The Net: Ultimate Internet Guide/WWLCD1.ISO/pc/java/un2maiq4/pjjava/src/pj/awt/arrayformatter.java

Java Source | 1996-08-14 | 8.5 KB | 292 lines

/*---------------------------------------------------------------------------

    Written by the Personal Journal developers of Dow Jones & Company, Inc.

    Dow Jones makes no representations or warranties about
    the suitability of this software, either express or
    implied, including but not limited to the implied warranties
    of merchantability, fitness for a particular purpose,
    or non-infringement.  Dow Jones will not be liable for
    any damages suffered by a user as a result of using,
    modifying or distributing this software or its derivatives.


    @(#)ArrayFormatter.java  0.00 05-Feb-96

        A StoryFormatter that creates a 4-column layout from a comma-delimited
        array.

    Authors:

        rphall   Rick Hall

    Version Ident:

        $Header: /PjJavaClient/src/pj/awt/ArrayFormatter.java 3     2/13/96 9:56p Rphall $

    History:

        0.00 05-Feb-96  rphall   Initial Creation

---------------------------------------------------------------------------*/

package pj.awt;

import pj.awt.StoryFormatter;

import collections.Assertable;
import collections.ImplementationError;
import java.util.StringTokenizer;
import pj.io.Paper;
import pj.io.PaperStory;

/**
 * A special-purpose StoryFormatter that creates a 4-column layout from
 * a sequence of entries.  The entries are grouped four to a line, and
 * typically separated by commas. When formatted, the left-most column
 * is left-justified, and remaining columns are right justified.
 * ArrayFormatter is designed for formatting stock indexes, exchange rates,
 * treasurys, and quotes, but a subclass of ArrayFormatter is also used to
 * format Weather pages.
 * <P>
 * Column positions are specified in units of a space-width.  That is, if
 * the space character in a particular font has a screen width of 5 pixels,
 * then a column position of "7" would correspond to 35 pixels from the left.
 * <pre>
 * |<--Position_0-->
 * |<-----------------------------Position_1-->|
 * |<--------------------------------------------Position_2-->|
 * |<-----------------------------------------------------------Position_3-->|
 *
 *                  Column 0            Column 1       Column 2       Column 3
 *                  Entry                  Entry          Entry          Entry
 *                  A long entry    A long entry   A long entry   A long entry
 *                  Another entry  Another entry  Another entry  Another entry
 *                  Entry                  Entry          Entry          Entry
 *
 * </pre>
 * NOTE: THE CURRENT IMPLEMENTATION ASSUMES THE CURRENT FONT IS A FIXED-PITCH
 * FONT (e.g. Courier)
 *
 * @see        pj.io.StoryFormatter
 * @version    0.00 05-Feb-96
 * @author     rphall
*/
public class ArrayFormatter implements StoryFormatter, Assertable
    {



    // --- Class variables

    private static final int[] aiStkIdx = {0, 25, 35, 45};
    private static final int[] aiExch   = {0, 25, 35, 45};
    private static final int[] aiTreas  = {0, 25, 35, 45};
    private static final int[] aiPort   = {0, 15, 25, 35};

    private static final String strEOL  = "\r\n";

    private static final String[] hdrStkIdx =
            {
            " ,Previous,Last,Change",
            " ,   Close,    ,      ",
            " ,        ,    ,      "
            };

    private static final String[] hdrExch =
            {
            " ,Previous,Last,Change",
            " ,   Close,    ,      ",
            " ,        ,    ,      "
            };

    private static final String[] hdrTreas  =
            {
            " ,Ask,Change,Yield",
            " ,   ,      ,     "
            };

    private static final String[] hdrPort =
            {
            " ,Previous,Last,Change",
            " ,   Close,    ,      ",
            " ,        ,    ,      "
            };


    // --- Instance variables

    private int[] pos;
    private String[] header;
    private String strEntryDelim;


    // --- Public constructors

    /**
     * General purpose constructor.
     *
     * @param p0 Position of left-edge of column 0
     * @param p1 Position of right-edge of column 1
     * @param p2 Position of right-edge of column 2
     * @param p3 Position of right-edge of column 3
     * @param delim Delimiters used to separate entries in a line.
    */
    public ArrayFormatter(int p0, int p1, int p2, int p3, String delim)
        {
        pos = new int[4];
        pos[0] = p0;
        pos[1] = p1;
        pos[2] = p2;
        pos[3] = p3;
        strEntryDelim = delim;
        }

    /**
     * A special-purpose constructor that sets up column
     * positions for Stock Indexes, Exchange Rates, Treasurys
     * and Quotes.
     *
     * @param strId An string equal to Paper.idMrkStkIdx, Paper.idMrkExch,
     * Paper.idMrkTreas or Paper.idPortQuote
    */
    public ArrayFormatter(String strId)
        {
        pos = new int[4];
        strEntryDelim = ",";

        if (strId.equals(Paper.idMrkStkIdx) )
            {
            assignPositions( aiStkIdx );
            header = hdrStkIdx;
            }

        else if (strId.equals(Paper.idMrkExch) )
            {
            assignPositions( aiExch );
            header = hdrExch;
            }

        else if (strId.equals(Paper.idMrkTreas) )
            {
            assignPositions( aiTreas );
            header = hdrTreas;
            }

        else if (strId.equals(Paper.idPortQuote) )
            {
            assignPositions( aiPort );
            header = hdrPort;
            }

        else
            assert(false);

        } // special-purpose constructor

    // --- Public operations

    /**
     * @param story The PaperStory to format.
     * @return A String representation of the story.
    */
    public String formatToString(PaperStory story)
        {
        String strReturn = "";

        // Create column headers
        if (header != null)
            for (int i=0; i<header.length; i++)
                {
                strReturn += formatToString( header[i] );
                strReturn += strEOL;
                }

        // Loop over lines in the story body
        StringTokenizer stLines = new StringTokenizer
                ( story.getBody(), "\n\r", /*returnTokens*/false );

        while (stLines.hasMoreTokens())
            {
            strReturn += formatToString( stLines.nextToken() );
            strReturn += strEOL;
            }

        return strReturn;
        } // public formatToString(PaperStory)

    /**
     * Raise an exception if predicate is false.
     * @see collections.Assertable
    */
    public void assert(boolean predicate) throws ImplementationError
        {
        ImplementationError.assert(this, predicate);
        }

    // --- Private operations

    /**
     * A helper utility
    */
    private void assignPositions(int[] ap)
        {
        for (int i=0; i<4; i++) pos[i] = ap[i];
        }

    /**
     * @param line A line to format.  (The line should NOT be
     * terminated with CRLF.)
     * @return A formatted version of the line.
    */
    private String formatToString(String line)
        {
        String strReturn = "";
        int i;
        String[] entries = { "", "", "", "" };

        // Treat line as entries delimited by commas
        //System.out.println("Debug line == " + line);
        StringTokenizer stEntries = new StringTokenizer
                ( line, strEntryDelim, /*returnTokens*/false );
        i = 0;
        while (stEntries.hasMoreTokens())
            {
            String entry = stEntries.nextToken();
            //System.out.println("Debug entry == " + entry);
            entries[i] = entry;
            i++;
            }

        // Pad first entry
        int len = 0;
        while (len < pos[0])
            {
            strReturn += " ";
            len++;
            }

        strReturn += entries[0];
        len += entries[0].length();

        // Loop over remaining entries 1 - 3
        for (i=1; i<4; i++)
            {
            int start = pos[i] - entries[i].length();
            while (len < start)
                {
                strReturn += " ";
                len++;
                }
            strReturn += entries[i];
            len += entries[i].length();

            } // for entries

        return strReturn;
        } // private formatToString(String)



    }; // ArrayFormatter