source: trunk/workshop-routing-foss4g/web/ext/src/util/CSS.js @ 81

/*!
 * Ext JS Library 3.4.0
 * Copyright(c) 2006-2011 Sencha Inc.
 * licensing@sencha.com
 * http://www.sencha.com/license
 */
/**
 * @class Ext.util.CSS
 * Utility class for manipulating CSS rules
 * @singleton
 */
Ext.util.CSS = function(){
        var rules = null;
        var doc = document;

    var camelRe = /(-[a-z])/gi;
    var camelFn = function(m, a){ return a.charAt(1).toUpperCase(); };

   return {
   /**
    * Creates a stylesheet from a text blob of rules.
    * These rules will be wrapped in a STYLE tag and appended to the HEAD of the document.
    * @param {String} cssText The text containing the css rules
    * @param {String} id An id to add to the stylesheet for later removal
    * @return {StyleSheet}
    */
   createStyleSheet : function(cssText, id){
       var ss;
       var head = doc.getElementsByTagName("head")[0];
       var rules = doc.createElement("style");
       rules.setAttribute("type", "text/css");
       if(id){
           rules.setAttribute("id", id);
       }
       if(Ext.isIE){
           head.appendChild(rules);
           ss = rules.styleSheet;
           ss.cssText = cssText;
       }else{
           try{
                rules.appendChild(doc.createTextNode(cssText));
           }catch(e){
               rules.cssText = cssText;
           }
           head.appendChild(rules);
           ss = rules.styleSheet ? rules.styleSheet : (rules.sheet || doc.styleSheets[doc.styleSheets.length-1]);
       }
       this.cacheStyleSheet(ss);
       return ss;
   },

   /**
    * Removes a style or link tag by id
    * @param {String} id The id of the tag
    */
   removeStyleSheet : function(id){
       var existing = doc.getElementById(id);
       if(existing){
           existing.parentNode.removeChild(existing);
       }
   },

   /**
    * Dynamically swaps an existing stylesheet reference for a new one
    * @param {String} id The id of an existing link tag to remove
    * @param {String} url The href of the new stylesheet to include
    */
   swapStyleSheet : function(id, url){
       this.removeStyleSheet(id);
       var ss = doc.createElement("link");
       ss.setAttribute("rel", "stylesheet");
       ss.setAttribute("type", "text/css");
       ss.setAttribute("id", id);
       ss.setAttribute("href", url);
       doc.getElementsByTagName("head")[0].appendChild(ss);
   },
   
   /**
    * Refresh the rule cache if you have dynamically added stylesheets
    * @return {Object} An object (hash) of rules indexed by selector
    */
   refreshCache : function(){
       return this.getRules(true);
   },

   // private
   cacheStyleSheet : function(ss){
       if(!rules){
           rules = {};
       }
       try{// try catch for cross domain access issue
           var ssRules = ss.cssRules || ss.rules;
           for(var j = ssRules.length-1; j >= 0; --j){
               rules[ssRules[j].selectorText.toLowerCase()] = ssRules[j];
           }
       }catch(e){}
   },
   
   /**
    * Gets all css rules for the document
    * @param {Boolean} refreshCache true to refresh the internal cache
    * @return {Object} An object (hash) of rules indexed by selector
    */
   getRules : function(refreshCache){
                if(rules === null || refreshCache){
                        rules = {};
                        var ds = doc.styleSheets;
                        for(var i =0, len = ds.length; i < len; i++){
                            try{
                        this.cacheStyleSheet(ds[i]);
                    }catch(e){} 
                }
                }
                return rules;
        },
        
        /**
    * Gets an an individual CSS rule by selector(s)
    * @param {String/Array} selector The CSS selector or an array of selectors to try. The first selector that is found is returned.
    * @param {Boolean} refreshCache true to refresh the internal cache if you have recently updated any rules or added styles dynamically
    * @return {CSSRule} The CSS rule or null if one is not found
    */
   getRule : function(selector, refreshCache){
                var rs = this.getRules(refreshCache);
                if(!Ext.isArray(selector)){
                    return rs[selector.toLowerCase()];
                }
                for(var i = 0; i < selector.length; i++){
                        if(rs[selector[i]]){
                                return rs[selector[i].toLowerCase()];
                        }
                }
                return null;
        },
        
        
        /**
    * Updates a rule property
    * @param {String/Array} selector If it's an array it tries each selector until it finds one. Stops immediately once one is found.
    * @param {String} property The css property
    * @param {String} value The new value for the property
    * @return {Boolean} true If a rule was found and updated
    */
   updateRule : function(selector, property, value){
                if(!Ext.isArray(selector)){
                        var rule = this.getRule(selector);
                        if(rule){
                                rule.style[property.replace(camelRe, camelFn)] = value;
                                return true;
                        }
                }else{
                        for(var i = 0; i < selector.length; i++){
                                if(this.updateRule(selector[i], property, value)){
                                        return true;
                                }
                        }
                }
                return false;
        }
   };   
}();