urlslider2.java

Java 范例实战 光盘使用说明 ========================== 本光盘的文件结构如下所示： =====================================

import java.applet.Applet;
import java.applet.AppletContext;
import java.awt.*;
import java.io.PrintStream;
import java.net.MalformedURLException;
import java.net.URL;

public class UrlSlider2 extends Applet
    implements Runnable
{

    int cursor = 0;
    Thread runner = null;
    MediaTracker tracker = null;
    Object frame = null;
    int showNr = 0;
    int totalShowNr = 0;
    URL url[] = null;
    String statusText[] = null;
    String text[] = null;
    Color textColor = null;
    Color linkColor = null;
    Color BGColor = null;
    Image BGImage = null;
    int shadowXOffset = 0;
    int shadowYOffset = 0;
    Color shadowColor = null;
    int x = 0;
    int y = 0;
    int xAdd = 0;
    int yAdd = 0;
    int textSize = 0;
    int textType = 0;
    String textFont = null;
    boolean mouseIn = false;
    int delay = 0;
    Font f = null;
    FontMetrics fm = null;
    Image offscreenI = null;
    Graphics offscreenG = null;
    int breaker = 0;
    int borderSize = 0;
    Color borderColor = null;
    int headHeight = 0;
    int yHeadText = 0;
    int xHeadText = 0;
    String headText = null;
    int headTextSize = 0;
    int headTextType = 0;
    Font headTextFont = null;
    FontMetrics headTextFontMetrics = null;
    Color headTextColor = null;
    Color headerBackgroundColor = null;
    boolean statusbarAlwaysOn = false;
    String defaultTarget = null;
    String target[] = null;

    int getParameter(String s1, int s2) 
    {
        String s = getParameter(s1) ;
        return (s != null) ? Integer.parseInt(s) : s2 ;
    }
    
    Color getParameter(String s1, Color s2)
    {
        String s = getParameter(s1);
        return (s != null) ? new Color(Integer.parseInt(s, 16)) : s2 ;
    }
    
    String getParameter(String s1, String s2) 
    {
        String s = getParameter(s1) ;
        return (s != null) ? s : s2 ;
    }
        
    
    public void init()
    {
        totalShowNr = 0;
        String tempString;
        for(tempString = getParameter("text" + (totalShowNr + 1)); tempString != null; tempString = getParameter("text" + (totalShowNr + 1)))
            totalShowNr++;

        statusText = new String[totalShowNr + 1];
        text = new String[totalShowNr + 1];
        url = new URL[totalShowNr + 1];
        target = new String[totalShowNr + 1];
        for(int tempInt = 1; tempInt <= totalShowNr; tempInt++)
            text[tempInt] = getParameter("text" + tempInt);

        for(int tempInt = 1; tempInt <= totalShowNr; tempInt++)
        {
            tempString = getParameter("url" + tempInt);
            if(!tempString.startsWith("http://") && !tempString.startsWith("mailto:") && !tempString.startsWith("file:"))
                tempString = getCodeBase().toString() + tempString;
            statusText[tempInt] = tempString;
        }

        for(int tempInt = 1; tempInt <= totalShowNr; tempInt++)
        {
            try
            {
                url[tempInt] = new URL(statusText[tempInt]);
            }
            catch(MalformedURLException _ex)
            {
                System.out.println("Bad Url = " + url[tempInt]);
            }
            if(url[tempInt] != null)
            {
                tempString = getParameter("target" + tempInt,"_self");
                if(tempString != null)
                    target[tempInt] = tempString;
            }
        }

        for(int tempInt = 1; tempInt <= totalShowNr; tempInt++)
        {
            tempString = getParameter("statustext" + tempInt);
            if(tempString != null)
                statusText[tempInt] = tempString;
        }
        textColor = getParameter("textcolor",Color.black);
        BGColor = getParameter("bgcolor",Color.white);
        linkColor = getParameter("linkcolor",Color.red);
        shadowColor = getParameter("shadowcolor",Color.gray);
        offscreenI = createImage(getSize().width, getSize().height);
        offscreenG = offscreenI.getGraphics();
        shadowXOffset = getParameter("shadowxoffset",0);
        shadowYOffset = getParameter("shadowyoffset",0);
        tempString = getParameter("bgimage");
        if(tempString != null)
        {
            tracker = new MediaTracker(this);
            BGImage = getImage(getCodeBase(), tempString);
            tracker.addImage(BGImage, 0);
            getAppletContext().showStatus("loading the pictures");
            try
            {
                tracker.waitForID(0);
            }
            catch(InterruptedException _ex)
            {
                return;
            }
        }
        else
        {
            BGImage = null;
        }
        borderColor = getParameter("bordercolor",Color.yellow);
        borderSize = getParameter("bordersize",0);
        textFont = getParameter("textfont","TimesRoman");
        delay = getParameter("delay",20);
        for(frame = this; frame != null && !(frame instanceof Frame); frame = ((Component)frame).getParent());
        headHeight = getParameter("headheight",0);
        if(headHeight > 0)
        {
            headerBackgroundColor = getParameter("headbackgroundcolor",BGColor);
            offscreenG.fillRect(0, 0, getSize().width, headHeight);
            tempString = getParameter("headtextsize");
            if(tempString == null)
                headTextSize = ((headHeight - borderSize) * 2) / 3;
            else
                headTextSize = Integer.parseInt(tempString);
            tempString = getParameter("headtext");
            if(tempString != null)
            {
                headText = tempString;
                tempString = getParameter("headtexttype");
                if(tempString == null)
                {
                    headTextType = 1;
                }
                else
                {
                    headTextType = Integer.parseInt(tempString);
                    if(headTextType < 0 || headTextType > 3)
                        headTextType = 1;
                }
                headTextFont = new Font(textFont, headTextType, headTextSize);
                headTextFontMetrics = getFontMetrics(headTextFont);
                tempString = getParameter("xheadtext");
                if(tempString == null)
                    xHeadText = (getSize().width - headTextFontMetrics.stringWidth(headText)) / 2;
                else
                    xHeadText = Integer.parseInt(tempString);
                tempString = getParameter("yheadtext");
                if(tempString == null)
                    yHeadText = (((headHeight - borderSize) / 2 + (headTextFontMetrics.getAscent() - headTextFontMetrics.getDescent()) / 2) - headTextFontMetrics.getLeading()) + borderSize;
                else
                    yHeadText = Integer.parseInt(tempString);
               headTextColor = getParameter("headtextcolor",Color.white);
               offscreenG.setColor(headTextColor);
               offscreenG.setFont(headTextFont);
               offscreenG.drawString(headText, xHeadText, yHeadText);
            }
        }
        
        tempString = getParameter("textsize");
        if(tempString == null)
            textSize = ((getSize().height - borderSize - headHeight) * 2) / 3;
        else
            textSize = Integer.parseInt(tempString);
        if(textSize == 0)
            textSize = ((getSize().height - 2 * borderSize) * 2) / 3;
        tempString = getParameter("texttype");
        if(tempString == null)
            textType = 1;
        else
            textType = Integer.parseInt(tempString);
        if(textType < 0 || textType > 3)
            textType = 1;
        switch(textType)
        {
        case 0: // '\0'
            f = new Font(textFont, 0, textSize);
            break;

        case 1: // '\001'
            f = new Font(textFont, 1, textSize);
            break;

        case 2: // '\002'
            f = new Font(textFont, 2, textSize);
            break;

        case 3: // '\003'
            f = new Font(textFont, 3, textSize);
            break;

        }
        fm = getFontMetrics(f);
        tempString = getParameter("xadd");
        if(tempString == null)
            xAdd = 0;
        else
            xAdd = Integer.parseInt(tempString);
        tempString = getParameter("yadd");
        if(tempString == null)
            yAdd = -1;
        else
            yAdd = Integer.parseInt(tempString);
        showNr = 1;
        calculateX(showNr);
        calculateY(showNr);
        if(BGImage == null)
        {
            offscreenG.setColor(BGColor);
            offscreenG.fillRect(borderSize, headHeight, getSize().width - 2 * borderSize, getSize().height - borderSize - headHeight);
        }
        else
        {
            offscreenG.drawImage(BGImage, borderSize, headHeight, getSize().width - 2 * borderSize, getSize().height - headHeight, this);
        }
        if(borderSize != 0)
        {
            offscreenG.setColor(borderColor);
            for(int temp = 0; temp < borderSize; temp++)
                offscreenG.drawRect(temp, temp, getSize().width - 2 * temp - 1, getSize().height - 2 * temp - 1);

        }
        repaint();
        y = (((getSize().height - borderSize - headHeight) / 2 + (fm.getAscent() - fm.getDescent()) / 2) - fm.getLeading()) + headHeight;
        tempString = getParameter("y");
        if(tempString != null)
            y = Integer.parseInt(tempString);
        offscreenG.setFont(f);
        if(headHeight == 0)
            offscreenG.clipRect(borderSize, borderSize, getSize().width - 2 * borderSize, getSize().height - 2 * borderSize);
        else
            offscreenG.clipRect(borderSize, headHeight, getSize().width - 2 * borderSize, getSize().height - borderSize - headHeight);
        tempString = getParameter("statusbaralwayson");
        if(tempString != null)
        {
            int tempInt = Integer.parseInt(tempString);
            if(tempInt == 1)
                statusbarAlwaysOn = true;
        }
    }

    public void start()
    {
        if(runner == null)
        {
            runner = new Thread(this);
            runner.start();
        }
    }

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

    public boolean handleEvent(Event evt)
    {
        switch(evt.id)
        {
        case 504: // Event.MOUSE_EVENT
            mouseIn = true;
            ((Frame)frame).setCursor(14);
            System.out.println(1);
            System.out.println(0);
            System.out.println(11);
            System.out.println(12);
            System.out.println(13);
            System.out.println(7);
            System.out.println(6);
            System.out.println(8);
            System.out.println(5);
            System.out.println(10);
            System.out.println(4);
            System.out.println(9);
            System.out.println(2);
            System.out.println(3);
            System.out.println(10);
            cursor++;
            getAppletContext().showStatus(statusText[showNr]);
            return true;

        case 505: // Event.MOUSE_EXIT
            mouseIn = false;
            ((Frame)frame).setCursor(14);
            if(!statusbarAlwaysOn)
                getAppletContext().showStatus(" ");
            return true;

        case 501: // Event.MOUSE_DOWN
            if(mouseIn = true)
                if(target[showNr] == null)
                    getAppletContext().showDocument(url[showNr]);
                else
                    getAppletContext().showDocument(url[showNr], target[showNr]);
            return true;

        }
        return false;
    }

    public void run()
    {
        for(; Thread.currentThread() == runner; textMove())
        {
            if(BGImage == null)
            {
                offscreenG.setColor(BGColor);
                offscreenG.fillRect(borderSize, headHeight, getSize().width - 2 * borderSize, getSize().height - borderSize - headHeight);
            }
            else
            {
                offscreenG.drawImage(BGImage, borderSize, headHeight, this);
            }
            offscreenG.setColor(shadowColor);
            offscreenG.drawString(text[showNr], x + shadowXOffset, y + shadowYOffset);
            if(mouseIn)
                offscreenG.setColor(linkColor);
            else
                offscreenG.setColor(textColor);
            offscreenG.drawString(text[showNr], x, y);
            breaker = 0;
            repaint();
            pause(delay);
            breaker = 1;
        }

    }

    public void update(Graphics g)
    {
        if(mouseIn || statusbarAlwaysOn)
            getAppletContext().showStatus(statusText[showNr]);
        if(breaker == 0)
            g.drawImage(offscreenI, 0, 0, this);
    }

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

    public void calculateX(int nr)
    {
        if(xAdd > 0)
            x = -fm.stringWidth(text[nr] + borderSize);
        if(xAdd < 0)
            x = getSize().width - borderSize;
        if(xAdd == 0)
            x = (getSize().width - fm.stringWidth(text[nr])) / 2;
    }

    public void calculateY(int nr)
    {
        if(yAdd > 0)
            y = -fm.getDescent() + headHeight;
        if(yAdd < 0)
            y = (getSize().height + fm.getAscent()) - borderSize;
    }

    public void textMove()
    {
        boolean outOffApplet = false;
        x += xAdd;
        y += yAdd;
        if(x > getSize().width && xAdd > 0)
            outOffApplet = true;
        if(x + fm.stringWidth(text[showNr]) < 0 && xAdd < 0)
            outOffApplet = true;
        if(y < -fm.getDescent() + headHeight && yAdd < 0)
            outOffApplet = true;
        if(y > getSize().height + fm.getAscent() && yAdd > 0)
            outOffApplet = true;
        if(outOffApplet)
            nextLine();
    }

    public void nextLine()
    {
        showNr++;
        if(showNr > totalShowNr)
            showNr = 1;
        calculateX(showNr);
        calculateY(showNr);
    }

    public void pause(int sleeper)
    {
        try
        {
            Thread.sleep(sleeper);
            return;
        }
        catch(InterruptedException _ex)
        {
            return;
        }
    }

    public UrlSlider2()
    {
        cursor = -1;
        statusbarAlwaysOn = false;
    }
}