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 class ServoStyleSet;
  26 struct URLExtraData;
  27 struct StyleFontFamilyList;
  28 struct StyleFontStretch;
  29 struct StyleFontWeight;
  30 struct StyleFontStyle;
  31 struct StyleLockedDeclarationBlock;
  32 struct StyleParsingMode;
  33 union StyleComputedFontStyleDescriptor;
  34
  35 template <typename Integer, typename Number, typename LinearStops>
  36 struct StyleTimingFunction;
  37 struct StylePiecewiseLinearFunction;
  38 using StyleComputedTimingFunction =
  39     StyleTimingFunction<int32_t, float, StylePiecewiseLinearFunction>;
  40
  41 namespace css {
  42 class Loader;
  43 }
  44
  45 namespace dom {
  46 class Document;
  47 }
  48
  49 class ServoCSSParser {
  50  public:
  51   using ParsingEnvironment = nsDOMCSSDeclaration::ParsingEnvironment;
  52
  53   /**
  54    * Returns whether the specified string can be parsed as a valid CSS
  55    * <color> value.
  56    *
  57    * This includes Mozilla-specific keywords such as -moz-default-color.
  58    */
  59   static bool IsValidCSSColor(const nsACString& aValue);
  60
  61   /**
  62    * Computes an nscolor from the given CSS <color> value.
  63    *
  64    * @param aStyleSet The style set whose nsPresContext will be used to
  65    *   compute system colors and other special color values.
  66    * @param aCurrentColor The color value that currentcolor should compute to.
  67    * @param aValue The CSS <color> value.
  68    * @param aResultColor The resulting computed color value.
  69    * @param aWasCurrentColor Whether aValue was currentcolor. Can be nullptr
  70    *   if the caller doesn't care.
  71    * @param aLoader The CSS loader for document we're parsing a color for,
  72    *   so that parse errors can be reported to the console. If nullptr, errors
  73    *   won't be reported to the console.
  74    * @return Whether aValue was successfully parsed and aResultColor was set.
  75    */
  76   static bool ComputeColor(ServoStyleSet* aStyleSet, nscolor aCurrentColor,
  77                            const nsACString& aValue, nscolor* aResultColor,
  78                            bool* aWasCurrentColor = nullptr,
  79                            css::Loader* aLoader = nullptr);
  80
  81   /**
  82    * Parse a string representing a CSS property value into a
  83    * StyleLockedDeclarationBlock.
  84    *
  85    * @param aProperty The property to be parsed.
  86    * @param aValue The specified value.
  87    * @param aParsingEnvironment All the parsing environment data we need.
  88    * @param aParsingMode The parsing mode we apply.
  89    * @return The parsed value as a StyleLockedDeclarationBlock. We put the value
  90    *   in a declaration block since that is how we represent specified values
  91    *   in Servo.
  92    */
  93   static already_AddRefed<StyleLockedDeclarationBlock> ParseProperty(
  94       nsCSSPropertyID aProperty, const nsACString& aValue,
  95       const ParsingEnvironment& aParsingEnvironment,
  96       const StyleParsingMode& aParsingMode);
  97
  98   /**
  99    * Parse a animation timing function.
 100    *
 101    * @param aValue The specified value.
 102    * @param aResult The output timing function. (output)
 103    * @return Whether the value was successfully parsed.
 104    */
 105   static bool ParseEasing(const nsACString& aValue,
 106                           StyleComputedTimingFunction& aResult);
 107
 108   /**
 109    * Parse a specified transform list into a gfx matrix.
 110    *
 111    * @param aValue The specified value.
 112    * @param aContains3DTransform The output flag indicates whether this is any
 113    *   3d transform function. (output)
 114    * @param aResult The output matrix. (output)
 115    * @return Whether the value was successfully parsed.
 116    */
 117   static bool ParseTransformIntoMatrix(const nsACString& aValue,
 118                                        bool& aContains3DTransform,
 119                                        gfx::Matrix4x4& aResult);
 120
 121   /**
 122    * Parse a font shorthand for FontFaceSet matching, so we only care about
 123    * FontFamily, FontStyle, FontStretch, and FontWeight.
 124    *
 125    * @param aValue The specified value.
 126    * @param aUrl The parser url extra data.
 127    * @param aList The parsed FontFamily list. (output)
 128    * @param aStyle The parsed FontStyle. (output)
 129    * @param aStretch The parsed FontStretch. (output)
 130    * @param aWeight The parsed FontWeight. (output)
 131    * @param aSize If non-null, returns the parsed font size. (output)
 132    * @param aSmallCaps If non-null, whether small-caps was specified (output)
 133    * @return Whether the value was successfully parsed.
 134    */
 135   static bool ParseFontShorthandForMatching(
 136       const nsACString& aValue, URLExtraData* aUrl, StyleFontFamilyList& aList,
 137       StyleFontStyle& aStyle, StyleFontStretch& aStretch,
 138       StyleFontWeight& aWeight, float* aSize = nullptr,
 139       bool* aSmallCaps = nullptr);
 140
 141   /**
 142    * Get a URLExtraData from a document.
 143    */
 144   static already_AddRefed<URLExtraData> GetURLExtraData(dom::Document*);
 145
 146   /**
 147    * Get a ParsingEnvironment from a document.
 148    */
 149   static ParsingEnvironment GetParsingEnvironment(dom::Document*);
 150 };
 151
 152 }  // namespace mozilla
 153
 154 #endif  // mozilla_ServoCSSParser_h