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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
commit | 6bf0a5cb5034a7e684dcc3500e841785237ce2dd (patch) | |
tree | a68f146d7fa01f0134297619fbe7e33db084e0aa /layout/style/ImportScanner.h | |
parent | Initial commit. (diff) | |
download | thunderbird-upstream.tar.xz thunderbird-upstream.zip |
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | layout/style/ImportScanner.h | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/layout/style/ImportScanner.h b/layout/style/ImportScanner.h new file mode 100644 index 0000000000..ff1755fb8b --- /dev/null +++ b/layout/style/ImportScanner.h @@ -0,0 +1,94 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=2 sw=2 et tw=78: */ +/* 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_ImportScanner_h +#define mozilla_ImportScanner_h + +/* A simple best-effort scanner for @import rules for the HTML parser */ + +#include "nsString.h" +#include "nsTArray.h" + +namespace mozilla { + +struct ImportScanner final { + ImportScanner() = default; + + // Called when a <style> element starts. + // + // Note that this function cannot make assumptions about the internal state, + // as you can nest <svg:style> elements. + void Start(); + + // Called when a <style> element ends. Returns the list of URLs scanned. + nsTArray<nsString> Stop(); + + // Whether Scan() should be called. + bool ShouldScan() const { + return mState != State::OutsideOfStyleElement && mState != State::Done; + } + + // Scan() should be called when text content is parsed, and returns an array + // of found URLs, if any. + // + // Asserts ShouldScan() returns true. + nsTArray<nsString> Scan(Span<const char16_t> aFragment); + + private: + enum class State { + // Initial state, doesn't scan anything until Start() is called. + OutsideOfStyleElement, + // In an idle state during the stylesheet scanning, either at the + // beginning or after parsing a rule. + Idle, + // We've seen a '/' character, but not the '*' yet, so we don't know if + // it's a comment. + MaybeAtCommentStart, + // We're inside a comment. + AtComment, + // We've seen a '*' while we're in a comment, but we don't now yet whether + // '/' comes afterwards (thus ending the comment). + MaybeAtCommentEnd, + // We're parsing the '@' rule name. + AtRuleName, + // We're parsing the '@' rule value. + AtRuleValue, + // We're parsing the '@' rule value and we've seen the delimiter (quote or + // url() function) that encloses the url. + AtRuleValueDelimited, + // We've seen the url, but haven't seen the ';' finishing the rule yet. + AfterRuleValue, + // We've seen anything that is not an @import or a @charset rule, and thus + // further @import / @charset should not be parsed. + Done, + }; + + void ResetState(); + void EmitUrl(); + [[nodiscard]] State Scan(char16_t aChar); + + static constexpr const uint32_t kMaxRuleNameLength = 7; // (charset, import) + + State mState = State::OutsideOfStyleElement; + nsAutoStringN<kMaxRuleNameLength> mRuleName; + nsAutoStringN<128> mRuleValue; + nsAutoStringN<128> mAfterRuleValue; + nsTArray<nsString> mUrlsFound; + + // This is conceptually part of the AtRuleValue* / AfterRuleValue states, + // and serves to differentiate between @import (where we actually care about + // the value) and @charset (where we don't). It's just more convenient this + // way than having separate states for them. + bool mInImportRule = false; + // If we're in the AtRuleValueDelimited state, what is the closing character + // that will end the value. This is either a parenthesis (for unquoted + // urls), or a quote, either single or double. + char16_t mUrlValueDelimiterClosingChar = 0; +}; + +} // namespace mozilla + +#endif |