// Used for 'position' and 'size'.
static bool scanPercentage(VTTScanner& input, const VTTScanner::Run& valueRun, int& number)
{
// 1. If value contains any characters other than U+0025 PERCENT SIGN
// characters (%) and characters in the range U+0030 DIGIT ZERO (0) to
// U+0039 DIGIT NINE (9), then jump to the step labeled next setting.
// 2. If value does not contain at least one character in the range U+0030
// DIGIT ZERO (0) to U+0039 DIGIT NINE (9), then jump to the step
// labeled next setting.
if (!input.scanDigits(number))
return false;
// 3. If any character in value other than the last character is a U+0025
// PERCENT SIGN character (%), then jump to the step labeled next
// setting.
// 4. If the last character in value is not a U+0025 PERCENT SIGN character
// (%), then jump to the step labeled next setting.
if (!input.scan('%') || !input.isAt(valueRun.end()))
return false;
// 5. Ignoring the trailing percent sign, interpret value as an integer,
// and let number be that number.
// 6. If number is not in the range 0 ≤ number ≤ 100, then jump to the step
// labeled next setting.
return number >= 0 && number <= 100;
}
void VTTCue::parseSettings(const String& inputString)
{
VTTScanner input(inputString);
while (!input.isAtEnd()) {
// The WebVTT cue settings part of a WebVTT cue consists of zero or more of the following components, in any order,
// separated from each other by one or more U+0020 SPACE characters or U+0009 CHARACTER TABULATION (tab) characters.
input.skipWhile<VTTParser::isValidSettingDelimiter>();
if (input.isAtEnd())
break;
// When the user agent is to parse the WebVTT settings given by a string input for a text track cue cue,
// the user agent must run the following steps:
// 1. Let settings be the result of splitting input on spaces.
// 2. For each token setting in the list settings, run the following substeps:
// 1. If setting does not contain a U+003A COLON character (:), or if the first U+003A COLON character (:)
// in setting is either the first or last character of setting, then jump to the step labeled next setting.
// 2. Let name be the leading substring of setting up to and excluding the first U+003A COLON character (:) in that string.
CueSetting name = settingName(input);
// 3. Let value be the trailing substring of setting starting from the character immediately after the first U+003A COLON character (:) in that string.
VTTScanner::Run valueRun = input.collectUntil<VTTParser::isValidSettingDelimiter>();
// 4. Run the appropriate substeps that apply for the value of name, as follows:
switch (name) {
case Vertical: {
// If name is a case-sensitive match for "vertical"
// 1. If value is a case-sensitive match for the string "rl", then let cue's text track cue writing direction
// be vertical growing left.
if (input.scanRun(valueRun, verticalGrowingLeftKeyword()))
m_writingDirection = VerticalGrowingLeft;
// 2. Otherwise, if value is a case-sensitive match for the string "lr", then let cue's text track cue writing
// direction be vertical growing right.
else if (input.scanRun(valueRun, verticalGrowingRightKeyword()))
m_writingDirection = VerticalGrowingRight;
break;
}
case Line: {
// 1-2 - Collect chars that are either '-', '%', or a digit.
// 1. If value contains any characters other than U+002D HYPHEN-MINUS characters (-), U+0025 PERCENT SIGN
// characters (%), and characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), then jump
// to the step labeled next setting.
bool isNegative = input.scan('-');
int linePosition;
unsigned numDigits = input.scanDigits(linePosition);
bool isPercentage = input.scan('%');
if (!input.isAt(valueRun.end()))
break;
// 2. If value does not contain at least one character in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT
// NINE (9), then jump to the step labeled next setting.
// 3. If any character in value other than the first character is a U+002D HYPHEN-MINUS character (-), then
// jump to the step labeled next setting.
// 4. If any character in value other than the last character is a U+0025 PERCENT SIGN character (%), then
// jump to the step labeled next setting.
// 5. If the first character in value is a U+002D HYPHEN-MINUS character (-) and the last character in value is a
// U+0025 PERCENT SIGN character (%), then jump to the step labeled next setting.
if (!numDigits || (isPercentage && isNegative))
break;
// 6. Ignoring the trailing percent sign, if any, interpret value as a (potentially signed) integer, and
// let number be that number.
// 7. If the last character in value is a U+0025 PERCENT SIGN character (%), but number is not in the range
// 0 ≤ number ≤ 100, then jump to the step labeled next setting.
// 8. Let cue's text track cue line position be number.
// 9. If the last character in value is a U+0025 PERCENT SIGN character (%), then let cue's text track cue
// snap-to-lines flag be false. Otherwise, let it be true.
if (isPercentage) {
if (linePosition < 0 || linePosition > 100)
break;
// 10 - If '%' then set snap-to-lines flag to false.
m_snapToLines = false;
} else {
if (isNegative)
linePosition = -linePosition;
m_snapToLines = true;
}
m_linePosition = linePosition;
break;
}
case Position: {
int number;
// Steps 1 - 6.
if (!scanPercentage(input, valueRun, number))
break;
// 7. Let cue's text track cue text position be number.
m_textPosition = number;
break;
}
case Size: {
int number;
// Steps 1 - 6.
if (!scanPercentage(input, valueRun, number))
break;
// 7. Let cue's text track cue size be number.
m_cueSize = number;
break;
}
case Align: {
// 1. If value is a case-sensitive match for the string "start", then let cue's text track cue alignment be start alignment.
if (input.scanRun(valueRun, startKeyword()))
m_cueAlignment = Start;
// 2. If value is a case-sensitive match for the string "middle", then let cue's text track cue alignment be middle alignment.
else if (input.scanRun(valueRun, middleKeyword()))
m_cueAlignment = Middle;
// 3. If value is a case-sensitive match for the string "end", then let cue's text track cue alignment be end alignment.
else if (input.scanRun(valueRun, endKeyword()))
m_cueAlignment = End;
// 4. If value is a case-sensitive match for the string "left", then let cue's text track cue alignment be left alignment.
else if (input.scanRun(valueRun, leftKeyword()))
m_cueAlignment = Left;
// 5. If value is a case-sensitive match for the string "right", then let cue's text track cue alignment be right alignment.
else if (input.scanRun(valueRun, rightKeyword()))
m_cueAlignment = Right;
break;
}
case RegionId:
m_regionId = input.extractString(valueRun);
break;
case None:
break;
}
// Make sure the entire run is consumed.
input.skipRun(valueRun);
}
// If cue's line position is not auto or cue's size is not 100 or cue's
// writing direction is not horizontal, but cue's region identifier is not
// the empty string, let cue's region identifier be the empty string.
if (m_regionId.isEmpty())
return;
if (m_linePosition != undefinedPosition || m_cueSize != 100 || m_writingDirection != Horizontal)
m_regionId = emptyString();
}
static inline bool parsedEntireRun(const VTTScanner& input, const VTTScanner::Run& run)
{
return input.isAt(run.end());
}
void VTTCue::parseSettings(const String& inputString)
{
VTTScanner input(inputString);
while (!input.isAtEnd()) {
// The WebVTT cue settings part of a WebVTT cue consists of zero or more of the following components, in any order,
// separated from each other by one or more U+0020 SPACE characters or U+0009 CHARACTER TABULATION (tab) characters.
input.skipWhile<VTTParser::isValidSettingDelimiter>();
if (input.isAtEnd())
break;
// When the user agent is to parse the WebVTT settings given by a string input for a text track cue cue,
// the user agent must run the following steps:
// 1. Let settings be the result of splitting input on spaces.
// 2. For each token setting in the list settings, run the following substeps:
// 1. If setting does not contain a U+003A COLON character (:), or if the first U+003A COLON character (:)
// in setting is either the first or last character of setting, then jump to the step labeled next setting.
// 2. Let name be the leading substring of setting up to and excluding the first U+003A COLON character (:) in that string.
CueSetting name = settingName(input);
// 3. Let value be the trailing substring of setting starting from the character immediately after the first U+003A COLON character (:) in that string.
VTTScanner::Run valueRun = input.collectUntil<VTTParser::isValidSettingDelimiter>();
// 4. Run the appropriate substeps that apply for the value of name, as follows:
switch (name) {
case Vertical: {
// If name is a case-sensitive match for "vertical"
// 1. If value is a case-sensitive match for the string "rl", then
// let cue's WebVTT cue writing direction be vertical
// growing left.
if (input.scanRun(valueRun, verticalGrowingLeftKeyword()))
m_writingDirection = VerticalGrowingLeft;
// 2. Otherwise, if value is a case-sensitive match for the string
// "lr", then let cue's WebVTT cue writing direction be
// vertical growing right.
else if (input.scanRun(valueRun, verticalGrowingRightKeyword()))
m_writingDirection = VerticalGrowingRight;
break;
}
case Line: {
// If name is a case-sensitive match for "line"
// Steps 1 - 2 skipped.
float number;
// 3. If linepos does not contain at least one ASCII digit, then
// jump to the step labeled next setting.
// 4. If the last character in linepos is a U+0025 PERCENT SIGN character (%)
//
// If parse a percentage string from linepos doesn't fail, let
// number be the returned percentage, otherwise jump to the step
// labeled next setting.
bool isPercentage = scanPercentage(input, number);
if (!isPercentage) {
// Otherwise
//
// 1. If linepos contains any characters other than U+002D
// HYPHEN-MINUS characters (-) and ASCII digits, then jump to
// the step labeled next setting.
// 2. If any character in linepos other than the first character is
// a U+002D HYPHEN-MINUS character (-), then jump to the step
// labeled next setting.
bool isNegative = input.scan('-');
int intLinePosition;
if (!input.scanDigits(intLinePosition))
break;
// 3. Interpret linepos as a (potentially signed) integer, and let
// number be that number.
number = isNegative ? -intLinePosition : intLinePosition;
}
if (!input.isAt(valueRun.end()))
break;
// 5. Let cue's WebVTT cue line be number.
m_linePosition = number;
// 6. If the last character in linepos is a U+0025 PERCENT SIGN
// character (%), then let cue's WebVTT cue snap-to-lines
// flag be false. Otherwise, let it be true.
m_snapToLines = !isPercentage;
// Steps 7 - 9 skipped.
break;
}
case Position: {
// If name is a case-sensitive match for "position".
float number;
// Steps 1 - 2 skipped.
// 3. If parse a percentage string from colpos doesn't fail, let
// number be the returned percentage, otherwise jump to the step
// labeled next setting (text track cue text position's value
// remains the special value auto).
if (!scanPercentage(input, number))
break;
if (!input.isAt(valueRun.end()))
break;
// 4. Let cue's cue position be number.
m_textPosition = number;
// Steps 5 - 7 skipped.
break;
}
case Size: {
// If name is a case-sensitive match for "size"
float number;
// 1. If parse a percentage string from value doesn't fail, let
// number be the returned percentage, otherwise jump to the step
// labeled next setting.
if (!scanPercentage(input, number))
break;
if (!input.isAt(valueRun.end()))
break;
// 2. Let cue's WebVTT cue size be number.
m_cueSize = number;
break;
}
case Align: {
// If name is a case-sensitive match for "align"
// 1. If value is a case-sensitive match for the string "start",
// then let cue's WebVTT cue text alignment be start alignment.
if (input.scanRun(valueRun, startKeyword()))
m_cueAlignment = Start;
// 2. If value is a case-sensitive match for the string "middle",
// then let cue's WebVTT cue text alignment be middle alignment.
else if (input.scanRun(valueRun, middleKeyword()))
m_cueAlignment = Middle;
// 3. If value is a case-sensitive match for the string "end", then
// let cue's WebVTT cue text alignment be end alignment.
else if (input.scanRun(valueRun, endKeyword()))
m_cueAlignment = End;
// 4. If value is a case-sensitive match for the string "left",
// then let cue's WebVTT cue text alignment be left alignment.
else if (input.scanRun(valueRun, leftKeyword()))
m_cueAlignment = Left;
// 5. If value is a case-sensitive match for the string "right",
// then let cue's WebVTT cue text alignment be right alignment.
else if (input.scanRun(valueRun, rightKeyword()))
m_cueAlignment = Right;
break;
}
case RegionId:
m_regionId = input.extractString(valueRun);
break;
case None:
break;
}
// Make sure the entire run is consumed.
input.skipRun(valueRun);
}
// If cue's line position is not auto or cue's size is not 100 or cue's
// writing direction is not horizontal, but cue's region identifier is not
// the empty string, let cue's region identifier be the empty string.
if (m_regionId.isEmpty())
return;
if (!lineIsAuto() || m_cueSize != 100 || m_writingDirection != Horizontal)
m_regionId = emptyString();
}