RTBinaryMessage Class Reference

Represents a binary based message for real-time data plots. More...

#include <rtbinarymessage.h>

Inheritance diagram for RTBinaryMessage:

Public Types
enum	FieldType {   Padding, PadTo, PadByField, PadToField,   Int8, Int16, Int32, Int64,   Uint8, Uint16, Uint32, Uint64,   Float32, Float64 }
	Fixed field types. More...

Public Member Functions
	RTBinaryMessage (bool littleEndian=false)
	Create a binary message. More...
bool	littleEndian () const
	Does the message write little Endian? More...
void	setMessage (QByteArray &buffer) override
	Writes the binary message to buffer. More...
int	readMessage (const QByteArray &buffer) override
	Read and update values from the buffer. More...
QStringList	headings () const override
	Return the list of headings. More...
unsigned	populateValues (std::vector< double > &values) const override
	Request the most up to date field values. More...
void	addField (const QString &name, FieldType type, bool heading=false, const QVariant &value=QVariant())
	Registers a field. More...
int	fieldIndex (const QString &key) const
	Query the index of a field named key. More...
double	fieldValueD (const QString &key) const
	Requests a field value by name, converting to a double. More...
QVariant	fieldValueV (const QString &key) const
	Requests a field value by name, returning a QVariant. More...
Public Member Functions inherited from RTMessage
virtual	~RTMessage ()
	Virtual destructor.

Static Public Attributes
static const unsigned	TypeSizes []
	Sizes for various FieldType items (bytes).

Detailed Description

Represents a binary based message for real-time data plots.

This stores a number of fields and may read or write these appropriately. Each field has a known type and a default value. When writing, each field has its default value written to the buffer. When reading, each field is read from the stream, changing its value.

A field may also be a padding field. Padding may be specified

• Padding - pad by adding a fixed byte count
• PadTo - pad the buffer out to the specified byte count
• PadToField - pad the buffer out to a specified byte count. The byte count is attained by reading another field. The padding field name is stored as a string in the original field's value.

The same padding process is used on reading or writing, with zero bytes used for writing padding, and padding bytes skipped while reading.

Supports writing little or big Endian.

Registered fields may be marked as headings. Only those marked as such are reported by headings() and populateValues().

Member Enumeration Documentation

enum RTBinaryMessage::FieldType

Fixed field types.

Enumerator
Padding	Padding. Integer value specifies how much.
PadTo	Pad out to the specified amount.
PadByField	Relative padding like Padding, but lookup a field for the amount.
PadToField	Pad out to the specified amount, but lookup a field for the amount.

Constructor & Destructor Documentation

RTBinaryMessage::RTBinaryMessage

(

bool

littleEndian = false

)

Create a binary message.

Parameters

littleEndian

True to write little Endian, false to write big.

Member Function Documentation

void RTBinaryMessage::addField	(	const QString &	name,
		FieldType	type,
		bool	heading = false,
		const QVariant &	value = QVariant()
	)

Registers a field.

Parameters

name	The field name. May be used as a heading.
type	The field type.
heading	True if this field is exposed as a heading.
value	The default or initial value.

int RTBinaryMessage::fieldIndex

(

const QString &

key

)

const

Query the index of a field named key.

Parameters

key	The field name to query.

Returns

The index of key or -1 if there is no such field.

double RTBinaryMessage::fieldValueD

(

const QString &

key

)

const

Requests a field value by name, converting to a double.

Parameters

key	The field name requested.

Returns

The field value converted to a double. Returns zero on any failure.

QVariant RTBinaryMessage::fieldValueV

(

const QString &

key

)

const

Requests a field value by name, returning a QVariant.

Parameters

key	The field name requested.

Returns

The field value as a QVariant. Returns a null value on any failure, but a valid field value may also be null.

QStringList RTBinaryMessage::headings ( ) const

overridevirtual

Return the list of headings.

This is the list of fields marked as headings.

Returns

The list of fields used as headings.

Implements RTMessage.

bool RTBinaryMessage::littleEndian ( ) const

inline

Does the message write little Endian?

Returns

True if writing little Endian, false if writing big.

unsigned RTBinaryMessage::populateValues ( std::vector< double > &  values ) const

overridevirtual

Request the most up to date field values.

Only exposes those marked as headings.

Parameters

values

The values array to populate.

Returns

The number of values written.

Implements RTMessage.

int RTBinaryMessage::readMessage ( const QByteArray &  buffer )

overridevirtual

Read and update values from the buffer.

Parameters

buffer

The buffer to read from.

Returns

The number of bytes read on success, negative on error. Zero if nothing to read.

Implements RTMessage.

void RTBinaryMessage::setMessage ( QByteArray &  buffer )

overridevirtual

Writes the binary message to buffer.

Parameters

buffer

The buffer to write to.

Implements RTMessage.

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

• rtbinarymessage.h