Ticker
Java Source:
/* Ticker Ver 1.21 by Toh Lik Khoong
/ Vertical Scroller developed using JDK 1.2
/ Last revised 22/05/2000
/ Please contact me at lktoh@mail.com for any comments or suggestions
*/
/* sample applet for ticker
<applet code=ticker.class width=120 height=180>
<param name=filename value="news.txt">
<param name=font value="Helvetica">
<param name=size value="10">
<param name=target value="_new">
<param name=xmargin value="10">
<param name=ymargin value="25">
<param name=irect value="6688EE">
<param name=orect value="000000">
<param name=ntext value="000000">
<param name=htext value="FF0000">
<param name=speed value="20">
</applet>
*/
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.net.*;
import java.io.*;
public class ticker extends Applet implements Runnable{
// global parameters
private Thread m_thread;
private Image m_imgBuffer = null;
private int y_pos = 0; // scroller
private int cur_news = 0; // current news item
private int cur_pos = 0; // mouse cursor position
private boolean pause = false; // pause
private boolean m_over = false; // mouse over
private Vector news = new Vector(); // contains the text to display
private Vector urls = new Vector(); // contains the corresponding URL
// default parameters
private int size = 10;
private Font ft = new Font("TimesRoman",Font.PLAIN,size);
private String filename = "news.txt";
private String target = "_new";
private int height;
private int xmargin = 10;
private int ymargin = 0;
private Color irect = new Color(8388736);
private Color orect = new Color(0);
private Color ntext = new Color(0);
private Color htext = new Color(16711680);
private int speed = 100;
public void init(){
// retrieval of applet parameters
String param;
param = getParameter("size");
if (param != null) size = Integer.parseInt(param);
param = getParameter("font");
if (param != null) ft = new Font(param,Font.PLAIN,size);
param = getParameter("target");
if (param != null) target = param;
param = getParameter("xmargin");
if (param != null) xmargin = Integer.parseInt(param);
param = getParameter("ymargin");
if (param != null) ymargin = Integer.parseInt(param);
param = getParameter("irect");
if (param != null) irect = new Color(Integer.parseInt(param,16));
param = getParameter("orect");
if (param != null) orect = new Color(Integer.parseInt(param,16));
param = getParameter("ntext");
if (param != null) ntext = new Color(Integer.parseInt(param,16));
param = getParameter("htext");
if (param != null) htext = new Color(Integer.parseInt(param,16));
param = getParameter("filename");
if (param != null) filename = param;
param = getParameter("speed");
if (param != null) speed = Integer.parseInt(param);
setFont(ft);
FontMetrics fm = getFontMetrics(ft);
height = fm.getAscent() + fm.getDescent();
if (height > ymargin) ymargin = height; // ymargin cannot be too small
// Mouse Listener for the applet
/*MouseListener ml = new MouseListener(){
public void mouseClicked(MouseEvent e){
if (urls.elementAt(cur_news) instanceof URL){
URL myURL = (URL) urls.elementAt(cur_news);
getAppletContext().showDocument(myURL,getParameter("target"));
}
}
public void mouseEntered(MouseEvent e){
stop();
m_over = true;
cur_pos = e.getY();
repaint();
}
public void mouseExited(MouseEvent e){
start();
m_over = false;
repaint();
}
public void mousePressed(MouseEvent e){}
public void mouseReleased(MouseEvent e){}
};
addMouseListener(ml);
MouseMotionListener mml = new MouseMotionListener(){
public void mouseMoved(MouseEvent e){
cur_pos = e.getY();
m_over = true;
repaint();
}
public void mouseDragged(MouseEvent e){
}
};
addMouseMotionListener(mml);*/
// read the news file
readFile();
}
public boolean mouseEnter(Event e, int x, int y){
stop();
m_over = true;
cur_pos = e.y;
repaint();
return true;
}
public boolean mouseExit(Event e, int x, int y){
start();
m_over = false;
repaint();
return true;
}
public boolean mouseMove(Event e, int x, int y){
cur_pos = e.y;
m_over = true;
repaint();
return true;
}
public boolean mouseDown(Event e, int x, int y){
if (urls.elementAt(cur_news) instanceof URL){
URL myURL = (URL) urls.elementAt(cur_news);
getAppletContext().showDocument(myURL,getParameter("target"));
}
return true;
}
// function to read file
private void readFile()
{
String line;
try{
URL url = new URL(getDocumentBase(), filename);
try{ // read file
BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
do{
line = in.readLine();
if (line != null){
try{
StringTokenizer st = new StringTokenizer(line, "|");
news.addElement(st.nextToken()); // get display text
if (st.hasMoreTokens()){ // get url
urls.addElement(new URL(getDocumentBase(), st.nextToken()));
}
else{ // no url, adding indicator
urls.addElement("nourl");
}
}catch (NoSuchElementException nsee){} // exception if carriage return at eof
}
}while (line != null);
}
catch (IOException e){
news.addElement("Could not open news feed file.");
urls.addElement("nourl");
System.err.println("Could not open news feed file.");
}
}catch (MalformedURLException e){}
}
public void paint(Graphics g){
if (m_imgBuffer == null){ // double buffering
m_imgBuffer = createImage(size().width, size().height);
render(g); // display the ticker
}
g.drawImage(m_imgBuffer, 0, 0, null);
}
public void update(Graphics g){
render(g);
paint(g);
}
// function that displays the ticker
public void render(Graphics g)
{
// drawing of the background
g = m_imgBuffer.getGraphics();
g.setColor(orect);
g.fillRect(0, 0, size().width, size().height);
g.setColor(irect);
g.fillRect(xmargin, ymargin, size().width - 2 * xmargin, size().height - 2 * ymargin);
g.setColor(ntext);
FontMetrics fm = getFontMetrics(ft); // to calculate string width later
boolean reset = false; // reset the value of y_pos
int y = 0;
String s = "";
while (y + y_pos < size().height){
// calculate the position of the news item
for (int i = 0; i < news.size(); i++){
if (m_over){ // mouse over the text
int b1 = y_pos + 14; // top current news border
int b2 = y_pos + 14; // bottom current news border
// search for the current news to highlight
while (b2 < size().height - height){
for (int j = 0; j < news.size(); j++){
b1 = b2; // set top border
StringTokenizer st = new StringTokenizer((String) news.elementAt(j)," ",false);
String t = "";
while (st.hasMoreTokens()){
s = "";
while (fm.stringWidth(s + t) < size().width - 2 * xmargin - 5 && st.hasMoreTokens()){
if (!t.equals("")) s += t + " ";
t = st.nextToken();
}
if (!st.hasMoreTokens() && fm.stringWidth(s + t) > size().width - 2 * xmargin - 5){
b2 += 2 * height;
}
else{
b2 += height;
}
}
if (cur_pos > b1 && cur_pos < b2){ // look for current news
cur_news = j;
}
b2 += 20; // calculate bottom border
}
}
// highlight item
if (i == cur_news && (urls.elementAt(i) instanceof URL)) g.setColor(htext);
else g.setColor(ntext);
}
// pause the ticker when new item appears
if (y_pos + y == 3){
pause = true;
}
// display the text
String t = "";
StringTokenizer st = new StringTokenizer((String) news.elementAt(i)," ",false);
while (st.hasMoreTokens()){
s = "";
while (fm.stringWidth(s + t) < size().width - 2 * xmargin - 5 && st.hasMoreTokens()){
if (!t.equals("")) s += t + " ";
t = st.nextToken();
}
y += height;
if (st.hasMoreTokens()){
if ( y + y_pos > ymargin - height && y + y_pos < size().height - ymargin - 2 * height){
g.drawString(s, xmargin + 2, y + y_pos + ymargin);
}
}
else{ // special treatment for last line (no more tokens left)
if (fm.stringWidth(s + t) > size().width - 2 * xmargin - 5){
// not enough space, draw on different lines
if ( y + y_pos > ymargin - height && y + y_pos < size().height - ymargin - 2 * height){
g.drawString(s, xmargin + 2, y + y_pos + ymargin);
}
y += height;
if ( y + y_pos > ymargin - height && y + y_pos < size().height - ymargin - 2 * height){
g.drawString(t, xmargin + 2, y + y_pos + ymargin);
}
}
else{ // if not, draw on same line
if ( y + y_pos > ymargin - height && y + y_pos < size().height - ymargin - 2 * height){
g.drawString(s + t, xmargin + 2, y + y_pos + ymargin);
}
}
}
}
y += 20;
}
if (y + y_pos < 0) reset = true;
}
if (reset) y_pos = 0; // reset the scroller position
}
public void start(){
m_thread = new Thread(this);
m_thread.start();
}
public void stop(){
m_thread.stop();
}
public void run(){
try{
while(true){
if (pause){ // pause when new item appears
m_thread.sleep(4000);
pause = false;
}
m_thread.sleep(speed);
if (!m_over) y_pos--; // scroll the ticker
repaint();
}
}
catch (InterruptedException e){}
}
}
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