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

Java Source | 1996-08-14 | 11.3 KB | 425 lines

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

    @(#)PjTicker.java  0.00 8-Feb-96

        A prototype of a scrolling, word-wrapping text area.

    Authors:

        lning    Lindee Ning

    Version Ident:

        $Header:$

    History:

        0.00  8-Feb-96  lning   Initial Creation
             25-Mar-96  jlee    Changed Ticker'super class from Panel to Canvas for
                                consistent use of Canvas component for drawing.
             25-Mar-96  jlee    Changed ticker's height from 25 to 27
             28-Mar-96  jlee    Used PjFinals for Ticker size
---------------------------------------------------------------------------*/

package pj.awt;

import pj.awt.PjFinals;

import java.awt.Canvas;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Event;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Image;

import java.util.Date;

/**
 * Display the default messages in a scrolling text area.
 *
 * @version 0.00 09-Feb-96
 * @author Lindee Ning
*/
public class Ticker extends Canvas implements Runnable
{
    // --- Public constructors: set default message, speed, text color, background color and size

    public Ticker()
        {
        m_astrMessages[0] = "Welcome to Personal Journal!  ...  ";
        m_astrMessages[1] = "This Just In From Personal Journal  ...  ";
        m_astrMessages[2] = "See This Just In For The Latest News Summaries  ...    At  ";
        m_astrMessages[3] = GetTimeDate();

        m_Speed = 4;
        m_MessageX = size().width;
        m_TxtColor = Color.white;
        m_BgColor = Color.black;
        m_Size = PjFinals.dimTickerSize;
        } // Ticker

    // --- Public operations


    /**
     * Set the message
    */

    public void SetMessage(String str)
        {
        if(!(str == ""))
            {
            m_astrNewMessages[0] = "This Just In From Personal Journal  ...  See This Just In For The Latest News Summaries  ...   ";
            m_astrNewMessages[1] = "Your Quotes (At Least 15-Minute Delayed):   ";
            m_astrNewMessages[2] = str + "  ...   At  ";
            m_astrNewMessages[3] = GetTimeDate();
            m_ChangeMessage = true;
            }
        } //SetMessage

    /**
     * Set the size
    */

    public void SetSize(Dimension size)
        {
        m_Size = size;
        } //SetSize


    /**
     * Set the speed
    */
    public void SetSpeed(int speed)
        {
        m_Speed = speed;
        } //SetSpeed

    /**
     * Set back the default speed
    */
    public void SetSpeed()
        {
        m_Speed = 4;
        } //SetSpeed


    /**
     * Set the start x-position on the ticker
    */
    public void SetStartPosition(int x)
        {
        m_MessageX = x;
        } //SetStartPosition

    /**
     * Set back the default start x-position on the ticker
    */
    public void SetStartPosition()
        {
        m_MessageX = size().width;
        } //SetStartPosition



    /**
     * Set the background color
    */

    public void SetBgColor(Color col)
        {
        m_BgColor = col;
        } //SetBgColor

    /**
     * Set the test color
    */

    public void SetTxtColor(Color col)
        {
        m_TxtColor = col;
        } //SetTxtColor

    /**
     * Set the minimum size of the ticker
    */

    public Dimension minimumSize()
        {
        return m_Size;
        } //minimunSize

    /**
     * Set the preferred size of the ticker
    */

    public Dimension preferredSize()
        {
        return minimumSize();
        } //preferredSize

    /**
     * Get the number of messages being displayed
    */

    public int GetNumMessages()
        {
        return m_astrMessages.length;
        } //GetNumMessages


    /**
     * Catch the mouse clicking
    */

    public boolean mouseDown(Event evt, int x, int y)
        {
        if(m_Action)
            {
            m_Action = false;
            m_Speed = 0;
            }
        else
            {
            m_Action = true;
            m_Speed = 4;
            }
        return true;
        } //mouseDown


    /**
     * Run the loop.
    */

    public void run()
        {
        while(true)
            {
            NextPos();
            try {Thread.sleep(100);}
            catch (InterruptedException e){ }
            }
        } //run


    /**
     * Paint
    */

    public void paint(Graphics gr) { update(gr); }

    /**
     *  Show the stuff
    */

    public synchronized void update(Graphics gr)
        {
        CreateParams();

        // fill area with bgcolor
        m_Graphics.setColor(m_BgColor);
        m_Graphics.fillRect(0,0,m_PrevRec.width,m_PrevRec.height);
        // draw the text
        m_Graphics.setColor(m_TxtColor);
        m_Graphics.setFont(m_Font);

        int head = m_MessageX;
        int tail = 0;
        for(int i=0;i<m_astrMessages.length;i++)
        {
            tail = head + m_MsgLengthVec[i];
            if(! ((head > m_PrevRec.width) || (tail < 0)) )
            {
                        m_Graphics.drawString((String) m_astrMessages[i], head, m_MessageY);
            }
            head = tail + 2;
        }

        // Display message on the screen
        gr.drawImage(m_Image,0,0,this);

        } //update



    // --- Private operations


    /**
     * Create the image Parameters.
    */
    private void CreateParams()
        {
        // if size changed. re-create image
        boolean bSizeChanged = false;
        if ((size().height != m_PrevRec.height) ||
            (size().width != m_PrevRec.width))
            {
            bSizeChanged = true;

            // delete old
            if (m_Graphics != null) { m_Graphics.finalize(); }
            if (m_Image != null)    { m_Image = null; }

            m_Image = createImage(size().width, size().height);
            m_Graphics = m_Image.getGraphics();


            m_PrevRec = size();
            }

            // if msg or size changed, re-calculate each message length and font
        if(m_ChangeMessage && m_endofdisplay)
            {
            m_astrMessages = m_astrNewMessages;
            m_endofdisplay = false;
            m_ChangeMessage = false;
            m_resetMessage = true;
            }
        if( m_resetMessage || bSizeChanged )
            {
            // Select a proper font size
            int refFont = 10;
            Font font = new Font("TimesRoman", Font.BOLD + Font.ITALIC, refFont);
            FontMetrics fontM = getFontMetrics(font);

            int fontH = fontM.getHeight();
            if(size().height > 10)
                fontH = refFont*(size().height - 10)/fontH;
            else
            fontH = 0;

            // calculate message length and X,Y position
            m_Font = new Font("TimesRoman", Font.BOLD + Font.ITALIC, fontH);
            FontMetrics fontMtx = getFontMetrics(m_Font);
            fontH = fontMtx.getHeight();
            m_MessageY = ((size().height-fontH) >> 1)+fontMtx.getAscent();

            m_MsgLength = 0;
            for(int i=0; i<m_astrMessages.length;i++)
                {
                m_MsgLengthVec[i] = fontMtx.stringWidth((String) m_astrMessages[i]);
                m_MsgLength += m_MsgLengthVec[i];
                }
            m_resetMessage = false;
            }//endif
        }//CreateParams


    /**
     * Calculate the next position of message
     * and call repaint
    */

    private synchronized void NextPos()
        {
        m_MessageX -= m_Speed;
        if ((m_MessageX + m_MsgLength) < 0)
            {
            m_endofdisplay = true;
            }
        if ((m_MessageX + m_MsgLength) < 0)
            {
            m_MessageX = m_PrevRec.width;
            }
        repaint();
        }

    protected String GetTimeDate()
        {
        String time = new String();

        String month[] = {"January","February","March","April","May","June",
                        "July","August","September","October","November","December"};

        String day[] = {"Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"};
        String dd = new String();
        String mm = new String();
        String yy = new String();
        String ddmmyy = new String();
        int min = 0;
        int pm= 0;
        Date date = new Date();
        int itemp = 0;
        String str = new String();

        // Get the current time!
        if(date.getHours() >= 12)
            pm = 1;
        else
            pm = 0;

        if(pm == 1)
            {
            itemp = date.getHours();
            if(itemp == 12)
                time  = String.valueOf(12);
            else
                time = String.valueOf(date.getHours()-12);
            }
        else
            {
            itemp = date.getHours();
            if(itemp == 0)
                time = String.valueOf(12);
            else
                time = String.valueOf(itemp);
            }

        time = time.concat(":");

        min = date.getMinutes();
        if(min >= 10)
            time = time.concat(String.valueOf(min));
        else
            {
            time = time.concat("0");
            time = time.concat(String.valueOf(min));
            }

        if(pm == 1)
            time = time.concat(" pm ET ");
        else
            time = time.concat(" am ET ");
        dd = String.valueOf(date.getDate());
        mm = month[date.getMonth()];
        yy = String.valueOf(date.getYear() + 1900);
        str = str.concat(mm + " " + dd + ", " + yy );
        str = time.concat(str);
        return str;
        }// End GetTimeDate


    // --- Private attributes

    private Color m_TxtColor;                               // The Text Color
    private Color m_BgColor;                                // The background Color
    private Font  m_Font;                                           // The Font to be displayed

    private Dimension m_Size = new Dimension();         // Tne size of the ticker
    private Dimension m_PrevRec = new Dimension(-1,-1); // The rect previously used

    private String m_astrMessages[] = new String[4];    // The messages to be displayed
    private boolean m_endofdisplay = false;              // The end of displaying the old messages
    private String m_astrNewMessages[] = new String[4]; // New messages needed to be displayed
    private int m_MsgLengthVec[]   = new int[4];        // length of each message

    private int m_MessageX = 0;                                 // x-position of the massage
    private int m_MessageY = 0;                                 // y-position of the message
    private int m_MsgLength = 0;                                // Length of the the message

    private int m_Speed;

    private Image    m_Image = null;                    // The offscreen image
    private Graphics m_Graphics = null;                 // The image's Graphics context

    private boolean m_ChangeMessage = false;            // if message is changed
    private boolean m_resetMessage = false;                         // if message has been reset
    private boolean m_Action = true;

} // Ticker