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/*
* Copyright (C) 2013 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "third_party/blink/renderer/core/html/html_dimension.h"
#include "third_party/blink/renderer/core/css/css_value_clamping_utils.h"
#include "third_party/blink/renderer/core/html/parser/html_parser_idioms.h"
#include "third_party/blink/renderer/platform/wtf/math_extras.h"
#include "third_party/blink/renderer/platform/wtf/text/character_visitor.h"
#include "third_party/blink/renderer/platform/wtf/text/parsing_utilities.h"
#include "third_party/blink/renderer/platform/wtf/text/string_to_number.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
namespace blink {
template <typename CharacterType>
static HTMLDimension ParseDimension(
base::span<const CharacterType> characters) {
// HTML5's split removes leading and trailing spaces so we need to skip the
// leading spaces here.
const size_t digits_start =
SkipWhile<CharacterType, IsASCIISpace>(characters, 0);
// This is Step 5.5. in the algorithm. Going to the last step would make the
// code less readable.
if (digits_start >= characters.size()) {
return HTMLDimension(0., HTMLDimension::kRelative);
}
size_t position =
SkipWhile<CharacterType, IsASCIIDigit>(characters, digits_start);
double value = 0.;
if (position > digits_start) {
bool ok = false;
unsigned integer_value = CharactersToUInt(
characters.subspan(digits_start, position - digits_start),
WTF::NumberParsingOptions(), &ok);
if (!ok)
return HTMLDimension(0., HTMLDimension::kRelative);
value += integer_value;
if (SkipExactly<CharacterType>(characters, '.', position)) {
Vector<CharacterType> fraction_numbers;
while (position < characters.size() &&
(IsASCIIDigit(characters[position]) ||
IsASCIISpace(characters[position]))) {
if (IsASCIIDigit(characters[position]))
fraction_numbers.push_back(characters[position]);
++position;
}
if (fraction_numbers.size()) {
double fraction_value = CharactersToUInt(
base::span(fraction_numbers), WTF::NumberParsingOptions(), &ok);
if (!ok)
return HTMLDimension(0., HTMLDimension::kRelative);
value += fraction_value /
pow(10., static_cast<double>(fraction_numbers.size()));
}
}
}
position = SkipWhile<CharacterType, IsASCIISpace>(characters, position);
HTMLDimension::HTMLDimensionType type = HTMLDimension::kAbsolute;
if (position < characters.size()) {
if (characters[position] == '*')
type = HTMLDimension::kRelative;
else if (characters[position] == '%')
type = HTMLDimension::kPercentage;
}
return HTMLDimension(value, type);
}
static HTMLDimension ParseDimension(const String& raw_token,
size_t last_parsed_index,
size_t end_of_current_token) {
return WTF::VisitCharacters(
raw_token, [last_parsed_index, end_of_current_token](auto chars) {
return ParseDimension(chars.subspan(
last_parsed_index, end_of_current_token - last_parsed_index));
});
}
// This implements the "rules for parsing a list of dimensions" per HTML5.
// http://www.whatwg.org/specs/web-apps/current-work/multipage/common-microsyntaxes.html#rules-for-parsing-a-list-of-dimensions
Vector<HTMLDimension> ParseListOfDimensions(const String& input) {
static const char kComma = ',';
// Step 2. Remove the last character if it's a comma.
String trimmed_string = input;
if (trimmed_string.EndsWith(kComma))
trimmed_string.Truncate(trimmed_string.length() - 1);
// HTML5's split doesn't return a token for an empty string so
// we need to match them here.
if (trimmed_string.empty())
return Vector<HTMLDimension>();
// Step 3. To avoid String copies, we just look for commas instead of
// splitting.
Vector<HTMLDimension> parsed_dimensions;
wtf_size_t last_parsed_index = 0;
while (true) {
wtf_size_t next_comma = trimmed_string.find(kComma, last_parsed_index);
if (next_comma == kNotFound)
break;
parsed_dimensions.push_back(
ParseDimension(trimmed_string, last_parsed_index, next_comma));
last_parsed_index = next_comma + 1;
}
parsed_dimensions.push_back(ParseDimension(trimmed_string, last_parsed_index,
trimmed_string.length()));
return parsed_dimensions;
}
template <typename CharacterType>
static bool ParseDimensionValue(base::span<const CharacterType> characters,
HTMLDimension& dimension) {
size_t current = SkipWhile<CharacterType, IsHTMLSpace>(characters, 0);
// Deviation: HTML allows '+' here.
const size_t number_start = current;
if (!SkipExactly<CharacterType, IsASCIIDigit>(characters, current)) {
return false;
}
current = SkipWhile<CharacterType, IsASCIIDigit>(characters, current);
if (SkipExactly<CharacterType>(characters, '.', current)) {
// Deviation: HTML requires a digit after the full stop to be able to treat
// the value as a percentage (if not, the '.' will considered "garbage",
// yielding a regular length.) Gecko and Edge does not.
current = SkipWhile<CharacterType, IsASCIIDigit>(characters, current);
}
bool ok;
double value = CSSValueClampingUtils::ClampDouble(CharactersToDouble(
characters.subspan(number_start,
static_cast<size_t>(current - number_start)),
&ok));
if (!ok)
return false;
HTMLDimension::HTMLDimensionType type = HTMLDimension::kAbsolute;
if (current < characters.size()) {
const auto c = characters[current];
if (c == '%') {
type = HTMLDimension::kPercentage;
} else if (c == '*') {
// Deviation: HTML does not recognize '*' in this context, and we don't
// treat it as a valid value. We do count it though, so this is purely
// for statistics. Note though that per the specced behavior, "<number>*"
// would be the same as "<number>" (i.e '*' would just be trailing
// garbage.)
type = HTMLDimension::kRelative;
}
}
dimension = HTMLDimension(value, type);
return true;
}
// https://html.spec.whatwg.org/C/#rules-for-parsing-dimension-values
bool ParseDimensionValue(const String& input, HTMLDimension& dimension) {
if (input.empty()) {
return false;
}
return WTF::VisitCharacters(input, [&dimension](auto chars) {
return ParseDimensionValue(chars, dimension);
});
}
} // namespace blink
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