Confusing code in org.apache.flex.collections.ArrayList

[Gary Yang]

Hi,

I am reading

org.apache.flex.collections.ArrayList.as

I am confused about this private property:



    /**
     *  @private
     *  Indicates if events should be dispatched.
     *  calls to enableEvents() and disableEvents() effect the value when
== 0
     *  events should be dispatched.
     */
    private var _dispatchEvents:int = 0;

It is changed in following 2 private methods only:


    /**
     *  Disables event dispatch for this list.
     *  To re-enable events call enableEvents(), enableEvents() must be
called
     *  a matching number of times as disableEvents().
     *
     *  @langversion 3.0
     *  @playerversion Flash 9
     *  @playerversion AIR 1.1
     *  @productversion Flex 3
     */
    private function disableEvents():void
    {
        _dispatchEvents--;
    }



    /**
     *  Enables event dispatch for this list.
     *
     *  @langversion 3.0
     *  @playerversion Flash 9
     *  @playerversion AIR 1.1
     *  @productversion Flex 3
     */
    private function enableEvents():void
    {
        _dispatchEvents++;
        if (_dispatchEvents > 0)
            _dispatchEvents = 0;
    }



And these 2 methods only get called in constructor:


    public function ArrayList(source:Array = null)
    {
        super();

        disableEvents();
        this.source = source;
        enableEvents();
    }



I think this private property can be simplified as:

private var _constructed:Boolean = false;


and:
    public function ArrayList(source:Array = null)
    {
        super();

        this.source = source;
        _constructed = true;
    }

Could anyone help me see the difference plz??

Best,

-Gary