A PlotGenerator which generated plots by evaluating PlotExpression objects. More...

#include <plotexpressiongenerator.h>

Inheritance diagram for PlotExpressionGenerator:

Public Types
enum	AddExpressionResult { AER_QueuedPartial = -1, AER_AlreadyComplete, AER_Queued }
	Return value sfor `addExpression()` and `addExpressions()`. More...

Public Types inherited from PlotGenerator
enum	ControlFlag { None = 0, RelativeTime = (1 << 0) }
	Plot generation control flags. Must be set before execution. More...

Public Member Functions
	PlotExpressionGenerator (Curves curves, const QList< PlotExpression > &expressions, const QStringList &sourceNames)
	Create an expression generator based on the given expressions and curves. More...

	PlotExpressionGenerator (Curves curves, const QList< const PlotExpression > &expressions, const QStringList &sourceNames)

	~PlotExpressionGenerator ()
	Destructor.

int	addExpression (const PlotExpression *expression)
	Adds an expression to be generated even if already running. More...

int	addExpressions (const QList< const PlotExpression * > &expressions)
	Adds a set of expression to be generated even if already running. More...

bool	removeExpression (const PlotExpression *expression)
	Aborts generation of `expression` if it has yet to be generated. More...

Public Member Functions inherited from PlotGenerator
	PlotGenerator (Curves *curves)
	Instantiate the generator thread to load data into `curves`. More...

virtual	~PlotGenerator ()
	Destructor. The thread should generally be stopped before destructing.

const Curves *	curves () const
	Access the curves model to load data into.

void	setTimeColumn (uint number)
	Set the expected time column for all curves created by this generator. More...

uint	timeColumn () const
	The time column value in used. More...

void	setTimeScale (double scale)
	Set the scale factor applied to all curves created by this generator. More...

double	timeScale () const
	Access the time scale used by this generator. More...

void	setControlFlags (uint flags)
	Sets `ControlFlag` values for this generator. More...

void	setControlFlags (uint flags, bool on)
	Set the state of subset of `ControlFlag` values without affecting other flags. More...

uint	controlFlags () const
	Access the current `ControlFlag` values.

void	quit ()
	Call to request the generator terminate operation.

virtual bool	isFileLoad () const
	True if this is a file loader. More...

Protected Member Functions
void	run () override
	Generation loop.

bool	curveExists (const PlotInstance &curve) const
	Check if the curve exists. More...

Additional Inherited Members
Public Slots inherited from PlotGenerator
void	abortLoad ()
	Request loading abort.

Signals inherited from PlotGenerator
void	itemName (const QString &name)
	Signal the current item name. More...

void	itemProgress (int current)
	Update progress through the current item. More...

void	overallProgress (int current, int total)
	This signal reports overall progress. More...

void	beginNewCurves ()
	Begin the addition of new curves via `Curves::newCurve()` Block notification occurs at a per `PlotSource` level. More...

void	endNewCurves ()
	End notification of new curves via `Curves::newCurve()`. More...

void	loadComplete (int curveCount)
	Notify completion of curve generation. More...

Protected Attributes inherited from PlotGenerator
Curves *	_curves
	Curves data model.

QMutex *	_dataMutex
	Data mutex.

uint	_controlFlags
	`ControlFlag` values affecting generation.

uint	_timeColumn
	Index of the time column, zero for none.

double	_timeScale
	Time scaling factor.

bool	_abortFlag
	Abort requested?

Detailed Description

A PlotGenerator which generated plots by evaluating PlotExpression objects.

The generator is designed to run asynchronously. As such, it makes copies of the data on which to operate in case these are destroyed. However, the PlotInstance::expression member is always set as the original expression, not the internal copy.

More explicitly, plots generated herein refer to the original PlotExpression objects, but internal calculations use a copy of the expressions for thread safety. The original expressions should remain valid and unmodified while the generator executes, but failure to do so will not result in a failure within the generator object. Instead, generated plots may be out of date or reference an invalid expression.

Plot binding is exhaustive, supporting regular expression based PlotExpression trees. However, this can lead to multiple bindings of the same data when referencing regular expressions from different plots. For example, the expression:

///   r'samples-.*'|'value' - r'samples-.*'|'value'
///

Consider where we have two files loaded 'samples-a' and 'samples-b'. This expression will bind the following:

'samples-a'|'value' - 'samples-a'|'value'
'samples-a'|'value' - 'samples-a'|'value'
'samples-a'|'value' - 'samples-b'|'value'
'samples-b'|'value' - 'samples-b'|'value'

Note: The PlotSource for PlotInstance objects generated here is the same as the original source. Expression curves can be distinguished by the fact that PlotInstance::expression() is not null.

Member Enumeration Documentation

enum PlotExpressionGenerator::AddExpressionResult

Return value sfor addExpression() and addExpressions().

Enumerator

AER_QueuedPartial

Returned when some of the new expressions are successfully queued, while others have already been generated.

AER_AlreadyComplete

Returned when all of the expression begin added have already been generated.

This occurs either because the generator thread has completed or because the expressions already exist and have been processed (or are currently being processed).

AER_Queued

Returned when all the new expressions are successfully queued and will be generated.

Constructor & Destructor Documentation

PlotExpressionGenerator::PlotExpressionGenerator	(	Curves *	curves,
		const QList< PlotExpression * > &	expressions,
		const QStringList &	sourceNames
	)

Create an expression generator based on the given expressions and curves.

The generator makes copies of the PlotExpression and PlotInstance objects for internal calculations. However, a copy of the original expression list is maintained so that the original expression objects are assigned to generated PlotInstance objects. See class comments.

Parameters

curves	The `Curves` model containing existing curves from which to generate new ones. New curves are added to this model.
expressions	The expressions to generate new curves from. These objects must remain valid until the generator completes.
sourceNames	List of all the source files from which `curves` were loaded.

PlotExpressionGenerator::PlotExpressionGenerator	(	Curves *	curves,
		const QList< const PlotExpression * > &	expressions,
		const QStringList &	sourceNames
	)

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

Member Function Documentation

int PlotExpressionGenerator::addExpression ( const PlotExpression * expression )

Adds an expression to be generated even if already running.

Thread-safe.

The caller retains ownership of expression.

Returns: One of the values in AddExpressionResult. Does not return AER_QueuedPartial.

int PlotExpressionGenerator::addExpressions ( const QList< const PlotExpression * > & expressions )

Adds a set of expression to be generated even if already running.

Thread-safe.

The caller retains ownership of expression.

Returns: One of the values in AddExpressionResult.

bool PlotExpressionGenerator::curveExists ( const PlotInstance & curve ) const

protected

Check if the curve exists.

This is used to duplicate binding.

Looks in _existingCurves for an item with the same PlotSource::name() and PlotInstance::name().

Parameters

curve The curve to look for a duplicate of.

Returns: True if a matching curves exists.

bool PlotExpressionGenerator::removeExpression ( const PlotExpression * expression )

Aborts generation of expression if it has yet to be generated.

Thread-safe.

Returns: True if the given expression has been removed or was not present. False if the expression has already been generated.

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

plotexpressiongenerator.h

Public Types

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation