com.xuexiang.xqrcode.camera

Class CameraManager

java.lang.Object

com.xuexiang.xqrcode.camera.CameraManager

public final class CameraManager
extends java.lang.Object

This object wraps the Camera service object and expects to be the only one talking to it. The implementation encapsulates the steps needed to take preview-sized images, which are used for both preview and decoding.

Field Summary

Fields

Modifier and Type	Field and Description
static int	FRAME_HEIGHT
static int	FRAME_MARGIN_TOP
static int	FRAME_WIDTH

Method Summary

Modifier and Type	Method and Description
PlanarYUVLuminanceSource	buildLuminanceSource(byte[] data, int width, int height) A factory method to build the appropriate LuminanceSource object based on the format of the preview buffers, as described by Camera.Parameters.
void	closeDriver() Closes the camera driver if still in use.
static CameraManager	get() Gets the CameraManager singleton instance.
AutoFocusCallback	getAutoFocusCallback()
android.hardware.Camera	getCamera()
android.content.Context	getContext()
android.graphics.Rect	getFramingRect() Calculates the framing rect which the UI should draw to show the user where to place the barcode.
android.graphics.Rect	getFramingRectInPreview() Like getFramingRect() but coordinates are in terms of the preview frame, not UI / screen.
PreviewCallback	getPreviewCallback()
static void	init(android.content.Context context) Initializes this static object with the Context of the calling Activity.
boolean	isPreviewing()
boolean	isUseOneShotPreviewCallback()
void	openDriver(android.view.SurfaceHolder holder) Opens the camera driver and initializes the hardware parameters.
void	requestAutoFocus(android.os.Handler handler, int message) Asks the camera hardware to perform an autofocus.
void	requestPreviewFrame(android.os.Handler handler, int message) A single preview frame will be returned to the handler supplied.
void	setPreviewing(boolean previewing)
void	startPreview() Asks the camera hardware to begin drawing preview frames to the screen.
void	stopPreview() Tells the camera to stop drawing preview frames.

Methods inherited from class java.lang.Object

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

Field Detail

FRAME_WIDTH

public static int FRAME_WIDTH

FRAME_HEIGHT

public static int FRAME_HEIGHT

FRAME_MARGIN_TOP

public static int FRAME_MARGIN_TOP

Method Detail

init

public static void init(android.content.Context context)

Initializes this static object with the Context of the calling Activity.

Parameters:

context - The Activity which wants to use the camera.

get

public static CameraManager get()

Gets the CameraManager singleton instance.

Returns:

A reference to the CameraManager singleton.

openDriver

public void openDriver(android.view.SurfaceHolder holder)
                throws java.io.IOException

Opens the camera driver and initializes the hardware parameters.

Parameters:

holder - The surface object which the camera will draw preview frames into.

Throws:

java.io.IOException - Indicates the camera driver failed to open.

closeDriver

public void closeDriver()

Closes the camera driver if still in use.

startPreview

public void startPreview()

Asks the camera hardware to begin drawing preview frames to the screen.

stopPreview

public void stopPreview()

Tells the camera to stop drawing preview frames.

requestPreviewFrame

public void requestPreviewFrame(android.os.Handler handler,
                                int message)

A single preview frame will be returned to the handler supplied. The data will arrive as byte[] in the message.obj field, with width and height encoded as message.arg1 and message.arg2, respectively.

Parameters:

handler - The handler to send the message to.

message - The what field of the message to be sent.

requestAutoFocus

public void requestAutoFocus(android.os.Handler handler,
                             int message)

Asks the camera hardware to perform an autofocus.

Parameters:

handler - The Handler to notify when the autofocus completes.

message - The message to deliver.

getFramingRect

public android.graphics.Rect getFramingRect()

Calculates the framing rect which the UI should draw to show the user where to place the barcode. This target helps with alignment as well as forces the user to hold the device far enough away to ensure the image will be in focus.

Returns:

The rectangle to draw on screen in window coordinates.

getFramingRectInPreview

public android.graphics.Rect getFramingRectInPreview()

Like getFramingRect() but coordinates are in terms of the preview frame, not UI / screen.

buildLuminanceSource

public PlanarYUVLuminanceSource buildLuminanceSource(byte[] data,
                                                     int width,
                                                     int height)

A factory method to build the appropriate LuminanceSource object based on the format of the preview buffers, as described by Camera.Parameters.

Parameters:

data - A preview frame.

width - The width of the image.

height - The height of the image.

Returns:

A PlanarYUVLuminanceSource instance.

getContext

public android.content.Context getContext()

getCamera

public android.hardware.Camera getCamera()

isPreviewing

public boolean isPreviewing()

isUseOneShotPreviewCallback

public boolean isUseOneShotPreviewCallback()

getPreviewCallback

public PreviewCallback getPreviewCallback()

getAutoFocusCallback

public AutoFocusCallback getAutoFocusCallback()

setPreviewing

public void setPreviewing(boolean previewing)