/**
* Consolidates background styles into a single background style
*
* @param array $styles Consolidates the provided array of background styles
* @return array Consolidated optimised background styles
*/
public static function consolidate(array $styles)
{
if (count($styles) < 1) {
return $styles;
}
$color = $image = $repeat = $attachment = $position = null;
foreach ($styles as $style) {
switch ($style->get_name()) {
case 'background-color':
$color = css_style_color::shrink_value($style->get_value());
break;
case 'background-image':
$image = $style->get_value();
break;
case 'background-repeat':
$repeat = $style->get_value();
break;
case 'background-attachment':
$attachment = $style->get_value();
break;
case 'background-position':
$position = $style->get_value();
break;
}
}
if ((is_null($image) || is_null($position) || is_null($repeat)) && ($image != null || $position != null || $repeat != null)) {
return $styles;
}
$value = array();
if (!is_null($color)) {
$value[] .= $color;
}
if (!is_null($image)) {
$value[] .= $image;
}
if (!is_null($repeat)) {
$value[] .= $repeat;
}
if (!is_null($attachment)) {
$value[] .= $attachment;
}
if (!is_null($position)) {
$value[] .= $position;
}
return array(new css_style_background('background', join(' ', $value)));
}
/**
* Returns true if the value for this style is valid
* @return bool
*/
public function is_valid()
{
return $this->is_special_empty_value() || parent::is_valid();
}
