casa::AttributeValuePoi< T > Class Template Reference

Templated class for storing a pointer to the value of an Attribute. More...

#include <AttValPoi.h>

Inheritance diagram for casa::AttributeValuePoi< T >:

Public Member Functions
	AttributeValuePoi (T *value, const casacore::Bool strict)
	Constructor for a pointer to a scalar. More...
	AttributeValuePoi (casacore::Vector< T > *value, const casacore::Bool strict)
	Constructor for a pointer to a casacore::Vector. More...
	AttributeValuePoi (const AttributeValuePoi< T > &other)
	Copy constructor. More...
virtual	~AttributeValuePoi ()
	Destructor. More...
const AttributeValuePoi< T > &	operator= (const AttributeValuePoi< T > &other)
	Assignment operator. More...
virtual AttributeValueBase *	clone () const
	Return a new copy of the AttributeValuePoi (virtual constructor). More...
virtual void	operator+= (const AttributeValueBase &other)
	Add other to *this. More...
virtual void	setValue (const T &value)
	Change the value of the AttributeValue. More...
virtual void	setValue (const casacore::Vector< T > &value)
virtual casacore::DataType	getPointerType () const
	Get the DataType of aliased variable. More...
virtual casacore::String	className () const
	Return class name. More...
Public Member Functions inherited from casa::AttributeValue< T >
	AttributeValue (const T &value, const casacore::Bool strict)
	Construct from a scalar value. More...
	AttributeValue (const casacore::Vector< T > &value, const casacore::Bool strict)
	Construct from a casacore::Vector. More...
virtual	~AttributeValue ()
	Destructor. More...
	AttributeValue (const AttributeValue< T > &other)
	Copy constructor. More...
const AttributeValue< T > &	operator= (const AttributeValue< T > &other)
	Assignment (copy semantics) More...
virtual casacore::Vector< T >	getValue () const
virtual void	print (std::ostream &os)
Public Member Functions inherited from casa::AttributeValueBase
	AttributeValueBase (AttValue::ValueType type, casacore::Bool strict)
	Constructor. More...
	AttributeValueBase (const AttributeValueBase &other)
	Copy constructor. More...
virtual	~AttributeValueBase ()
	Destructor. More...
const AttributeValueBase &	operator= (const AttributeValueBase &other)
	Copy assignment. More...
AttValue::ValueType	getType () const
	Get the type of the value stored. More...
casacore::Bool	operator== (const AttributeValueBase &other) const
	Check for equality (and inequality) of two objects derived from AttributeValueBase. More...
casacore::Bool	operator!= (const AttributeValueBase &other) const
virtual void	setStrictness (const casacore::Bool &newStrict)
	Set/get the strictness state of this AttributeValue. More...
virtual casacore::Bool	getStrictness () const

Private Member Functions
void	updatePointerValue () const
	Update the variable that is aliased to the AttributeValuePoi. More...
const AttributeValuePoi< T > &	myCast (const AttributeValueBase &other) const
	Cast from base class. More...
	AttributeValuePoi ()
	Default constructor. More...

Private Attributes
casacore::Vector< T > *	itsVectorPointerPtr
	Pointer to the aliased variable. More...
T *	itsScalarPointerPtr
casacore::DataType	itsPointerType
	The pointer DataType. More...

Additional Inherited Members
Protected Member Functions inherited from casa::AttributeValue< T >
virtual casacore::Bool	matches (const AttributeValueBase &other) const
	Implements when the values of two Attributes match or not. More...
const AttributeValue< T > &	myCast (const AttributeValueBase &other) const
	Cast from Base class. More...
Protected Member Functions inherited from casa::AttributeValueBase
virtual void	setType (const AttValue::ValueType &newType)
	Set the type of the value stored. More...
casacore::Bool	myMatch (const AttributeValueBase &other) const
	Check that private data match. More...
Protected Attributes inherited from casa::AttributeValueBase
AttValue::ValueType	itsValueType
	The type of what is stored. More...
casacore::Bool	itsStrictness
	Whether the match is strict or not. More...

Detailed Description

template<class T>
class casa::AttributeValuePoi< T >

Templated class for storing a pointer to the value of an Attribute.

Intended use:

Internal

Review Status

Date Reviewed:

yyyy/mm/dd

Test programs:

tAttribute

Prerequisite

• AttributeValue

Etymology

"AttributeValuePoi" is a contraction of "Attribute Value" and "Pointer", and stores a pointer to the value of an Attribute.

Synopsis

An AttributeValuePoi differs from a AttributeValue in that instead of using its own variable to store the actual value like AttributeValue does, it stores a pointer to the variable used in the constructor. This means that the AttributeValuePoi is just an alias to this variable, and then the user can modify the value of an AttributeValuePoi without using its interface. Alternatively, and perhaps more importantly, the Attribute interface can be used to modify members of a class.

Example

A simple example will help illustrate the utility of the AttributeValuePoi class:

casacore::Int varInt = 1;
AttributeValuePoi<casacore::Int> intAtt(&varInt, false);

casacore::Vector<casacore::Int> bla = intAtt.getValue();
// bla(0) is 1;

// This wil change also the AttributeValue:
varInt = 2;
bla = intAtt.getValue();
// bla(0) is now 2

intAtt.setValue(5);
// now also varInt == 5

Motivation

The motivation for this class is to be able to provide an Attribute interface for modifying private members of some classes. For example, this interface is used to control the linear coordinate system of the WorldCanvas.

Definition at line 100 of file AttValPoi.h.

Constructor & Destructor Documentation

template<class T>

casa::AttributeValuePoi< T >::AttributeValuePoi	(	T *	value,
		const casacore::Bool	strict
	)

Constructor for a pointer to a scalar.

template<class T>

casa::AttributeValuePoi< T >::AttributeValuePoi	(	casacore::Vector< T > *	value,
		const casacore::Bool	strict
	)

Constructor for a pointer to a casacore::Vector.

template<class T>

casa::AttributeValuePoi< T >::AttributeValuePoi

(

const AttributeValuePoi< T > &

other

)

Copy constructor.

template<class T>

virtual casa::AttributeValuePoi< T >::~AttributeValuePoi ( )

virtual

Destructor.

template<class T>

casa::AttributeValuePoi< T >::AttributeValuePoi ( )

private

Default constructor.

Member Function Documentation

template<class T>

virtual casacore::String casa::AttributeValuePoi< T >::className ( ) const

inlinevirtual

Return class name.

Reimplemented from casa::AttributeValue< T >.

Definition at line 137 of file AttValPoi.h.

template<class T>

virtual AttributeValueBase* casa::AttributeValuePoi< T >::clone ( ) const

virtual

Return a new copy of the AttributeValuePoi (virtual constructor).

Reimplemented from casa::AttributeValue< T >.

template<class T>

virtual casacore::DataType casa::AttributeValuePoi< T >::getPointerType ( ) const

virtual

Get the DataType of aliased variable.

template<class T>

const AttributeValuePoi<T>& casa::AttributeValuePoi< T >::myCast ( const AttributeValueBase &  other ) const

private

Cast from base class.

template<class T>

virtual void casa::AttributeValuePoi< T >::operator+= ( const AttributeValueBase &  other )

virtual

Add other to *this.

Needs to over-ride base class definition because the pointers need to be dereferenced prior to addition.

Reimplemented from casa::AttributeValue< T >.

template<class T>

const AttributeValuePoi<T>& casa::AttributeValuePoi< T >::operator=

(

const AttributeValuePoi< T > &

other

)

Assignment operator.

template<class T>

virtual void casa::AttributeValuePoi< T >::setValue ( const T &  value )

virtual

Change the value of the AttributeValue.

Reimplemented from casa::AttributeValue< T >.

template<class T>

virtual void casa::AttributeValuePoi< T >::setValue ( const casacore::Vector< T > &  value )

virtual

Reimplemented from casa::AttributeValue< T >.

template<class T>

void casa::AttributeValuePoi< T >::updatePointerValue ( ) const

private

Update the variable that is aliased to the AttributeValuePoi.

Member Data Documentation

template<class T>

casacore::DataType casa::AttributeValuePoi< T >::itsPointerType

private

The pointer DataType.

Definition at line 156 of file AttValPoi.h.

template<class T>

T* casa::AttributeValuePoi< T >::itsScalarPointerPtr

private

Definition at line 152 of file AttValPoi.h.

template<class T>

casacore::Vector<T>* casa::AttributeValuePoi< T >::itsVectorPointerPtr

private

Pointer to the aliased variable.

Only one is ever active depending upon how the object was constructed. The memory allocated to these pointers does not belong to this object.

Definition at line 151 of file AttValPoi.h.

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

• casa/code/display/Display/AttValPoi.h