AbstractShellProfileNode.java

package com.vladium.utils;

// ----------------------------------------------------------------------------
/**
 * Abstract base class for all shell pseudo-node implementations in this package.
 * It is used primarily to lower memory consumption by shell nodes.
 * 
 * @author (C) <a href="http://www.javaworld.com/columns/jw-qna-index.shtml">Vlad Roubtsov</a>, 2003
 */
abstract class AbstractShellProfileNode extends AbstractProfileNode
{
    // public: ................................................................    

    public final Object object ()
    {
        return null;
    }
    
    public final IObjectProfileNode shell ()
    {
        return null;
    }
    
    public final IObjectProfileNode [] children ()
    {
        return EMPTY_OBJECTPROFILENODE_ARRAY;
    }
    
    public final int refcount ()
    {
        return 0;
    }
    
    public final boolean traverse (final INodeFilter filter, final INodeVisitor visitor)
    {
        if ((visitor != null) && ((filter == null) || filter.accept (this)))
        {
            visitor.previsit (this);
            visitor.postvisit (this);
            
            return true;
        }
        
        return false;
    }
    
    // protected: .............................................................

    // package: ...............................................................
    
    
    AbstractShellProfileNode (final IObjectProfileNode parent)
    {
        super (parent);
    }
    
    // private: ...............................................................

} // end of class
// ----------------------------------------------------------------------------