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package net.sf.microlog.midp.appender;
import java.io.IOException;
import java.util.Vector;
import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Font;
import javax.microedition.lcdui.Graphics;
import net.sf.microlog.core.Appender;
import net.sf.microlog.core.Formatter;
import net.sf.microlog.core.Level;
import net.sf.microlog.core.format.SimpleFormatter;
/**
* An appender which writes entries to a Canvas. Supports scrolling.
*
* @author Ricardo Amores Hernandez
* @author Johan Karlsson (johan.karlsson@jayway.se)
*/
public class CanvasAppender extends Canvas implements Appender {
/**
* Saves log entries
*/
private Vector logStrings = new Vector();
/**
* Text formatter. Uses SimpleFormatter by default.
*/
private Formatter formatter;
/**
* True if the log is closed. The log is opened by default.
*/
private boolean isOpen;
/**
* Size of the offset for drawing string lines
*/
private int lineSize;
/**
* Offset in the screen
*/
private int screenOffset;
/**
* Set our logging font
*/
private Font loggingFont;
/**
* Create a <code>CanvasAppender</code>. constructor
*/
public CanvasAppender() {
// Set default formatter
formatter = new SimpleFormatter();
screenOffset = 0;
// Create logging font
loggingFont = Font.getFont(Font.FACE_MONOSPACE, Font.STYLE_PLAIN,
Font.SIZE_SMALL);
// Store size of a line writted writted in the screen with this font
lineSize = loggingFont.getHeight();
}
/**
* Draws log entries to the screen
*
* @param g
* the <code>Graphics</code> object to use for drawing.
*/
public void paint(Graphics g) {
// Erase screen
g.setColor(255, 255, 255);
g.fillRect(0, 0, this.getWidth(), this.getHeight());
g.setColor(0, 0, 0);
// Draw all lines
int count = 1;
for (int index = screenOffset; index < logStrings.size(); index++) {
g.drawString(logStrings.elementAt(index).toString(), 0, count
* lineSize, Graphics.BASELINE | Graphics.LEFT);
count++;
}
}
/**
* Called when a key is pressed.
*
* @param keyCode
* the key kode of the key that was pressed.
*/
protected void keyPressed(int keyCode) {
switch (this.getGameAction(keyCode)) {
case UP:
if (screenOffset > 0) {
screenOffset--;
}
break;
case DOWN:
if (lineSize * (logStrings.size() - screenOffset) > this
.getHeight()) {
screenOffset++;
}
break;
default:
break;
}
// Request screen repaint
repaint();
}
/**
* Do the logging.
*
* @param level
* the level at which the logging shall be done.
* @param message
* the message to log.
* @param throwable
* the exception to log.
*/
public void doLog(String clientID, String name, long time, Level level,
Object message, Throwable throwable) {
if (isOpen && formatter != null) {
logStrings.addElement(formatter.format(clientID, name, time, level,
message, throwable));
}
// Scroll down screen to show the last line entered when a new line is
// added
while (lineSize * (logStrings.size() - screenOffset) > this.getHeight()) {
screenOffset++;
}
// Request screen repaint
this.repaint();
}
/**
* Clear the log.
*
* @see net.sf.microlog.core.Appender#clear()
*/
public void clear() {
logStrings.removeAllElements();
}
/**
* Opens the log.
*
* @see net.sf.microlog.core.Appender#open()
*/
public void open() throws IOException {
clear();
isOpen = true;
}
/**
* Closes the log.
*
* @see net.sf.microlog.core.Appender#close()
*/
public void close() throws IOException {
isOpen = false;
}
/**
* Check if the log is open.
*
* @return true if the log is open, false if the log is closed.
*/
public boolean isLogOpen() {
return isOpen;
}
/**
* Gets the number of entries in the log.
*
* @return A long with the number of log entries
*/
public long getLogSize() {
return logStrings.size();
}
/**
* Sets the format used to represent the log strings
*
* @param formatter
*/
public void setFormatter(Formatter formatter) {
if (formatter == null) {
throw new NullPointerException("newFormatter is invalid");
}
this.formatter = formatter;
}
/**
* Gets the current formatter used to format the log entires.
*
* @return the current formatter.
*/
public Formatter getFormatter() {
return formatter;
}
/**
* @see Appender#getPropertyNames()
*/
public String[] getPropertyNames() {
return null;
}
/**
* @see Appender#setProperty(String, String)
*/
public void setProperty(String name, String value) {
// Ignore since we have no properties to set.
}
}