File	Doc	Category	Size	Date	Package
Ticker.java	API Doc	J2ME MIDP 2.0	8867	Thu Nov 07 12:02:28 GMT 2002	javax.microedition.lcdui

Ticker

• java.lang.Object

Fields Summary
private String	message The message set in this Ticker
private String	displayedMessage The message to display in this Ticker
private int	messageLoc The current location on screen of the scrolling message
private int	messageWidth The pixel width of the message being displayed
private int	tickSpeed tickSpeed is the distance in pixels the message will travel during one tick
private static final Image	TICKER_IMG The Image to display with this Ticker
static final long	TICK_RATE TICK_RATE is the number of milliseconds between ticks
static final int	PREFERRED_HEIGHT The preferred height of a Ticker is the same for all Tickers
static final int	DECORATION_HEIGHT The height of the border around this ticker on one side

Constructors Summary
public Ticker(String str) Constructs a new Ticker object, given its initial contents string. param str string to be set for the Ticker throws NullPointerException if str is null synchronized (Display.LCDUILock) { setupText(str); }

Methods Summary
public java.lang.String	getString() Gets the string currently being scrolled by the ticker. return string of the ticker see #setString // SYNC NOTE: return of atomic value, no locking necessary return message;
void	paintContent(Graphics g) Paint the contents of this Ticker param g The Graphics object to paint to // Optimization: The TickerPainter in Screen sets the clip to be // Screen.CONTENT_HEIGHT. If the clip height is greater than that, // then we go ahead and draw the images as well as the text if (g.getClipHeight() > Screen.CONTENT_HEIGHT) { // NOTE: We test to see if the width of the Display is // wider than the width of our image, if so, we re-draw // the image offset to the right as many times as necessary // to fill the width of the Display. Specific ports would // probably want to optimize this for the specific width // of their device. for (int imgLoc = 0; imgLoc < Display.WIDTH; imgLoc += 96) { // We draw the top border g.drawImage(TICKER_IMG, imgLoc, 0, Graphics.TOP | Graphics.LEFT); // We draw the bottom border g.drawImage(TICKER_IMG, imgLoc, Screen.CONTENT_HEIGHT + 3, Graphics.TOP | Graphics.LEFT); } } // We draw the text of the message regardless of the clip, because // its possible the paint call from TickerPainter has coalesced with // other paint calls and if we don't paint the text, we may miss our // chance to update the Ticker display. Note this has the side effect // of advancing the ticker on subsequent repaints even if there is not // a TickerPainter timer task firing repaints. This is ok because if // a Ticker is visible on the screen, it should always be "running". g.setColor(Display.ERASE_COLOR); g.fillRect(0, 2, Display.WIDTH, Screen.CONTENT_HEIGHT + 1); g.setColor(Display.FG_COLOR); messageLoc -= tickSpeed; g.drawString(displayedMessage, messageLoc, 2, Graphics.TOP | Graphics.LEFT); // Once the message is completely off the left side of // the screen, we reset its location to be the right side // of the screen if (messageLoc <= -messageWidth) { messageLoc = Display.WIDTH; }
void	reset() Reset this Ticker's message location to the right side of the screen messageLoc = Display.WIDTH;
public void	setString(java.lang.String str) Sets the string to be displayed by this ticker. If this ticker is active and is on the display, it immediately begins showing the new string. param str string to be set for the Ticker throws NullPointerException if str is null see #getString synchronized (Display.LCDUILock) { setupText(str); }
private final void	setupText(java.lang.String message) Initialize this Ticker with the given text param message The text this Ticker will display if (message == null) { throw new NullPointerException(); } /* * Search the message for linebreak characters, and replace * with spaces. */ StringBuffer msg = new StringBuffer(message); int offset = 0; boolean modified = false; while ((offset = message.indexOf('\n", offset)) != -1) { msg.setCharAt(offset, ' "); offset++; modified = true; } /* * Save the original unmodified message so that getString() * returns that. If the message is modified because it * contains linebreak characters, then set the display message * to the modified string. */ this.message = message; this.displayedMessage = modified ? msg.toString() : message; messageWidth = Screen.CONTENT_FONT.stringWidth(this.displayedMessage); if (messageWidth < 5) { tickSpeed = messageWidth; } else { tickSpeed = 5; } reset();