frameworks/projects/framework/src/mx/utils/ArrayUtil.as

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//  this work for additional information regarding copyright ownership.
//  The ASF licenses this file to You under the Apache License, Version 2.0
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package mx.utils
{

/**
 *  The ArrayUtil utility class is an all-static class
 *  with methods for working with arrays within Flex.
 *  You do not create instances of ArrayUtil;
 *  instead you call static methods such as the 
 *  <code>ArrayUtil.toArray()</code> method.
 *  
 *  @langversion 3.0
 *  @playerversion Flash 9
 *  @playerversion AIR 1.1
 *  @productversion Flex 3
 */
public class ArrayUtil
{
    include "../core/Version.as";
	
	import mx.collections.IList;

    //--------------------------------------------------------------------------
    //
    //  Class methods
    //
    //--------------------------------------------------------------------------

    /**
     *  Ensures that an Object can be used as an Array.
     *
     *  <p>If the Object is already an Array, it returns the object. 
     *  If the object is not an Array, it returns an Array
     *  in which the only element is the Object.
	 *  If the Object implements IList it returns the IList's array.
     *  As a special case, if the Object is null,
     *  it returns an empty Array.</p>
     *
     *  @param obj Object that you want to ensure is an array.
     *
     *  @return An Array. If the original Object is already an Array, 
     *  the original Array is returned. If the original Object is an
	 *  IList then it's array is returned. Otherwise, a new Array whose
     *  only element is the Object is returned or an empty Array if 
     *  the Object was null. 
     *  
     *  @langversion 3.0
     *  @playerversion Flash 9
     *  @playerversion AIR 1.1
     *  @productversion Flex 3
     */
    public static function toArray(obj:Object):Array
    {
        if (obj == null) 
            return [];
        
		else if (obj is Array)
			return obj as Array;
		
		else if (obj is IList)
			return (obj as IList).toArray();
        
        else
            return [ obj ];
    }
    
    /**
     *  Returns the index of the item in the Array.
     * 
     *  @param item The item to find in the Array. 
     *
     *  @param source The Array to search for the item.
     * 
     *  @return The index of the item, and -1 if the item is not in the list.
     *  
     *  @langversion 3.0
     *  @playerversion Flash 9
     *  @playerversion AIR 1.1
     *  @productversion Flex 3
     */
    public static function getItemIndex(item:Object, source:Array):int
    {
        var n:int = source.length;
        for (var i:int = 0; i < n; i++)
        {
            if (source[i] === item)
                return i;
        }

        return -1;           
    }
}

}