/**
* Grabs background images with no-repeat attribute from css and merge them in one file called a sprite.
* Css is updated with sprite url and correct background positions for affected images.
* Sprite saved in {Joomla! base}/images/jch-optimize/
*
* @param string $sCss Aggregated css file before sprite generation
* @param string $sLnEnd Document line end
* @return string Css updated with sprite information on success. Original css on failure
*/
protected function generateSprite($sCss, $sLnEnd)
{
if (extension_loaded('imagick') && extension_loaded('exif')) {
$sImageLibrary = 'imagick';
} else {
if (!extension_loaded('gd') || !extension_loaded('exif')) {
return $sCss;
}
$sImageLibrary = 'gd';
}
$iMinMaxImages = $this->params->get('csg_min_max_images', 0);
$sDelStart = '~';
$sRegexStart = '(?:(?<=^|})
(?=([^{]+?)({[^}]+?(url\\(([^}]+?\\.(?:png|gif|jpe?g))[^}]*?\\))[^}]+?}))
(?:(?!(?:\\s(?<!no-)repeat(?:-(?:x|y))?)|(?:background[^;]+?(?:\\s(?:left|right|center|top|bottom)';
$sRegexMin = '|(?:\\s0)|(?:\\s\\d{1,5}(?:%|in|(?:c|m)m|e(?:m|x)|p(?:t|c|x)))){1,2}[^;]*?;)';
$sRegexMax = '|(?:\\s[1-9]\\d{0,4}(?:%|in|(?:c|m)m|e(?:m|x)|p(?:t|c|x)))){1,2}[^;]*?;)';
$sRegexEnd = ')[^}])*?})';
$sDelEnd = '~sx';
$aIncludeImages = $this->getArray($this->params->get('csg_include_images'));
$aExcludeImages = $this->getArray($this->params->get('csg_exclude_images'));
$sIncImagesRegex = '';
if (!empty($aIncludeImages[0]) && !$iMinMaxImages) {
foreach ($aIncludeImages as $sIncImage) {
$sIncImage = str_replace('.', '\\.', $sIncImage);
$sIncImagesRegex .= '|(?:(?<=^|})([^{]+?){[^}]+?(url\\(([^}]+?' . $sIncImage . ')[^}]*?\\))[^}]*?})';
}
}
$sExImagesRegex = '';
if (!empty($aExcludeImages[0]) && $iMinMaxImages) {
foreach ($aExcludeImages as $sExImage) {
$sExImage = str_replace('.', '\\.', $sExImage);
$sExImagesRegex .= '|(?:\\b' . $sExImage . ')';
}
}
$sMinMaxRegex = $iMinMaxImages ? $sRegexMax : $sRegexMin;
$sRegex = $sDelStart . $sRegexStart . $sMinMaxRegex . $sExImagesRegex . $sRegexEnd . $sIncImagesRegex . $sDelEnd;
$iResult = preg_match_all($sRegex, $sCss, $aMatches);
//print_r($aMatches);
if ($iResult <= 0) {
return $sCss;
}
require_once dirname(__FILE__) . DS . 'cache' . DS . 'css-sprite-gen.inc.php';
$aDeclaration = $aMatches[2];
$aImages = $aMatches[4];
//print_r($aDeclaration);
//print_r($sImages);
$aFormValues = array();
$aFormValues['wrap-columns'] = $this->params->get('csg_wrap_images', 'off');
$aFormValues['build-direction'] = $this->params->get('csg_direction', 'vertical');
$aFormValues['image-output'] = $this->params->get('csg_file_output', 'PNG');
$oSpriteGen = new CssSpriteGen($sImageLibrary, $aFormValues);
$aImageTypes = $oSpriteGen->GetImageTypes();
$oSpriteGen->CreateSprite($aImages);
$aSpriteCss = $oSpriteGen->GetCssBackground();
//print_r($aSpriteCss);
$aNeedles = array();
$aReplacements = array();
$sImageSelector = '';
$sBaseUrl = JURI::base(true);
$sBaseUrl = $sBaseUrl == '/' ? $sBaseUrl : $sBaseUrl . '/';
for ($i = 0; $i < count($aSpriteCss); $i++) {
if (@$aSpriteCss[$i]) {
$aNeedles[] = $aDeclaration[$i];
preg_match('~(?<=background)(?:[^;]+?)(
(?<!/)\\b(?:aqua|black|blue|fuchsia|gray|green|lime|maroon|navy|olive|purple|red|silver|teal|white|yellow)\\b(?!/)
|\\#[a-fA-F\\d]{3,6}
|rgb\\([^\\)]+?\\))
(?:[^;]*?);~ix', $aDeclaration[$i], $aBgColor);
preg_match('~(?<=background)(?:[^;]+?)\\s(
scroll|fixed
)\\s(?:(?:[^;]+?)?;)~ix', $aDeclaration[$i], $aBgAttach);
$sBgImage = 'url(' . $sBaseUrl . 'images/jch-optimize/' . $oSpriteGen->GetSpriteFilename() . ')';
$sBackground = 'background: ' . @$aBgColor[1] . ' ' . $sBgImage . ' ' . @$aBgAttach[1] . ' ' . $aSpriteCss[$i] . ' no-repeat; ';
$sDecUnique = preg_replace('~background[^;]+?;~sx', '', $aDeclaration[$i]);
$aReplacements[] = str_replace('{', '{' . $sLnEnd . $sBackground, $sDecUnique);
}
}
$sCss = str_replace($aNeedles, $aReplacements, $sCss);
//$sCss = $sImageSelector.'{background-image:'.$sBgImage.');}'.$sCss;
return $sCss;
}
