class.csstidy_optimise.php

<?php

/**
 * CSSTidy - CSS Parser and Optimiser
 *
 * CSS Optimising Class
 * This class optimises CSS data generated by csstidy.
 *
 * Copyright 2005, 2006, 2007 Florian Schmitz
 *
 * This file is part of CSSTidy.
 *
 *   CSSTidy is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published by
 *   the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   CSSTidy is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * @license http://opensource.org/licenses/lgpl-license.php GNU Lesser General Public License
 * @package csstidy
 * @author Florian Schmitz (floele at gmail dot com) 2005-2007
 * @author Brett Zamir (brettz9 at yahoo dot com) 2007
 * @author Nikolay Matsievsky (speed at webo dot name) 2009-2010
 * @author Cedric Morin (cedric at yterium dot com) 2010-2012
 */

/**
 * CSS Optimising Class
 *
 * This class optimises CSS data generated by csstidy.
 *
 * @package csstidy
 * @author Florian Schmitz (floele at gmail dot com) 2005-2006
 * @version 1.0
 */
class csstidy_optimise {

	/**
	 * Constructor
	 * @param array $css contains the class csstidy
	 * @access private
	 * @version 1.0
	 */
	function csstidy_optimise(&$css) {
		$this->parser = & $css;
		$this->css = & $css->css;
		$this->sub_value = & $css->sub_value;
		$this->at = & $css->at;
		$this->selector = & $css->selector;
		$this->property = & $css->property;
		$this->value = & $css->value;
	}

	/**
	 * Optimises $css after parsing
	 * @access public
	 * @version 1.0
	 */
	function postparse() {
		if ($this->parser->get_cfg('preserve_css')) {
			return;
		}

		if ($this->parser->get_cfg('merge_selectors') === 2) {
			foreach ($this->css as $medium => $value) {
				$this->merge_selectors($this->css[$medium]);
			}
		}

		if ($this->parser->get_cfg('discard_invalid_selectors')) {
			foreach ($this->css as $medium => $value) {
				$this->discard_invalid_selectors($this->css[$medium]);
			}
		}

		if ($this->parser->get_cfg('optimise_shorthands') > 0) {
			foreach ($this->css as $medium => $value) {
				foreach ($value as $selector => $value1) {
					$this->css[$medium][$selector] = csstidy_optimise::merge_4value_shorthands($this->css[$medium][$selector]);

					if ($this->parser->get_cfg('optimise_shorthands') < 2) {
						continue;
					}

					$this->css[$medium][$selector] = csstidy_optimise::merge_font($this->css[$medium][$selector]);

					if ($this->parser->get_cfg('optimise_shorthands') < 3) {
						continue;
					}

					$this->css[$medium][$selector] = csstidy_optimise::merge_bg($this->css[$medium][$selector]);
					if (empty($this->css[$medium][$selector])) {
						unset($this->css[$medium][$selector]);
					}
				}
			}
		}
	}

	/**
	 * Optimises values
	 * @access public
	 * @version 1.0
	 */
	function value() {
		$shorthands = & $GLOBALS['csstidy']['shorthands'];

		// optimise shorthand properties
		if (isset($shorthands[$this->property])) {
			$temp = csstidy_optimise::shorthand($this->value); // FIXME - move
			if ($temp != $this->value) {
				$this->parser->log('Optimised shorthand notation (' . $this->property . '): Changed "' . $this->value . '" to "' . $temp . '"', 'Information');
			}
			$this->value = $temp;
		}

		// Remove whitespace at ! important
		if ($this->value != $this->compress_important($this->value)) {
			$this->parser->log('Optimised !important', 'Information');
		}
	}

	/**
	 * Optimises shorthands
	 * @access public
	 * @version 1.0
	 */
	function shorthands() {
		$shorthands = & $GLOBALS['csstidy']['shorthands'];

		if (!$this->parser->get_cfg('optimise_shorthands') || $this->parser->get_cfg('preserve_css')) {
			return;
		}

		if ($this->property === 'font' && $this->parser->get_cfg('optimise_shorthands') > 1) {
			$this->css[$this->at][$this->selector]['font']='';
			$this->parser->merge_css_blocks($this->at, $this->selector, csstidy_optimise::dissolve_short_font($this->value));
		}
		if ($this->property === 'background' && $this->parser->get_cfg('optimise_shorthands') > 2) {
			$this->css[$this->at][$this->selector]['background']='';
			$this->parser->merge_css_blocks($this->at, $this->selector, csstidy_optimise::dissolve_short_bg($this->value));
		}
		if (isset($shorthands[$this->property])) {
			$this->parser->merge_css_blocks($this->at, $this->selector, csstidy_optimise::dissolve_4value_shorthands($this->property, $this->value));
			if (is_array($shorthands[$this->property])) {
				$this->css[$this->at][$this->selector][$this->property] = '';
			}
		}
	}

	/**
	 * Optimises a sub-value
	 * @access public
	 * @version 1.0
	 */
	function subvalue() {
		$replace_colors = & $GLOBALS['csstidy']['replace_colors'];

		$this->sub_value = trim($this->sub_value);
		if ($this->sub_value == '') { // caution : '0'
			return;
		}

		$important = '';
		if (csstidy::is_important($this->sub_value)) {
			$important = '!important';
		}
		$this->sub_value = csstidy::gvw_important($this->sub_value);

		// Compress font-weight
		if ($this->property === 'font-weight' && $this->parser->get_cfg('compress_font-weight')) {
			if ($this->sub_value === 'bold') {
				$this->sub_value = '700';
				$this->parser->log('Optimised font-weight: Changed "bold" to "700"', 'Information');
			} elseif ($this->sub_value === 'normal') {
				$this->sub_value = '400';
				$this->parser->log('Optimised font-weight: Changed "normal" to "400"', 'Information');
			}
		}

		$temp = $this->compress_numbers($this->sub_value);
		if (strcasecmp($temp, $this->sub_value) !== 0) {
			if (strlen($temp) > strlen($this->sub_value)) {
				$this->parser->log('Fixed invalid number: Changed "' . $this->sub_value . '" to "' . $temp . '"', 'Warning');
			} else {
				$this->parser->log('Optimised number: Changed "' . $this->sub_value . '" to "' . $temp . '"', 'Information');
			}
			$this->sub_value = $temp;
		}
		if ($this->parser->get_cfg('compress_colors')) {
			$temp = $this->cut_color($this->sub_value);
			if ($temp !== $this->sub_value) {
				if (isset($replace_colors[$this->sub_value])) {
					$this->parser->log('Fixed invalid color name: Changed "' . $this->sub_value . '" to "' . $temp . '"', 'Warning');
				} else {
					$this->parser->log('Optimised color: Changed "' . $this->sub_value . '" to "' . $temp . '"', 'Information');
				}
				$this->sub_value = $temp;
			}
		}
		$this->sub_value .= $important;
	}

	/**
	 * Compresses shorthand values. Example: margin:1px 1px 1px 1px -> margin:1px
	 * @param string $value
	 * @access public
	 * @return string
	 * @version 1.0
	 */
	function shorthand($value) {
		$important = '';
		if (csstidy::is_important($value)) {
			$values = csstidy::gvw_important($value);
			$important = '!important';
		}
		else
			$values = $value;

		$values = explode(' ', $values);
		switch (count($values)) {
			case 4:
				if ($values[0] == $values[1] && $values[0] == $values[2] && $values[0] == $values[3]) {
					return $values[0] . $important;
				} elseif ($values[1] == $values[3] && $values[0] == $values[2]) {
					return $values[0] . ' ' . $values[1] . $important;
				} elseif ($values[1] == $values[3]) {
					return $values[0] . ' ' . $values[1] . ' ' . $values[2] . $important;
				}
				break;

			case 3:
				if ($values[0] == $values[1] && $values[0] == $values[2]) {
					return $values[0] . $important;
				} elseif ($values[0] == $values[2]) {
					return $values[0] . ' ' . $values[1] . $important;
				}
				break;

			case 2:
				if ($values[0] == $values[1]) {
					return $values[0] . $important;
				}
				break;
		}

		return $value;
	}

	/**
	 * Removes unnecessary whitespace in ! important
	 * @param string $string
	 * @return string
	 * @access public
	 * @version 1.1
	 */
	function compress_important(&$string) {
		if (csstidy::is_important($string)) {
			$string = csstidy::gvw_important($string) . '!important';
		}
		return $string;
	}

	/**
	 * Color compression function. Converts all rgb() values to #-values and uses the short-form if possible. Also replaces 4 color names by #-values.
	 * @param string $color
	 * @return string
	 * @version 1.1
	 */
	function cut_color($color) {
		$replace_colors = & $GLOBALS['csstidy']['replace_colors'];

		// if it's a string, don't touch !
		if (strncmp($color,"'",1)==0 OR strncmp($color,'"',1)==0)
			return $color;

		/* expressions complexes de type gradient */
		if (strpos($color,"(")!==false AND strncmp($color,'rgb(',4)!=0) {
			// on ne touche pas aux couleurs dans les expression ms, c'est trop sensible
			if (stripos($color,"progid:")!==false)
				return $color;
			preg_match_all(",rgb\([^)]+\),i",$color,$matches,PREG_SET_ORDER);
			if (count($matches)) {
				foreach ($matches as $m) {
					$color = str_replace($m[0],$this->cut_color($m[0]),$color);
				}
			}
			preg_match_all(",#[0-9a-f]{6}(?=[^0-9a-f]),i",$color,$matches,PREG_SET_ORDER);
			if (count($matches)) {
				foreach ($matches as $m) {
					$color = str_replace($m[0],$this->cut_color($m[0]),$color);
				}
			}
			return $color;
		}

		// rgb(0,0,0) -> #000000 (or #000 in this case later)
		if (strncasecmp($color, 'rgb(', 4)==0) {
			$color_tmp = substr($color, 4, strlen($color) - 5);
			$color_tmp = explode(',', $color_tmp);
			for ($i = 0; $i < count($color_tmp); $i++) {
				$color_tmp[$i] = trim($color_tmp[$i]);
				if (substr($color_tmp[$i], -1) === '%') {
					$color_tmp[$i] = round((255 * $color_tmp[$i]) / 100);
				}
				if ($color_tmp[$i] > 255)
					$color_tmp[$i] = 255;
			}
			$color = '#';
			for ($i = 0; $i < 3; $i++) {
				if ($color_tmp[$i] < 16) {
					$color .= '0' . dechex($color_tmp[$i]);
				} else {
					$color .= dechex($color_tmp[$i]);
				}
			}
		}

		// Fix bad color names
		if (isset($replace_colors[strtolower($color)])) {
			$color = $replace_colors[strtolower($color)];
		}

		// #aabbcc -> #abc
		if (strlen($color) == 7) {
			$color_temp = strtolower($color);
			if ($color_temp{0} === '#' && $color_temp{1} == $color_temp{2} && $color_temp{3} == $color_temp{4} && $color_temp{5} == $color_temp{6}) {
				$color = '#' . $color{1} . $color{3} . $color{5};
			}
		}

		switch (strtolower($color)) {
			/* color name -> hex code */
			case 'black': return '#000';
			case 'fuchsia': return '#f0f';
			case 'white': return '#fff';
			case 'yellow': return '#ff0';

			/* hex code -> color name */
			case '#800000': return 'maroon';
			case '#ffa500': return 'orange';
			case '#808000': return 'olive';
			case '#800080': return 'purple';
			case '#008000': return 'green';
			case '#000080': return 'navy';
			case '#008080': return 'teal';
			case '#c0c0c0': return 'silver';
			case '#808080': return 'gray';
			case '#f00': return 'red';
		}

		return $color;
	}

	/**
	 * Compresses numbers (ie. 1.0 becomes 1 or 1.100 becomes 1.1 )
	 * @param string $subvalue
	 * @return string
	 * @version 1.2
	 */
	function compress_numbers($subvalue) {
		$unit_values = & $GLOBALS['csstidy']['unit_values'];
		$color_values = & $GLOBALS['csstidy']['color_values'];

		// for font:1em/1em sans-serif...;
		if ($this->property === 'font') {
			$temp = explode('/', $subvalue);
		} else {
			$temp = array($subvalue);
		}
		for ($l = 0; $l < count($temp); $l++) {
			// if we are not dealing with a number at this point, do not optimise anything
			$number = $this->AnalyseCssNumber($temp[$l]);
			if ($number === false) {
				return $subvalue;
			}

			// Fix bad colors
			if (in_array($this->property, $color_values)) {
				$temp[$l] = '#' . $temp[$l];
				continue;
			}

			if (abs($number[0]) > 0) {
				if ($number[1] == '' && in_array($this->property, $unit_values, true)) {
					$number[1] = 'px';
				}
			} else {
				$number[1] = '';
			}

			$temp[$l] = $number[0] . $number[1];
		}

		return ((count($temp) > 1) ? $temp[0] . '/' . $temp[1] : $temp[0]);
	}

	/**
	 * Checks if a given string is a CSS valid number. If it is,
	 * an array containing the value and unit is returned
	 * @param string $string
	 * @return array ('unit' if unit is found or '' if no unit exists, number value) or false if no number
	 */
	function AnalyseCssNumber($string) {
		// most simple checks first
		if (strlen($string) == 0 || ctype_alpha($string{0})) {
			return false;
		}

		$units = & $GLOBALS['csstidy']['units'];
		$return = array(0, '');

		$return[0] = floatval($string);
		if (abs($return[0]) > 0 && abs($return[0]) < 1) {
			if ($return[0] < 0) {
				$return[0] = '-' . ltrim(substr($return[0], 1), '0');
			} else {
				$return[0] = ltrim($return[0], '0');
			}
		}

		// Look for unit and split from value if exists
		foreach ($units as $unit) {
			$expectUnitAt = strlen($string) - strlen($unit);
			if (!($unitInString = stristr($string, $unit))) { // mb_strpos() fails with "false"
				continue;
			}
			$actualPosition = strpos($string, $unitInString);
			if ($expectUnitAt === $actualPosition) {
				$return[1] = $unit;
				$string = substr($string, 0, - strlen($unit));
				break;
			}
		}
		if (!is_numeric($string)) {
			return false;
		}
		return $return;
	}

	/**
	 * Merges selectors with same properties. Example: a{color:red} b{color:red} -> a,b{color:red}
	 * Very basic and has at least one bug. Hopefully there is a replacement soon.
	 * @param array $array
	 * @return array
	 * @access public
	 * @version 1.2
	 */
	function merge_selectors(&$array) {
		$css = $array;
		foreach ($css as $key => $value) {
			if (!isset($css[$key])) {
				continue;
			}
			$newsel = '';

			// Check if properties also exist in another selector
			$keys = array();
			// PHP bug (?) without $css = $array; here
			foreach ($css as $selector => $vali) {
				if ($selector == $key) {
					continue;
				}

				if ($css[$key] === $vali) {
					$keys[] = $selector;
				}
			}

			if (!empty($keys)) {
				$newsel = $key;
				unset($css[$key]);
				foreach ($keys as $selector) {
					unset($css[$selector]);
					$newsel .= ',' . $selector;
				}
				$css[$newsel] = $value;
			}
		}
		$array = $css;
	}

	/**
	 * Removes invalid selectors and their corresponding rule-sets as
	 * defined by 4.1.7 in REC-CSS2. This is a very rudimentary check
	 * and should be replaced by a full-blown parsing algorithm or
	 * regular expression
	 * @version 1.4
	 */
	function discard_invalid_selectors(&$array) {
		$invalid = array('+' => true, '~' => true, ',' => true, '>' => true);
		foreach ($array as $selector => $decls) {
			$ok = true;
			$selectors = array_map('trim', explode(',', $selector));
			foreach ($selectors as $s) {
				$simple_selectors = preg_split('/\s*[+>~\s]\s*/', $s);
				foreach ($simple_selectors as $ss) {
					if ($ss === '')
						$ok = false;
					// could also check $ss for internal structure,
					// but that probably would be too slow
				}
			}
			if (!$ok)
				unset($array[$selector]);
		}
	}

	/**
	 * Dissolves properties like padding:10px 10px 10px to padding-top:10px;padding-bottom:10px;...
	 * @param string $property
	 * @param string $value
	 * @return array
	 * @version 1.0
	 * @see merge_4value_shorthands()
	 */
	function dissolve_4value_shorthands($property, $value) {
		$shorthands = & $GLOBALS['csstidy']['shorthands'];
		if (!is_array($shorthands[$property])) {
			$return[$property] = $value;
			return $return;
		}

		$important = '';
		if (csstidy::is_important($value)) {
			$value = csstidy::gvw_important($value);
			$important = '!important';
		}
		$values = explode(' ', $value);


		$return = array();
		if (count($values) == 4) {
			for ($i = 0; $i < 4; $i++) {
				$return[$shorthands[$property][$i]] = $values[$i] . $important;
			}
		} elseif (count($values) == 3) {
			$return[$shorthands[$property][0]] = $values[0] . $important;
			$return[$shorthands[$property][1]] = $values[1] . $important;
			$return[$shorthands[$property][3]] = $values[1] . $important;
			$return[$shorthands[$property][2]] = $values[2] . $important;
		} elseif (count($values) == 2) {
			for ($i = 0; $i < 4; $i++) {
				$return[$shorthands[$property][$i]] = (($i % 2 != 0)) ? $values[1] . $important : $values[0] . $important;
			}
		} else {
			for ($i = 0; $i < 4; $i++) {
				$return[$shorthands[$property][$i]] = $values[0] . $important;
			}
		}

		return $return;
	}

	/**
	 * Explodes a string as explode() does, however, not if $sep is escaped or within a string.
	 * @param string $sep seperator
	 * @param string $string
	 * @return array
	 * @version 1.0
	 */
	function explode_ws($sep, $string) {
		$status = 'st';
		$to = '';

		$output = array();
		$num = 0;
		for ($i = 0, $len = strlen($string); $i < $len; $i++) {
			switch ($status) {
				case 'st':
					if ($string{$i} == $sep && !csstidy::escaped($string, $i)) {
						++$num;
					} elseif ($string{$i} === '"' || $string{$i} === '\'' || $string{$i} === '(' && !csstidy::escaped($string, $i)) {
						$status = 'str';
						$to = ($string{$i} === '(') ? ')' : $string{$i};
						(isset($output[$num])) ? $output[$num] .= $string{$i} : $output[$num] = $string{$i};
					} else {
						(isset($output[$num])) ? $output[$num] .= $string{$i} : $output[$num] = $string{$i};
					}
					break;

				case 'str':
					if ($string{$i} == $to && !csstidy::escaped($string, $i)) {
						$status = 'st';
					}
					(isset($output[$num])) ? $output[$num] .= $string{$i} : $output[$num] = $string{$i};
					break;
			}
		}

		if (isset($output[0])) {
			return $output;
		} else {
			return array($output);
		}
	}

	/**
	 * Merges Shorthand properties again, the opposite of dissolve_4value_shorthands()
	 * @param array $array
	 * @return array
	 * @version 1.2
	 * @see dissolve_4value_shorthands()
	 */
	function merge_4value_shorthands($array) {
		$return = $array;
		$shorthands = & $GLOBALS['csstidy']['shorthands'];

		foreach ($shorthands as $key => $value) {
			if (isset($array[$value[0]]) && isset($array[$value[1]])
							&& isset($array[$value[2]]) && isset($array[$value[3]]) && $value !== 0) {
				$return[$key] = '';

				$important = '';
				for ($i = 0; $i < 4; $i++) {
					$val = $array[$value[$i]];
					if (csstidy::is_important($val)) {
						$important = '!important';
						$return[$key] .= csstidy::gvw_important($val) . ' ';
					} else {
						$return[$key] .= $val . ' ';
					}
					unset($return[$value[$i]]);
				}
				$return[$key] = csstidy_optimise::shorthand(trim($return[$key] . $important));
			}
		}
		return $return;
	}

	/**
	 * Dissolve background property
	 * @param string $str_value
	 * @return array
	 * @version 1.0
	 * @see merge_bg()
	 * @todo full CSS 3 compliance
	 */
	function dissolve_short_bg($str_value) {
		// don't try to explose background gradient !
		if (stripos($str_value, "gradient(")!==FALSE)
			return array('background'=>$str_value);

		$background_prop_default = & $GLOBALS['csstidy']['background_prop_default'];
		$repeat = array('repeat', 'repeat-x', 'repeat-y', 'no-repeat', 'space');
		$attachment = array('scroll', 'fixed', 'local');
		$clip = array('border', 'padding');
		$origin = array('border', 'padding', 'content');
		$pos = array('top', 'center', 'bottom', 'left', 'right');
		$important = '';
		$return = array('background-image' => null, 'background-size' => null, 'background-repeat' => null, 'background-position' => null, 'background-attachment' => null, 'background-clip' => null, 'background-origin' => null, 'background-color' => null);

		if (csstidy::is_important($str_value)) {
			$important = ' !important';
			$str_value = csstidy::gvw_important($str_value);
		}

		$str_value = csstidy_optimise::explode_ws(',', $str_value);
		for ($i = 0; $i < count($str_value); $i++) {
			$have['clip'] = false;
			$have['pos'] = false;
			$have['color'] = false;
			$have['bg'] = false;

			if (is_array($str_value[$i])) {
				$str_value[$i] = $str_value[$i][0];
			}
			$str_value[$i] = csstidy_optimise::explode_ws(' ', trim($str_value[$i]));

			for ($j = 0; $j < count($str_value[$i]); $j++) {
				if ($have['bg'] === false && (substr($str_value[$i][$j], 0, 4) === 'url(' || $str_value[$i][$j] === 'none')) {
					$return['background-image'] .= $str_value[$i][$j] . ',';
					$have['bg'] = true;
				} elseif (in_array($str_value[$i][$j], $repeat, true)) {
					$return['background-repeat'] .= $str_value[$i][$j] . ',';
				} elseif (in_array($str_value[$i][$j], $attachment, true)) {
					$return['background-attachment'] .= $str_value[$i][$j] . ',';
				} elseif (in_array($str_value[$i][$j], $clip, true) && !$have['clip']) {
					$return['background-clip'] .= $str_value[$i][$j] . ',';
					$have['clip'] = true;
				} elseif (in_array($str_value[$i][$j], $origin, true)) {
					$return['background-origin'] .= $str_value[$i][$j] . ',';
				} elseif ($str_value[$i][$j]{0} === '(') {
					$return['background-size'] .= substr($str_value[$i][$j], 1, -1) . ',';
				} elseif (in_array($str_value[$i][$j], $pos, true) || is_numeric($str_value[$i][$j]{0}) || $str_value[$i][$j]{0} === null || $str_value[$i][$j]{0} === '-' || $str_value[$i][$j]{0} === '.') {
					$return['background-position'] .= $str_value[$i][$j];
					if (!$have['pos'])
						$return['background-position'] .= ' '; else
						$return['background-position'].= ',';
					$have['pos'] = true;
				} elseif (!$have['color']) {
					$return['background-color'] .= $str_value[$i][$j] . ',';
					$have['color'] = true;
				}
			}
		}

		foreach ($background_prop_default as $bg_prop => $default_value) {
			if ($return[$bg_prop] !== null) {
				$return[$bg_prop] = substr($return[$bg_prop], 0, -1) . $important;
			}
			else
				$return[$bg_prop] = $default_value . $important;
		}
		return $return;
	}

	/**
	 * Merges all background properties
	 * @param array $input_css
	 * @return array
	 * @version 1.0
	 * @see dissolve_short_bg()
	 * @todo full CSS 3 compliance
	 */
	function merge_bg($input_css) {
		$background_prop_default = & $GLOBALS['csstidy']['background_prop_default'];
		// Max number of background images. CSS3 not yet fully implemented
		$number_of_values = @max(count(csstidy_optimise::explode_ws(',', $input_css['background-image'])), count(csstidy_optimise::explode_ws(',', $input_css['background-color'])), 1);
		// Array with background images to check if BG image exists
		$bg_img_array = @csstidy_optimise::explode_ws(',', csstidy::gvw_important($input_css['background-image']));
		$new_bg_value = '';
		$important = '';

		// if background properties is here and not empty, don't try anything
		if (isset($input_css['background']) AND $input_css['background'])
			return $input_css;

		for ($i = 0; $i < $number_of_values; $i++) {
			foreach ($background_prop_default as $bg_property => $default_value) {
				// Skip if property does not exist
				if (!isset($input_css[$bg_property])) {
					continue;
				}

				$cur_value = $input_css[$bg_property];
				// skip all optimisation if gradient() somewhere
				if (stripos($cur_value, "gradient(")!==FALSE)
					return $input_css;

				// Skip some properties if there is no background image
				if ((!isset($bg_img_array[$i]) || $bg_img_array[$i] === 'none')
								&& ($bg_property === 'background-size' || $bg_property === 'background-position'
								|| $bg_property === 'background-attachment' || $bg_property === 'background-repeat')) {
					continue;
				}

				// Remove !important
				if (csstidy::is_important($cur_value)) {
					$important = ' !important';
					$cur_value = csstidy::gvw_important($cur_value);
				}

				// Do not add default values
				if ($cur_value === $default_value) {
					continue;
				}

				$temp = csstidy_optimise::explode_ws(',', $cur_value);

				if (isset($temp[$i])) {
					if ($bg_property === 'background-size') {
						$new_bg_value .= '(' . $temp[$i] . ') ';
					} else {
						$new_bg_value .= $temp[$i] . ' ';
					}
				}
			}

			$new_bg_value = trim($new_bg_value);
			if ($i != $number_of_values - 1)
				$new_bg_value .= ',';
		}

		// Delete all background-properties
		foreach ($background_prop_default as $bg_property => $default_value) {
			unset($input_css[$bg_property]);
		}

		// Add new background property
		if ($new_bg_value !== '')
			$input_css['background'] = $new_bg_value . $important;
		elseif(isset ($input_css['background']))
			$input_css['background'] = 'none';

		return $input_css;
	}

	/**
	 * Dissolve font property
	 * @param string $str_value
	 * @return array
	 * @version 1.3
	 * @see merge_font()
	 */
	function dissolve_short_font($str_value) {
		$font_prop_default = & $GLOBALS['csstidy']['font_prop_default'];
		$font_weight = array('normal', 'bold', 'bolder', 'lighter', 100, 200, 300, 400, 500, 600, 700, 800, 900);
		$font_variant = array('normal', 'small-caps');
		$font_style = array('normal', 'italic', 'oblique');
		$important = '';
		$return = array('font-style' => null, 'font-variant' => null, 'font-weight' => null, 'font-size' => null, 'line-height' => null, 'font-family' => null);

		if (csstidy::is_important($str_value)) {
			$important = '!important';
			$str_value = csstidy::gvw_important($str_value);
		}

		$have['style'] = false;
		$have['variant'] = false;
		$have['weight'] = false;
		$have['size'] = false;
		// Detects if font-family consists of several words w/o quotes
		$multiwords = false;

		// Workaround with multiple font-family
		$str_value = csstidy_optimise::explode_ws(',', trim($str_value));

		$str_value[0] = csstidy_optimise::explode_ws(' ', trim($str_value[0]));

		for ($j = 0; $j < count($str_value[0]); $j++) {
			if ($have['weight'] === false && in_array($str_value[0][$j], $font_weight)) {
				$return['font-weight'] = $str_value[0][$j];
				$have['weight'] = true;
			} elseif ($have['variant'] === false && in_array($str_value[0][$j], $font_variant)) {
				$return['font-variant'] = $str_value[0][$j];
				$have['variant'] = true;
			} elseif ($have['style'] === false && in_array($str_value[0][$j], $font_style)) {
				$return['font-style'] = $str_value[0][$j];
				$have['style'] = true;
			} elseif ($have['size'] === false && (is_numeric($str_value[0][$j]{0}) || $str_value[0][$j]{0} === null || $str_value[0][$j]{0} === '.')) {
				$size = csstidy_optimise::explode_ws('/', trim($str_value[0][$j]));
				$return['font-size'] = $size[0];
				if (isset($size[1])) {
					$return['line-height'] = $size[1];
				} else {
					$return['line-height'] = ''; // don't add 'normal' !
				}
				$have['size'] = true;
			} else {
				if (isset($return['font-family'])) {
					$return['font-family'] .= ' ' . $str_value[0][$j];
					$multiwords = true;
				} else {
					$return['font-family'] = $str_value[0][$j];
				}
			}
		}
		// add quotes if we have several qords in font-family
		if ($multiwords !== false) {
			$return['font-family'] = '"' . $return['font-family'] . '"';
		}
		$i = 1;
		while (isset($str_value[$i])) {
			$return['font-family'] .= ',' . trim($str_value[$i]);
			$i++;
		}

		// Fix for 100 and more font-size
		if ($have['size'] === false && isset($return['font-weight']) &&
						is_numeric($return['font-weight']{0})) {
			$return['font-size'] = $return['font-weight'];
			unset($return['font-weight']);
		}

		foreach ($font_prop_default as $font_prop => $default_value) {
			if ($return[$font_prop] !== null) {
				$return[$font_prop] = $return[$font_prop] . $important;
			}
			else
				$return[$font_prop] = $default_value . $important;
		}
		return $return;
	}

	/**
	 * Merges all fonts properties
	 * @param array $input_css
	 * @return array
	 * @version 1.3
	 * @see dissolve_short_font()
	 */
	function merge_font($input_css) {
		$font_prop_default = & $GLOBALS['csstidy']['font_prop_default'];
		$new_font_value = '';
		$important = '';
		// Skip if not font-family and font-size set
		if (isset($input_css['font-family']) && isset($input_css['font-size'])) {
			// fix several words in font-family - add quotes
			if (isset($input_css['font-family'])) {
				$families = explode(",", $input_css['font-family']);
				$result_families = array();
				foreach ($families as $family) {
					$family = trim($family);
					$len = strlen($family);
					if (strpos($family, " ") &&
									!(($family{0} == '"' && $family{$len - 1} == '"') ||
									($family{0} == "'" && $family{$len - 1} == "'"))) {
						$family = '"' . $family . '"';
					}
					$result_families[] = $family;
				}
				$input_css['font-family'] = implode(",", $result_families);
			}
			foreach ($font_prop_default as $font_property => $default_value) {

				// Skip if property does not exist
				if (!isset($input_css[$font_property])) {
					continue;
				}

				$cur_value = $input_css[$font_property];

				// Skip if default value is used
				if ($cur_value === $default_value) {
					continue;
				}

				// Remove !important
				if (csstidy::is_important($cur_value)) {
					$important = '!important';
					$cur_value = csstidy::gvw_important($cur_value);
				}

				$new_font_value .= $cur_value;
				// Add delimiter
				$new_font_value .= ( $font_property === 'font-size' &&
								isset($input_css['line-height'])) ? '/' : ' ';
			}

			$new_font_value = trim($new_font_value);

			// Delete all font-properties
			foreach ($font_prop_default as $font_property => $default_value) {
				if ($font_property!=='font' OR !$new_font_value)
					unset($input_css[$font_property]);
			}

			// Add new font property
			if ($new_font_value !== '') {
				$input_css['font'] = $new_font_value . $important;
			}
		}

		return $input_css;
	}

}