gecko-dev/layout/style/nsStyleUtil.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/. */
#ifndef nsStyleUtil_h___
#define nsStyleUtil_h___
#include "nsCoord.h"
#include "nsCSSPropertyID.h"
#include "nsString.h"
#include "nsTArrayForwardDeclare.h"
#include "gfxFontFamilyList.h"
#include "nsStyleStruct.h"
#include "nsCRT.h"
class nsCSSValue;
class nsStringComparator;
class nsStyleCoord;
class nsIContent;
class nsIPrincipal;
class nsIURI;
struct gfxFontFeature;
struct gfxAlternateValue;
struct nsCSSValueList;
// Style utility functions
class nsStyleUtil {
public:
static bool DashMatchCompare(const nsAString& aAttributeValue,
const nsAString& aSelectorValue,
const nsStringComparator& aComparator);
static bool ValueIncludes(const nsSubstring& aValueList,
const nsSubstring& aValue,
const nsStringComparator& aComparator);
// Append a quoted (with 'quoteChar') and escaped version of aString
// to aResult. 'quoteChar' must be ' or ".
static void AppendEscapedCSSString(const nsAString& aString,
nsAString& aResult,
char16_t quoteChar = '"');
// Append the identifier given by |aIdent| to |aResult|, with
// appropriate escaping so that it can be reparsed to the same
// identifier. An exception is if aIdent contains U+0000, which
// will be escaped as U+FFFD and then reparsed back to U+FFFD.
static void AppendEscapedCSSIdent(const nsAString& aIdent,
nsAString& aResult);
static void
AppendEscapedCSSFontFamilyList(const mozilla::FontFamilyList& aFamilyList,
nsAString& aResult);
// Append a bitmask-valued property's value(s) (space-separated) to aResult.
static void AppendBitmaskCSSValue(nsCSSPropertyID aProperty,
int32_t aMaskedValue,
int32_t aFirstMask,
int32_t aLastMask,
nsAString& aResult);
static void AppendAngleValue(const nsStyleCoord& aValue, nsAString& aResult);
static void AppendPaintOrderValue(uint8_t aValue, nsAString& aResult);
static void AppendFontTagAsString(uint32_t aTag, nsAString& aResult);
static void AppendFontFeatureSettings(const nsTArray<gfxFontFeature>& aFeatures,
nsAString& aResult);
static void AppendFontFeatureSettings(const nsCSSValue& src,
nsAString& aResult);
static void AppendFontVariationSettings(const nsTArray<gfxFontVariation>& aVariations,
nsAString& aResult);
static void AppendFontVariationSettings(const nsCSSValue& src,
nsAString& aResult);
static void AppendUnicodeRange(const nsCSSValue& aValue, nsAString& aResult);
static void AppendCSSNumber(float aNumber, nsAString& aResult)
{
aResult.AppendFloat(aNumber);
}
static void AppendStepsTimingFunction(nsTimingFunction::Type aType,
uint32_t aSteps,
nsAString& aResult);
static void AppendFramesTimingFunction(uint32_t aFrames,
nsAString& aResult);
static void AppendCubicBezierTimingFunction(float aX1, float aY1,
float aX2, float aY2,
nsAString& aResult);
static void AppendCubicBezierKeywordTimingFunction(
nsTimingFunction::Type aType,
nsAString& aResult);
static void AppendSerializedFontSrc(const nsCSSValue& aValue,
nsAString& aResult);
// convert bitmask value to keyword name for a functional alternate
static void GetFunctionalAlternatesName(int32_t aFeature,
nsAString& aFeatureName);
// Append functional font-variant-alternates values to string
static void
SerializeFunctionalAlternates(const nsTArray<gfxAlternateValue>& aAlternates,
nsAString& aResult);
// List of functional font-variant-alternates values to feature/value pairs
static void
ComputeFunctionalAlternates(const nsCSSValueList* aList,
nsTArray<gfxAlternateValue>& aAlternateValues);
/*
* Convert an author-provided floating point number to an integer (0
* ... 255) appropriate for use in the alpha component of a color.
*/
static uint8_t FloatToColorComponent(float aAlpha)
{
NS_ASSERTION(0.0 <= aAlpha && aAlpha <= 1.0, "out of range");
return NSToIntRound(aAlpha * 255);
}
/*
* Convert the alpha component of an nscolor (0 ... 255) to the
* floating point number with the least accurate *decimal*
* representation that is converted to that color.
*
* Should be used only by serialization code.
*/
static float ColorComponentToFloat(uint8_t aAlpha);
/*
* Does this child count as significant for selector matching?
*/
static bool IsSignificantChild(nsIContent* aChild,
bool aTextIsSignificant,
bool aWhitespaceIsSignificant);
/**
* Returns true if our object-fit & object-position properties might cause
* a replaced element's contents to overflow its content-box (requiring
* clipping), or false if we can be sure that this won't happen.
*
* This lets us optimize by skipping clipping when we can tell it's
* unnecessary (particularly with the default values of these properties).
*
* @param aStylePos The nsStylePosition whose object-fit & object-position
* properties should be checked for potential overflow.
* @return false if we can be sure that the object-fit & object-position
* properties on 'aStylePos' cannot cause a replaced element's
* contents to overflow its content-box. Otherwise (if overflow is
* is possible), returns true.
*/
static bool ObjectPropsMightCauseOverflow(const nsStylePosition* aStylePos);
/*
* Does this principal have a CSP that blocks the application of
* inline styles? Returns false if application of the style should
* be blocked.
*
* @param aContent
* The <style> element that the caller wants to know whether to honor.
* Included to check the nonce attribute if one is provided. Allowed to
* be null, if this is for something other than a <style> element (in
* which case nonces won't be checked).
* @param aPrincipal
* The principal of the of the document (*not* of the style sheet).
* The document's principal is where any Content Security Policy that
* should be used to block or allow inline styles will be located.
* @param aSourceURI
* URI of document containing inline style (for reporting violations)
* @param aLineNumber
* Line number of inline style element in the containing document (for
* reporting violations)
* @param aStyleText
* Contents of the inline style element (for reporting violations)
* @param aRv
* Return error code in case of failure
* @return
* Does CSP allow application of the specified inline style?
*/
static bool CSPAllowsInlineStyle(nsIContent* aContent,
nsIPrincipal* aPrincipal,
nsIURI* aSourceURI,
uint32_t aLineNumber,
const nsSubstring& aStyleText,
nsresult* aRv);
template<size_t N>
static bool MatchesLanguagePrefix(const char16_t* aLang, size_t aLen,
const char16_t (&aPrefix)[N])
{
return !nsCRT::strncmp(aLang, aPrefix, N - 1) &&
(aLen == N - 1 || aLang[N - 1] == '-');
}
template<size_t N>
static bool MatchesLanguagePrefix(const nsIAtom* aLang,
const char16_t (&aPrefix)[N])
{
MOZ_ASSERT(aLang);
return MatchesLanguagePrefix(aLang->GetUTF16String(),
aLang->GetLength(), aPrefix);
}
template<size_t N>
static bool MatchesLanguagePrefix(const nsAString& aLang,
const char16_t (&aPrefix)[N])
{
return MatchesLanguagePrefix(aLang.Data(), aLang.Length(), aPrefix);
}
};
#endif /* nsStyleUtil_h___ */