symbol.java

java和flash混合编程

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 * Copyright (c) 2001, David N. Main, All rights reserved.
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package com.anotherbigidea.flash.movie;

import java.io.IOException;

import com.anotherbigidea.flash.interfaces.SWFTagTypes;

/**
 * Base class for all defined symbols
 */
public abstract class Symbol
{
    protected int id = 0;
    
    protected Symbol() {}
    
    protected Symbol( int id )
    {
       this.id = id; 
    }
    
    /**
     * Get the internal SWF id for the symbol.  This will always be
     * zero for a Movie that was not loaded from an existing SWF until
     * the Movie is written out.
     */
    public int getId() { return id; }    
    
    /**
     * Make sure that the Symbol is fully defined in the given Movie and
     * return the character id
     * @param tags a vector into which to place any definition tags required
     */
    protected int define( Movie movie, 
                          SWFTagTypes timelineWriter,
                          SWFTagTypes definitionWriter )
        throws IOException 
    {
        Integer integerId = (Integer)movie.definedSymbols.get( this );
                
        if( integerId == null )
        {
            integerId = new Integer( defineSymbol( movie, 
                                                   timelineWriter,
                                                   definitionWriter ) );
            movie.definedSymbols.put( this, integerId );
        }

        id = integerId.intValue();
        return id;
    }

    protected int getNextId( Movie movie )
    {
        return movie.maxId++;
    }

    /**
     * Override to provide symbol definition
     * @return the new symbol id
     */
    protected abstract int defineSymbol( Movie movie, 
                                         SWFTagTypes timelineWriter,
                                         SWFTagTypes definitionwriter )
        throws IOException;    
}