gecko-dev/layout/style/nsCSSParser.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */
/* parsing of CSS stylesheets, based on a token stream from the CSS scanner */
#ifndef nsCSSParser_h___
#define nsCSSParser_h___
#include "mozilla/Attributes.h"
#include "mozilla/css/Loader.h"
#include "nsCSSPropertyID.h"
#include "nsCSSScanner.h"
#include "nsCOMPtr.h"
#include "nsAutoPtr.h"
#include "nsStringFwd.h"
#include "nsTArrayForwardDeclare.h"
class nsIPrincipal;
class nsIURI;
struct nsCSSSelectorList;
class nsMediaList;
class nsMediaQuery;
class nsCSSKeyframeRule;
class nsCSSValue;
struct nsRuleData;
namespace mozilla {
class CSSStyleSheet;
class CSSVariableValues;
namespace css {
class Rule;
class Declaration;
class StyleRule;
enum class SupportsParsingSettings {
Normal,
ImpliedParentheses
};
} // namespace css
} // namespace mozilla
// Interface to the css parser.
class MOZ_STACK_CLASS nsCSSParser {
public:
explicit nsCSSParser(mozilla::css::Loader* aLoader = nullptr,
mozilla::CSSStyleSheet* aSheet = nullptr);
~nsCSSParser();
static void Shutdown();
private:
nsCSSParser(nsCSSParser const&) = delete;
nsCSSParser& operator=(nsCSSParser const&) = delete;
public:
/**
* Parse aInput into the stylesheet that was previously passed to the
* constructor. Calling this method on an nsCSSParser that had nullptr
* passed in as the style sheet is an error.
*
* @param aInput the data to parse
* @param aSheetURL the URI to use as the sheet URI (for error reporting).
* This must match the URI of the sheet passed to
* the constructor.
* @param aBaseURI the URI to use for relative URI resolution
* @param aSheetPrincipal the principal of the stylesheet. This must match
* the principal of the sheet passed to the
* constructor.
* @param aLineNumber the line number of the first line of the sheet.
* @param aReusableSheets style sheets that can be reused by an @import.
* This can be nullptr.
*/
nsresult ParseSheet(const nsAString& aInput,
nsIURI* aSheetURL,
nsIURI* aBaseURI,
nsIPrincipal* aSheetPrincipal,
uint32_t aLineNumber,
mozilla::css::LoaderReusableStyleSheets* aReusableSheets =
nullptr);
// Parse HTML style attribute or its equivalent in other markup
// languages. aBaseURL is the base url to use for relative links in
// the declaration.
already_AddRefed<mozilla::css::Declaration>
ParseStyleAttribute(const nsAString& aAttributeValue,
nsIURI* aDocURL,
nsIURI* aBaseURL,
nsIPrincipal* aNodePrincipal);
// Parse the body of a declaration block. Very similar to
// ParseStyleAttribute, but used under different circumstances.
// The contents of aDeclaration will be erased and replaced with the
// results of parsing; aChanged will be set true if the aDeclaration
// argument was modified.
nsresult ParseDeclarations(const nsAString& aBuffer,
nsIURI* aSheetURL,
nsIURI* aBaseURL,
nsIPrincipal* aSheetPrincipal,
mozilla::css::Declaration* aDeclaration,
bool* aChanged);
nsresult ParseRule(const nsAString& aRule,
nsIURI* aSheetURL,
nsIURI* aBaseURL,
nsIPrincipal* aSheetPrincipal,
mozilla::css::Rule** aResult);
// Parse the value of a single CSS property, and add or replace that
// property in aDeclaration.
//
// SVG "mapped attributes" (which correspond directly to CSS
// properties) are parsed slightly differently from regular CSS; in
// particular, units may be omitted from <length>. The 'aIsSVGMode'
// argument controls this quirk. Note that this *only* applies to
// mapped attributes, not inline styles or full style sheets in SVG.
void ParseProperty(const nsCSSPropertyID aPropID,
const nsAString& aPropValue,
nsIURI* aSheetURL,
nsIURI* aBaseURL,
nsIPrincipal* aSheetPrincipal,
mozilla::css::Declaration* aDeclaration,
bool* aChanged,
bool aIsImportant,
bool aIsSVGMode = false);
// Same as ParseProperty but returns an nsCSSValue in aResult
// rather than storing the property in a Declaration. aPropID
// must be a longhand property.
void ParseLonghandProperty(const nsCSSPropertyID aPropID,
const nsAString& aPropValue,
nsIURI* aSheetURL,
nsIURI* aBaseURL,
nsIPrincipal* aSheetPrincipal,
nsCSSValue& aResult);
// Parse the value of a CSS transform property. Returns
// whether the value was successfully parsed. If
// aDisallowRelativeValues is true then this method will
// only successfully parse if all values are numbers or
// have non-relative dimensions.
bool ParseTransformProperty(const nsAString& aPropValue,
bool aDisallowRelativeValues,
nsCSSValue& aResult);
// The same as ParseProperty but for a variable.
void ParseVariable(const nsAString& aVariableName,
const nsAString& aPropValue,
nsIURI* aSheetURL,
nsIURI* aBaseURL,
nsIPrincipal* aSheetPrincipal,
mozilla::css::Declaration* aDeclaration,
bool* aChanged,
bool aIsImportant);
/**
* Parse aBuffer into a media list |aMediaList|, which must be non-null,
* replacing its current contents. |aURL| and |aLineNumber| are used for error
* reporting.
*/
void ParseMediaList(const nsAString& aBuffer,
nsIURI* aURL,
uint32_t aLineNumber,
nsMediaList* aMediaList);
/*
* Parse aBuffer into a list of media queries and their associated values,
* according to grammar:
* <source-size-list> = <source-size>#?
* <source-size> = <media-condition>? <length>
*
* Note that this grammar is top-level: The function expects to consume the
* entire input buffer.
*
* Output arrays overwritten (not appended) and are cleared in case of parse
* failure.
*/
bool ParseSourceSizeList(const nsAString& aBuffer,
nsIURI* aURI, // for error reporting
uint32_t aLineNumber, // for error reporting
InfallibleTArray< nsAutoPtr<nsMediaQuery> >& aQueries,
InfallibleTArray<nsCSSValue>& aValues);
/**
* Parse aBuffer into a nsCSSValue |aValue|. Will return false
* if aBuffer is not a valid font family list.
*/
bool ParseFontFamilyListString(const nsAString& aBuffer,
nsIURI* aURL,
uint32_t aLineNumber,
nsCSSValue& aValue);
/**
* Parse aBuffer into a nsCSSValue |aValue|. Will return false
* if aBuffer is not a valid CSS color specification.
* One can use nsRuleNode::ComputeColor to compute an nscolor from
* the returned nsCSSValue.
*/
bool ParseColorString(const nsAString& aBuffer,
nsIURI* aURL,
uint32_t aLineNumber,
nsCSSValue& aValue,
bool aSuppressErrors = false);
/**
* Parse aBuffer into a nsCSSValue |aValue|. Will return false
* if aBuffer is not a valid CSS margin specification.
* One can use nsRuleNode::GetRectValue to compute an nsCSSRect from
* the returned nsCSSValue.
*/
bool ParseMarginString(const nsAString& aBuffer,
nsIURI* aURL,
uint32_t aLineNumber,
nsCSSValue& aValue,
bool aSuppressErrors = false);
/**
* Parse aBuffer into a selector list. On success, caller must
* delete *aSelectorList when done with it.
*/
nsresult ParseSelectorString(const nsAString& aSelectorString,
nsIURI* aURL,
uint32_t aLineNumber,
nsCSSSelectorList** aSelectorList);
/*
* Parse a keyframe rule (which goes inside an @keyframes rule).
* Return it if the parse was successful.
*/
already_AddRefed<nsCSSKeyframeRule>
ParseKeyframeRule(const nsAString& aBuffer,
nsIURI* aURL,
uint32_t aLineNumber);
/*
* Parse a selector list for a keyframe rule. Return whether
* the parse succeeded.
*/
bool ParseKeyframeSelectorString(const nsAString& aSelectorString,
nsIURI* aURL,
uint32_t aLineNumber,
InfallibleTArray<float>& aSelectorList);
/**
* Parse a property and value and return whether the property/value pair
* is supported.
*/
bool EvaluateSupportsDeclaration(const nsAString& aProperty,
const nsAString& aValue,
nsIURI* aDocURL,
nsIURI* aBaseURL,
nsIPrincipal* aDocPrincipal);
/**
* Parse an @supports condition and returns the result of evaluating the
* condition.
*
* The one-argument CSS.supports() allows for providing a parentheses-less
* @supports condition, i.e. the parentheses are "implied". In such a case,
* aSettings can be set to ImpliedParentheses.
*/
bool EvaluateSupportsCondition(const nsAString& aCondition,
nsIURI* aDocURL,
nsIURI* aBaseURL,
nsIPrincipal* aDocPrincipal,
mozilla::css::SupportsParsingSettings aSettings
= mozilla::css::SupportsParsingSettings::Normal);
typedef void (*VariableEnumFunc)(const nsAString&, void*);
/**
* Parses aPropertyValue as a property value and calls aFunc for each
* variable reference that is found. Returns false if there was
* a syntax error in the use of variable references.
*/
bool EnumerateVariableReferences(const nsAString& aPropertyValue,
VariableEnumFunc aFunc,
void* aData);
/**
* Parses aPropertyValue as a property value and resolves variable references
* using the values in aVariables.
*/
bool ResolveVariableValue(const nsAString& aPropertyValue,
const mozilla::CSSVariableValues* aVariables,
nsString& aResult,
nsCSSTokenSerializationType& aFirstToken,
nsCSSTokenSerializationType& aLastToken);
/**
* Parses a string as a CSS token stream value for particular property,
* resolving any variable references. The parsed property value is stored
* in the specified nsRuleData object. If aShorthandPropertyID has a value
* other than eCSSProperty_UNKNOWN, this is the property that will be parsed;
* otherwise, aPropertyID will be parsed. Either way, only aPropertyID,
* a longhand property, will be copied over to the rule data.
*
* If the property cannot be parsed, it will be treated as if 'initial' or
* 'inherit' were specified, for non-inherited and inherited properties
* respectively.
*/
void ParsePropertyWithVariableReferences(
nsCSSPropertyID aPropertyID,
nsCSSPropertyID aShorthandPropertyID,
const nsAString& aValue,
const mozilla::CSSVariableValues* aVariables,
nsRuleData* aRuleData,
nsIURI* aDocURL,
nsIURI* aBaseURL,
nsIPrincipal* aDocPrincipal,
mozilla::CSSStyleSheet* aSheet,
uint32_t aLineNumber,
uint32_t aLineOffset);
/**
* Parses a string as a counter-style name. Returns nullptr if fails.
*/
already_AddRefed<nsIAtom> ParseCounterStyleName(const nsAString& aBuffer,
nsIURI* aURL);
bool ParseCounterDescriptor(nsCSSCounterDesc aDescID,
const nsAString& aBuffer,
nsIURI* aSheetURL,
nsIURI* aBaseURL,
nsIPrincipal* aSheetPrincipal,
nsCSSValue& aValue);
bool ParseFontFaceDescriptor(nsCSSFontDesc aDescID,
const nsAString& aBuffer,
nsIURI* aSheetURL,
nsIURI* aBaseURL,
nsIPrincipal* aSheetPrincipal,
nsCSSValue& aValue);
// Check whether a given value can be applied to a property.
bool IsValueValidForProperty(const nsCSSPropertyID aPropID,
const nsAString& aPropValue);
// Return the default value to be used for -moz-control-character-visibility,
// from preferences (cached by our Startup(), so that both nsStyleText and
// nsRuleNode can have fast access to it).
static uint8_t ControlCharVisibilityDefault();
protected:
// This is a CSSParserImpl*, but if we expose that type name in this
// header, we can't put the type definition (in nsCSSParser.cpp) in
// the anonymous namespace.
void* mImpl;
};
#endif /* nsCSSParser_h___ */