zbar::QZBar Class Reference

barcode reader Qt4 widget. More...

Inheritance diagram for zbar::QZBar:

Collaboration diagram for zbar::QZBar:

Public Slots
void	scanImage (const QImage &image)
	scan for barcodes in a QImage. More...
void	setVideoDevice (const QString &videoDevice)
	open a new video device. More...
void	setVideoEnabled (bool videoEnabled=true)
	enable/disable video scanning. More...

Signals
void	decoded (int type, const QString &data)
	emitted when a barcode is decoded from an image. More...
void	decodedText (const QString &text)
	emitted when a barcode is decoded from an image. More...
void	videoOpened (bool videoOpened)
	emitted when when a video device is opened or closed. More...

Public Member Functions
	QZBar (QWidget *parent=NULL)
	constructs a barcode reader widget with the given parent More...
	~QZBar ()
bool	isVideoEnabled () const
	retrieve the current video enabled state. More...
bool	isVideoOpened () const
	retrieve the current video opened state. More...
QString	videoDevice () const
	retrieve the currently opened video device. More...
QSize	sizeHint () const
int	heightForWidth (int) const
QPaintEngine *	paintEngine () const

Properties
QString	videoDevice
	the currently opened video device. More...
bool	videoEnabled
	video device streaming state. More...
bool	videoOpened
	video device opened state. More...

Private Attributes
bool	_attached
QString	_videoDevice
bool	_videoEnabled
QZBarThread *	thread
void	attach ()
void	showEvent (QShowEvent *)
void	paintEvent (QPaintEvent *)
void	resizeEvent (QResizeEvent *)
void	changeEvent (QEvent *)
void	dragEnterEvent (QDragEnterEvent *)
void	dropEvent (QDropEvent *)
void	sizeChange ()

Detailed Description

barcode reader Qt4 widget.

embeds a barcode reader directly into a Qt4 based GUI. the widget can process barcodes from a video source (using the QZBar::videoDevice and QZBar::videoEnabled properties) or from individual QImages supplied to the QZBar::scanImage() slot

Since

1.5

Constructor & Destructor Documentation

QZBar::QZBar

(

QWidget *

parent = NULL

)

constructs a barcode reader widget with the given parent

References _attached, zbar::Window::attach(), decoded(), decodedText(), sizeChange(), thread, videoOpened, and zbar::QZBarThread::window.

Here is the call graph for this function:

QZBar::~QZBar

(

)

References zbar::QZBarThread::Exit, zbar::QZBarThread::pushEvent(), and thread.

Here is the call graph for this function:

Member Function Documentation

void QZBar::attach ( )

protected

References _attached, _videoDevice, _videoEnabled, zbar::Window::attach(), zbar::QZBarThread::pushEvent(), thread, and zbar::QZBarThread::window.

Referenced by showEvent().

Here is the call graph for this function:

Here is the caller graph for this function:

void QZBar::changeEvent ( QEvent *  event )

protected

References zbar::Window::attach(), zbar::QZBarThread::mutex, thread, and zbar::QZBarThread::window.

Here is the call graph for this function:

void zbar::QZBar::decoded ( int  type, const QString &  data  )

signal

emitted when a barcode is decoded from an image.

the symbol type and contained data are provided as separate parameters.

Referenced by QZBar().

Here is the caller graph for this function:

void zbar::QZBar::decodedText ( const QString &  text )

signal

emitted when a barcode is decoded from an image.

the symbol type name is prefixed to the data, separated by a colon

Referenced by QZBar().

Here is the caller graph for this function:

void QZBar::dragEnterEvent ( QDragEnterEvent *  event )

protected

void QZBar::dropEvent ( QDropEvent *  event )

protected

References scan_image::image, and scanImage().

Here is the call graph for this function:

int QZBar::heightForWidth

(

int

width

)

const

References zbar::QZBarThread::mutex, zbar::QZBarThread::reqHeight, zbar::QZBarThread::reqWidth, and thread.

bool QZBar::isVideoEnabled

(

)

const

retrieve the current video enabled state.

Returns

true if video scanning is currently enabled, false otherwise

References _videoEnabled.

bool QZBar::isVideoOpened

(

)

const

retrieve the current video opened state.

Returns

true if video device is currently opened, false otherwise

References zbar::QZBarThread::_videoOpened, zbar::QZBarThread::mutex, and thread.

QPaintEngine * QZBar::paintEngine

(

)

const

References _videoDevice, and videoDevice().

Here is the call graph for this function:

void QZBar::paintEvent ( QPaintEvent *  event )

protected

References zbar::Window::redraw(), thread, and zbar::QZBarThread::window.

Here is the call graph for this function:

void QZBar::resizeEvent ( QResizeEvent *  event )

protected

References zbar::Window::resize(), test_zbar::size, thread, and zbar::QZBarThread::window.

Here is the call graph for this function:

void QZBar::scanImage ( const QImage &  image )

slot

scan for barcodes in a QImage.

References zbar::QZBarThread::pushEvent(), and thread.

Referenced by dropEvent().

Here is the call graph for this function:

Here is the caller graph for this function:

void QZBar::setVideoDevice ( const QString &  videoDevice )

slot

open a new video device.

use an empty string to close a currently opened device.

Note

since opening a device may take some time, this call will return immediately and the device will be opened asynchronously

References _attached, _videoDevice, _videoEnabled, zbar::QZBarThread::pushEvent(), thread, and videoDevice().

Here is the call graph for this function:

void QZBar::setVideoEnabled ( bool  videoEnabled = true )

slot

enable/disable video scanning.

has no effect unless a video device is opened

References _videoEnabled, zbar::QZBarThread::pushEvent(), thread, and videoEnabled.

Here is the call graph for this function:

void QZBar::showEvent ( QShowEvent *  event )

protected

References _attached, attach(), and thread.

Here is the call graph for this function:

void QZBar::sizeChange ( )

protectedslot

Referenced by QZBar().

Here is the caller graph for this function:

QSize QZBar::sizeHint

(

)

const

References zbar::QZBarThread::mutex, zbar::QZBarThread::reqHeight, zbar::QZBarThread::reqWidth, and thread.

QString zbar::QZBar::videoDevice

(

)

const

retrieve the currently opened video device.

Returns

the current video device or the empty string if no device is opened

Referenced by paintEngine(), and setVideoDevice().

Here is the caller graph for this function:

void zbar::QZBar::videoOpened ( bool  videoOpened )

signal

emitted when when a video device is opened or closed.

(re)setting QZBar::videoDevice should eventually cause it to be opened or closed. any errors while streaming/scanning will also cause the device to be closed

Member Data Documentation

bool zbar::QZBar::_attached

private

Referenced by attach(), QZBar(), setVideoDevice(), and showEvent().

QString zbar::QZBar::_videoDevice

private

Referenced by attach(), paintEngine(), and setVideoDevice().

bool zbar::QZBar::_videoEnabled

private

Referenced by attach(), isVideoEnabled(), setVideoDevice(), and setVideoEnabled().

QZBarThread* zbar::QZBar::thread

private

Referenced by attach(), changeEvent(), heightForWidth(), isVideoOpened(), paintEvent(), QZBar(), resizeEvent(), scanImage(), setVideoDevice(), setVideoEnabled(), showEvent(), sizeHint(), and ~QZBar().

Property Documentation

QString QZBar::videoDevice

readwrite

the currently opened video device.

setting a new device opens it and automatically sets QZBar::videoEnabled

See also

videoDevice(), setVideoDevice()

bool zbar::QZBar::videoEnabled

readwrite

video device streaming state.

use to pause/resume video scanning.

See also

isVideoEnabled(), setVideoEnabled()

Referenced by setVideoEnabled().

bool zbar::QZBar::videoOpened

read

video device opened state.

(re)setting QZBar::videoDevice should eventually cause it to be opened or closed. any errors while streaming/scanning will also cause the device to be closed

See also

isVideoOpened()

Referenced by QZBar().

---

The documentation for this class was generated from the following files:

• QZBar.h
• QZBar.cpp