Provides operations and type testing for Sass colours.
Colour operations are all piecewise, e.g. when adding two colours each
component is added independantly; Rr = R1 + R2, Gr = G1 + G2, Br = B1 + B2.
Resulting colours are returned as a named colour if possible or #rrggbb.
Transparent is a SassColour. Operations on transparent return transparent.
/**
* Lex an expression into SassScript tokens.
* @param string $string expression to lex
* @param SassContext $context the context in which the expression is lexed
* @return array tokens
*/
public function lex($string, $context)
{
// if it's already lexed, just return it as-is
if (is_object($string)) {
return array($string);
}
if (is_array($string)) {
return $string;
}
$tokens = array();
// whilst the string is not empty, split it into it's tokens.
while ($string !== false) {
if (($match = $this->isWhitespace($string)) !== false) {
$tokens[] = null;
} elseif (($match = SassScriptFunction::isa($string)) !== false) {
preg_match(SassScriptFunction::MATCH_FUNC, $match, $matches);
$args = array();
foreach (SassScriptFunction::extractArgs($matches[SassScriptFunction::ARGS], false, $context) as $key => $expression) {
$args[$key] = $this->parser->evaluate($expression, $context);
}
$tokens[] = new SassScriptFunction($matches[SassScriptFunction::NAME], $args);
} elseif (($match = SassBoolean::isa($string)) !== false) {
$tokens[] = new SassBoolean($match);
} elseif (($match = SassColour::isa($string)) !== false) {
$tokens[] = new SassColour($match);
} elseif (($match = SassNumber::isa($string)) !== false) {
$tokens[] = new SassNumber($match);
} elseif (($match = SassString::isa($string)) !== false) {
$stringed = new SassString($match);
if (strlen($stringed->quote) == 0 && SassList::isa($string) !== false && !preg_match("/^\\-\\w+\\-\\w+\$/", $stringed->value)) {
$tokens[] = new SassList($string);
} else {
$tokens[] = $stringed;
}
} elseif ($string == '()') {
$match = $string;
$tokens[] = new SassList($match);
} elseif (($match = SassScriptOperation::isa($string)) !== false) {
$tokens[] = new SassScriptOperation($match);
} elseif (($match = SassScriptVariable::isa($string)) !== false) {
$tokens[] = new SassScriptVariable($match);
} else {
$_string = $string;
$match = '';
while (strlen($_string) && !$this->isWhitespace($_string)) {
foreach (SassScriptOperation::$inStrOperators as $operator) {
if (substr($_string, 0, strlen($operator)) == $operator) {
break 2;
}
}
$match .= $_string[0];
$_string = substr($_string, 1);
}
$tokens[] = new SassString($match);
}
$string = substr($string, strlen($match));
}
return $tokens;
}
/**
* Lex an expression into SassScript tokens.
* @param string expression to lex
* @param SassContext the context in which the expression is lexed
* @return array tokens
*/
public function lex($string, $context)
{
$tokens = array();
while ($string !== false) {
if (($match = $this->isWhitespace($string)) !== false) {
$tokens[] = null;
} elseif (($match = SassScriptFunction::isa($string)) !== false) {
preg_match(SassScriptFunction::MATCH_FUNC, $match, $matches);
$args = array();
foreach (SassScriptFunction::extractArgs($matches[SassScriptFunction::ARGS]) as $expression) {
$args[] = $this->parser->evaluate($expression, $context);
}
$tokens[] = new SassScriptFunction($matches[SassScriptFunction::NAME], $args);
} elseif (($match = SassString::isa($string)) !== false) {
$tokens[] = new SassString($match);
} elseif (($match = SassBoolean::isa($string)) !== false) {
$tokens[] = new SassBoolean($match);
} elseif (($match = SassColour::isa($string)) !== false) {
$tokens[] = new SassColour($match);
} elseif (($match = SassNumber::isa($string)) !== false) {
$tokens[] = new SassNumber($match);
} elseif (($match = SassScriptOperation::isa($string)) !== false) {
$tokens[] = new SassScriptOperation($match);
} elseif (($match = SassScriptVariable::isa($string)) !== false) {
$tokens[] = new SassScriptVariable($match);
} else {
$_string = $string;
$match = '';
while (strlen($_string) && !$this->isWhitespace($_string)) {
foreach (SassScriptOperation::$inStrOperators as $operator) {
if (substr($_string, 0, strlen($operator)) == $operator) {
break 2;
}
}
$match .= $_string[0];
$_string = substr($_string, 1);
}
$tokens[] = new SassString($match);
}
$string = substr($string, strlen($match));
}
return $tokens;
}
/**
* Returns a value indicating if a token of this type can be matched at
* the start of the subject string.
* @param string the subject string
* @return mixed match at the start of the string or false if no match
*/
public static function isa($subject)
{
if (empty(self::$regex)) {
self::$regex = str_replace('{CSS_COLOURS}', join('|', array_reverse(array_keys(self::$svgColours))), self::MATCH);
}
return preg_match(self::$regex, strtolower($subject), $matches) ? $matches[0] : false;
}
/**
* Returns the next token from the string.
* @param string string to tokenise
* @return mixed token. Either a SassLiteral, a SassScriptOperation
* @throws SassScriptLexerException if unable to tokenise string
*/
private function nextToken(&$string)
{
if (($match = $this->isWhitespace($string)) !== false) {
$string = substr($string, strlen($match));
return $this->nextToken($string);
} elseif (($match = SassNumber::isa($string)) !== false) {
$string = substr($string, strlen($match));
return new SassNumber($match);
} elseif (($match = SassColour::isa($string)) !== false) {
$string = substr($string, strlen($match));
return new SassColour($match);
} elseif (($match = SassBoolean::isa($string)) !== false) {
$string = substr($string, strlen($match));
return new SassBoolean($match);
} elseif (($match = SassString::isa($string)) !== false) {
$string = substr($string, strlen($match));
return new SassString($match);
} elseif (($match = SassScriptFunction::isa($string)) !== false) {
$string = substr($string, strlen($match));
return new SassScriptFunction($match);
} elseif (($match = SassScriptOperation::isa($string)) !== false) {
$string = substr($string, strlen($match));
return new SassScriptOperation($match);
} else {
throw new SassScriptLexerException("Unable to tokenise \"{$string}\"");
}
}
/**
* Substitute variables in an expression with their values.
* @param string expression to substitue variables in
* @param SassContext the context for variable substitution
* @return string expression with variables substitued
*/
private function substituteVariables($string, $context)
{
for ($i = 0, $n = preg_match_all(self::MATCH_VARIABLE, $string, $matches); $i < $n; $i++) {
$var = $context->getVariable($matches[1][$i]);
if (is_bool($var)) {
$var = $var ? 'true' : 'false';
} elseif (!(SassColour::isa($var) || SassNumber::isa($var))) {
$var = "\"{$var}\"";
}
$string = str_replace($matches[0][$i], $var, $string);
}
return $string;
}
/**
* Returns a copy of this colour with one or more channels changed.
* RGB or HSL attributes may be changed, but not both at once.
* @param array attributes to change
*/
public function with($attributes)
{
if ($this->assertValid($attributes, false) === 'hsl') {
$colour = array_merge(array('hue' => $this->getHue(), 'saturation' => $this->getSaturation(), 'lightness' => $this->getLightness(), 'alpha' => $this->alpha), $attributes);
} else {
$colour = array_merge(array('red' => $this->getRed(), 'green' => $this->getGreen(), 'blue' => $this->getBlue(), 'alpha' => $this->alpha), $attributes);
}
$colour = new SassColour($colour);
$colour->getRed();
# will get RGB and HSL
return $colour;
}
/**
* returns an IE hex string for a color with an alpha channel
* suitable for passing to IE filters.
*/
public static function ie_hex_str($color)
{
if (!$color instanceof SassColour) {
$color = new SassColour($color);
}
$alpha = str_replace(',', '.', round($color->alpha * 255));
$alpha_str = str_pad(dechex($alpha), 2, '0', STR_PAD_LEFT);
$col = $color->asHex(FALSE);
return new SassString(strtoupper('#' . $alpha_str . $col));
}
