/**
 * @class Ext.ComponentMgr
 * @extends Ext.AbstractManager
 * 
Provides a registry of all Components (instances of {@link Ext.Component} or any subclass
 * thereof) on a page so that they can be easily accessed by {@link Ext.Component component}
 * {@link Ext.Component#id id} (see {@link #get}, or the convenience method {@link Ext#getCmp Ext.getCmp}).
 * 
This object also provides a registry of available Component classes
 * indexed by a mnemonic code known as the Component's {@link Ext.Component#xtype xtype}.
 * The {@link Ext.Component#xtype xtype} provides a way to avoid instantiating child Components
 * when creating a full, nested config object for a complete Ext page.
 * 
A child Component may be specified simply as a config object
 * as long as the correct {@link Ext.Component#xtype xtype} is specified so that if and when the Component
 * needs rendering, the correct type can be looked up for lazy instantiation.
 * 
For a list of all available {@link Ext.Component#xtype xtypes}, see {@link Ext.Component}.
 * @singleton
 */
Ext.define('Ext.ComponentMgr', {
    extend: 'Ext.AbstractManager',
    
    singleton: true,
    
    typeName: 'xtype',

    
/**
     * Creates a new Component from the specified config object using the
     * config object's {@link Ext.component#xtype xtype} to determine the class to instantiate.
     * @param {Object} config A configuration object for the Component you wish to create.
     * @param {Constructor} defaultType The constructor to provide the default Component type if
     * the config object does not contain a xtype. (Optional if the config contains a xtype).
     * @return {Ext.Component} The newly instantiated Component.
     */
    create: function(component, defaultType){
        if (component instanceof Ext.AbstractComponent) {
            return component;
        }
        else if (Ext.isString(component)) {
            return Ext.createByAlias('widget.' + component);
        }
        else {
            var type = component.xtype || defaultType,
                config = component;
            
            return Ext.createByAlias('widget.' + type, config);
        }
    },

    registerType: function(type, cls) {
        this.types[type] = cls;
        cls[this.typeName] = type;
        cls.prototype[this.typeName] = type;
    }
});