Nuria::ReferenceDevice Class Reference

Operates on a part of another QIODevice. More...

#include <referencedevice.hpp>

Inheritance diagram for Nuria::ReferenceDevice:

Public Member Functions
	ReferenceDevice (QIODevice *referencedDevice, QObject *parent=0)
	~ReferenceDevice () override
bool	atEnd () const override
qint64	bytesAvailable () const override
void	close () override
void	extendRange (qint64 bytes)
bool	isSequential () const override
bool	open (OpenMode mode) override
qint64	pos () const override
qint64	rangeBegin () const
qint64	rangeEnd () const
QIODevice *	referencedDevice () const
bool	reset () override
bool	seek (qint64 pos) override
void	setRange (qint64 begin, qint64 end=-1)
qint64	size () const override

Protected Member Functions
qint64	readData (char *data, qint64 maxlen)
qint64	writeData (const char *data, qint64 len)

Detailed Description

Operates on a part of another QIODevice.

ReferenceDevice references a given part of a random-access QIODevice. This device does not store any data itself. This means, that the referenced QIODevice must be kept alive as long a ReferenceDevice is operating on it.

Note

If the referenced device is destroyed, all reference devices will be closed.

Open mode

The open mode is copied form the referenced device in the constructor. The implementation of open() will only allow modes compatible with the current open mode of the device. This means, that if the referenced device is currently in QIODevice::ReadWrite mode, then QIODevice::NotOpen, QIODevice::ReadOnly, QIODevice::WriteOnly and QIODevice::ReadWrite are allowed. If the device is in QIODevice::ReadOnly mode, only QIODevice::NotOpen and QIODevice::ReadOnly are allowed - and so on.

Constructor & Destructor Documentation

Nuria::ReferenceDevice::ReferenceDevice ( QIODevice *  referencedDevice, QObject *  parent = 0  )

explicit

Constructs a ReferenceDevice referencing referencedDevice.

See also

setRange

Nuria::ReferenceDevice::~ReferenceDevice ( )

override

Destructor.

Member Function Documentation

void Nuria::ReferenceDevice::extendRange

(

qint64

bytes

)

Extends the current range by bytes. The same range extension mechanism like in setRange() takes place. Signals are emitted accordingly.

qint64 Nuria::ReferenceDevice::rangeBegin

(

)

const

Returns the begin of the referenced range.

qint64 Nuria::ReferenceDevice::rangeEnd

(

)

const

Returns the end of the referenced range.

QIODevice* Nuria::ReferenceDevice::referencedDevice

(

)

const

Returns the device the ReferenceDevice is operating on.

void Nuria::ReferenceDevice::setRange	(	qint64	begin,
		qint64	end = -1
	)

Sets the operated range to be from begin till end (exclusive). If end is longer than the current size() of the referencedDevice(), then the range will be extended automatically when data has been written to the referenced device, until it matches the given one.

If begin is not currently outside the referenced device and the range is greater than 0, then readyRead() will be emitted.

If end is -1, then the range will span from begin till the current size() of the referenced device.

Note

After this operation, the position of this device will be 0.

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

• referencedevice.hpp