gecko-dev/layout/style/SheetParsingMode.h

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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 mozilla_css_SheetParsingMode_h
#define mozilla_css_SheetParsingMode_h
#include <stdint.h>
namespace mozilla {
namespace css {
/**
* Enum defining the mode in which a sheet is to be parsed. This is
* usually, but not always, the same as the cascade level at which the
* sheet will apply (see nsStyleSet.h). Most of the Loader APIs only
* support loading of author sheets.
*
* Author sheets are the normal case: styles embedded in or linked
* from HTML pages. They are also the most restricted.
*
* User sheets can do anything author sheets can do, and also get
* access to a few CSS extensions that are not yet suitable for
* exposure on the public Web, but are very useful for expressing
* user style overrides, such as @-moz-document rules.
*
* XXX: eUserSheetFeatures was added in bug 1035091, but some patches in
* that bug never landed to use this enum value. Currently, all the features
* in user sheet are also available in author sheet.
*
* Agent sheets have access to all author- and user-sheet features
* plus more extensions that are necessary for internal use but,
* again, not yet suitable for exposure on the public Web. Some of
* these are outright unsafe to expose; in particular, incorrect
* styling of anonymous box pseudo-elements can violate layout
* invariants.
*
* Agent sheets that do not use any unsafe rules could use
* eSafeAgentSheetFeatures when creating the sheet. This enum value allows
* Servo backend to recognize the sheets as the agent level, but Gecko
* backend will parse it under _author_ level.
*/
enum SheetParsingMode : uint8_t {
eAuthorSheetFeatures = 0,
eUserSheetFeatures,
eAgentSheetFeatures,
eSafeAgentSheetFeatures,
};
} // namespace css
} // namespace mozilla
#endif // mozilla_css_SheetParsingMode_h