net.sf.javaocr.demos.android.utils.camera
Class CameraManager

java.lang.Object
  net.sf.javaocr.demos.android.utils.camera.CameraManager

All Implemented Interfaces:

android.hardware.Camera.AutoFocusCallback, android.hardware.Camera.PreviewCallback

public class CameraManager
extends Object
implements android.hardware.Camera.AutoFocusCallback, android.hardware.Camera.PreviewCallback

android camera manager encapsulating camera management and image acquisition

Author:

Konstantin Pribluda

Field Summary

(package private) android.hardware.Camera	camera
(package private) boolean	cameraActive
(package private) boolean	focusState
private static String	LOG_TAG
static int	MIN_PREVIEW_WIDTH
(package private) boolean	previewActive
(package private) byte[]	previewImage
private android.hardware.Camera.Size	previewSize
(package private) boolean	waitingForFocus
(package private) boolean	waitingForPreview

Constructor Summary

CameraManager()

Method Summary

boolean	doAutofocus() acquire autofocus.
android.hardware.Camera	getCamera() return camera object of any
byte[]	getPreviewFrame() acquires preview frame.
android.hardware.Camera.Size	getPreviewSize() preview size ist read only
boolean	isCameraActive() whether we are active at the moment
void	onAutoFocus(boolean b, android.hardware.Camera camera) synchronize on object itself to prevent race condition
void	onPreviewFrame(byte[] bytes, android.hardware.Camera camera) save data to pointer and wake up sleeping thread.
void	start(android.view.SurfaceHolder holder) start camera manager (call it in onStart() )
private void	startPreview(android.view.SurfaceHolder holder) configure camera, start preview and pipe it to surface holder use it to whenever you are starting preview - in resume - when surface changed - on config changes etc
void	stop() stop camera manager and give up resources (shall be called from onPause() )
private void	stopPreview() stop preview before starting it again

Methods inherited from class java.lang.Object

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

Field Detail

LOG_TAG

private static final String LOG_TAG

See Also:

Constant Field Values

camera

android.hardware.Camera camera

cameraActive

boolean cameraActive

previewActive

boolean previewActive

previewSize

private android.hardware.Camera.Size previewSize

MIN_PREVIEW_WIDTH

public static final int MIN_PREVIEW_WIDTH

See Also:

Constant Field Values

focusState

boolean focusState

waitingForFocus

boolean waitingForFocus

waitingForPreview

boolean waitingForPreview

previewImage

byte[] previewImage

Constructor Detail

CameraManager

public CameraManager()

Method Detail

getPreviewSize

public android.hardware.Camera.Size getPreviewSize()

preview size ist read only

Returns:

start

public void start(android.view.SurfaceHolder holder)
           throws IOException

start camera manager (call it in onStart() )

Throws:

IOException

stop

public void stop()

stop camera manager and give up resources (shall be called from onPause() )

startPreview

private void startPreview(android.view.SurfaceHolder holder)
                   throws IOException

configure camera, start preview and pipe it to surface holder use it to whenever you are starting preview - in resume - when surface changed - on config changes etc

Parameters:

holder -

Throws:

IOException

stopPreview

private void stopPreview()

stop preview before starting it again

getCamera

public android.hardware.Camera getCamera()

return camera object of any

Returns:

isCameraActive

public boolean isCameraActive()

whether we are active at the moment

Returns:

doAutofocus

public boolean doAutofocus()

acquire autofocus. this method blocks current thread until autofocus callback is called.

Returns:

autofocus callback

getPreviewFrame

public byte[] getPreviewFrame()

acquires preview frame. thread is blocked until callback is fired

Returns:

byte data of preview frame, null is not successfull

onAutoFocus

public void onAutoFocus(boolean b,
                        android.hardware.Camera camera)

synchronize on object itself to prevent race condition

Specified by:

onAutoFocus in interface android.hardware.Camera.AutoFocusCallback

Parameters:

b - status of ayto focus

camera - camera acquiring focus

onPreviewFrame

public void onPreviewFrame(byte[] bytes,
                           android.hardware.Camera camera)

save data to pointer and wake up sleeping thread.

Specified by:

onPreviewFrame in interface android.hardware.Camera.PreviewCallback

Parameters:

bytes - byte array containig image data

camera - camera object