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()

Constructs a QBuffer that uses the QByteArray pointed to by buffer as its internal buffer, and with the given parent. The caller is responsible for ensuring that buffer remains valid until the QBuffer is destroyed, or until setBuffer() is called to change the buffer. QBuffer does not take ownership of the QByteArray.

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

See also

open(), setBuffer(), setData()

Destroys the buffer.

Returns true if the current read and write position is at the end of the device (i.e. there is no more data available for reading on the device), otherwise returns false.

For some devices, atEnd() can return true even though there is more data to read. This special case only applies to devices that generate data in direct response to you calling read() (e.g., /dev or /proc files on Unix and Mac OS X, or console input / stdin on all platforms).

See also

bytesAvailable(), read(), isSequential()

Reimplemented from QIODevice.

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()

Equivalent to calling data().

Returns true if a complete line of data can be read from the device, otherwise returns false. Unbuffered devices, which have no way of determining what can be read, always return false. This method is often called in conjunction with the readyRead() signal.

Subclasses that reimplement this method must call the base implementation in order to include the contents of the QIODevice's buffer.

See also

readyRead(), readLine()

Reimplemented from QIODevice.

First emits aboutToClose(), then closes the device and sets its OpenMode to NotOpen. The error string is also reset.

See also

setOpenMode(), OpenMode

Reimplemented from QIODevice.

This method is called when a connection has been made to signalMethod in this object.

See also

connect(), disconnectNotify()

Reimplemented from QObject.

Returns the data contained in the buffer. Equivalent to calling buffer().

See also

setData(), setBuffer()

This method is called when a slot is disconnected from signalMethod in this object.

See also

disconnect(), connectNotify()

Reimplemented from QObject.

Opens the device and sets its OpenMode to mode. Returns true if successful, otherwise returns false. This method should be called from any existing reimplementation of open() or other functions that open the device.

See also

openMode(), OpenMode

Reimplemented from QIODevice.

For random-access devices, this method returns the position that data is written to or read from. For sequential devices or closed devices, where there is no concept of a "current position", 0 is returned.

The current read/write position of the device is maintained internally by QIODevice, so reimplementing this method is not necessary. When subclassing QIODevice, use QIODevice::seek() to notify QIODevice about changes in the device position.

See also

isSequential(), seek()

Reimplemented from QIODevice.

Reads up to maxSize bytes from the device into data, and returns the number of bytes read or -1 if an error occurred. If there are no bytes to be read and there can never be more bytes available (examples include socket closed, pipe closed, sub-process finished), returns -1.

This method is called by QIODevice. Reimplement this method when creating a subclass of QIODevice.

When reimplementing it is important this method reads all the required data before returning. This is required in order for QDataStream to be able to operate on the class. QDataStream assumes all the requested information was read and therefore does not retry reading if there was a problem.

See also

read(), readLine(), writeData()

Implements QIODevice.

For random-access devices, this method sets the current position to pos, returning true on success, or false if an error occurred. For sequential devices, the default behavior is to do nothing and return false.

When subclassing QIODevice, you must call QIODevice::seek() at the start of your function to ensure integrity with QIODevice's built-in buffer. The base implementation always returns true.

See also

pos(), isSequential()

Reimplemented from QIODevice.

Makes QBuffer uses the QByteArray pointed to by buffer 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 does not 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 buffer will be modified.

If buffer is a nullptr the QBuffer creates its own internal QByteArray. This byte array is initially empty.

See also

buffer(), setData(), open()

Sets the contents of the internal buffer to be the first size bytes of data.

Sets the contents of the internal buffer to be buffer. This is the same as assigning data to buffer(). This method does nothing if isOpen() is true.

See also

data(), setBuffer()

For open random-access devices, this method returns the size of the device. For open sequential devices, bytesAvailable() is returned.If the device is closed, the size returned will not reflect the actual size of the device.

See also

isSequential(), pos()

Reimplemented from QIODevice.

Writes up to maxSize bytes from data to the device. Returns the number of bytes written, or -1 if an error occurred.

This method is called by QIODevice. Reimplement when creating a subclass of QIODevice. When reimplementing it is important that this method writes all the data available before returning. This is required in order for QDataStream to be able to operate on the class. QDataStream assumes all the information was written and therefore does not retry writing if there was a problem.

See also

read(), write()

Implements QIODevice.