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Diffstat (limited to 'layout/style/nsStyleUtil.h')
| -rw-r--r-- | layout/style/nsStyleUtil.h | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/layout/style/nsStyleUtil.h b/layout/style/nsStyleUtil.h new file mode 100644 index 0000000000..990996fdbc --- /dev/null +++ b/layout/style/nsStyleUtil.h @@ -0,0 +1,175 @@ +/* -*- 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 nsStyleUtil_h___ +#define nsStyleUtil_h___ + +#include "nsCoord.h" +#include "nsCSSPropertyID.h" +#include "nsTArrayForwardDeclare.h" +#include "nsStringFwd.h" +#include "nsCRT.h" +#include "nsColor.h" +#include "nsGkAtoms.h" + +class nsCSSValue; +class nsIContent; +class nsIPrincipal; +class nsIURI; +struct gfxFontFeature; +struct nsCSSKTableEntry; +struct nsCSSValueList; +struct nsStylePosition; + +namespace mozilla { +namespace dom { +class Document; +class Element; +} // namespace dom +} // namespace mozilla + +// Style utility functions +class nsStyleUtil { + public: + static bool DashMatchCompare(const nsAString& aAttributeValue, + const nsAString& aSelectorValue, + const nsStringComparator& aComparator); + + static bool LangTagCompare(const nsACString& aAttributeValue, + const nsACString& aSelectorValue); + + static bool ValueIncludes(const nsAString& aValueList, + const nsAString& 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); + + public: + static void AppendCSSNumber(float aNumber, nsAString& aResult) { + aResult.AppendFloat(aNumber); + } + + /* + * 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 static_cast<uint8_t>(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); + + /** + * GetSerializedColorValue() computes serialized color value of aColor and + * returns it with aSerializedColor. + * https://drafts.csswg.org/cssom/#serialize-a-css-component-value + */ + static void GetSerializedColorValue(nscolor aColor, + nsAString& aSerializedColor); + + /* + * Does this child count as significant for selector matching? + */ + static bool IsSignificantChild(nsIContent* aChild, + bool aWhitespaceIsSignificant); + + /* + * Thread-safe version of IsSignificantChild() + */ + static bool ThreadSafeIsSignificantChild(const nsIContent* aChild, + 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 the document 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 aDocument + * The document containing the inline style (for querying the CSP); + * @param aTriggeringPrincipal + * The principal of the scripted caller which added the inline + * stylesheet, or null if no scripted caller can be identified. + * @param aLineNumber + * Line number of inline style element in the containing document (for + * reporting violations) + * @param aColumnNumber + * Column 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(mozilla::dom::Element* aContent, + mozilla::dom::Document* aDocument, + nsIPrincipal* aTriggeringPrincipal, + uint32_t aLineNumber, uint32_t aColumnNumber, + const nsAString& aStyleText, nsresult* aRv); + + template <size_t N> + static bool MatchesLanguagePrefix(const char16_t* aLang, size_t aLen, + const char16_t (&aPrefix)[N]) { + return !NS_strncmp(aLang, aPrefix, N - 1) && + (aLen == N - 1 || aLang[N - 1] == '-'); + } + + template <size_t N> + static bool MatchesLanguagePrefix(const nsAtom* 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___ */ |