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+/* -*- 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___ */