Java Development

[mohunt]

I am writing a scanning application takes multiple snapshots until it finds a barcode that it can decode.  

I have created a do loop that depends on a boolean field to determine whether the user has decided to cancel the scan.

I have found that while it is in the scanning loop, the screen is not responding to the keypress event.

My code below:

import java.io.*;
import java.util.Hashtable;
import java.util.Vector;

import net.rim.device.api.system.Alert;
import net.rim.device.api.system.Audio;
import net.rim.device.api.system.Bitmap;
import net.rim.device.api.system.Display;
import net.rim.device.api.ui.Field;
import net.rim.device.api.ui.Keypad;
import net.rim.device.api.ui.UiApplication;
import net.rim.device.api.ui.component.BitmapField;
import net.rim.device.api.ui.component.Dialog;
import net.rim.device.api.ui.container.AbsoluteFieldManager;
import net.rim.device.api.ui.container.ComponentCanvas;
import net.rim.device.api.ui.container.MainScreen;
import net.rim.device.api.amms.control.camera.*;
import javax.microedition.amms.control.camera.CameraControl;
import javax.microedition.amms.control.camera.ZoomControl;
import javax.microedition.io.Connector;
import javax.microedition.io.file.*;
import javax.microedition.media.*; 
import javax.microedition.media.control.*;
import javax.microedition.lcdui.Image;

public class CameraImageCapture extends MainScreen {
Player _camera;
VideoControl _cameracontrol;
String _results = "";
String _textline = "";
String _outputfile = "";
private EnhancedFocusControl _efc;
private ZoomControl _zoomControl;
private Field _videoField;
boolean _notFound = true;
AbsoluteFieldManager _afm;
BitmapField bfmAimer;


public CameraImageCapture()
{
    try
    {
	_afm = new AbsoluteFieldManager();
	_camera = javax.microedition.media.Manager.createPlayer("capture://video?encoding=jpeg&width=1024&height=768");
	_camera.realize();
	_cameracontrol = (VideoControl) _camera.getControl("VideoControl");
	_zoomControl =  (ZoomControl)  _camera.getControl("javax.microedition.amms.control.camera.ZoomControl");
	_camera.start();
	if (_cameracontrol != null)
	{
		_videoField = (Field) _cameracontrol.initDisplayMode(VideoControl.USE_GUI_PRIMITIVE, "net.rim.device.api.ui.Field");
		if(_videoField != null)
	        {
		 _afm.add(_videoField);
		 _cameracontrol.setDisplayFullScreen(true);
		 _cameracontrol.setVisible(true);
		 if (_zoomControl != null) {
			 _zoomControl.setDigitalZoom(_zoomControl.getMaxDigitalZoom());
		}
		add(_afm);
		
	}
	}
    }
    catch(Exception e)
    {
	Dialog.alert(e.toString());
    }
}

 protected boolean invokeAction(int action)
    {
     byte[] rawImage = null;
      boolean handled = super.invokeAction(action);
	if(!handled)
	{
	    if(action == ACTION_INVOKE)
	    {   
		try
		{
			while (_notFound)
			{
			   if (_camera.getState() != Player.STARTED)
			   {
				_camera.start();
			    }
			    _efc = (EnhancedFocusControl) _camera.getControl("net.rim.device.api.amms.control.camera.EnhancedFocusControl");
			    if (_efc != null)
			    {
				if (_efc.isFocusModeSupported(EnhancedFocusControl.FOCUS_MODE_SINGLESHOT)) {
					_efc.setFocusMode(EnhancedFocusControl.FOCUS_MODE_SINGLESHOT);                    
				}
				try
				{
				_efc.startAutoFocus();
				}
				catch (Exception e1)
				{
					_notFound = false;
					Dialog.alert(e1.toString());
					break;
				}
			    }
			    rawImage = _cameracontrol.getSnapshot(null);
			    _camera.stop();
			    if(rawImage != null)
			    {
				Dialog.alert("Got Picture");
			    }
			 
			}
							
		}
		catch(Exception e)
		{
			_notFound = false;
		    Dialog.alert(e.toString());
		}
	    }
	}
	terminatescan();
	return handled;                
    }
	 
    private boolean terminatescan()
    {
	try
	{
		_notFound = false;
		if (_camera.getState() == Player.STARTED)
		{
			_camera.stop();
		}
		if (_camera.getState() != Player.CLOSED)
		{
			_camera.close();
		}
		if (!_closed)
		{
			_closed = true;
			UiApplication.getUiApplication().invokeLater(new Runnable() {
				public void run() {
					 UiApplication.getUiApplication().popScreen(UiApplication.getUiApplication().getActiveScreen());
				}
			});
		}
	}
	catch (Exception e)
	{
	
	}
	return true;
  }

   public boolean keyDown(int keycode, int time) {

	// First convert the keycode into an actual key event, taking
	// modifiers into account
	int key = Keypad.key(keycode);

	// From there we can compare against the escape key constant. If
	// we get it, we stop the scan and pop this screen off the stack
	if (key == Keypad.KEY_ESCAPE) {
		
		_notFound = false;
		terminatescan();
		return true;

	}
	// Otherwise, we'll return false so as not to consume the
	// keyDown event
	return false;
    }
}

Any help would be appreciated.