/**
* The WCAG specification specifies two thresholds for AA and AAA compliance.
* One specifies the threshold for large text, the other is for any sized
* text. AA and AAA specify different thresholds.
*
* @param ColorContext $color
* The color to analyze.
* @param float $anySizeThreshold
* The minimum threshold for luminosity for any text.
* @param float $largeTextThreshold
* The minimum threshold for luminosity for large text.
*
* @return string
*/
private function calculateWcagCompliance(ColorContext $color, $anySizeThreshold, $largeTextThreshold)
{
if ($color->diffLuminosity() >= $anySizeThreshold) {
return 'Yes';
} elseif ($color->diffLuminosity() >= $largeTextThreshold) {
return 'Large';
}
return 'No';
}
public function columnValue(ColorContext $color)
{
switch ($this->layer) {
case self::BACKGROUND:
return $this->formatClass->formatColor($this->resolveColor($color->background()));
case self::FOREGROUND:
return $this->formatClass->formatColor($this->resolveColor($color->foreground()));
}
return NULL;
}
public function blendColors(\OttawaDeveloper\Tools\ColorAnalyzer\ColorContext $context)
{
$convertedBackgroundAlpha = $context->background()->alpha() * (1 - $context->foreground()->alpha());
$resultAlpha = $context->foreground()->alpha() + $convertedBackgroundAlpha;
// Tiny result alphas means that the color is transparent, so we just
// return a transparent color.
if ($resultAlpha < 0.001) {
return new \OttawaDeveloper\Tools\ColorAnalyzer\BlendedColor($context->foreground(), $context->background(), 0, 0, 0, 0);
}
return new \OttawaDeveloper\Tools\ColorAnalyzer\BlendedColor($context->foreground(), $context->background(), $this->blendColorComponent($context->foreground()->red(), $context->background()->red(), $context->foreground()->alpha(), $context->background()->alpha(), $resultAlpha), $this->blendColorComponent($context->foreground()->green(), $context->background()->green(), $context->foreground()->alpha(), $context->background()->alpha(), $resultAlpha), $this->blendColorComponent($context->foreground()->blue(), $context->background()->blue(), $context->foreground()->alpha(), $context->background()->alpha(), $resultAlpha), $resultAlpha);
}
public function columnValue(ColorContext $color)
{
return number_format(round($color->diffLuminosity(), $this->decimals), $this->decimals);
}
