_IF_IS(DISABLE_AA);
  RETURN_IF_IS(FLIPS_IN_RTL);
  RETURN_IF_IS(END);
#undef RETURN_IF_IS

  NOTREACHED() << "Unrecognized command: " << source;
  return CLOSE;
}

std::vector<PathElement> PathFromSource(const std::string& source) {
  std::vector<PathElement> path;
  std::vector<std::string> pieces = base::SplitString(
      source, "\n ,f", base::TRIM_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
  for (const auto& piece : pieces) {
    double value = 0;
    int hex_value = 0;
    if (base::StringToDouble(piece, &value))
      path.push_back(PathElement(SkDoubleToScalar(value)));
    else if (base::HexStringToInt(piece, &hex_value))
      path.push_back(PathElement(SkIntToScalar(hex_value)));
    else
      path.push_back(PathElement(CommandFromString(piece)));
  }
  return path;
}

void PaintPath(Canvas* canvas,
               const PathElement* path_elements,
               int dip_size,
               SkColor color) {
  SkPath path;
  path.setFillType(SkPath::kEvenOdd_FillType);

  int canvas_size = kReferenceSizeDip;
  std::vector<SkPath> paths;
  std::vector<cc::PaintFlags> flags_array;
  SkRect clip_rect = SkRect::MakeEmpty();
  bool flips_in_rtl = false;
  CommandType previous_command_type = NEW_PATH;

  for (size_t i = 0; path_elements[i].type != END; i++) {
    if (paths.empty() || path_elements[i].type == NEW_PATH) {
      paths.push_back(SkPath());
      paths.back().setFillType(SkPath::kEvenOdd_FillType);

      flags_array.push_back(cc::PaintFlags());
      flags_array.back().setColor(color);
      flags_array.back().setAntiAlias(true);
      flags_array.back().setStrokeCap(cc::PaintFlags::kRound_Cap);
    }

    SkPath& path = paths.back();
    cc::PaintFlags& flags = flags_array.back();
    CommandType command_type = path_elements[i].type;
    switch (command_type) {
      // Handled above.
      case NEW_PATH:
        continue;

      case PATH_COLOR_ARGB: {
        int a = SkScalarFloorToInt(path_elements[++i].arg);
        int r = SkScalarFloorToInt(path_elements[++i].arg);
        int g = SkScalarFloorToInt(path_elements[++i].arg);
        int b = SkScalarFloorToInt(path_elements[++i].arg);
        flags.setColor(SkColorSetARGB(a, r, g, b));
        break;
      }

      case PATH_MODE_CLEAR: {
        flags.setBlendMode(SkBlendMode::kClear);
        break;
      };

      case STROKE: {
        flags.setStyle(cc::PaintFlags::kStroke_Style);
        SkScalar width = path_elements[++i].arg;
        flags.setStrokeWidth(width);
        break;
      }

      case CAP_SQUARE: {
        flags.setStrokeCap(cc::PaintFlags::kSquare_Cap);
        break;
      }

      case MOVE_TO: {
        SkScalar x = path_elements[++i].arg;
        SkScalar y = path_elements[++i].arg;
        path.moveTo(x, y);
        break;
      }

      case R_MOVE_TO: {
        if (previous_command_type == CLOSE) {
          // This triggers injectMoveToIfNeeded() so that the next subpath will
          // start at the correct place. See
          // [ https://www.w3.org/TR/SVG/paths.html#PathDataClosePathCommand ].
          path.rLineTo(0, 0);
        }

        SkScalar x = path_elements[++i].arg;
        SkScalar y = path_elements[++i].arg;
        path.rMoveTo(x, y);
        break;
      }

      case ARC_TO:
      case R_ARC_TO: {
        SkScalar rx = path_elements[++i].arg;
        SkScalar ry = path_elements[++i].arg;
        SkScalar angle = path_elements[++i].arg;
        SkScalar large_arc_flag = path_elements[++i].arg;
        SkScalar arc_sweep_flag = path_elements[++i].arg;
        SkScalar x = path_elements[++i].arg;
        SkScalar y = path_elements[++i].arg;

        auto path_fn =
            command_type == ARC_TO
                ? static_cast<void (SkPath::*)(
                      SkScalar, SkScalar, SkScalar, SkPath::ArcSize,
                      SkPath::Direction, SkScalar, SkScalar)>(&SkPath::arcTo)
                : &SkPath::rArcTo;
        (path.*path_fn)(
            rx, ry, angle,
            large_arc_flag ? SkPath::kLarge_ArcSize : SkPath::kSmall_ArcSize,
            arc_sweep_flag ? SkPath::kCW_Direction : SkPath::kCCW_Direction,
            x, y);
        break;
      }

      case LINE_TO: {
        SkScalar x = path_elements[++i].arg;
        SkScalar y = path_elements[++i].arg;
        path.lineTo(x, y);
        break;
      }

      case R_LINE_TO: {
        SkScalar x = path_elements[++i].arg;
        SkScalar y = path_elements[++i].arg;
        path.rLineTo(x, y);
        break;
      }

      case H_LINE_TO: {
        SkPoint last_point;
        path.getLastPt(&last_point);
        SkScalar x = path_elements[++i].arg;
        path.lineTo(x, last_point.fY);
        break;
      }

      case R_H_LINE_TO: {
        SkScalar x = path_elements[++i].arg;
        path.rLineTo(x, 0);
        break;
      }

      case V_LINE_TO: {
        SkPoint last_point;
        path.getLastPt(&last_point);
        SkScalar y = path_elements[++i].arg;
        path.lineTo(last_point.fX, y);
        break;
      }

      case R_V_LINE_TO: {
        SkScalar y = path_elements[++i].arg;
        path.rLineTo(0, y);
        break;
      }

      case CUBIC_TO: {
        SkScalar x1 = path_elements[++i].arg;
        SkScalar y1 = path_elements[++i].arg;
        SkScalar x2 = path_elements[++i].arg;
        SkScalar y2 = path_elements[++i].arg;
        SkScalar x3 = path_elements[++i].arg;
        SkScalar y3 = path_elements[++i].arg;
        path.cubicTo(x1, y1, x2, y2, x3, y3);
        break;
      }

      case R_CUBIC_TO: {
        SkScalar x1 = path_elements[++i].arg;
        SkScalar y1 = path_elements[++i].arg;
        SkScalar x2 = path_elements[++i].arg;
        SkScalar y2 = path_elements[++i].arg;
        SkScalar x3 = path_elements[++i].arg;
        SkScalar y3 = path_elements[++i].arg;
        path.rCubicTo(x1, y1, x2, y2, x3, y3);
        break;
      }

      case CUBIC_TO_SHORTHAND: {
        // Compute the first control point (|x1| and |y1|) as the reflection
        // of the second control point on the previous command relative to
        // the current point. If there is no previous command or if the
        // previous command is not a cubic Bezier curve, the first control
        // point is coincident with the current point. Refer to the SVG
        // path specs for further details.
        SkPoint last_point;
        path.getLastPt(&last_point);
        SkScalar delta_x = 0;
        SkScalar delta_y = 0;
        if (previous_command_type == CUBIC_TO ||
            previous_command_type == R_CUBIC_TO ||
            previous_command_type == CUBIC_TO_SHORTHAND) {
          SkPoint last_control_point = path.getPoint(path.countPoints() - 2);
          delta_x = last_point.fX - last_control_point.fX;
          delta_y = last_point.fY - last_control_point.fY;
        }

        SkScalar x1 = last_point.fX + delta_x;
        SkScalar y1 = last_point.fY + delta_y;
        SkScalar x2 = path_elements[++i].arg;
        SkScalar y2 = path_elements[++i].arg;
        SkScalar x3 = path_elements[++i].arg;
        SkScalar y3 = path_elements[++i].arg;
        path.cubicTo(x1, y1, x2, y2, x3, y3);
        break;
      }

      case CIRCLE: {
        SkScalar x = path_elements[++i].arg;
        SkScalar y = path_elements[++i].arg;
        SkScalar r = path_elements[++i].arg;
        path.addCircle(x, y, r);
        break;
      }

      case ROUND_RECT: {
        SkScalar x = path_elements[++i].arg;
        SkScalar y = path_elements[++i].arg;
        SkScalar w = path_elements[++i].arg;
        SkScalar h = path_elements[++i].arg;
        SkScalar radius = path_elements[++i].arg;
        path.addRoundRect(SkRect::MakeXYWH(x, y, w, h), radius, radius);
        break;
      }

      case CLOSE: {
        path.close();
        break;
      }

      case CANVAS_DIMENSIONS: {
        SkScalar width = path_elements[++i].arg;
        canvas_size = SkScalarTruncToInt(width);
        break;
      }

      case CLIP: {
        SkScalar x = path_elements[++i].arg;
        SkScalar y = path_elements[++i].arg;
        SkScalar w = path_elements[++i].arg;
        SkScalar h = path_elements[++i].arg;
        clip_rect = SkRect::MakeXYWH(x, y, w, h);
        break;
      }

      case DISABLE_AA: {
        flags.setAntiAlias(false);
        break;
      }

      case FLIPS_IN_RTL: {
        flips_in_rtl = true;
        break;
      }

      case END:
        NOTREACHED();
        break;
    }

    previous_command_type = command_type;
  }

  gfx::ScopedRTLFlipCanvas scoped_rtl_flip_canvas(canvas, canvas_size,
                                                  flips_in_rtl);

  if (dip_size != canvas_size) {
    SkScalar scale = SkIntToScalar(dip_size) / SkIntToScalar(canvas_size);
    canvas->sk_canvas()->scale(scale, scale);
  }

  if (!clip_rect.isEmpty())
    canvas->sk_canvas()->clipRect(clip_rect);

  DCHECK_EQ(flags_array.size(), paths.size());
  for (size_t i = 0; i < paths.size(); ++i)
    canvas->DrawPath(paths[i], flags_array[i]);
}

class VectorIconSource : public CanvasImageSource {
 public:
  VectorIconSource(const VectorIcon& icon,
                   int dip_size,
                   SkColor color,
                   const VectorIcon& badge_icon)
      : CanvasImageSource(gfx::Size(dip_size, dip_size), false),
        color_(color),
        icon_(icon),
        badge_(badge_icon) {}

  ~VectorIconSource() override {}

  // CanvasImageSource:
  bool HasRepresentationAtAllScales() const override {
    return !icon_.is_empty();
  }

  void Draw(gfx::Canvas* canvas) override {
    PaintVectorIcon(canvas, icon_, size_.width(), color_);
    if (!badge_.is_empty())
      PaintVectorIcon(canvas, badge_, size_.width(), color_);
  }

 private:
  const SkColor color_;
  const VectorIcon& icon_;
  const VectorIcon& badge_;

  DISALLOW_COPY_AND_ASSIGN(VectorIconSource);
};

class VectorIconSourceLegacy : public CanvasImageSource {
 public:
  VectorIconSourceLegacy(VectorIconId id,
                         int dip_size,
                         SkColor color,
                         VectorIconId badge_id)
      : CanvasImageSource(gfx::Size(dip_size, dip_size), false),
        id_(id),
        color_(color),
        badge_id_(badge_id) {}

  VectorIconSourceLegacy(const std::string& definition,
                         int dip_size,
                         SkColor color)
      : CanvasImageSource(gfx::Size(dip_size, dip_size), false),
        id_(VectorIconId::VECTOR_ICON_NONE),
        path_(PathFromSource(definition)),
        color_(color),
        badge_id_(VectorIconId::VECTOR_ICON_NONE) {}

  ~VectorIconSourceLegacy() override {}

  // CanvasImageSource:
  bool HasRepresentationAtAllScales() const override {
    return id_ != VectorIconId::VECTOR_ICON_NONE;
  }

  void Draw(gfx::Canvas* canvas) override {
    if (path_.empty()) {
      PaintVectorIcon(canvas, id_, size_.width(), color_);
      if (badge_id_ != VectorIconId::VECTOR_ICON_NONE)
        PaintVectorIcon(canvas, badge_id_, size_.width(), color_);
    } else {
      PaintPath(canvas, path_.data(), size_.width(), color_);
    }
  }

 private:
  const VectorIconId id_;
  const std::vector<PathElement> path_;
  const SkColor color_;
  const VectorIconId badge_id_;

  DISALLOW_COPY_AND_ASSIGN(VectorIconSourceLegacy);
};

// This class caches vector icons (as ImageSkia) so they don't have to be drawn
// more than once. This also guarantees the backing data for the images returned
// by CreateVectorIcon will persist in memory until program termination.
class VectorIconCache {
 public:
  VectorIconCache() {}
  ~VectorIconCache() {}

  ImageSkia GetOrCreateIcon(const VectorIcon& icon,
                            int dip_size,
                            SkColor color,
                            const VectorIcon& badge_icon) {
    IconDescription description(&icon, dip_size, color, &badge_icon);
    auto iter = images_.find(description);
    if (iter != images_.end())
      return iter->second;

    ImageSkia icon_image(
        new VectorIconSource(icon, dip_size, color, badge_icon),
        gfx::Size(dip_size, dip_size));
    images_.insert(std::make_pair(description, icon_image));
    return icon_image;
  }

 private:
  struct IconDescription {
    IconDescription(const VectorIcon* icon,
                    int dip_size,
                    SkColor color,
                    const VectorIcon* badge_icon)
        : icon(icon),
          dip_size(dip_size),
          color(color),
          badge_icon(badge_icon) {}

    bool operator<(const IconDescription& other) const {
      return std::tie(icon, dip_size, color, badge_icon) <
             std::tie(other.icon, other.dip_size, other.color,
                      other.badge_icon);
    }

    const gfx::VectorIcon* icon;
    int dip_size;
    SkColor color;
    const gfx::VectorIcon* badge_icon;
  };

  std::map<IconDescription, ImageSkia> images_;

  DISALLOW_COPY_AND_ASSIGN(VectorIconCache);
};

static base::LazyInstance<VectorIconCache> g_icon_cache =
    LAZY_INSTANCE_INITIALIZER;

class VectorIconCacheLegacy {
 public:
  VectorIconCacheLegacy() {}
  ~VectorIconCacheLegacy() {}

  ImageSkia GetOrCreateIcon(VectorIconId id,
                            int dip_size,
                            SkColor color,
                            VectorIconId badge_id) {
    IconDescription description(id, dip_size, color, badge_id);
    auto iter = images_.find(description);
    if (iter != images_.end())
      return iter->second;

    ImageSkia icon(new VectorIconSourceLegacy(id, dip_size, color, badge_id),
                   gfx::Size(dip_size, dip_size));
    images_.insert(std::make_pair(description, icon));
    return icon;
  }

 private:
  struct IconDescription {
    IconDescription(VectorIconId id,
                    int dip_size,
                    SkColor color,
                    VectorIconId badge_id)
        : id(id), dip_size(dip_size), color(color), badge_id(badge_id) {}

    bool operator<(const IconDescription& other) const {
      return std::tie(id, dip_size, color, badge_id) <
             std::tie(other.id, other.dip_size, other.color, other.badge_id);
    }

    VectorIconId id;
    int dip_size;
    SkColor color;
    VectorIconId badge_id;
  };

  std::map<IconDescription, ImageSkia> images_;

  DISALLOW_COPY_AND_ASSIGN(VectorIconCacheLegacy);
};

static base::LazyInstance<VectorIconCacheLegacy> g_icon_cache_legacy =
    LAZY_INSTANCE_INITIALIZER;

}  // namespace

const VectorIcon kNoneIcon = {};

void PaintVectorIcon(Canvas* canvas,
                     VectorIconId id,
                     int dip_size,
                     SkColor color) {
  DCHECK(VectorIconId::VECTOR_ICON_NONE != id);
  const PathElement* path = canvas->image_scale() == 1.f
                                ? GetPathForVectorIconAt1xScale(id)
                                : GetPathForVectorIcon(id);
  PaintPath(canvas, path, dip_size, color);
}

void PaintVectorIcon(Canvas* canvas,
                     const VectorIcon& icon,
                     int dip_size,
                     SkColor color) {
  DCHECK(!icon.is_empty());
  const PathElement* path = (canvas->image_scale() == 1.f && icon.path_1x_)
                                ? icon.path_1x_
                                : icon.path_;
  PaintPath(canvas, path, dip_size, color);
}

ImageSkia CreateVectorIcon(VectorIconId id, SkColor color) {
  const PathElement* one_x_path = GetPathForVectorIconAt1xScale(id);
  int size = (one_x_path[0].type == CANVAS_DIMENSIONS)
                 ? SkScalarTruncToInt(one_x_path[1].arg)
                 : kReferenceSizeDip;
  return CreateVectorIcon(id, size, color);
}

ImageSkia CreateVectorIcon(const VectorIcon& icon, SkColor color) {
  const PathElement* one_x_path = icon.path_1x_ ? icon.path_1x_ : icon.path_;
  int size = one_x_path[0].type == CANVAS_DIMENSIONS ? one_x_path[1].arg
                                                     : kReferenceSizeDip;
  return CreateVectorIcon(icon, size, color);
}

ImageSkia CreateVectorIcon(VectorIconId id, int dip_size, SkColor color) {
  return CreateVectorIconWithBadge(id, dip_size, color,
                                   VectorIconId::VECTOR_ICON_NONE);
}

ImageSkia CreateVectorIcon(const VectorIcon& icon,
                           int dip_size,
                           SkColor color) {
  return CreateVectorIconWithBadge(icon, dip_size, color, kNoneIcon);
}

ImageSkia CreateVectorIconWithBadge(VectorIconId id,
                                    int dip_size,
                                    SkColor color,
                                    VectorIconId badge_id) {
  return (id == VectorIconId::VECTOR_ICON_NONE)
             ? gfx::ImageSkia()
             : g_icon_cache_legacy.Get().GetOrCreateIcon(id, dip_size, color,
                                                         badge_id);
}

ImageSkia CreateVectorIconWithBadge(const VectorIcon& icon,
                                    int dip_size,
                                    SkColor color,
                                    const VectorIcon& badge_icon) {
  return icon.is_empty() ? gfx::ImageSkia()
                         : g_icon_cache.Get().GetOrCreateIcon(
                               icon, dip_size, color, badge_icon);
}

ImageSkia CreateVectorIconFromSource(const std::string& source,
                                     int dip_size,
                                     SkColor color) {
  return CanvasImageSource::MakeImageSkia<VectorIconSourceLegacy>(
      source, dip_size, color);
}

}  // namespace gfx