net.rim.device.api.barcodelib
Class BarcodeScanner

java.lang.Object
  net.rim.device.api.amms.control.camera.ImageScanner
      net.rim.device.api.barcodelib.BarcodeScanner

public final class BarcodeScanner
extends ImageScanner

An ImageScanner intended for barcode scanning. See com.google.zxing for the detection and decoding libraries.

You are notified of the decoded text by the BarcodeDecoderListener when a barcode is detected by the zxing library. Alternatively, you can use ImageDecoderListener which will give you access to all the decoded information via Result.

Typical usage for scanning QR barcodes:

 
   BarcodeDecoderListener listener = new BarcodeDecoderListener() {
       public void barcodeDecoded( String rawText ) {
           // called when a barcode has been detected.  Process the rawText here.
           // stopScan has been automatically called.
       }
  };
 

 
   Hashtable hints = new Hashtable();
   Vector formats  = new Vector();
   formats.addElement(BarcodeFormat.QR_CODE);
   hints.put(DecodeHintType.POSSIBLE_FORMATS, formats);
   BarcodeDecoder decoder = new BarcodeDecoder(hints); 
 

 
   MainScreen screen = new MainScreen();
   BarcodeScanner scanner = new BarcodeScanner( decoder, listener );
   screen.add( scanner.getViewfinder() );
   UiApplication.getUiApplication().pushScreen( screen );
   scanner.startScan(); 
 

You might try hints.put(DecoderHintType.TRY_HARDER, Boolean.TRUE) as well for a more thorough detection, especially when decoding 1D barcodes. However, decoding time for each frame will significantly increase.

When attempting to scan 1D barcodes, barcodes are read left to right. Thus, orientation of the barcode in the viewfinder matters, and should be aligned to be read left to right.

Since:

BlackBerry API 6.0.0

Constructor Summary

BarcodeScanner(BarcodeDecoder decoder, ImageDecoderListener listener)
Creates a new instance of BarcodeScanner.

BarcodeScanner(BarcodeDecoder decoder, BarcodeDecoderListener listener)
Creates a new instance of BarcodeScanner.

Method Summary
Player	getPlayer() Retrieves the camera player.
Field	getVanillaViewfinder() Retrieves a non-augmented viewfinder for the player returned by BarcodeScanner.getPlayer().
VideoControl	getVideoControl() Retrieves the VideoControl for the player returned by BarcodeScanner.getPlayer().
Field	getViewfinder() Retrieves the viewfinder for the player returned by BarcodeScanner.getPlayer().
void	setBarcodeDecoder(BarcodeDecoder decoder) Sets the BarcodeDecoder.
void	startScan() Starts scanning for a barcode.
void	stopScan() Stops scanning for a barcode.

Methods inherited from class net.rim.device.api.amms.control.camera.ImageScanner

getDecoder, isColorIncluded, isScanning, setDecoder, setHint

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BarcodeScanner

public BarcodeScanner(BarcodeDecoder decoder,
                      BarcodeDecoderListener listener)
               throws IOException,
                      MediaException

Creates a new instance of BarcodeScanner. This class sets a hint setHint with ImageScannerHint.BARCODE_SCANNING.

Parameters:

decoder - BarcodeDecoder that can be configured to detect barcodes.

listener - BarcodeDecoderListener to be notified when a barcode has been detected.

Throws:

IllegalArgumentException - if decoder or listener is null.

SecurityException - if the caller does not have security permission to create the Player.

MediaException - if Manager.createPlayer(java.lang.String) specifies capture://video?encoding=image/jpeg as its encoding.

IOException - if there was a problem connecting with the source.

Since:

BlackBerry API 6.0.0

BarcodeScanner

public BarcodeScanner(BarcodeDecoder decoder,
                      ImageDecoderListener listener)
               throws IOException,
                      MediaException

Creates a new instance of BarcodeScanner. When used in conjunction with the zxing library, your ImageDecoderListener will get notified via ImageDecoderListener.imageDecoded(Object) with an object of type Result. This class sets a hint setHint with ImageScannerHint.BARCODE_SCANNING.

Parameters:

decoder - BarcodeDecoder that can be configured to detect barcodes.

listener - BarcodeDecoderListener to be notified when a barcode has been detected.

Throws:

IllegalArgumentException - if decoder or listener is null

SecurityException - if the caller does not have security permission to create the Player.

MediaException - if Manager.createPlayer(java.lang.String) specifies capture://video?encoding=image/jpeg as its encoding.

IOException - if there was a problem connecting with the source pointed to by the Locator.

Since:

BlackBerry API 7.0.0

Method Detail

getPlayer

public Player getPlayer()

Retrieves the camera player.

Overrides:

getPlayer in class ImageScanner

Returns:

camera player

Since:

BlackBerry API 6.0.0

getVideoControl

public VideoControl getVideoControl()

Retrieves the VideoControl for the player returned by BarcodeScanner.getPlayer().

Overrides:

getVideoControl in class ImageScanner

Returns:

VideoControl The VideoControl associated with this BarcodeScanner.

Since:

BlackBerry API 6.0.0

getViewfinder

public Field getViewfinder()

Retrieves the viewfinder for the player returned by BarcodeScanner.getPlayer(). This viewfinder is a ViewfinderOverlay. If getDecoder returns an instance of BarcodeDecoder at the time this method is called, the ViewfinderOverlay will also contain a single BarcodeScannerOverlayField.

Overrides:

getViewfinder in class ImageScanner

Returns:

A viewfinder that can be added to the screen directly. Invoking this method multiple times will return the same ViewfinderOverlay.

Since:

BlackBerry API 6.0.0

getVanillaViewfinder

public final Field getVanillaViewfinder()

Retrieves a non-augmented viewfinder for the player returned by BarcodeScanner.getPlayer().

Returns:

A viewfinder that can be added to the screen directly. Invoking this method multiple times will return the same Viewfinder.

See Also:

ImageScanner.getViewfinder()

Since:

BlackBerry API 7.0.0

startScan

public void startScan()
               throws MediaException

Starts scanning for a barcode.

Overrides:

startScan in class ImageScanner

Throws:

MediaException - if the Player cannot be started or scanning cannot be started.

IllegalStateException - if no BarcodeDecoder has been set, or if the Player is in the CLOSED state.

SecurityException - if the caller does not have security permission to start the Player.

Since:

BlackBerry API 6.0.0

stopScan

public void stopScan()
              throws MediaException

Stops scanning for a barcode. Note that scanning is automatically stopped after a barcode has been detected and decoded.

Overrides:

stopScan in class ImageScanner

Throws:

MediaException - if the Player cannot be stopped or scanning cannot be stopped.

IllegalStateException - if the Player is in the CLOSED state.

Since:

BlackBerry API 6.0.0

setBarcodeDecoder

public void setBarcodeDecoder(BarcodeDecoder decoder)
                       throws IllegalArgumentException

Sets the BarcodeDecoder. This method can be called if scanning has already been started.

Parameters:

decoder - The barcode decoder.

Throws:

IllegalArgumentException - if decoder is null.

See Also:

ImageScanner.setDecoder(net.rim.device.api.amms.control.camera.ImageDecoder)

Since:

BlackBerry API 6.0.0