QBuffer Class Reference

The QBuffer class provides a QIODevice interface for a QByteArray. More...

#include <qbuffer.h>

Inheritance diagram for QBuffer:

Public Functions
bool	atEnd () const
	Reimplemented Function More...
QByteArray &	buffer ()
	Returns a reference to the QBuffer's internal buffer. More...
const QByteArray &	buffer () const
	This is the same as data(). More...
bool	canReadLine () const
	Reimplemented Function More...
void	close ()
	Reimplemented Function More...
const QByteArray &	data () const
	Returns the data contained in the buffer. More...
bool	open (OpenMode openMode)
	Reimplemented Function More...
qint64	pos () const
	Reimplemented Function More...
	QBuffer (QObject *parent=0)
	Constructs an empty buffer with the given parent. More...
	QBuffer (QByteArray *buf, QObject *parent=0)
	Constructs a QBuffer that uses the QByteArray pointed to by byteArray as its internal buffer, and with the given parent. More...
bool	seek (qint64 off)
	Reimplemented Function More...
void	setBuffer (QByteArray *a)
	Makes QBuffer uses the QByteArray pointed to by byteArray as its internal buffer. More...
void	setData (const QByteArray &data)
	Sets the contents of the internal buffer to be data. More...
void	setData (const char *data, int len)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Sets the contents of the internal buffer to be the first size bytes of data. More...
qint64	size () const
	Reimplemented Function More...
	~QBuffer ()
	Destroys the buffer. More...
Public Functions inherited from QIODevice
virtual qint64	bytesAvailable () const
	Returns the number of bytes that are available for reading. More...
virtual qint64	bytesToWrite () const
	For buffered devices, this function returns the number of bytes waiting to be written. More...
QString	errorString () const
	Returns a human-readable description of the last device error that occurred. More...
bool	getChar (char *c)
	Reads one character from the device and stores it in c. More...
bool	isOpen () const
	Returns true if the device is open; otherwise returns false. More...
bool	isReadable () const
	Returns true if data can be read from the device; otherwise returns false. More...
virtual bool	isSequential () const
	Returns true if this device is sequential; otherwise returns false. More...
bool	isTextModeEnabled () const
	Returns true if the Text flag is enabled; otherwise returns false. More...
bool	isWritable () const
	Returns true if data can be written to the device; otherwise returns false. More...
OpenMode	openMode () const
	Returns the mode in which the device has been opened; i.e. More...
qint64	peek (char *data, qint64 maxlen)
	Reads at most maxSize bytes from the device into data, without side effects (i. More...
QByteArray	peek (qint64 maxlen)
	Peeks at most maxSize bytes from the device, returning the data peeked as a QByteArray. More...
bool	putChar (char c)
	Writes the character c to the device. More...
	QIODevice ()
	Constructs a QIODevice object. More...
	QIODevice (QObject *parent)
	Constructs a QIODevice object with the given parent. More...
qint64	read (char *data, qint64 maxlen)
	Reads at most maxSize bytes from the device into data, and returns the number of bytes read. More...
QByteArray	read (qint64 maxlen)
	Reads at most maxSize bytes from the device, and returns the data read as a QByteArray. More...
QByteArray	readAll ()
	Reads all available data from the device, and returns it as a QByteArray. More...
qint64	readLine (char *data, qint64 maxlen)
	This function reads a line of ASCII characters from the device, up to a maximum of maxSize - 1 bytes, stores the characters in data, and returns the number of bytes read. More...
QByteArray	readLine (qint64 maxlen=0)
	Reads a line from the device, but no more than maxSize characters, and returns the result as a QByteArray. More...
virtual bool	reset ()
	Seeks to the start of input for random-access devices. More...
void	setTextModeEnabled (bool enabled)
	If enabled is true, this function sets the Text flag on the device; otherwise the Text flag is removed. More...
void	ungetChar (char c)
	Puts the character c back into the device, and decrements the current position unless the position is 0. More...
virtual bool	waitForBytesWritten (int msecs)
	For buffered devices, this function waits until a payload of buffered written data has been written to the device and the bytesWritten() signal has been emitted, or until msecs milliseconds have passed. More...
virtual bool	waitForReadyRead (int msecs)
	Blocks until new data is available for reading and the readyRead() signal has been emitted, or until msecs milliseconds have passed. More...
qint64	write (const char *data, qint64 len)
	Writes at most maxSize bytes of data from data to the device. More...
qint64	write (const char *data)
	Writes data from a zero-terminated string of 8-bit characters to the device. More...
qint64	write (const QByteArray &data)
	Writes the content of byteArray to the device. More...
virtual	~QIODevice ()
	The destructor is virtual, and QIODevice is an abstract base class. More...
Public Functions inherited from QObject
bool	blockSignals (bool b)
	If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it). More...
const QObjectList &	children () const
	Returns a list of child objects. More...
bool	connect (const QObject *sender, const char *signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const
bool	disconnect (const char *signal=0, const QObject *receiver=0, const char *member=0)
bool	disconnect (const QObject *receiver, const char *member=0)
void	dumpObjectInfo ()
	Dumps information about signal connections, etc. More...
void	dumpObjectTree ()
	Dumps a tree of children to the debug output. More...
QList< QByteArray >	dynamicPropertyNames () const
	Returns the names of all properties that were dynamically added to the object using setProperty(). More...
virtual bool	event (QEvent *)
	This virtual function receives events to an object and should return true if the event e was recognized and processed. More...
virtual bool	eventFilter (QObject *, QEvent *)
	Filters events if this object has been installed as an event filter for the watched object. More...
template<typename T >
T	findChild (const QString &aName=QString()) const
	Returns the child of this object that can be cast into type T and that is called name, or 0 if there is no such object. More...
template<typename T >
QList< T >	findChildren (const QString &aName=QString()) const
	Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects. More...
template<typename T >
QList< T >	findChildren (const QRegExp &re) const
bool	inherits (const char *classname) const
	Returns true if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns false. More...
void	installEventFilter (QObject *)
	Installs an event filter filterObj on this object. More...
bool	isWidgetType () const
	Returns true if the object is a widget; otherwise returns false. More...
void	killTimer (int id)
	Kills the timer with timer identifier, id. More...
virtual const QMetaObject *	metaObject () const
	Returns a pointer to the meta-object of this object. More...
void	moveToThread (QThread *thread)
	Changes the thread affinity for this object and its children. More...
QString	objectName () const
QObject *	parent () const
	Returns a pointer to the parent object. More...
QVariant	property (const char *name) const
	Returns the value of the object's name property. More...
Q_INVOKABLE	QObject (QObject *parent=0)
	Constructs an object with parent object parent. More...
void	removeEventFilter (QObject *)
	Removes an event filter object obj from this object. More...
void	setObjectName (const QString &name)
void	setParent (QObject *)
	Makes the object a child of parent. More...
bool	setProperty (const char *name, const QVariant &value)
	Sets the value of the object's name property to value. More...
void	setUserData (uint id, QObjectUserData *data)
bool	signalsBlocked () const
	Returns true if signals are blocked; otherwise returns false. More...
int	startTimer (int interval)
	Starts a timer and returns a timer identifier, or returns zero if it could not start a timer. More...
QThread *	thread () const
	Returns the thread in which the object lives. More...
QObjectUserData *	userData (uint id) const
virtual	~QObject ()
	Destroys the object, deleting all its child objects. More...

Protected Functions
void	connectNotify (const char *)
	Reimplemented Function More...
void	disconnectNotify (const char *)
	Reimplemented Function More...
qint64	readData (char *data, qint64 maxlen)
	Reimplemented Function More...
qint64	writeData (const char *data, qint64 len)
	Reimplemented Function More...
Protected Functions inherited from QIODevice
	QIODevice (QIODevicePrivate &dd, QObject *parent=0)
virtual qint64	readLineData (char *data, qint64 maxlen)
	Reads up to maxSize characters into data and returns the number of characters read. More...
void	setErrorString (const QString &errorString)
	Sets the human readable description of the last device error that occurred to str. More...
void	setOpenMode (OpenMode openMode)
	Sets the OpenMode of the device to openMode. More...
Protected Functions inherited from QObject
virtual void	childEvent (QChildEvent *)
	This event handler can be reimplemented in a subclass to receive child events. More...
virtual void	customEvent (QEvent *)
	This event handler can be reimplemented in a subclass to receive custom events. More...
	QObject (QObjectPrivate &dd, QObject *parent=0)
int	receivers (const char *signal) const
	Returns the number of receivers connected to the signal. More...
QObject *	sender () const
	Returns a pointer to the object that sent the signal, if called in a slot activated by a signal; otherwise it returns 0. More...
int	senderSignalIndex () const
virtual void	timerEvent (QTimerEvent *)
	This event handler can be reimplemented in a subclass to receive timer events for the object. More...

Additional Inherited Members
Public Types inherited from QIODevice
enum	OpenModeFlag {   NotOpen = 0x0000, ReadOnly = 0x0001, WriteOnly = 0x0002, ReadWrite = ReadOnly | WriteOnly,   Append = 0x0004, Truncate = 0x0008, Text = 0x0010, Unbuffered = 0x0020 }
	This enum is used with open() to describe the mode in which a device is opened. More...
Public Slots inherited from QObject
void	deleteLater ()
	Schedules this object for deletion. More...
Signals inherited from QIODevice
void	aboutToClose ()
	This signal is emitted when the device is about to close. More...
void	bytesWritten (qint64 bytes)
	This signal is emitted every time a payload of data has been written to the device. More...
void	readChannelFinished ()
	This signal is emitted when the input (reading) stream is closed in this device. More...
void	readyRead ()
	This signal is emitted once every time new data is available for reading from the device. More...
Signals inherited from QObject
void	destroyed (QObject *=0)
	This signal is emitted immediately before the object obj is destroyed, and can not be blocked. More...
Static Public Functions inherited from QObject
static bool	connect (const QObject *sender, const char *signal, const QObject *receiver, const char *member, Qt::ConnectionType=Qt::AutoConnection)
	Creates a connection of the given type from the signal in the sender object to the method in the receiver object. More...
static bool	connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection)
static bool	disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *member)
	Disconnects signal in object sender from method in object receiver. More...
static bool	disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &member)
static uint	registerUserData ()
static QString	tr (const char *sourceText, const char *comment=0, int n=-1)
static QString	trUtf8 (const char *sourceText, const char *comment=0, int n=-1)
Static Public Variables inherited from QObject
static const QMetaObject	staticMetaObject
	This variable stores the meta-object for the class. More...
Protected Variables inherited from QObject
QScopedPointer< QObjectData >	d_ptr
Static Protected Variables inherited from QObject
static const QMetaObject	staticQtMetaObject
Related Functions inherited from QObject
T	qFindChildqFindChildren (const QObject *obj, const QString &name)()
QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QString &name)()
QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QRegExp &regExp)()
T *	qobject_cast (QObject *object)
	QObjectList
void *	qt_find_obj_child (QObject *parent, const char *type, const QString &name)
	Returns a pointer to the object named name that inherits type and with a given parent. More...

Detailed Description

The QBuffer class provides a QIODevice interface for a QByteArray.

Note

This class or function is reentrant.

QBuffer allows you to access a QByteArray using the QIODevice interface. The QByteArray is treated just as a standard random-accessed file. Example:

    QBuffer buffer;
    char ch;

    buffer.open(QBuffer::ReadWrite);
    buffer.write("Qt rocks!");
    buffer.seek(0);
    buffer.getChar(&ch);  // ch == 'Q'
    buffer.getChar(&ch);  // ch == 't'
    buffer.getChar(&ch);  // ch == ' '
    buffer.getChar(&ch);  // ch == 'r'

By default, an internal QByteArray buffer is created for you when you create a QBuffer. You can access this buffer directly by calling buffer(). You can also use QBuffer with an existing QByteArray by calling setBuffer(), or by passing your array to QBuffer's constructor.

Call open() to open the buffer. Then call write() or putChar() to write to the buffer, and read(), readLine(), readAll(), or getChar() to read from it. size() returns the current size of the buffer, and you can seek to arbitrary positions in the buffer by calling seek(). When you are done with accessing the buffer, call close().

The following code snippet shows how to write data to a QByteArray using QDataStream and QBuffer:

    QByteArray byteArray;
    QBuffer buffer(&byteArray);
    buffer.open(QIODevice::WriteOnly);

    QDataStream out(&buffer);
    out << QApplication::palette();

Effectively, we convert the application's QPalette into a byte array. Here's how to read the data from the QByteArray:

    QPalette palette;
    QBuffer buffer(&byteArray);
    buffer.open(QIODevice::ReadOnly);

    QDataStream in(&buffer);
    in >> palette;

QTextStream and QDataStream also provide convenience constructors that take a QByteArray and that create a QBuffer behind the scenes.

QBuffer emits readyRead() when new data has arrived in the buffer. By connecting to this signal, you can use QBuffer to store temporary data before processing it. For example, you can pass the buffer to QFtp when downloading a file from an FTP server. Whenever a new payload of data has been downloaded, readyRead() is emitted, and you can process the data that just arrived. QBuffer also emits bytesWritten() every time new data has been written to the buffer.

See also

QFile, QDataStream, QTextStream, QByteArray

Definition at line 57 of file qbuffer.h.

Constructors and Destructors

QBuffer() [1/2]

QBuffer::QBuffer ( QObject *  parent = 0 )

explicit

Constructs an empty buffer with the given parent.

You can call setData() to fill the buffer with data, or you can open it in write mode and use write().

See also

open()

Definition at line 183 of file qbuffer.cpp.

Referenced by QBufferPrivate::peek().

    : QIODevice(*new QBufferPrivate, parent)
{
    Q_D(QBuffer);
    d->buf = &d->defaultBuf;
    d->ioIndex = 0;
}

QBuffer() [2/2]

QBuffer::QBuffer	(	QByteArray *	byteArray,
		QObject *	parent = 0
	)

Constructs a QBuffer that uses the QByteArray pointed to by byteArray as its internal buffer, and with the given parent.

The caller is responsible for ensuring that byteArray remains valid until the QBuffer is destroyed, or until setBuffer() is called to change the buffer. QBuffer doesn't take ownership of the QByteArray.

If you open the buffer in write-only mode or read-write mode and write something into the QBuffer, byteArray will be modified.

Example:

    QByteArray byteArray("abc");
    QBuffer buffer(&byteArray);
    buffer.open(QIODevice::WriteOnly);
    buffer.seek(3);
    buffer.write("def", 3);
    buffer.close();
    // byteArray == "abcdef"

See also

open(), setBuffer(), setData()

Definition at line 208 of file qbuffer.cpp.

    : QIODevice(*new QBufferPrivate, parent)
{
    Q_D(QBuffer);
    d->buf = byteArray ? byteArray : &d->defaultBuf;
    d->defaultBuf.clear();
    d->ioIndex = 0;
}

~QBuffer()

QBuffer::~QBuffer

(

)

Destroys the buffer.

Definition at line 222 of file qbuffer.cpp.

{
}

Functions

atEnd()

bool QBuffer::atEnd ( ) const

virtual

Reimplemented Function

Reimplemented from QIODevice.

Definition at line 408 of file qbuffer.cpp.

Referenced by QAxServerBase::Load().

{
    return QIODevice::atEnd();
}

buffer() [1/2]

QByteArray & QBuffer::buffer

(

)

Returns a reference to the QBuffer's internal buffer.

You can use it to modify the QByteArray behind the QBuffer's back.

See also

setBuffer(), data()

Definition at line 271 of file qbuffer.cpp.

Referenced by QPicturePrivate::checkFormat(), QTestLiteStaticInfoPrivate::initializeSupportedAtoms(), QXlibMime::mimeConvertToFormat(), QNonContiguousByteDeviceBufferImpl::QNonContiguousByteDeviceBufferImpl(), qt_get_net_supported(), qt_get_net_virtual_roots(), QAxServerBase::Save(), and QX11Data::xdndMimeConvertToFormat().

{
    Q_D(QBuffer);
    return *d->buf;
}

buffer() [2/2]

const QByteArray & QBuffer::buffer

(

)

const

This is the same as data().

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 286 of file qbuffer.cpp.

{
    Q_D(const QBuffer);
    return *d->buf;
}

canReadLine()

bool QBuffer::canReadLine ( ) const

virtual

Reimplemented Function

Reimplemented from QIODevice.

Definition at line 416 of file qbuffer.cpp.

{
    Q_D(const QBuffer);
    if (!isOpen())
        return false;

    return d->buf->indexOf('\n', int(pos())) != -1 || QIODevice::canReadLine();
}

close()

void QBuffer::close ( )

virtual

Reimplemented Function

Reimplemented from QIODevice.

Definition at line 359 of file qbuffer.cpp.

Referenced by QPicturePrivate::checkFormat(), QPacket::clear(), QSvgPaintEngine::drawImage(), QXmlQuery::evaluateTo(), QAxServerBase::Load(), QFontEngineQPF::QFontEngineQPF(), QCacheItem::reset(), QAxServerBase::Save(), and QTextEditMimeData::setup().

{
    QIODevice::close();
}

connectNotify()

void QBuffer::connectNotify ( const char *  signal )

protectedvirtual

Reimplemented Function

Warning

This function is not part of the public interface.

Reimplemented from QObject.

Definition at line 472 of file qbuffer.cpp.

{
    if (strcmp(signal + 1, "readyRead()") == 0 || strcmp(signal + 1, "bytesWritten(qint64)") == 0)
        d_func()->signalConnectionCount++;
}

data()

const QByteArray & QBuffer::data

(

)

const

Returns the data contained in the buffer.

This is the same as buffer().

See also

setData(), setBuffer()

Definition at line 301 of file qbuffer.cpp.

Referenced by QXmlQuery::evaluateTo(), QSvgIOHandlerPrivate::load(), QFontEngineQPF::QFontEngineQPF(), QPicturePrivate::QPicturePrivate(), qt_fill_input_buffer(), QWSServer::sendIMEvent(), setData(), QTextEditMimeData::setup(), and QTextOdfWriter::writeInlineCharacter().

{
    Q_D(const QBuffer);
    return *d->buf;
}

disconnectNotify()

void QBuffer::disconnectNotify ( const char *  signal )

protectedvirtual

Reimplemented Function

Warning

This function is not part of the public interface.

Reimplemented from QObject.

Definition at line 482 of file qbuffer.cpp.

{
    if (!signal || strcmp(signal + 1, "readyRead()") == 0 || strcmp(signal + 1, "bytesWritten(qint64)") == 0)
        d_func()->signalConnectionCount--;
}

open()

bool QBuffer::open ( OpenMode  openMode )

virtual

Reimplemented Function

Reimplemented from QIODevice.

Definition at line 338 of file qbuffer.cpp.

Referenced by RequestAnalyzer::analyze(), QPicturePrivate::checkFormat(), QPacket::clear(), QNetworkDiskCache::data(), QDeclarativeXmlQueryEngine::doQueryJob(), QDeclarativeXmlQueryEngine::doSubQueryJob(), QSvgPaintEngine::drawImage(), QMimeDataWrapper::encodedData(), QXmlQuery::evaluateTo(), QRasterPixmapData::fromData(), QVGPixmapData::fromData(), QPixmapData::fromData(), QGLPixmapData::fromData(), QImage::fromData(), QTestLiteStaticInfoPrivate::initializeSupportedAtoms(), QXmlSchemaPrivate::load(), QAxServerBase::Load(), QXlibMime::mimeConvertToFormat(), QDeclarativePixmapReader::networkRequestDone(), QNetworkAccessManager::post(), QNetworkDiskCache::prepare(), QNetworkAccessManager::put(), QDataStream::QDataStream(), QFontEngineQPF::QFontEngineQPF(), QPacket::QPacket(), QPicturePrivate::QPicturePrivate(), qt_get_net_supported(), qt_get_net_virtual_roots(), QTextStream::QTextStream(), QAxServerBase::Save(), QWSServer::sendIMEvent(), QXmlQuery::setFocus(), QMovie::supportedFormats(), QXmlSchemaValidator::validate(), ICOReader::write(), and QX11Data::xdndMimeConvertToFormat().

{
    Q_D(QBuffer);

    if ((flags & (Append | Truncate)) != 0)
        flags |= WriteOnly;
    if ((flags & (ReadOnly | WriteOnly)) == 0) {
        qWarning("QBuffer::open: Buffer access not specified");
        return false;
    }

    if ((flags & Truncate) == Truncate)
        d->buf->resize(0);
    d->ioIndex = (flags & Append) == Append ? d->buf->size() : 0;

    return QIODevice::open(flags);
}

pos()

qint64 QBuffer::pos ( ) const

virtual

Reimplemented Function

Reimplemented from QIODevice.

Definition at line 367 of file qbuffer.cpp.

Referenced by canReadLine(), QSvgIOHandlerPrivate::load(), QNonContiguousByteDeviceBufferImpl::QNonContiguousByteDeviceBufferImpl(), QPicturePrivate::QPicturePrivate(), and qt_fill_input_buffer().

{
    return QIODevice::pos();
}

readData()

qint64 QBuffer::readData ( char *  data, qint64  maxlen  )

protectedvirtual

Reimplemented Function

Implements QIODevice.

Definition at line 428 of file qbuffer.cpp.

{
    Q_D(QBuffer);
    if ((len = qMin(len, qint64(d->buf->size()) - d->ioIndex)) <= 0)
        return qint64(0);
    memcpy(data, d->buf->constData() + d->ioIndex, len);
    d->ioIndex += int(len);
    return len;
}

seek()

bool QBuffer::seek ( qint64  off )

virtual

Reimplemented Function

Reimplemented from QIODevice.

Definition at line 384 of file qbuffer.cpp.

Referenced by QDeclarativeXmlQueryEngine::doSubQueryJob(), QSvgIOHandlerPrivate::load(), and QPicturePrivate::QPicturePrivate().

{
    Q_D(QBuffer);
    if (pos > d->buf->size() && isWritable()) {
        if (seek(d->buf->size())) {
            const qint64 gapSize = pos - d->buf->size();
            if (write(QByteArray(gapSize, 0)) != gapSize) {
                qWarning("QBuffer::seek: Unable to fill gap");
                return false;
            }
        } else {
            return false;
        }
    } else if (pos > d->buf->size() || pos < 0) {
        qWarning("QBuffer::seek: Invalid pos: %d", int(pos));
        return false;
    }
    d->ioIndex = int(pos);
    return QIODevice::seek(pos);
}

setBuffer()

void QBuffer::setBuffer

(

QByteArray *

byteArray

)

Makes QBuffer uses the QByteArray pointed to by byteArray as its internal buffer.

The caller is responsible for ensuring that byteArray remains valid until the QBuffer is destroyed, or until setBuffer() is called to change the buffer. QBuffer doesn't take ownership of the QByteArray.

Does nothing if isOpen() is true.

If you open the buffer in write-only mode or read-write mode and write something into the QBuffer, byteArray will be modified.

Example:

    QByteArray byteArray("abc");
    QBuffer buffer;
    buffer.setBuffer(&byteArray);
    buffer.open(QIODevice::WriteOnly);
    buffer.seek(3);
    buffer.write("def", 3);
    buffer.close();
    // byteArray == "abcdef"

If byteArray is 0, the buffer creates its own internal QByteArray to work on. This byte array is initially empty.

See also

buffer(), setData(), open()

Definition at line 248 of file qbuffer.cpp.

Referenced by QPacket::clear().

{
    Q_D(QBuffer);
    if (isOpen()) {
        qWarning("QBuffer::setBuffer: Buffer is open");
        return;
    }
    if (byteArray) {
        d->buf = byteArray;
    } else {
        d->buf = &d->defaultBuf;
    }
    d->defaultBuf.clear();
    d->ioIndex = 0;
}

setData() [1/2]

void QBuffer::setData

(

const QByteArray &

data

)

Sets the contents of the internal buffer to be data.

This is the same as assigning data to buffer().

Does nothing if isOpen() is true.

See also

setBuffer()

Definition at line 315 of file qbuffer.cpp.

Referenced by QNetworkDiskCache::data(), QImage::fromData(), QNetworkAccessManager::post(), QNetworkAccessManager::put(), QDataStream::QDataStream(), QPicturePrivate::QPicturePrivate(), QTextStream::QTextStream(), QDomDocument::setContent(), and QXmlQuery::setFocus().

{
    Q_D(QBuffer);
    if (isOpen()) {
        qWarning("QBuffer::setData: Buffer is open");
        return;
    }
    *d->buf = data;
    d->ioIndex = 0;
}

setData() [2/2]

void QBuffer::setData ( const char *  data, int  len  )

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Sets the contents of the internal buffer to be the first size bytes of data.

Definition at line 105 of file qbuffer.h.

{ setData(QByteArray(adata, alen)); }

size()

qint64 QBuffer::size ( ) const

virtual

Reimplemented Function

Reimplemented from QIODevice.

Definition at line 375 of file qbuffer.cpp.

Referenced by QPicturePrivate::checkFormat(), QNonContiguousByteDeviceBufferImpl::QNonContiguousByteDeviceBufferImpl(), QPicturePrivate::QPicturePrivate(), QWSServer::sendIMEvent(), and QCacheItem::size().

{
    Q_D(const QBuffer);
    return qint64(d->buf->size());
}

writeData()

qint64 QBuffer::writeData ( const char *  data, qint64  len  )

protectedvirtual

Reimplemented Function

Implements QIODevice.

Definition at line 441 of file qbuffer.cpp.

{
    Q_D(QBuffer);
    int extraBytes = d->ioIndex + len - d->buf->size();
    if (extraBytes > 0) { // overflow
        int newSize = d->buf->size() + extraBytes;
        d->buf->resize(newSize);
        if (d->buf->size() != newSize) { // could not resize
            qWarning("QBuffer::writeData: Memory allocation error");
            return -1;
        }
    }

    memcpy(d->buf->data() + d->ioIndex, (uchar *)data, int(len));
    d->ioIndex += int(len);

#ifndef QT_NO_QOBJECT
    d->writtenSinceLastEmit += len;
    if (d->signalConnectionCount && !d->signalsEmitted && !signalsBlocked()) {
        d->signalsEmitted = true;
        QMetaObject::invokeMethod(this, "_q_emitSignals", Qt::QueuedConnection);
    }
#endif
    return len;
}

---

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

• /src/corelib/io/qbuffer.h
• /src/corelib/io/qbuffer.cpp