t.java

java编程的一些Applets例子。值得深入研究一下。

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/*
* Permission to use, copy, modify and distribute this software and its * documentation without fee for NON-COMMERCIAL purposes is hereby granted * provided that this notice with a reference to the original source and * the author appears in all copies or derivatives of this software. *
* THE AUTHOR 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. THE AUTHOR SHALL NOT BE LIABLE FOR * ANY DAMAGES SUFFERED BY ANYBODY AS A RESULT OF USING, MODIFYING OR * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. */

import java.awt.*;
import java.awt.image.*;
import java.lang.*;
import java.util.*;

/**
* pointer - Text and sliding Triangles with automatic timedependant slowdown and fading<br> *
* <p>V b1.00, 10/01/95: ported by Thomas Wendt (thw) to pre-beta<br> * V b1.01, 11/18/95: Cleaning up the code by thw<br> *
* <p><a href="http://www.uni-kassel.de/fb16/ipm/mt/java/javae.html"><b>origin</b></a> of pointer.<br> *
*@author	<A HREF="http://www.uni-kassel.de/fb16/ipm/mt/staff/thwendte.html">Thomas Wendt</A>
*@version	b1.01, 11/18/95
*/
public class pointer extends java.applet.Applet implements Runnable { 
/** The message to be displayed. */
public String message;

/** x-position of message. */
public int messageX;

/** y-position of message. */
public int messageY;

/** Image to create with the triangles. */ public Image img = null;

/** x-position of image. */
public int imgX;

/** Minimal x-position. */
int imgXmin;

/** The animating thread. */
public Thread t = null;

/** State of the applet. */
public boolean active = false;

/** Animation speed: position increment. */ public int iSpeed;

/** Animation speed: Threads pause. */
public int tSpeed;

/** The direction of animation. */
public int dir;

/** The Text-color. */
public Color txtCo;

/** The color of the triangles. */
public Color fgCo;

/** The backgroundcolor. */
public Color bgCo;

/**
* The age of the applet
* 1 = new, 0 = old
*/
public float age = 1.0f;

/**
* The time-dependant state of the applet * True, if expired
*/
public boolean expired = false;

/**
* The size used to calc the Font.
* Makes resizing possible.
*/
public Dimension lastS = new Dimension(1,1); 

/**
* Initialize: Read Attributes
* Calc speeds to give other threads a chance. * Resizes to (2,2) and do nothing if expired; */
public void init () {
String at = getParameter("msg");
message = (at == null) ? "New!" : at;

// silly, but Color matches Date very well fgCo = readColor(getParameter("exp"), Color.white);
if (!fgCo.equals(Color.white)) {
Date exp = new Date(fgCo.getRed(),fgCo.getGreen()-1,fgCo.getBlue()); Date today = new Date();
expired = today.after(exp);
fgCo = readColor(getParameter("creat"), Color.white); if (!fgCo.equals(Color.white)) {
Date creat = new Date(fgCo.getRed(),fgCo.getGreen()-1,fgCo.getBlue()); float diff = exp.getTime() - creat.getTime(); age = exp.getTime() - today.getTime();
age = age/diff;
if (age<0.01f) { age = 0.001f; }
}
}

// dont show, if expired
if (expired) {
resize(2,2);
return;
}

// calc speeds to let others a chance
at = getParameter("speed");
tSpeed = (at == null) ? 100 : (Integer.valueOf(at).intValue()); dir = (tSpeed > 0) ? 1 : -1;
tSpeed = new Float(1000*dir/(tSpeed*age)).intValue(); if (tSpeed < 1) { tSpeed = 1; }
iSpeed = dir*(1+20/tSpeed);
tSpeed = dir*iSpeed*tSpeed;

txtCo = readColorAge(getParameter("txtco"), Color.blue); fgCo = readColorAge(getParameter("fgco"), getBackground()); bgCo = readColorAge(getParameter("bgco"), Color.yellow); 

}

/** Parameter Info. */
public String[][] getParameterInfo() {
String[][] info = {
{"msg", "String", "Message to display (New!)"}, {"speed", "int",	"animation speed (1/msec)"},
{"txtco", "int[3]", "RGB-Color of Message (blue)"}, {"fgco", "int[3]", "RGB-Color of triangles (getBackground)"}, {"bgco", "int[3]", "RGB-Color of background (yellow)"}, {"creat", "int[3]", "Date of creation: Y, M, D; if not set, no slowdown, fading"}, {"exp", "int[3]", "Date to expire: Y, M, D; if not set, no slowdown, fading, expiration"}, {"debug", "?", "if to print some debugging infos"}, };
return info;
}

/** Applet Info. */
public String getAppletInfo() {
return "pointer.java, V b1.01, 11/18/95 by Thomas Wendt, http://www.uni-kassel.de/fb16/ipm/mt/staff/thwendte.html"; }

/**
* Convert a ','-delimited String with RGB-Values to Color * Uses aDefault, if no or not enough RGB-Values */
public Color readColor(String aColor, Color aDefault) { 
if (aColor == null) { return aDefault; } 

int r, g, b;
StringTokenizer st = new StringTokenizer(aColor, ","); 

try {
r = Integer.valueOf(st.nextToken()).intValue(); g = Integer.valueOf(st.nextToken()).intValue(); b = Integer.valueOf(st.nextToken()).intValue(); return new Color(r,g,b);
}
catch (Exception e) { return aDefault; } }

/** Compute a given color component with age. */ public int coAge(float fg, float bg) {
return new Float(fg*age+(1-age)*bg).intValue(); }

/**
* Convert by calling readColor and take age into account * @see #readColor
* @see #coAge
*/
public Color readColorAge(String aColor, Color aDefault) { 
Color co = readColor(aColor, aDefault);
int r = Color.lightGray.getRed();
int g = Color.lightGray.getGreen();
int b = Color.lightGray.getBlue();

return new Color(coAge(co.getRed(),r), coAge(co.getGreen(), g), coAge(co.getBlue(), b)); }

/** Create the image offline. */
public void createImg() {
// set some constants
int w = size().width;
int h = size().height;
lastS.width = w;
lastS.height = h;

// calc font: message must fit in applets area int refH = 14;
Font tf = new Font("TimesRoman", Font.BOLD, refH); setFont(tf);
FontMetrics tfm = getFontMetrics(tf);
int fw = tfm.stringWidth(message);
int fh = tfm.getHeight();
fh = Math.min(refH*h/fh, refH*w/(fw << 1)); Font f = new Font("TimesRoman", Font.BOLD, fh); FontMetrics fm = getFontMetrics(f);
fw = fm.stringWidth(message);
fh = fm.getHeight();
setFont(f);
messageX = (w-fw) >> 1;
messageY = ((h-fh) >> 1)+fm.getAscent(); 

// then draw offline image
w = ((w/h)+2)*h; // round up to multipl of height int pixels[] = new int[w*h];
int x;
int y;

// fill with background
int co = (255 << 24) | (bgCo.getRed() << 16) | (bgCo.getGreen() << 8) | bgCo.getBlue(); for (x = 0; x < (w*h); x++) { pixels[x] = co; } 

co = (255 << 24) | (fgCo.getRed() << 16) | (fgCo.getGreen() << 8) | fgCo.getBlue(); 

/*
* Create triangles
* Using bytearray might be faster than using offscreen Graphics */
for (x = h >> 1; x < w; x += h) {
for (y = 1; y <= (h >> 1); y++) {
for (int i = x; (i <= (x+y)) && (i >= (x-y)) ; i += dir) { 
pixels[y*w+i] = co;
pixels[(h-y-1)*w+i] = co;
}
}
}
// create an ImageProducer with the bytearray img = createImage(new MemoryImageSource(w, h, pixels, 0, w)); imgXmin = -h;
imgX = (dir > 0) ? imgXmin : 0;
}

/** Show the stuff */
public void paint(Graphics g) { update(g); } 

/** Show the stuff */
public void update(Graphics g) {
// do nothing, if expired
if (expired) { return; }

// if something has changed, create new image if ((img == null) || (size().height != lastS.height) || (size().width != lastS.width)) { createImg(); } 

// if position in bounds
if ((imgX <= 0) && (imgX >= imgXmin)) {
// draw first moving image
g.drawImage(img,imgX,0, this);
g.setColor(txtCo);
// then text
g.drawString(message, messageX, messageY); }
}

/** Run the loop. This method is called by class Thread. */ public void run() {
// do nothing, if expired
if (expired) { return; }

// others may be more important
Thread.currentThread().setPriority(Thread.MIN_PRIORITY); while (active) {
// increment position
imgX += iSpeed;
if (imgX > 0) {imgX = imgXmin; }
else { if (imgX < imgXmin) { imgX = 0; } } // paint the applet
repaint();
// and pause
try { Thread.sleep(tSpeed); }
catch (Exception e) { }
}
}

/** Start the applet by forking an animation thread. */ public void start() {
if (!active) {
t = new Thread(this);
active = true;
t.start();
}
}

/** Stop the applet. The thread will exit because run() exits. */ public void stop() {
active = false;
t = null; // give GC a chance.
}

}
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X-Sun-Data-Type: default-app
X-Sun-Data-Description: default
X-Sun-Data-Name: ticker.java
X-Sun-Charset: us-ascii
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/*
* Permission to use, copy, modify and distribute this software and its * documentation without fee for NON-COMMERCIAL purposes is hereby granted * provided that this notice with a reference to the original source and * the author appears in all copies or derivatives of this software. *
* THE AUTHOR 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. THE AUTHOR SHALL NOT BE LIABLE FOR * ANY DAMAGES SUFFERED BY ANYBODY AS A RESULT OF USING, MODIFYING OR * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. */

import java.awt.*;
import java.lang.*;
import java.net.*;
import java.util.*;

/**
* ticker - Scrolling Text with colors, speed, url and timedependant expiring<br> * Some Ideas from Sven Heinicke, Author of TickerTape<br> *
* <p>V b1.00, 10/06/95: Creation by Thomas Wendt (thw)<br> * V b1.01, 11/18/95: Cleaning up the code by thw<br> *
* <p><a href="http://www.uni-kassel.de/fb16/ipm/mt/java/javae.html"><b>origin</b></a> of ticker.<br> *
* @author	<A HREF="http://www.uni-kassel.de/fb16/ipm/mt/staff/thwendte.html">Thomas Wendt</A>
* @version	b1.01, 11/18/95
*/
public class ticker extends java.applet.Applet implements Runnable { 
/** The message to be displayed. */
public String message;

/** The Font to be displayed. */
public Font messageF;

/** x-position of message. */
public int messageX;

/** y-position of message. */
public int messageY;

/** Length of the message. */
public int messageW = 0;

/** URL to switch to */
public URL url_ = null;

/** How far to skip across the screen. */ int speed;

/** The animating thread. */
public Thread t = null;

/** State of the applet. */
public boolean active = false;

/** The Text-color. */
public Color txtCo;

/** The backgroundcolor. */
public Color bgCo;

/**
* The time-dependant state of the applet. * True, if expired
*/
public boolean expired = false;

/** The Size used to calc the Font. */
public Dimension lastS = new Dimension(1,1); 


/**
* Initialize: Read Attributes
* Resize to (2,2) and do nothing if expired; */
public void init () {
String at = getParameter("msg");
message = (at == null) ? "ticker for pre-beta" : at; 

// use readColor to read the Date; date and color both have 3 components. bgCo = readColor(getParameter("exp"), Color.white); if (!bgCo.equals(Color.white)) {
Date exp = new Date(bgCo.getRed(),bgCo.getGreen()-1,bgCo.getBlue()); Date today = new Date();
expired = today.after(exp);
}

// don't show, if expired
if (expired) {
resize(2,2);
return;
}

speed = ((at = getParameter("speed")) == null) ? 10 : (Integer.valueOf(at).intValue());