[−][src]Struct qt_core::QBuffer

#[repr(C)]pub struct QBuffer { /* fields omitted */ }

The QBuffer class provides a QIODevice interface for a QByteArray.

C++ class: QBuffer.

C++ documentation:

The QBuffer class provides a QIODevice interface for a QByteArray.

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. QBuffer also emits bytesWritten() every time new data has been written to the buffer.

Methods

impl QBuffer[src]

pub unsafe fn at_end(&self) -> bool[src]

Reimplemented from QIODevice::atEnd().

Calls C++ function: virtual bool QBuffer::atEnd() const.

C++ documentation:

Reimplemented from QIODevice::atEnd().

pub unsafe fn buffer_mut(&self) -> Ref<QByteArray>[src]

Returns a reference to the QBuffer's internal buffer. You can use it to modify the QByteArray behind the QBuffer's back.

Calls C++ function: QByteArray& QBuffer::buffer().

C++ documentation:

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() and data().

pub unsafe fn buffer(&self) -> Ref<QByteArray>[src]

This is an overloaded function.

Calls C++ function: const QByteArray& QBuffer::buffer() const.

C++ documentation:

This is an overloaded function.

This is the same as data().

pub unsafe fn can_read_line(&self) -> bool[src]

Reimplemented from QIODevice::canReadLine().

Calls C++ function: virtual bool QBuffer::canReadLine() const.

C++ documentation:

Reimplemented from QIODevice::canReadLine().

pub unsafe fn close(&self)[src]

Reimplemented from QIODevice::close().

Calls C++ function: virtual void QBuffer::close().

C++ documentation:

Reimplemented from QIODevice::close().

pub unsafe fn data(&self) -> Ref<QByteArray>[src]

Returns the data contained in the buffer.

Calls C++ function: const QByteArray& QBuffer::data() const.

C++ documentation:

Returns the data contained in the buffer.

This is the same as buffer().

See also setData() and setBuffer().

pub unsafe fn meta_object(&self) -> Ptr<QMetaObject>[src]

Calls C++ function: virtual const QMetaObject* QBuffer::metaObject() const.

pub unsafe fn from_q_object(
    parent: impl CastInto<Ptr<QObject>>
) -> QBox<QBuffer>[src]

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().

Calls C++ function: [constructor] void QBuffer::QBuffer(QObject* parent = …).

C++ documentation:

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().

pub unsafe fn from_q_byte_array_q_object(
    buf: impl CastInto<Ptr<QByteArray>>,
    parent: impl CastInto<Ptr<QObject>>
) -> QBox<QBuffer>[src]

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.

Calls C++ function: [constructor] void QBuffer::QBuffer(QByteArray* buf, QObject* parent = …).

C++ documentation:

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(), and setData().

pub unsafe fn new() -> QBox<QBuffer>[src]

The QBuffer class provides a QIODevice interface for a QByteArray.

Calls C++ function: [constructor] void QBuffer::QBuffer().

C++ documentation:

The QBuffer class provides a QIODevice interface for a QByteArray.

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. QBuffer also emits bytesWritten() every time new data has been written to the buffer.

pub unsafe fn from_q_byte_array(
    buf: impl CastInto<Ptr<QByteArray>>
) -> QBox<QBuffer>[src]

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.

Calls C++ function: [constructor] void QBuffer::QBuffer(QByteArray* buf).

C++ documentation:

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(), and setData().

pub unsafe fn open(&self, open_mode: QFlags<OpenModeFlag>) -> bool[src]

Reimplemented from QIODevice::open().

Calls C++ function: virtual bool QBuffer::open(QFlags<QIODevice::OpenModeFlag> openMode).

C++ documentation:

Reimplemented from QIODevice::open().

pub unsafe fn pos(&self) -> i64[src]

Reimplemented from QIODevice::pos().

Calls C++ function: virtual qint64 QBuffer::pos() const.

C++ documentation:

Reimplemented from QIODevice::pos().

pub unsafe fn qt_metacall(
    &self,
    arg1: Call,
    arg2: c_int,
    arg3: *mut *mut c_void
) -> c_int[src]

Calls C++ function: virtual int QBuffer::qt_metacall(QMetaObject::Call arg1, int arg2, void** arg3).

pub unsafe fn qt_metacast(&self, arg1: *const c_char) -> *mut c_void[src]

Calls C++ function: virtual void* QBuffer::qt_metacast(const char* arg1).

pub unsafe fn seek(&self, off: i64) -> bool[src]

Reimplemented from QIODevice::seek().

Calls C++ function: virtual bool QBuffer::seek(qint64 off).

C++ documentation:

Reimplemented from QIODevice::seek().

pub unsafe fn set_buffer(&self, a: impl CastInto<Ptr<QByteArray>>)[src]

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.

Calls C++ function: void QBuffer::setBuffer(QByteArray* a).

C++ documentation:

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(), and open().

pub unsafe fn set_data_1a(&self, data: impl CastInto<Ref<QByteArray>>)[src]

Sets the contents of the internal buffer to be data. This is the same as assigning data to buffer().

Calls C++ function: void QBuffer::setData(const QByteArray& data).

C++ documentation:

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 data() and setBuffer().

pub unsafe fn set_data_2a(&self, data: *const c_char, len: c_int)[src]

This is an overloaded function.

Calls C++ function: void QBuffer::setData(const char* data, int len).

C++ documentation:

This is an overloaded function.

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

pub unsafe fn size(&self) -> i64[src]

Reimplemented from QIODevice::size().

Calls C++ function: virtual qint64 QBuffer::size() const.

C++ documentation:

Reimplemented from QIODevice::size().

pub unsafe fn static_meta_object() -> Ref<QMetaObject>[src]

Returns a reference to the staticMetaObject field.

pub unsafe fn tr(
    s: *const c_char,
    c: *const c_char,
    n: c_int
) -> CppBox<QString>[src]

Calls C++ function: static QString QBuffer::tr(const char* s, const char* c, int n).

pub unsafe fn tr_utf8(
    s: *const c_char,
    c: *const c_char,
    n: c_int
) -> CppBox<QString>[src]

Calls C++ function: static QString QBuffer::trUtf8(const char* s, const char* c, int n).

Methods from Deref<Target = QIODevice>

pub fn ready_read(&self) -> Signal<()>[src]

This signal is emitted once every time new data is available for reading from the device's current read channel. It will only be emitted again once new data is available, such as when a new payload of network data has arrived on your network socket, or when a new block of data has been appended to your device.

Returns a built-in Qt signal QIODevice::readyRead that can be passed to qt_core::Signal::connect.

C++ documentation:

This signal is emitted once every time new data is available for reading from the device's current read channel. It will only be emitted again once new data is available, such as when a new payload of network data has arrived on your network socket, or when a new block of data has been appended to your device.

readyRead() is not emitted recursively; if you reenter the event loop or call waitForReadyRead() inside a slot connected to the readyRead() signal, the signal will not be reemitted (although waitForReadyRead() may still return true).

Note for developers implementing classes derived from QIODevice: you should always emit readyRead() when new data has arrived (do not emit it only because there's data still to be read in your buffers). Do not emit readyRead() in other conditions.

See also bytesWritten().

pub fn channel_ready_read(&self) -> Signal<(c_int,)>[src]

This signal is emitted when new data is available for reading from the device. The channel argument is set to the index of the read channel on which the data has arrived. Unlike readyRead(), it is emitted regardless of the current read channel.

Returns a built-in Qt signal QIODevice::channelReadyRead that can be passed to qt_core::Signal::connect.

C++ documentation:

This signal is emitted when new data is available for reading from the device. The channel argument is set to the index of the read channel on which the data has arrived. Unlike readyRead(), it is emitted regardless of the current read channel.

channelReadyRead() can be emitted recursively - even for the same channel.

This function was introduced in Qt 5.7.

See also readyRead() and channelBytesWritten().

pub fn bytes_written(&self) -> Signal<(i64,)>[src]

This signal is emitted every time a payload of data has been written to the device's current write channel. The bytes argument is set to the number of bytes that were written in this payload.

Returns a built-in Qt signal QIODevice::bytesWritten that can be passed to qt_core::Signal::connect.

C++ documentation:

This signal is emitted every time a payload of data has been written to the device's current write channel. The bytes argument is set to the number of bytes that were written in this payload.

bytesWritten() is not emitted recursively; if you reenter the event loop or call waitForBytesWritten() inside a slot connected to the bytesWritten() signal, the signal will not be reemitted (although waitForBytesWritten() may still return true).

See also readyRead().

pub fn channel_bytes_written(&self) -> Signal<(c_int, i64)>[src]

This signal is emitted every time a payload of data has been written to the device. The bytes argument is set to the number of bytes that were written in this payload, while channel is the channel they were written to. Unlike bytesWritten(), it is emitted regardless of the current write channel.

Returns a built-in Qt signal QIODevice::channelBytesWritten that can be passed to qt_core::Signal::connect.

C++ documentation:

This signal is emitted every time a payload of data has been written to the device. The bytes argument is set to the number of bytes that were written in this payload, while channel is the channel they were written to. Unlike bytesWritten(), it is emitted regardless of the current write channel.

channelBytesWritten() can be emitted recursively - even for the same channel.

This function was introduced in Qt 5.7.

See also bytesWritten() and channelReadyRead().

pub fn about_to_close(&self) -> Signal<()>[src]

This signal is emitted when the device is about to close. Connect this signal if you have operations that need to be performed before the device closes (e.g., if you have data in a separate buffer that needs to be written to the device).

Returns a built-in Qt signal QIODevice::aboutToClose that can be passed to qt_core::Signal::connect.

C++ documentation:

This signal is emitted when the device is about to close. Connect this signal if you have operations that need to be performed before the device closes (e.g., if you have data in a separate buffer that needs to be written to the device).

pub fn read_channel_finished(&self) -> Signal<()>[src]

This signal is emitted when the input (reading) stream is closed in this device. It is emitted as soon as the closing is detected, which means that there might still be data available for reading with read().

Returns a built-in Qt signal QIODevice::readChannelFinished that can be passed to qt_core::Signal::connect.

C++ documentation:

This signal is emitted when the input (reading) stream is closed in this device. It is emitted as soon as the closing is detected, which means that there might still be data available for reading with read().

This function was introduced in Qt 4.4.

See also atEnd() and read().

pub unsafe fn at_end(&self) -> bool[src]

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.

Calls C++ function: virtual bool QIODevice::atEnd() const.

C++ documentation:

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 macOS, or console input / stdin on all platforms).

See also bytesAvailable(), read(), and isSequential().

pub unsafe fn bytes_available(&self) -> i64[src]

Returns the number of bytes that are available for reading. This function is commonly used with sequential devices to determine the number of bytes to allocate in a buffer before reading.

Calls C++ function: virtual qint64 QIODevice::bytesAvailable() const.

C++ documentation:

Returns the number of bytes that are available for reading. This function is commonly used with sequential devices to determine the number of bytes to allocate in a buffer before reading.

Subclasses that reimplement this function must call the base implementation in order to include the size of the buffer of QIODevice. Example:

qint64 CustomDevice::bytesAvailable() const
{
      return buffer.size() + QIODevice::bytesAvailable();
}

See also bytesToWrite(), readyRead(), and isSequential().

pub unsafe fn bytes_to_write(&self) -> i64[src]

For buffered devices, this function returns the number of bytes waiting to be written. For devices with no buffer, this function returns 0.

Calls C++ function: virtual qint64 QIODevice::bytesToWrite() const.

C++ documentation:

For buffered devices, this function returns the number of bytes waiting to be written. For devices with no buffer, this function returns 0.

Subclasses that reimplement this function must call the base implementation in order to include the size of the buffer of QIODevice.

See also bytesAvailable(), bytesWritten(), and isSequential().

pub unsafe fn can_read_line(&self) -> bool[src]

Returns true if a complete line of data can be read from the device; otherwise returns false.

Calls C++ function: virtual bool QIODevice::canReadLine() const.

C++ documentation:

Returns true if a complete line of data can be read from the device; otherwise returns false.

Note that unbuffered devices, which have no way of determining what can be read, always return false.

This function is often called in conjunction with the readyRead() signal.

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

bool CustomDevice::canReadLine() const
{
      return buffer.contains('\n') || QIODevice::canReadLine();
}

See also readyRead() and readLine().

pub unsafe fn close(&self)[src]

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

Calls C++ function: virtual void QIODevice::close().

C++ documentation:

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

See also setOpenMode() and OpenMode.

pub unsafe fn commit_transaction(&self)[src]

Completes a read transaction.

Calls C++ function: void QIODevice::commitTransaction().

C++ documentation:

Completes a read transaction.

For sequential devices, all data recorded in the internal buffer during the transaction will be discarded.

This function was introduced in Qt 5.7.

See also startTransaction() and rollbackTransaction().

pub unsafe fn current_read_channel(&self) -> c_int[src]

Returns the index of the current read channel.

Calls C++ function: int QIODevice::currentReadChannel() const.

C++ documentation:

Returns the index of the current read channel.

This function was introduced in Qt 5.7.

See also setCurrentReadChannel(), readChannelCount(), and QProcess.

pub unsafe fn current_write_channel(&self) -> c_int[src]

Returns the the index of the current write channel.

Calls C++ function: int QIODevice::currentWriteChannel() const.

C++ documentation:

Returns the the index of the current write channel.

This function was introduced in Qt 5.7.

See also setCurrentWriteChannel() and writeChannelCount().

pub unsafe fn error_string(&self) -> CppBox<QString>[src]

Returns a human-readable description of the last device error that occurred.

Calls C++ function: QString QIODevice::errorString() const.

C++ documentation:

Returns a human-readable description of the last device error that occurred.

See also setErrorString().

pub unsafe fn get_char(&self, c: *mut c_char) -> bool[src]

Reads one character from the device and stores it in c. If c is 0, the character is discarded. Returns true on success; otherwise returns false.

Calls C++ function: bool QIODevice::getChar(char* c).

C++ documentation:

Reads one character from the device and stores it in c. If c is 0, the character is discarded. Returns true on success; otherwise returns false.

See also read(), putChar(), and ungetChar().

pub unsafe fn is_open(&self) -> bool[src]

Returns true if the device is open; otherwise returns false. A device is open if it can be read from and/or written to. By default, this function returns false if openMode() returns NotOpen.

Calls C++ function: bool QIODevice::isOpen() const.

C++ documentation:

Returns true if the device is open; otherwise returns false. A device is open if it can be read from and/or written to. By default, this function returns false if openMode() returns NotOpen.

See also openMode() and OpenMode.

pub unsafe fn is_readable(&self) -> bool[src]

Returns true if data can be read from the device; otherwise returns false. Use bytesAvailable() to determine how many bytes can be read.

Calls C++ function: bool QIODevice::isReadable() const.

C++ documentation:

Returns true if data can be read from the device; otherwise returns false. Use bytesAvailable() to determine how many bytes can be read.

This is a convenience function which checks if the OpenMode of the device contains the ReadOnly flag.

See also openMode() and OpenMode.

pub unsafe fn is_sequential(&self) -> bool[src]

Returns true if this device is sequential; otherwise returns false.

Calls C++ function: virtual bool QIODevice::isSequential() const.

C++ documentation:

Returns true if this device is sequential; otherwise returns false.

Sequential devices, as opposed to a random-access devices, have no concept of a start, an end, a size, or a current position, and they do not support seeking. You can only read from the device when it reports that data is available. The most common example of a sequential device is a network socket. On Unix, special files such as /dev/zero and fifo pipes are sequential.

Regular files, on the other hand, do support random access. They have both a size and a current position, and they also support seeking backwards and forwards in the data stream. Regular files are non-sequential.

See also bytesAvailable().

pub unsafe fn is_text_mode_enabled(&self) -> bool[src]

Returns true if the Text flag is enabled; otherwise returns false.

Calls C++ function: bool QIODevice::isTextModeEnabled() const.

C++ documentation:

Returns true if the Text flag is enabled; otherwise returns false.

See also setTextModeEnabled().

pub unsafe fn is_transaction_started(&self) -> bool[src]

Returns true if a transaction is in progress on the device, otherwise false.

Calls C++ function: bool QIODevice::isTransactionStarted() const.

C++ documentation:

Returns true if a transaction is in progress on the device, otherwise false.

This function was introduced in Qt 5.7.

See also startTransaction().

pub unsafe fn is_writable(&self) -> bool[src]

Returns true if data can be written to the device; otherwise returns false.

Calls C++ function: bool QIODevice::isWritable() const.

C++ documentation:

Returns true if data can be written to the device; otherwise returns false.

This is a convenience function which checks if the OpenMode of the device contains the WriteOnly flag.

See also openMode() and OpenMode.

pub unsafe fn meta_object(&self) -> Ptr<QMetaObject>[src]

Calls C++ function: virtual const QMetaObject* QIODevice::metaObject() const.

pub unsafe fn open(&self, mode: QFlags<OpenModeFlag>) -> bool[src]

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

Calls C++ function: virtual bool QIODevice::open(QFlags<QIODevice::OpenModeFlag> mode).

C++ documentation:

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

See also openMode() and OpenMode.

pub unsafe fn open_mode(&self) -> QFlags<OpenModeFlag>[src]

Returns the mode in which the device has been opened; i.e. ReadOnly or WriteOnly.

Calls C++ function: QFlags<QIODevice::OpenModeFlag> QIODevice::openMode() const.

C++ documentation:

Returns the mode in which the device has been opened; i.e. ReadOnly or WriteOnly.

See also setOpenMode() and OpenMode.

pub unsafe fn peek_2a(&self, data: *mut c_char, maxlen: i64) -> i64[src]

Reads at most maxSize bytes from the device into data, without side effects (i.e., if you call read() after peek(), you will get the same data). Returns the number of bytes read. If an error occurs, such as when attempting to peek a device opened in WriteOnly mode, this function returns -1.

Calls C++ function: qint64 QIODevice::peek(char* data, qint64 maxlen).

C++ documentation:

Reads at most maxSize bytes from the device into data, without side effects (i.e., if you call read() after peek(), you will get the same data). Returns the number of bytes read. If an error occurs, such as when attempting to peek a device opened in WriteOnly mode, this function returns -1.

0 is returned when no more data is available for reading.

Example:

bool isExeFile(QFile *file)
{
      char buf[2];
      if (file->peek(buf, sizeof(buf)) == sizeof(buf))
          return (buf[0] == 'M' && buf[1] == 'Z');
      return false;
}

This function was introduced in Qt 4.1.

See also read().

pub unsafe fn peek_1a(&self, maxlen: i64) -> CppBox<QByteArray>[src]

This is an overloaded function.

Calls C++ function: QByteArray QIODevice::peek(qint64 maxlen).

C++ documentation:

This is an overloaded function.

Peeks at most maxSize bytes from the device, returning the data peeked as a QByteArray.

Example:

bool isExeFile(QFile *file)
{
      return file->peek(2) == "MZ";
}

This function has no way of reporting errors; returning an empty QByteArray can mean either that no data was currently available for peeking, or that an error occurred.

This function was introduced in Qt 4.1.

See also read().

pub unsafe fn pos(&self) -> i64[src]

For random-access devices, this function 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.

Calls C++ function: virtual qint64 QIODevice::pos() const.

C++ documentation:

For random-access devices, this function 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 function is not necessary. When subclassing QIODevice, use QIODevice::seek() to notify QIODevice about changes in the device position.

See also isSequential() and seek().

pub unsafe fn put_char(&self, c: c_char) -> bool[src]

Writes the character c to the device. Returns true on success; otherwise returns false.

Calls C++ function: bool QIODevice::putChar(char c).

C++ documentation:

Writes the character c to the device. Returns true on success; otherwise returns false.

See also write(), getChar(), and ungetChar().

pub unsafe fn qt_metacall(
    &self,
    arg1: Call,
    arg2: c_int,
    arg3: *mut *mut c_void
) -> c_int[src]

Calls C++ function: virtual int QIODevice::qt_metacall(QMetaObject::Call arg1, int arg2, void** arg3).

pub unsafe fn qt_metacast(&self, arg1: *const c_char) -> *mut c_void[src]

Calls C++ function: virtual void* QIODevice::qt_metacast(const char* arg1).

pub unsafe fn read_2a(&self, data: *mut c_char, maxlen: i64) -> i64[src]

Reads at most maxSize bytes from the device into data, and returns the number of bytes read. If an error occurs, such as when attempting to read from a device opened in WriteOnly mode, this function returns -1.

Calls C++ function: qint64 QIODevice::read(char* data, qint64 maxlen).

C++ documentation:

Reads at most maxSize bytes from the device into data, and returns the number of bytes read. If an error occurs, such as when attempting to read from a device opened in WriteOnly mode, this function returns -1.

0 is returned when no more data is available for reading. However, reading past the end of the stream is considered an error, so this function returns -1 in those cases (that is, reading on a closed socket or after a process has died).

See also readData(), readLine(), and write().

pub unsafe fn read_1a(&self, maxlen: i64) -> CppBox<QByteArray>[src]

This is an overloaded function.

Calls C++ function: QByteArray QIODevice::read(qint64 maxlen).

C++ documentation:

This is an overloaded function.

Reads at most maxSize bytes from the device, and returns the data read as a QByteArray.

This function has no way of reporting errors; returning an empty QByteArray can mean either that no data was currently available for reading, or that an error occurred.

pub unsafe fn read_all(&self) -> CppBox<QByteArray>[src]

Reads all remaining data from the device, and returns it as a byte array.

Calls C++ function: QByteArray QIODevice::readAll().

C++ documentation:

Reads all remaining data from the device, and returns it as a byte array.

This function has no way of reporting errors; returning an empty QByteArray can mean either that no data was currently available for reading, or that an error occurred.

pub unsafe fn read_channel_count(&self) -> c_int[src]

Returns the number of available read channels if the device is open; otherwise returns 0.

Calls C++ function: int QIODevice::readChannelCount() const.

C++ documentation:

Returns the number of available read channels if the device is open; otherwise returns 0.

This function was introduced in Qt 5.7.

See also writeChannelCount() and QProcess.

pub unsafe fn read_line_2a(&self, data: *mut c_char, maxlen: i64) -> i64[src]

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. If a line could not be read but no error ocurred, this function returns 0. If an error occurs, this function returns the length of what could be read, or -1 if nothing was read.

Calls C++ function: qint64 QIODevice::readLine(char* data, qint64 maxlen).

C++ documentation:

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. If a line could not be read but no error ocurred, this function returns 0. If an error occurs, this function returns the length of what could be read, or -1 if nothing was read.

A terminating '\0' byte is always appended to data, so maxSize must be larger than 1.

Data is read until either of the following conditions are met:

  • The first '\n' character is read.
  • maxSize - 1 bytes are read.
  • The end of the device data is detected.

For example, the following code reads a line of characters from a file:

QFile file("box.txt");
if (file.open(QFile::ReadOnly)) {
      char buf[1024];
      qint64 lineLength = file.readLine(buf, sizeof(buf));
      if (lineLength != -1) {
          // the line is available in buf
      }
}

The newline character ('\n') is included in the buffer. If a newline is not encountered before maxSize - 1 bytes are read, a newline will not be inserted into the buffer. On windows newline characters are replaced with '\n'.

This function calls readLineData(), which is implemented using repeated calls to getChar(). You can provide a more efficient implementation by reimplementing readLineData() in your own subclass.

See also getChar(), read(), and write().

pub unsafe fn read_line_1a(&self, maxlen: i64) -> CppBox<QByteArray>[src]

This is an overloaded function.

Calls C++ function: QByteArray QIODevice::readLine(qint64 maxlen = …).

C++ documentation:

This is an overloaded function.

Reads a line from the device, but no more than maxSize characters, and returns the result as a byte array.

This function has no way of reporting errors; returning an empty QByteArray can mean either that no data was currently available for reading, or that an error occurred.

pub unsafe fn read_line_0a(&self) -> CppBox<QByteArray>[src]

This is an overloaded function.

Calls C++ function: QByteArray QIODevice::readLine().

C++ documentation:

This is an overloaded function.

Reads a line from the device, but no more than maxSize characters, and returns the result as a byte array.

This function has no way of reporting errors; returning an empty QByteArray can mean either that no data was currently available for reading, or that an error occurred.

pub unsafe fn reset(&self) -> bool[src]

Seeks to the start of input for random-access devices. Returns true on success; otherwise returns false (for example, if the device is not open).

Calls C++ function: virtual bool QIODevice::reset().

C++ documentation:

Seeks to the start of input for random-access devices. Returns true on success; otherwise returns false (for example, if the device is not open).

Note that when using a QTextStream on a QFile, calling reset() on the QFile will not have the expected result because QTextStream buffers the file. Use the QTextStream::seek() function instead.

See also seek().

pub unsafe fn rollback_transaction(&self)[src]

Rolls back a read transaction.

Calls C++ function: void QIODevice::rollbackTransaction().

C++ documentation:

Rolls back a read transaction.

Restores the input stream to the point of the startTransaction() call. This function is commonly used to rollback the transaction when an incomplete read was detected prior to committing the transaction.

This function was introduced in Qt 5.7.

See also startTransaction() and commitTransaction().

pub unsafe fn seek(&self, pos: i64) -> bool[src]

For random-access devices, this function sets the current position to pos, returning true on success, or false if an error occurred. For sequential devices, the default behavior is to produce a warning and return false.

Calls C++ function: virtual bool QIODevice::seek(qint64 pos).

C++ documentation:

For random-access devices, this function sets the current position to pos, returning true on success, or false if an error occurred. For sequential devices, the default behavior is to produce a warning 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.

See also pos() and isSequential().

pub unsafe fn set_current_read_channel(&self, channel: c_int)[src]

Sets the current read channel of the QIODevice to the given channel. The current input channel is used by the functions read(), readAll(), readLine(), and getChar(). It also determines which channel triggers QIODevice to emit readyRead().

Calls C++ function: void QIODevice::setCurrentReadChannel(int channel).

C++ documentation:

Sets the current read channel of the QIODevice to the given channel. The current input channel is used by the functions read(), readAll(), readLine(), and getChar(). It also determines which channel triggers QIODevice to emit readyRead().

This function was introduced in Qt 5.7.

See also currentReadChannel(), readChannelCount(), and QProcess.

pub unsafe fn set_current_write_channel(&self, channel: c_int)[src]

Sets the current write channel of the QIODevice to the given channel. The current output channel is used by the functions write(), putChar(). It also determines which channel triggers QIODevice to emit bytesWritten().

Calls C++ function: void QIODevice::setCurrentWriteChannel(int channel).

C++ documentation:

Sets the current write channel of the QIODevice to the given channel. The current output channel is used by the functions write(), putChar(). It also determines which channel triggers QIODevice to emit bytesWritten().

This function was introduced in Qt 5.7.

See also currentWriteChannel() and writeChannelCount().

pub unsafe fn set_text_mode_enabled(&self, enabled: bool)[src]

If enabled is true, this function sets the Text flag on the device; otherwise the Text flag is removed. This feature is useful for classes that provide custom end-of-line handling on a QIODevice.

Calls C++ function: void QIODevice::setTextModeEnabled(bool enabled).

C++ documentation:

If enabled is true, this function sets the Text flag on the device; otherwise the Text flag is removed. This feature is useful for classes that provide custom end-of-line handling on a QIODevice.

The IO device should be opened before calling this function.

See also isTextModeEnabled(), open(), and setOpenMode().

pub unsafe fn size(&self) -> i64[src]

For open random-access devices, this function returns the size of the device. For open sequential devices, bytesAvailable() is returned.

Calls C++ function: virtual qint64 QIODevice::size() const.

C++ documentation:

For open random-access devices, this function 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() and pos().

pub unsafe fn skip(&self, max_size: i64) -> i64[src]

This is supported on cpp_lib_version="5.11.3" or cpp_lib_version="5.12.2" or cpp_lib_version="5.13.0" or cpp_lib_version="5.14.0" only.

Skips up to maxSize bytes from the device. Returns the number of bytes actually skipped, or -1 on error.

Calls C++ function: qint64 QIODevice::skip(qint64 maxSize).

C++ documentation:

Skips up to maxSize bytes from the device. Returns the number of bytes actually skipped, or -1 on error.

This function does not wait and only discards the data that is already available for reading.

If the device is opened in text mode, end-of-line terminators are translated to '\n' symbols and count as a single byte identically to the read() and peek() behavior.

This function works for all devices, including sequential ones that cannot seek(). It is optimized to skip unwanted data after a peek() call.

For random-access devices, skip() can be used to seek forward from the current position. Negative maxSize values are not allowed.

This function was introduced in Qt 5.10.

See also peek(), seek(), and read().

pub unsafe fn start_transaction(&self)[src]

Starts a new read transaction on the device.

Calls C++ function: void QIODevice::startTransaction().

C++ documentation:

Starts a new read transaction on the device.

Defines a restorable point within the sequence of read operations. For sequential devices, read data will be duplicated internally to allow recovery in case of incomplete reads. For random-access devices, this function saves the current position. Call commitTransaction() or rollbackTransaction() to finish the transaction.

Note: Nesting transactions is not supported.

This function was introduced in Qt 5.7.

See also commitTransaction() and rollbackTransaction().

pub unsafe fn unget_char(&self, c: c_char)[src]

Puts the character c back into the device, and decrements the current position unless the position is 0. This function is usually called to "undo" a getChar() operation, such as when writing a backtracking parser.

Calls C++ function: void QIODevice::ungetChar(char c).

C++ documentation:

Puts the character c back into the device, and decrements the current position unless the position is 0. This function is usually called to "undo" a getChar() operation, such as when writing a backtracking parser.

If c was not previously read from the device, the behavior is undefined.

Note: This function is not available while a transaction is in progress.

pub unsafe fn wait_for_bytes_written(&self, msecs: c_int) -> bool[src]

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. If msecs is -1, this function will not time out. For unbuffered devices, it returns immediately.

Calls C++ function: virtual bool QIODevice::waitForBytesWritten(int msecs).

C++ documentation:

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. If msecs is -1, this function will not time out. For unbuffered devices, it returns immediately.

Returns true if a payload of data was written to the device; otherwise returns false (i.e. if the operation timed out, or if an error occurred).

This function can operate without an event loop. It is useful when writing non-GUI applications and when performing I/O operations in a non-GUI thread.

If called from within a slot connected to the bytesWritten() signal, bytesWritten() will not be reemitted.

Reimplement this function to provide a blocking API for a custom device. The default implementation does nothing, and returns false.

Warning: Calling this function from the main (GUI) thread might cause your user interface to freeze.

See also waitForReadyRead().

pub unsafe fn wait_for_ready_read(&self, msecs: c_int) -> bool[src]

Blocks until new data is available for reading and the readyRead() signal has been emitted, or until msecs milliseconds have passed. If msecs is -1, this function will not time out.

Calls C++ function: virtual bool QIODevice::waitForReadyRead(int msecs).

C++ documentation:

Blocks until new data is available for reading and the readyRead() signal has been emitted, or until msecs milliseconds have passed. If msecs is -1, this function will not time out.

Returns true if new data is available for reading; otherwise returns false (if the operation timed out or if an error occurred).

This function can operate without an event loop. It is useful when writing non-GUI applications and when performing I/O operations in a non-GUI thread.

If called from within a slot connected to the readyRead() signal, readyRead() will not be reemitted.

Reimplement this function to provide a blocking API for a custom device. The default implementation does nothing, and returns false.

Warning: Calling this function from the main (GUI) thread might cause your user interface to freeze.

See also waitForBytesWritten().

pub unsafe fn write_char_i64(&self, data: *const c_char, len: i64) -> i64[src]

Writes at most maxSize bytes of data from data to the device. Returns the number of bytes that were actually written, or -1 if an error occurred.

Calls C++ function: qint64 QIODevice::write(const char* data, qint64 len).

C++ documentation:

Writes at most maxSize bytes of data from data to the device. Returns the number of bytes that were actually written, or -1 if an error occurred.

See also read() and writeData().

pub unsafe fn write_char(&self, data: *const c_char) -> i64[src]

This is an overloaded function.

Calls C++ function: qint64 QIODevice::write(const char* data).

C++ documentation:

This is an overloaded function.

Writes data from a zero-terminated string of 8-bit characters to the device. Returns the number of bytes that were actually written, or -1 if an error occurred. This is equivalent to

...
QIODevice::write(data, qstrlen(data));
...

This function was introduced in Qt 4.5.

See also read() and writeData().

pub unsafe fn write_q_byte_array(
    &self,
    data: impl CastInto<Ref<QByteArray>>
) -> i64[src]

This is an overloaded function.

Calls C++ function: qint64 QIODevice::write(const QByteArray& data).

C++ documentation:

This is an overloaded function.

Writes the content of byteArray to the device. Returns the number of bytes that were actually written, or -1 if an error occurred.

See also read() and writeData().

pub unsafe fn write_channel_count(&self) -> c_int[src]

Returns the number of available write channels if the device is open; otherwise returns 0.

Calls C++ function: int QIODevice::writeChannelCount() const.

C++ documentation:

Returns the number of available write channels if the device is open; otherwise returns 0.

This function was introduced in Qt 5.7.

See also readChannelCount().

Trait Implementations

impl CppDeletable for QBuffer[src]

unsafe fn delete(&self)[src]

Destroys the buffer.

Calls C++ function: virtual [destructor] void QBuffer::~QBuffer().

C++ documentation:

Destroys the buffer.

impl Deref for QBuffer[src]

type Target = QIODevice

The resulting type after dereferencing.

fn deref(&self) -> &QIODevice[src]

Calls C++ function: QIODevice* static_cast<QIODevice*>(QBuffer* ptr).

impl DynamicCast<QBuffer> for QIODevice[src]

unsafe fn dynamic_cast(ptr: Ptr<QIODevice>) -> Ptr<QBuffer>[src]

Calls C++ function: QBuffer* dynamic_cast<QBuffer*>(QIODevice* ptr).

impl DynamicCast<QBuffer> for QObject[src]

unsafe fn dynamic_cast(ptr: Ptr<QObject>) -> Ptr<QBuffer>[src]

Calls C++ function: QBuffer* dynamic_cast<QBuffer*>(QObject* ptr).

impl Size for QBuffer[src]

unsafe fn size(&self) -> usize[src]

Reimplemented from QIODevice::size().

Calls C++ function: virtual qint64 QBuffer::size() const.

C++ documentation:

Reimplemented from QIODevice::size().

impl StaticDowncast<QBuffer> for QIODevice[src]

unsafe fn static_downcast(ptr: Ptr<QIODevice>) -> Ptr<QBuffer>[src]

Calls C++ function: QBuffer* static_cast<QBuffer*>(QIODevice* ptr).

impl StaticDowncast<QBuffer> for QObject[src]

unsafe fn static_downcast(ptr: Ptr<QObject>) -> Ptr<QBuffer>[src]

Calls C++ function: QBuffer* static_cast<QBuffer*>(QObject* ptr).

impl StaticUpcast<QIODevice> for QBuffer[src]

unsafe fn static_upcast(ptr: Ptr<QBuffer>) -> Ptr<QIODevice>[src]

Calls C++ function: QIODevice* static_cast<QIODevice*>(QBuffer* ptr).

impl StaticUpcast<QObject> for QBuffer[src]

unsafe fn static_upcast(ptr: Ptr<QBuffer>) -> Ptr<QObject>[src]

Calls C++ function: QObject* static_cast<QObject*>(QBuffer* ptr).

Auto Trait Implementations

impl RefUnwindSafe for QBuffer

impl Send for QBuffer

impl Sync for QBuffer

impl Unpin for QBuffer

impl UnwindSafe for QBuffer

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized, [src]

impl<T> Borrow<T> for T where
    T: ?Sized, [src]

impl<T> BorrowMut<T> for T where
    T: ?Sized, [src]

impl<T, U> CastInto<U> for T where
    U: CastFrom<T>, [src]

impl<T> From<T> for T[src]

impl<T, U> Into<U> for T where
    U: From<T>, [src]

impl<T> StaticUpcast<T> for T[src]

impl<T, U> TryFrom<U> for T where
    U: Into<T>, [src]

type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, [src]

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.