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Prefuse is a set of software tools for creating rich interactive data visualizations in the Java programming language.

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package prefuse.data.io;

import java.io.BufferedOutputStream;
import java.io.OutputStream;
import java.io.PrintStream;

import prefuse.data.Table;
import prefuse.util.TypeLib;
import prefuse.util.collections.IntIterator;

/**
 * TableWriter for fixed-width text files, that encode one row of table
 * data per line use a fixed number of characters for each data column.
 * Writing such tables requires use of a schema description that describes
 * the fixed-widths for each individual column.
 * The {@link prefuse.data.io.FixedWidthTextTableSchema} class provides
 * this functionality. A schema description must be written separately into
 * a different file.
 * 
 * @author jeffrey heer
 */
public class FixedWidthTextTableWriter extends AbstractTableWriter {

	// the schema description
	private FixedWidthTextTableSchema m_schema;
	
	/**
	 * Creates a new FixedWidthTextTableWriter using the given schema.
	 * @param schema the schema description of the fixed-width text column lengths
	 */
	public FixedWidthTextTableWriter(FixedWidthTextTableSchema schema) {
		m_schema = schema;
	}
	
	/**
	 * Creates a new FixedWidthTextTableWriter using the schema at
	 * the given location.
	 * @param location a location string (filename, URL, or resource 
	 * locator) for the schema description of the fixed-width text column lengths
	 * @throws DataIOException if an IO exception occurs while loading the schema
	 */
	public FixedWidthTextTableWriter(String location) throws DataIOException {
		this(FixedWidthTextTableSchema.load(location));
	}
	
	// ------------------------------------------------------------------------    
    
    /**
     * Get the schema description describing the data columns' fixed widths
     * @return the fixed-width table schema description
     */
    public FixedWidthTextTableSchema getFixedWidthSchema() {
        return m_schema;
    }

    /**
     * Set the schema description describing the data columns' fixed widths
     * @param schema the fixed-width table schema description
     */
    public void setFixedWidthSchema(FixedWidthTextTableSchema schema) {
        m_schema = schema;
    }
    
	// ------------------------------------------------------------------------

    /**
     * @see prefuse.data.io.TableWriter#writeTable(prefuse.data.Table, java.io.OutputStream)
     */
    public void writeTable(Table table, OutputStream os) throws DataIOException {
        try {            
            // get print stream
            PrintStream out = new PrintStream(new BufferedOutputStream(os));
            
            // build array of column padding
            char[] pad = new char[table.getColumnCount()];
            boolean[] pre = new boolean[table.getColumnCount()];
            for (int i=0; i