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

Java Source | 1996-08-14 | 7.6 KB | 294 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.


    @(#)Chart.java  0.00 01-Jan-96

        A simple PageView that views charts in one PaperSection.

    Authors:

       alkarao   Alka Rao
       Nimesh    Nimesh Shah
       jlee      James Lee

    Version Ident:

        $Header$

    History:

        0.00 05-Feb-96  alkarao         Initial Creation
        0.01 15-Feb-96  Nimesh          Revised
             23-Feb-96  Nimesh & jlee   Fixed resizing problem of DJChart based on observer notification

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

package pj.awt;

import pj.awt.PageView;
import pj.awt.DJChart;
import pj.io.Paper;
import pj.io.PaperSection;
import pj.io.PaperStory;
import pj.io.StoryContainerNotification;

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Font;
import java.awt.Insets;
import java.awt.Component;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Panel;
import java.awt.Canvas;
import java.awt.Container;
import java.awt.Color;

import java.lang.Integer;
import java.util.Observable;
import java.util.Observer;
import java.util.StringTokenizer;
import java.util.NoSuchElementException;



/**
 * A simple PageView that observes one PaperSection and displays
 * data from that section in a chart form.
 * Charts may be used inside other pages or may be used as standalone pages.
 *
 * @version 0.00 05-Feb-96
 * @author  alkarao
*/
public class Chart extends PageView implements Observer
    {

    // --- Instance variables
    private Paper           paper;
    private String          chartTitle;
    private String          strPaperSection;
    private StringTokenizer stChartData;
    private int             xValues[];
    private int             yValues[];
    private int             nDataValues;
    private DJChart         djChart;
    private int             bottom, left;
    private int             outerwt, outerht;

    // --- Public constructors

    /**
     * Construct a Chart as a standalone page.
     * @param pagename  The name of the standalone page.
     * @param section   The name of the observed section.
     * @param p         The paper that contains the observed section.
    */
    public Chart(String pagename, String title, String section, Paper p)
        {
        super(pagename);
        chartTitle = title;
        strPaperSection = section;

        paper = p;

        xValues = new int[50];
        yValues = new int[50];

        paper.addObserver(this);

        Initialize();   // get x and y values from the section data

        if(nDataValues > 1)
            {
            djChart = new DJChart(xValues, yValues, nDataValues, chartTitle);
            add("Center",djChart);
            }
        System.out.println("Debug-Chart:constructed");
        }

    /**
     * Construct a Chart as a page component.
     * @param section   The name of the observed section.
     * @param paper     The paper that contains the observed section.
    */
    public Chart(String section, Paper paper)
        {
        this(null,null,section,paper);
        }

    // --- Public operations

    /**
     * @return The number of stories in the observed section.
    */
    public int countViews()
        {
        return getSection().numStories();
        }

    /**
     * Update view upon notification from a PaperSection. The x-y vlaue
     * pairs are initialized.
     * @param src The object that sent or forwarded the notification.
     * @param arg The notification.  An instance of StoryContainerNotification
     * is expected.
    */
    public synchronized void update(Observable src, Object arg)
        {
        if ( !(arg instanceof StoryContainerNotification) )
            return;

        StoryContainerNotification scn = (StoryContainerNotification) arg;

        if ( !(strPaperSection.equals(scn.strSubsect)) )
            return;

        if (scn.newState != PaperSection.stateAdded)
            return;

        Initialize();

        if(djChart != null)
            remove(djChart);

        djChart = new DJChart(xValues, yValues, nDataValues, chartTitle);
        add("Center",djChart);

        layout();

        } // update


    public int getCount()
        {
        return (nDataValues+1);
        }

    public int[] getXValues()
        {
        return (xValues);
        }

    public int[] getYValues()
        {
        return (yValues);
        }

    public String getTitle()
        {
        return chartTitle;
        }

    public DJChart getChart()
        {
        return djChart;
        }


    public DJChart getDJChart()
        {
        return djChart;
        }

    public synchronized void reshape(int x, int y, int width, int height)
        {
        bottom = y;
        left =   x;

        outerwt = width;
        outerht = height;

        super.reshape(x, y, width, height);

        if ( djChart != null )
            {
            djChart.resizeDjChart( width, height );
            }
        else
            {
            djChart = new DJChart();
            djChart.resizeDjChart( width, height );
            }
        }
    // --- Protected operations

    protected String formatToString(PaperStory story)
        {
        return story.getTitle() + "\n" + story.getBody() + "\n";
        }

    protected PaperSection getSection()
        {
        return paper.section(strPaperSection);
        }

     /**
       * Get x and y values from the specified section
       * Assumptions: values are integer values
       * Maximum of 50 x-y pairs are in any section
      */
    protected void Initialize()
        {
        // convert paper section to string
        if (getSection().numStories() < 1)
            return;

        String tempStr;

        try
            {
            tempStr = getSection().firstStory().getBody();
            }
        catch(NoSuchElementException e)
            {
            return;
            }

        // create the tokenizer
        stChartData = new StringTokenizer(tempStr,  ".,\n\r");

        TokenLoop:
        for (int i=0; i<50 ; i++)
            {
            // Implementation note: countTokens() does not seem to be
            // working correctly.  Hence this loop continues until an
            // exception occurs, rather than politely using countTokens
            // to limit iterations.
            try
                {
                String strX = stChartData.nextToken();
                String strY = stChartData.nextToken();
                xValues[i] =  Integer.parseInt(strX);
                yValues[i] =  Integer.parseInt(strY);
                stChartData.nextToken();
                }
            catch (NoSuchElementException e)
                {
                nDataValues = i;
                break TokenLoop;
                }
            }//for

        nDataValues++;
        }






    } // Chart