DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Implementation

Mercurial (b6d82b1a6b02)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_dom_SVGGeometryProperty_SVGGeometryProperty_h
#define mozilla_dom_SVGGeometryProperty_SVGGeometryProperty_h

#include "mozilla/dom/SVGElement.h"
#include "ComputedStyle.h"
#include "SVGAnimatedLength.h"
#include "nsComputedDOMStyle.h"
#include "nsGkAtoms.h"
#include "nsIFrame.h"
#include "nsSVGImageFrame.h"
#include <type_traits>

namespace mozilla {
namespace dom {

namespace SVGGeometryProperty {
namespace ResolverTypes {
struct LengthPercentNoAuto {};
struct LengthPercentRXY {};
struct LengthPercentWidthHeight {};
}  // namespace ResolverTypes

namespace Tags {

#define SVGGEOMETRYPROPERTY_GENERATETAG(tagName, resolver, direction, \
                                        styleStruct)                  \
  struct tagName {                                                    \
    using ResolverType = ResolverTypes::resolver;                     \
    constexpr static auto CtxDirection = SVGContentUtils::direction;  \
    constexpr static auto Getter = &styleStruct::m##tagName;          \
  }

SVGGEOMETRYPROPERTY_GENERATETAG(X, LengthPercentNoAuto, X, nsStyleSVGReset);
SVGGEOMETRYPROPERTY_GENERATETAG(Y, LengthPercentNoAuto, Y, nsStyleSVGReset);
SVGGEOMETRYPROPERTY_GENERATETAG(Cx, LengthPercentNoAuto, X, nsStyleSVGReset);
SVGGEOMETRYPROPERTY_GENERATETAG(Cy, LengthPercentNoAuto, Y, nsStyleSVGReset);
SVGGEOMETRYPROPERTY_GENERATETAG(R, LengthPercentNoAuto, XY, nsStyleSVGReset);

#undef SVGGEOMETRYPROPERTY_GENERATETAG

struct Height;
struct Width {
  using ResolverType = ResolverTypes::LengthPercentWidthHeight;
  constexpr static auto CtxDirection = SVGContentUtils::X;
  constexpr static auto Getter = &nsStylePosition::mWidth;
  constexpr static auto SizeGetter = &gfx::Size::width;
  static AspectRatio AspectRatioRelative(AspectRatio aAspectRatio) {
    return aAspectRatio.Inverted();
  }
  constexpr static uint32_t DefaultObjectSize = 300;
  using CounterPart = Height;
};
struct Height {
  using ResolverType = ResolverTypes::LengthPercentWidthHeight;
  constexpr static auto CtxDirection = SVGContentUtils::Y;
  constexpr static auto Getter = &nsStylePosition::mHeight;
  constexpr static auto SizeGetter = &gfx::Size::height;
  static AspectRatio AspectRatioRelative(AspectRatio aAspectRatio) {
    return aAspectRatio;
  }
  constexpr static uint32_t DefaultObjectSize = 150;
  using CounterPart = Width;
};

struct Ry;
struct Rx {
  using ResolverType = ResolverTypes::LengthPercentRXY;
  constexpr static auto CtxDirection = SVGContentUtils::X;
  constexpr static auto Getter = &nsStyleSVGReset::mRx;
  using CounterPart = Ry;
};
struct Ry {
  using ResolverType = ResolverTypes::LengthPercentRXY;
  constexpr static auto CtxDirection = SVGContentUtils::Y;
  constexpr static auto Getter = &nsStyleSVGReset::mRy;
  using CounterPart = Rx;
};

}  // namespace Tags

namespace details {
template <class T>
using AlwaysFloat = float;
using dummy = int[];

using CtxDirectionType = decltype(SVGContentUtils::X);

template <CtxDirectionType CTD>
float ResolvePureLengthPercentage(SVGElement* aElement,
                                  const LengthPercentage& aLP) {
  return aLP.ResolveToCSSPixelsWith(
      [&] { return CSSCoord{SVGElementMetrics(aElement).GetAxisLength(CTD)}; });
}

template <class Tag>
float ResolveImpl(ComputedStyle const& aStyle, SVGElement* aElement,
                  ResolverTypes::LengthPercentNoAuto) {
  auto const& value = aStyle.StyleSVGReset()->*Tag::Getter;
  return ResolvePureLengthPercentage<Tag::CtxDirection>(aElement, value);
}

template <class Tag>
float ResolveImpl(ComputedStyle const& aStyle, SVGElement* aElement,
                  ResolverTypes::LengthPercentWidthHeight) {
  static_assert(
      std::is_same<Tag, Tags::Width>{} || std::is_same<Tag, Tags::Height>{},
      "Wrong tag");

  auto const& value = aStyle.StylePosition()->*Tag::Getter;
  if (value.IsLengthPercentage()) {
    return ResolvePureLengthPercentage<Tag::CtxDirection>(
        aElement, value.AsLengthPercentage());
  }

  if (aElement->IsSVGElement(nsGkAtoms::image)) {
    // It's not clear per SVG2 spec what should be done for values other
    // than |auto| (e.g. |max-content|). We treat them as nonsense, thus
    // using the initial value behavior, i.e. |auto|.
    // The following procedure follows the Default Sizing Algorithm as
    // specified in:
    // https://svgwg.org/svg2-draft/embedded.html#ImageElement

    auto* f = aElement->GetPrimaryFrame();
    MOZ_ASSERT(f && f->IsSVGImageFrame());
    auto* imgf = static_cast<nsSVGImageFrame const*>(f);

    using Other = typename Tag::CounterPart;
    auto const& valueOther = aStyle.StylePosition()->*Other::Getter;

    gfx::Size intrinsicImageSize;
    AspectRatio aspectRatio;
    if (!imgf->GetIntrinsicImageDimensions(intrinsicImageSize, aspectRatio)) {
      // No image container, just return 0.
      return 0.f;
    }

    if (valueOther.IsLengthPercentage()) {
      // We are |auto|, but the other side has specifed length.
      float lengthOther = ResolvePureLengthPercentage<Other::CtxDirection>(
          aElement, valueOther.AsLengthPercentage());

      if (aspectRatio) {
        // Preserve aspect ratio if it's present.
        return Other::AspectRatioRelative(aspectRatio).ApplyTo(lengthOther);
      }

      float intrinsicLength = intrinsicImageSize.*Tag::SizeGetter;
      if (intrinsicLength >= 0) {
        // Use the intrinsic length if it's present.
        return intrinsicLength;
      }

      // No specified size, no aspect ratio, no intrinsic length,
      // then use default size.
      return Tag::DefaultObjectSize;
    }

    // |width| and |height| are both |auto|
    if (intrinsicImageSize.*Tag::SizeGetter >= 0) {
      return intrinsicImageSize.*Tag::SizeGetter;
    }

    if (intrinsicImageSize.*Other::SizeGetter >= 0 && aspectRatio) {
      return Other::AspectRatioRelative(aspectRatio)
          .ApplyTo(intrinsicImageSize.*Other::SizeGetter);
    }

    if (aspectRatio) {
      // Resolve as a contain constraint against the default object size.
      auto defaultAspectRatioRelative =
          AspectRatio{float(Other::DefaultObjectSize) / Tag::DefaultObjectSize};
      auto aspectRatioRelative = Tag::AspectRatioRelative(aspectRatio);

      if (defaultAspectRatioRelative < aspectRatioRelative) {
        // Using default length in our side and the intrinsic aspect ratio,
        // the other side cannot be contained.
        return aspectRatioRelative.Inverted().ApplyTo(Other::DefaultObjectSize);
      }

      return Tag::DefaultObjectSize;
    }

    return Tag::DefaultObjectSize;
  }

  // For other elements, |auto| and |max-content| etc. are treated as 0.
  return 0.f;
}

template <class Tag>
float ResolveImpl(ComputedStyle const& aStyle, SVGElement* aElement,
                  ResolverTypes::LengthPercentRXY) {
  static_assert(std::is_same<Tag, Tags::Rx>{} || std::is_same<Tag, Tags::Ry>{},
                "Wrong tag");

  auto const& value = aStyle.StyleSVGReset()->*Tag::Getter;
  if (value.IsLengthPercentage()) {
    return ResolvePureLengthPercentage<Tag::CtxDirection>(
        aElement, value.AsLengthPercentage());
  }

  MOZ_ASSERT(value.IsAuto());
  using Rother = typename Tag::CounterPart;
  auto const& valueOther = aStyle.StyleSVGReset()->*Rother::Getter;

  if (valueOther.IsAuto()) {
    // Per SVG2, |Rx|, |Ry| resolve to 0 if both are |auto|
    return 0.f;
  }

  // If |Rx| is auto while |Ry| not, |Rx| gets the value of |Ry|.
  return ResolvePureLengthPercentage<Rother::CtxDirection>(
      aElement, valueOther.AsLengthPercentage());
}

}  // namespace details

template <class Tag>
float ResolveWith(const ComputedStyle& aStyle, const SVGElement* aElement) {
  // TODO: There are a lot of utilities lacking const-ness in dom/svg.
  // We should fix that problem and remove this `const_cast`.
  return details::ResolveImpl<Tag>(aStyle, const_cast<SVGElement*>(aElement),
                                   typename Tag::ResolverType{});
}

template <class Func>
bool DoForComputedStyle(SVGElement* aElement, Func aFunc) {
  if (const nsIFrame* f = aElement->GetPrimaryFrame()) {
    aFunc(f->Style());
    return true;
  }

  if (RefPtr<ComputedStyle> computedStyle =
          nsComputedDOMStyle::GetComputedStyleNoFlush(aElement, nullptr)) {
    aFunc(computedStyle.get());
    return true;
  }

  return false;
}

#define SVGGEOMETRYPROPERTY_EVAL_ALL(expr) \
  (void)details::dummy { 0, (static_cast<void>(expr), 0)... }

// To add support for new properties, or to handle special cases for
// existing properties, you can add a new tag in |Tags| and |ResolverTypes|
// namespace, then implement the behavior in |details::ResolveImpl|.
template <class... Tags>
bool ResolveAll(const SVGElement* aElement,
                details::AlwaysFloat<Tags>*... aRes) {
  if (nsIFrame const* f = aElement->GetPrimaryFrame()) {
    SVGGEOMETRYPROPERTY_EVAL_ALL(*aRes =
                                     ResolveWith<Tags>(*f->Style(), aElement));
    return true;
  }
  return false;
}

template <class... Tags>
bool ResolveAllAllowFallback(SVGElement* aElement,
                             details::AlwaysFloat<Tags>*... aRes) {
  bool res = DoForComputedStyle(aElement, [&](auto const* style) {
    SVGGEOMETRYPROPERTY_EVAL_ALL(*aRes = ResolveWith<Tags>(*style, aElement));
  });

  if (res) {
    return true;
  }

  SVGGEOMETRYPROPERTY_EVAL_ALL(*aRes = 0);
  return false;
}

#undef SVGGEOMETRYPROPERTY_EVAL_ALL

nsCSSUnit SpecifiedUnitTypeToCSSUnit(uint8_t aSpecifiedUnit);
nsCSSPropertyID AttrEnumToCSSPropId(const SVGElement* aElement,
                                    uint8_t aAttrEnum);

bool IsNonNegativeGeometryProperty(nsCSSPropertyID aProp);
bool ElementMapsLengthsToStyle(SVGElement const* aElement);

}  // namespace SVGGeometryProperty
}  // namespace dom
}  // namespace mozilla

#endif