/**
  *
  * @copyright Copyright 2001-2008 Laszlo Systems, Inc.  All Rights Reserved.
  *            Use is subject to license terms.
  *
  * @affects lzcssstylesheet
  * @access public
  * @topic LFC
  * @subtopic CSS
  */

/**
  * This service represents a CSS Style sheet
  * Introduced in DOM Level 2:
  * interface CSSStyleSheet : stylesheets::StyleSheet {
  * readonly attribute CSSRule          ownerRule;
  * readonly attribute CSSRuleList      cssRules;
  * unsigned long      insertRule(in DOMString rule, 
  * in unsigned long index)
  * raises(DOMException);
  *  void               deleteRule(in unsigned long index)
  *                                        raises(DOMException);
  * };
  * 
  */

class LzCSSStyleSheet extends LzStyleSheet {


/**
  * @param String title: Title
  * @param String href: Location of the style sheet.
  * @param String media: Media where the document is to be rendered.
  * @param String sstype: Language of the style sheet resource.
  * @param String ownerRule:
  * @param Array cssRules: Initial stylesheet rules array
  * @access public
 */ 
function LzCSSStyleSheet( title, href, media, sstype, ownerRule, cssRules ) {
    super (title, href, media, sstype);

    this.ownerRule = ownerRule;
    this.cssRules = cssRules;
}

/** @access private */
var ownerRule = null;

/** @access private */
var cssRules = null;


/**
 * insertRule Used to insert a new rule into the style sheet. The new rule now
 * becomes part of the cascade. 
 * 
 * <p>Error conditions: 
 * <ul>
 * <li>HIERARCHY_REQUEST_ERR: Raised if the rule cannot be inserted at the specified
 * index e.g. if an @import rule is inserted after a standard rule set or other
 * at-rule.</li>
 * <li>INDEX_SIZE_ERR: Raised if the specified index is not a valid insertion point.</li>
 * <li>NO_MODIFICATION_ALLOWED_ERR: Raised if this style sheet is readonly.</li>
 * <li>SYNTAX_ERR: Raised if the specified rule has a syntax error and is unparsable</li>
 * </ul>
 * </p>
 *
 * @access public
 *
 * @param String rule: The parsable text representing the rule. For rule
 * sets this contains both the selector and the style declaration. For
 * at-rules, this specifies both the at-identifier and the rule content.
 * 
 * @param Number index: The index within the style sheet's rule list
 * of the rule before which to insert the specified rule. If the specified
 * index is equal to the length of the style sheet's rule collection, the rule
 * will be added to the end of the style sheet.
 * 
 * @return Number: The index within the style sheet's rule collection of
 * the newly inserted rule. 
 *
 */ 
function insertRule (rule, index) {
    if (!this.cssRules) {
        this.cssRules = [];
    }
    
    if (index < 0) {
        // INDEX_SIZE_ERR
        return null;
    } 
    if (index < this.cssRules.length) {
        // INDEX_SIZE_ERR
        this.cssRules.splice(index,0,rule);
        return index; 
    } 
    if (index == this.cssRules.length) {
        // the array.push returns the new rule's index + 1
        // we correct with -1.
        return (this.cssRules.push(rule) - 1);
    }
    // INDEX_SIZE_ERR
    return null; 
}

} // End of LzCSSStyleSheet
lz.CSSStyleSheet = LzCSSStyleSheet;  // publish