com.jtm.qrcode.camera

Class CameraManager

java.lang.Object

com.jtm.qrcode.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.

Constructor Summary

Constructors

Constructor and Description
CameraManager(android.content.Context context)

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.
android.hardware.Camera	getCamera()
CameraConfigurationManager	getConfigurationManager()
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.
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	setManualFramingRect(int width, int height) Allows third party apps to specify the scanning rectangle dimensions, rather than determine them automatically based on screen resolution.
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

Constructor Detail

CameraManager

public CameraManager(android.content.Context context)

Method Detail

getConfigurationManager

public CameraConfigurationManager getConfigurationManager()

getCamera

public android.hardware.Camera getCamera()

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

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.

setManualFramingRect

public void setManualFramingRect(int width,
                                 int height)

Allows third party apps to specify the scanning rectangle dimensions, rather than determine them automatically based on screen resolution.

Parameters:

width - The width in pixels to scan.

height - The height in pixels to scan.

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.