UniqueList

/*
    CASA Lib for ActionScript 3.0
    Copyright (c) 2011, Aaron Clinger & Contributors of CASA Lib
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    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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*/
package org.casalib.collection {
    import org.casalib.collection.List;
    import org.casalib.util.ArrayUtil;
    
    /**
        An ordered or sequence collection that contains no duplicates. Similar to Java's Set but contains all the methods of List.
        
        @author Aaron Clinger
        @version 04/27/08
        @see List
    */
    public class UniqueList extends List {
        
        
        /**
            Creates a new UniqueList;
            
            @param collection: An Array of items to populate the contents of this list; UniqueList will only accept the unique elements of the Array.
        */
        public function UniqueList(collection:Array = null) {
            super((collection == null) ? null : ArrayUtil.removeDuplicates(collection));
        }
        
        /**
            {@inheritDoc}
            
            @param item: {@inheritDoc}
            @return Returns true if the element was unique and added; otherwise false.
        */
        override public function addItem(item:*):Boolean {
            if (this.contains(item))
                return false;
            
            this._collection.push(item);
            
            return true;
        }
        
        /**
            {@inheritDoc}
            
            @param item: {@inheritDoc}
            @param index: {@inheritDoc}
            @return Returns true if the element was unique and added; otherwise false.
        */
        override public function addItemAt(item:*, index:int):Boolean {
            if (this.contains(item))
                return false;
            
            this._collection.splice(index, 0, item);
            
            return true;
        }
        
        /**
            Modifies original list by adding all the elements from another list that aren't already present.
            
            @param items: {@inheritDoc}
            @return Returns true if any elements of the specified list were unique and added; otherwise false.
        */
        override public function addItems(items:IList):Boolean {
            var uniqueItems:Array = items.toArray();
            
            ArrayUtil.removeItems(uniqueItems, this.toArray());
            
            if (uniqueItems.length == 0)
                return false;
            
            this._collection = this._collection.concat(uniqueItems);
            
            return true;
        }
        
        /**
            Modifies original list by adding all the elements from another list, that aren't already present, at a specified position.
            
            @param items: {@inheritDoc}
            @param index: {@inheritDoc}
            @return Returns true if any elements of the specified list were unique and added; otherwise false.
        */
        override public function addItemsAt(items:IList, index:int = 0x7fffffff):Boolean {
            var uniqueItems:Array = items.toArray();
            
            ArrayUtil.removeItems(uniqueItems, this.toArray());
            
            if (uniqueItems.length == 0)
                return false;
            
            return ArrayUtil.addItemsAt(this._collection, uniqueItems, index);
        }
        
        /**
            {@inheritDoc}
            
            @param item: {@inheritDoc}
            @param index: {@inheritDoc}
            @return {@inheritDoc}
            @throws Error if you try to set an item that is already contained in the list.
        */
        override public function setItem(item:*, index:int):* {
            if (this.contains(item))
                throw new Error('List already contains specified item (' + item + ').');
            
            return this._collection.splice(index, 1, item)[0];
        }
        
        /**
            {@inheritDoc}
            
            @param startIndex: {@inheritDoc}
            @param endIndex: {@inheritDoc}
            @return {@inheritDoc}
        */
        override public function subList(startIndex:int = 0, endIndex:int = 16777215):IList {
            return new UniqueList(this._collection.slice(startIndex, endIndex));
        }
        
        /**
            {@inheritDoc}
            
            @return {@inheritDoc}
        */
        override public function clone():IList {
            return new UniqueList(this.toArray());
        }
    }
}