layout/style/ServoCSSParser.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 /* CSS parsing utility functions */
   8
   9 #ifndef mozilla_ServoCSSParser_h
  10 #define mozilla_ServoCSSParser_h
  11
  12 #include "mozilla/AlreadyAddRefed.h"
  13 #include "mozilla/gfx/Matrix.h"
  14 #include "nsColor.h"
  15 #include "nsCSSPropertyID.h"
  16 #include "nsDOMCSSDeclaration.h"
  17 #include "nsStringFwd.h"
  18
  19 struct nsCSSRect;
  20 template <class T>
  21 class RefPtr;
  22
  23 namespace mozilla {
  24
  25 struct AnimatedPropertyID;
  26 class ServoStyleSet;
  27 struct URLExtraData;
  28 struct StyleFontFamilyList;
  29 struct StyleFontStretch;
  30 struct StyleFontWeight;
  31 struct StyleFontStyle;
  32 struct StyleLockedDeclarationBlock;
  33 struct StyleParsingMode;
  34 union StyleComputedFontStyleDescriptor;
  35
  36 template <typename Integer, typename Number, typename LinearStops>
  37 struct StyleTimingFunction;
  38 struct StylePiecewiseLinearFunction;
  39 using StyleComputedTimingFunction =
  40     StyleTimingFunction<int32_t, float, StylePiecewiseLinearFunction>;
  41
  42 namespace css {
  43 class Loader;
  44 }
  45
  46 namespace dom {
  47 class Document;
  48 }
  49
  50 class ServoCSSParser {
  51  public:
  52   using ParsingEnvironment = nsDOMCSSDeclaration::ParsingEnvironment;
  53
  54   /**
  55    * Returns whether the specified string can be parsed as a valid CSS
  56    * <color> value.
  57    *
  58    * This includes Mozilla-specific keywords such as -moz-default-color.
  59    */
  60   static bool IsValidCSSColor(const nsACString& aValue);
  61
  62   /**
  63    * Computes an nscolor from the given CSS <color> value.
  64    *
  65    * @param aStyleSet The style set whose nsPresContext will be used to
  66    *   compute system colors and other special color values.
  67    * @param aCurrentColor The color value that currentcolor should compute to.
  68    * @param aValue The CSS <color> value.
  69    * @param aResultColor The resulting computed color value.
  70    * @param aWasCurrentColor Whether aValue was currentcolor. Can be nullptr
  71    *   if the caller doesn't care.
  72    * @param aLoader The CSS loader for document we're parsing a color for,
  73    *   so that parse errors can be reported to the console. If nullptr, errors
  74    *   won't be reported to the console.
  75    * @return Whether aValue was successfully parsed and aResultColor was set.
  76    */
  77   static bool ComputeColor(ServoStyleSet* aStyleSet, nscolor aCurrentColor,
  78                            const nsACString& aValue, nscolor* aResultColor,
  79                            bool* aWasCurrentColor = nullptr,
  80                            css::Loader* aLoader = nullptr);
  81
  82   /**
  83   * Takes a CSS <color> and convert it to another color space.
  84   *
  85   * @param aStyleSet The style set whose nsPresContext will be used to
  86   *   compute system colors and other special color values.
  87   * @param aFromColor The CSS <color> we use to convert from.
  88   * @param aToColorSpace The CSS <color-space> to convert the color into.
  89   * @param aResultColor The resulting converted color value.
  90   * @param aResultAdjusted Whether the color was adjusted to fit into the SRGB
  91       color space.
  92   * @param aLoader The CSS loader for document we're parsing a color for,
  93   *   so that parse errors can be reported to the console. If nullptr, errors
  94   *   won't be reported to the console.
  95   * @return Whether aFromColor and aToColorSpace was successfully parsed and
  96   *   aResultColor and aResultAdjusted was set.
  97   */
  98   static bool ColorTo(const nsACString& aFromColor,
  99                       const nsACString& aToColorSpace, nsACString* aResultColor,
 100                       nsTArray<float>* aResultComponents, bool* aResultAdjusted,
 101                       css::Loader* aLoader = nullptr);
 102
 103   /**
 104    * Parse a string representing a CSS property value into a
 105    * StyleLockedDeclarationBlock.
 106    *
 107    * @param aProperty The property to be parsed.
 108    * @param aValue The specified value.
 109    * @param aParsingEnvironment All the parsing environment data we need.
 110    * @param aParsingMode The parsing mode we apply.
 111    * @return The parsed value as a StyleLockedDeclarationBlock. We put the value
 112    *   in a declaration block since that is how we represent specified values
 113    *   in Servo.
 114    */
 115   static already_AddRefed<StyleLockedDeclarationBlock> ParseProperty(
 116       nsCSSPropertyID aProperty, const nsACString& aValue,
 117       const ParsingEnvironment& aParsingEnvironment,
 118       const StyleParsingMode& aParsingMode);
 119   static already_AddRefed<StyleLockedDeclarationBlock> ParseProperty(
 120       const AnimatedPropertyID& aProperty, const nsACString& aValue,
 121       const ParsingEnvironment& aParsingEnvironment,
 122       const StyleParsingMode& aParsingMode);
 123
 124   /**
 125    * Parse a animation timing function.
 126    *
 127    * @param aValue The specified value.
 128    * @param aResult The output timing function. (output)
 129    * @return Whether the value was successfully parsed.
 130    */
 131   static bool ParseEasing(const nsACString& aValue,
 132                           StyleComputedTimingFunction& aResult);
 133
 134   /**
 135    * Parse a specified transform list into a gfx matrix.
 136    *
 137    * @param aValue The specified value.
 138    * @param aContains3DTransform The output flag indicates whether this is any
 139    *   3d transform function. (output)
 140    * @param aResult The output matrix. (output)
 141    * @return Whether the value was successfully parsed.
 142    */
 143   static bool ParseTransformIntoMatrix(const nsACString& aValue,
 144                                        bool& aContains3DTransform,
 145                                        gfx::Matrix4x4& aResult);
 146
 147   /**
 148    * Parse a font shorthand for FontFaceSet matching, so we only care about
 149    * FontFamily, FontStyle, FontStretch, and FontWeight.
 150    *
 151    * @param aValue The specified value.
 152    * @param aUrl The parser url extra data.
 153    * @param aList The parsed FontFamily list. (output)
 154    * @param aStyle The parsed FontStyle. (output)
 155    * @param aStretch The parsed FontStretch. (output)
 156    * @param aWeight The parsed FontWeight. (output)
 157    * @param aSize If non-null, returns the parsed font size. (output)
 158    * @param aSmallCaps If non-null, whether small-caps was specified (output)
 159    * @return Whether the value was successfully parsed.
 160    */
 161   static bool ParseFontShorthandForMatching(
 162       const nsACString& aValue, URLExtraData* aUrl, StyleFontFamilyList& aList,
 163       StyleFontStyle& aStyle, StyleFontStretch& aStretch,
 164       StyleFontWeight& aWeight, float* aSize = nullptr,
 165       bool* aSmallCaps = nullptr);
 166
 167   /**
 168    * Get a URLExtraData from a document.
 169    */
 170   static already_AddRefed<URLExtraData> GetURLExtraData(dom::Document*);
 171
 172   /**
 173    * Get a ParsingEnvironment from a document.
 174    */
 175   static ParsingEnvironment GetParsingEnvironment(dom::Document*);
 176 };
 177
 178 }  // namespace mozilla
 179
 180 #endif  // mozilla_ServoCSSParser_h