MacTech 1 to 12/MacTech-vol-1-12.toast/Source/MacTech® Magazine/Volume 12 - 1996/12.09 Sep 96/Getting Started/CWBlink.java

Java Source | 1996-08-14 | 4.7 KB | 266 lines | [TEXT/CWIE]

package com.metrowerks.example.CWBlink;

import java.awt.*;

public class CWBlink extends java.applet.Applet
{
    private Button blinkButton;
    private BlinkingText blinkText;

    public String getParameter(String name)
    {
        String result = null;

        try
        {
            result = super.getParameter(name);
        }
        catch ( Exception e )
        {
            result = null;
        }

        return result;
    }

    public void init()
    {
        Panel tempPanel;

        String att = getParameter("speed");
        int speed = (att == null) ?
            500 : (1000 / Integer.valueOf(att).intValue());

        setLayout( new BorderLayout() );

        att = getParameter("blinker");
        String blinkString = (att == null) ?
            "CodeWarrior!!!" : att;

        blinkButton = new Button( "Blink" );

        tempPanel = new Panel();
        tempPanel.add( blinkButton );
        this.add( "North", tempPanel );

        blinkText = new BlinkingText( blinkString, speed );

        tempPanel = new Panel();
        tempPanel.add( blinkText );
        this.add( "Center", tempPanel );

        resize( 570, 170 );
    }

    public void start()
    {
        blinkText.start();
    }

    public void stop()
    {
        blinkText.stop();
    }

    public boolean action(Event evt, Object arg)
    {
        if ( "Blink".equals(arg) )
        {
            blinkText.ToggleBlinking();
        }
        return true;
    }

    public static void main(String args[])
    {
        com.metrowerks.AppletFrame.startApplet(
                "com.metrowerks.example.CWBlink.CWBlink",
                "Blink", args);
    }
}


class BlinkingText extends Canvas implements Runnable
{
    private Thread blinkThread = null;
    private String blinkString;
    private Font font;
    private int speed;
    private boolean isBlinking = false;
    private Color[] letters;
    private boolean[] is_black;
    private int current_letter = 0;
    private int old_width, old_height;

    private Color RandomColor()
    {
        int red, green, blue;

        do {
            red = (int)(Math.random() * 256);
        } while ( red > 0x8000 );

        do {
            green = (int)(Math.random() * 256);
        } while ( green > 0x8000 );

        do {
            blue = (int)(Math.random() * 256);
        } while ( blue > 0x8000 );

        return new java.awt.Color( red, green, blue );
    }

    public BlinkingText( String blinkString, int speed )
    {
        this.blinkString = blinkString;
        this.speed = speed / blinkString.length();
        this.font = new java.awt.Font( "TimesRoman",
                                                                Font.PLAIN, 64 );
        this.letters = new Color[blinkString.length()];
        this.is_black = new boolean[blinkString.length()];

        for ( int i = 0; i < letters.length; i++ )
        {
            letters[i] = RandomColor();
            is_black[i] = true;
        }
        resize( 530, 70 );
        repaint();
    }

    public synchronized void ToggleBlinking()
    {
        isBlinking = ! isBlinking;
        notify();
    }

    public synchronized void PaintLetter( int the_letter )
    {
        Rectangle b = bounds();
        int width = b.width;
        int height = b.height;
        Graphics g = getGraphics();

        if ( old_width == width && old_height == height )
        {
            int x = 0;
            int y = height;

            g.setFont(font);
            FontMetrics fm = g.getFontMetrics();

            for (int index=0; index<the_letter; index++ )
            {
                int w = fm.charWidth(blinkString.charAt(index));
                x += w;
            }

            int w = fm.charWidth(blinkString.charAt(the_letter));
            g.setColor( isBlinking ?
                                letters[the_letter] : Color.black );
            g.clearRect( x, 0, w, height );
            g.drawString( blinkString.substring(
                                the_letter,the_letter+1), x, y );

            is_black[the_letter] = !isBlinking;
        }
        else
        {
            paint( g );
        }
    }

    public synchronized void paint(Graphics g)
    {
        Rectangle b = bounds();
        int width = b.width;
        int height = b.height;
        old_width = width;
        old_height = height;
        int x = 0;
        int y = height;

        g.setColor(Color.black);
        g.setFont(font);
        FontMetrics fm = g.getFontMetrics();

        g.clearRect( 0, 0, width, height );
        if ( isBlinking )
        {
            for (int index=0; index<blinkString.length();
                        index++ )
            {
                int w = fm.charWidth(blinkString.charAt(index));

                g.setColor( letters[index] );

                g.drawString(
                    blinkString.substring(index,index+1), x, y);
                x += w;
            }
        }
        else
        {
            g.drawString(blinkString, x, y );
        }

        for ( int index=0; index<blinkString.length(); index++ )
        {
            is_black[index] = !isBlinking;
        }
    }

    public void start()
    {
        stop();
        blinkThread = new Thread(this);
        blinkThread.start();
    }

    public void stop()
    {
        if ( blinkThread != null )
        {
            blinkThread.stop();
            blinkThread = null;
        }
    }

    public void run()
    {
        while (true)
        {
            synchronized ( this )
            {
                try
                {
                    wait( 1 );
                }
                catch (Exception e)
                {
                }

                if ( isBlinking || !is_black[current_letter] )
                {
                    if ( isBlinking )
                    {
                        letters[current_letter] = RandomColor();
                    }
                    PaintLetter( current_letter );
                }
                current_letter++;
                if ( current_letter >= blinkString.length() )
                {
                    current_letter = 0;
                }
            }
         }
    }

    public void finalize()
    {
        stop();
    }
}