I'm building a basic Point of Sale application and I've been looking for
ways of having my main POS JFrame listen for bar code input. I found
this code (slightly modified) posted by Cyrusmith, which looks like what
I want but I don't know how to implement it in my JFrame. It looks like
its intended to be a separate class, which is how I have it in my
project currently. I asked my coworker and he doesn't know either.
Thanks for your help.
package barcode;
import java.awt.KeyEventDispatcher;
import java.awt.KeyboardFocusManager;
import java.awt.event.KeyEvent;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
/**
* Listens for bar code input and puts it into a String Buffer.
*
*/
public class BarcodeReader {
private static final long THRESHOLD = 100;
private static final int MIN_BARCODE_LENGTH = 8;
public interface BarcodeListener {
void onBarcodeRead(String barcode);
}
private final StringBuffer barcode = new StringBuffer();
private final List<BarcodeListener> listeners = new
CopyOnWriteArrayList<>();
private long lastEventTimeStamp = 0L;
public BarcodeReader() {
KeyboardFocusManager.getCurrentKeyboardFocusManager().addKeyEventDispatcher(new
KeyEventDispatcher() {
@Override
public boolean dispatchKeyEvent(KeyEvent e) {
try {
if (e.getID() != KeyEvent.KEY_RELEASED) {
return false;
}
if (e.getWhen() - lastEventTimeStamp > THRESHOLD) {
barcode.delete(0, barcode.length());
}
lastEventTimeStamp = e.getWhen();
if (e.getKeyCode() == KeyEvent.VK_ENTER) {
if (barcode.length() >= MIN_BARCODE_LENGTH) {
fireBarcode(barcode.toString());
}
barcode.delete(0, barcode.length());
} else {
barcode.append(e.getKeyChar());
}
return false;
} catch (UnsupportedOperationException err) {
throw new UnsupportedOperationException(err);
change body of generated methods, choose Tools | Templates.
}
}
});
}
protected void fireBarcode(String barcode) {
for (BarcodeListener listener : listeners) {
listener.onBarcodeRead(barcode);
}
}
public void addBarcodeListener(BarcodeListener listener) {
listeners.add(listener);
}
public void removeBarcodeListener(BarcodeListener listener) {
listeners.remove(listener);
}
}
______________________________________
http://www.businessrefinery.com/