The Java Boutique: NewsScroller: Scroller.java - It showcases text-wrapping and reading data from a file located on the web server.

package crackers.Scroller; /** * A basic horizontal scrolling text applet. This was written under the * influence of the examples provided by Sun and copyright by them. * <P> * This program is copyrighted 1999 by the author under the GNU Public License * (GPL). Full text of this license is available at * <A HREF="http://www.gnu.org">GNU.org</A>. * <P> * For full usage information, see * <A HREF="http://www.io.com/~crackers">my web pages</A>. * * @author E. A. Graham, Jr. (crackers@io.com) * @version 2.0 */ import java.awt.*; import java.applet.*; import java.net.URL; import java.net.MalformedURLException; import java.awt.event.*; public class Scroller extends WebBase implements MouseListener { /** * The message text. */ private String message; /** * Current x coordinate of the text within the applet. */ private int messageX = 0; /** * Current y coordinate of the text within the applet. */ private int messageY = 0; /** * The width of the message. */ private int messageWidth = 0; /** * The font to draw the message with. Defaults to Serif. */ private Font messageFont; /** * Flag to indicate whether or not to draw a "shadow" of the message. */ private boolean shadowOn; /** * The string of the URL to link to. Optional. */ private String linkName; /** * The url of a link. Optional. */ private URL linkURL = null; /** * Initialize the applet. Over-rides super class (but calls it). * @see java.applet.Applet */ public void init() { super.init(); // get the HTML parameters or set to defaults message = readParam("MESSAGE","No message supplied!"); String shadowParam = readParam("SHADOW"); shadowOn = (shadowParam== null) ? false : shadowParam.equalsIgnoreCase("true"); linkName = readParam("URL"); if (linkName != null) { try { if (linkName.indexOf("http://") < 0) linkURL = new URL(getDocumentBase(),linkName); else linkURL = new URL(linkName); } catch (MalformedURLException e) {}; } // make ourselves listen to the mouse addMouseListener(this); } /** * Called when the applet is started. Over-rides super class (but calls it). */ public void start() { super.start(); // set up the font and initial positions int fontAttributes = Font.PLAIN; String name = readParam("FONT"); String style = readParam("FONTSTYLE"); if (style != null) { style = style.toUpperCase(); if (style.indexOf("BOLD") >= 0) fontAttributes += Font.BOLD; if (style.indexOf("ITALIC") >= 0) fontAttributes += Font.ITALIC; } // a font size of 14 seems a decent size to start with, especially with // applets try { messageFont = new Font(name,fontAttributes,14); } catch (Exception e) { } // didn't work? if (messageFont == null) { name = "Serif"; messageFont = new Font(name,fontAttributes,14); } // set the font on this applet so we can determine it's "true" size setFont(messageFont); FontMetrics fontStuff = getFontMetrics(messageFont); int fontHeight = fontStuff.getHeight(); // scale this down to the appropriate size (lots of rounding) // remake the font with the new point size double height = (double)(maxHeight - (2 * Math.abs(borderWidth))); fontHeight = (int)Math.floor(14 * height / (double)fontHeight); messageFont = new Font(name,fontAttributes,fontHeight); fontStuff = getFontMetrics(messageFont); messageX = maxWidth; messageY = ((maxHeight-fontStuff.getHeight()) >> 1) + fontStuff.getAscent() - 1; messageWidth = fontStuff.stringWidth(message); } /** * Over-rides the super class. Paint the text to the offscreen image and * place <B>image</B> onto the graphics context. */ public synchronized void update(Graphics g) { // are we running? if(loaded) { super.update(g); //...then draw shadow copy of text... if (shadowOn) { Color foreColorD1,foreColorD2; foreColorD1 = foreColor.darker(); foreColorD2 = foreColorD1.darker(); appGC.setColor(foreColorD2); appGC.drawString(message, messageX+2, messageY+2); appGC.setColor(foreColorD1); appGC.drawString(message, messageX+1, messageY+1); } //...then draw the text... appGC.setColor(foreColor); appGC.setFont(messageFont); appGC.drawString(message, messageX, messageY); //...next comes the border... drawBorder(); //...and drop the whole thing into place g.drawImage(appImage, 0, 0, this); } } /** * Implementation of the abstract method: increment the X-position of the * message by the indicated amount. This "jump" is the animation for the * message. */ protected synchronized void doAppThing() { messageX -= scrollUnit; // oops! too far - start over if((messageX + messageWidth) < 0) messageX = maxWidth; } /** * Required method for MouseListener: fired when the mouse button is * released. Resets the border to it's initial state. If there is a * link URL to jump to, do so. */ public void mouseReleased(MouseEvent e) { borderWidth = -borderWidth; if (linkURL !=null) { getAppletContext().showDocument(linkURL,frameTarget); } } /** * Required method for MouseListener: fired when the mouse leaves the * applet. Clears the status line. */ public void mouseExited(MouseEvent e) { showStatus(""); } /** * Required method for MouseListener: fired when the mouse button is clicked * (up and down). Note that this method is not used: there are separate * events for the down and up of the button(s). */ public void mouseClicked(MouseEvent e) { } /** * Required method for MouseListener: fired when the mouse enters the * applet. If there is a URL link for the applet, show the link in the * status line. */ public void mouseEntered(MouseEvent e) { if (linkURL != null) showStatus("Link to " + linkName); } /** * Required method for MouseListener: fired when the mouse button is pressed * down. Invert the border (this gives a "pressed" look to the applet). */ public void mousePressed(MouseEvent e) { borderWidth = -borderWidth; } }