IlvAccessible Class Reference

Abstract class providing queryValue, changeValue, conversion, and introspection methods. More...

#include <ilviews/protos/value.h>

Inheritance diagram for IlvAccessible:

Public Member Functions
virtual IlBoolean	changeValue (const IlvValue &v)
	Changes the object's value. Both the name and the new value are contained in val. More...
virtual IlBoolean	changeValues (const IlvValue *v, IlUShort c)
	Changes several values of an object in a single call. The default implementation calls changeValue for all values. More...
virtual IlUInt	compareAllValues (const IlvAccessible *ref, IlvValueArray &diffs, IlBoolean any=IlFalse) const
	Compares two objects and returns the differing attributes. More...
virtual IlUInt	compareValues (const IlvAccessible *ref, IlvValue *values, IlUShort count, IlvValueArray &diffs) const
	Compares two objects and returns the differing attributes. More...
virtual IlBoolean	convertValues (IlvValue *v, IlUShort c, IlvDisplay *d) const
	Convert values to match the types defined by the object accessors. More...
virtual void	getAccessors (const IlSymbol *const **a, const IlvValueTypeClass *const **t, IlUInt &c) const =0
	Returns the names of all the accessors known by this object. More...
virtual const char *	getName () const =0
	Returns the object name. More...
IlUInt	getSubscriptions (IlvAccessible *subscriber, IlSymbol **&sourceValue, IlSymbol **&subscriberValue, IlvValueTypeClass **&type, IlvValueSubscriptionMode *&mode, IlvAccessible ***subscribers=0) const
	Returns alls subscriptions made by subscriber. More...
virtual const IlvValueTypeClass *	getValueType (const IlSymbol *s) const
	Returns the type of a given attribute. More...
virtual IlBoolean	isOutputValue (const IlSymbol *value) const
	Indicates whether value designates an accessor that can generate notifying values. More...
virtual IlvValue &	pullValue (IlvValue &v) const
	See below.
virtual void	pullValues (IlvValue *vals, IlUShort c) const
	Propagates value queries to the subscribers to this object. More...
virtual IlBoolean	pushValue (const IlvValue &v) const
	See below.
virtual IlBoolean	pushValues (const IlvValue *vals, IlUShort c) const
	Propagates value changes to the subscribers to this object. More...
virtual IlvValue &	queryValue (IlvValue &value) const
	Queries the value designated by value from the object. Both the value and the value type are stored in value. More...
virtual void	queryValues (IlvValue *v, IlUShort c) const
	Queries several values in a single call. The default implementation calls queryValue for each value. More...
virtual void	subscribe (IlvAccessible *subscriber, IlSymbol *sourceValue, IlSymbol *subscriberValue, IlvValueTypeClass *type, IlvValueSubscriptionMode mode=IlvValueSubscriptionChange)
	Subscribes the subscriber object to the value sourceValue of this object. More...
virtual void	unSubscribe (IlvAccessible *subscriber, IlSymbol *sourceValue=0, IlSymbol *subscriberValue=0)
	Cancels subscriptions previously made. More...

Static Public Member Functions
static void	DeclareAccessor (const IlSymbol *attr, IlvValueTypeClass *type, const IlSymbol *const **accessors, const IlvValueTypeClass *const **types, IlUInt &count, IlBoolean checkDuplicates=IlFalse, IlAny accessorList=0)
static const IlvValueTypeClass *	GetType (IlSymbol *name)
	Returns the type instance from a name. More...
static IlBoolean	StringToValue (const char *s, IlSymbol *type, IlvValue &v, IlvDisplay *display)
	Converts the character string s to an IlvValue with the type type. More...
static IlBoolean	StringToValue (const char *s, const IlvValueTypeClass *typeClass, IlvValue &v, IlvDisplay *d)
	Converts the character string s to an IlvValue with the type type. More...
static IlBoolean	ValuesAreEqual (IlvValue &v1, IlvValue &v2, IlBoolean compareNames=IlTrue)
	Compares two values. More...

Detailed Description

Abstract class providing queryValue, changeValue, conversion, and introspection methods.

Library: ilvproto

IlvAccessible is an abstract base class used as a superclass for all objects in the prototype library that provide an interface based on the queryValue/changeValue methods. IlvAccessible also provides methods for converting and comparing values, and implements the value subscription interface.

See Also

IlvValue, IlvValueInterface, IlvAccessorHolder, IlvGroupNode.

Member Function Documentation

virtual IlBoolean IlvAccessible::changeValue ( const IlvValue &  v )

virtual

Changes the object's value. Both the name and the new value are contained in val.

Parameters

v	The value to be set (both name and value).

Returns

Whether the object considered the operation successful or not.

Reimplemented in IlvSubGroupNode, IlvGroup, IlvGraphicNode, IlvGroupMediator, and IlvAccessorHolder.

virtual IlBoolean IlvAccessible::changeValues ( const IlvValue *  v, IlUShort  c  )

virtual

Changes several values of an object in a single call. The default implementation calls changeValue for all values.

Parameters

v	The changed values (both name and values).
c	The number of values.

Returns

Whether the object considered the operation successful or not.

Reimplemented in IlvSubGroupNode, IlvGroup, IlvGraphicNode, IlvGroupMediator, and IlvAccessorHolder.

virtual IlUInt IlvAccessible::compareAllValues ( const IlvAccessible *  ref, IlvValueArray &  diffs, IlBoolean  any = IlFalse  ) const

virtual

Compares two objects and returns the differing attributes.

See below.

virtual IlUInt IlvAccessible::compareValues ( const IlvAccessible *  ref, IlvValue *  values, IlUShort  count, IlvValueArray &  diffs  ) const

virtual

Compares two objects and returns the differing attributes.

Compares the values of accessors known by this object with the corresponding values in the object ref. The values that differ are stored in diffs. The values stored are taken from the calling object (this), not from ref. The first method calls the getAccessors method to get the list of all known accessors, while the second only compares the provided values. Then, both methods call compareValues to actually compare the values.

Returns

The number of differing attributes.

Parameters

ref	The object to compare to.
values	The attributes to compare in both objects.
count	The number of attributes to compare.
diffs	The differing attributes.

Reimplemented in IlvSubGroupNode, and IlvAccessorHolder.

virtual IlBoolean IlvAccessible::convertValues ( IlvValue *  v, IlUShort  c, IlvDisplay *  d  ) const

virtual

Convert values to match the types defined by the object accessors.

Converts a set of values so their type match the type of accessors corresponding to the object. The values are normally stored in values as strings. They will be converted to the appropriate types. The result is returned in values.

Returns

Whether the conversion process was successful.

Parameters

v	The values to convert.
c	The number of values to convert.
d	A display, needed to allow font, color, and other resource conversions.

static void IlvAccessible::DeclareAccessor ( const IlSymbol *  attr, IlvValueTypeClass *  type, const IlSymbol *const **  accessors, const IlvValueTypeClass *const **  types, IlUInt &  count, IlBoolean  checkDuplicates = IlFalse, IlAny  accessorList = 0  )

static

Adds the accessor name attr and its type type to the accessors and types lists, and increments the count parameter. To add an accessor to the list, this method must be called from getAccessors.

virtual void IlvAccessible::getAccessors ( const IlSymbol *const **  a, const IlvValueTypeClass *const **  t, IlUInt &  c  ) const

pure virtual

Returns the names of all the accessors known by this object.

Subclasses of IlvAccessible must override this method by calling the static method DeclareAccessor for each accessor handled by the subclass. The returned arrays are filled by the method and must not be freed.

Parameters

a	Pointer to an array filled on return with the names of the accessors defined for the object.
t	Pointer to an array filled on return with the type of each accessor.
c	Number of accessors, set by the method.

Implemented in IlvSubGroupNode, IlvGroup, IlvGraphicNode, IlvGroupMediator, and IlvAccessorHolder.

virtual const char* IlvAccessible::getName ( ) const

pure virtual

Returns the object name.

Returns

The object name. This pointer must not be freed.

Implemented in IlvSubGroupNode, IlvGroupNode, IlvGraphicNode, IlvGroup, and IlvGroupMediator.

IlUInt IlvAccessible::getSubscriptions	(	IlvAccessible *	subscriber,
		IlSymbol **&	sourceValue,
		IlSymbol **&	subscriberValue,
		IlvValueTypeClass **&	type,
		IlvValueSubscriptionMode *&	mode,
		IlvAccessible ***	subscribers = 0
	)		const

Returns alls subscriptions made by subscriber.

The sourceValue, subscriberValues, types, and modes arguments are modified to contain the parameters of all the subscriptions for the specified subscriber. These parameters must be released using the delete[] operator when they are no longer needed. The method returns the number of elements returned in each array.

Returns

The number of subscriptions.

Parameters

subscriber	The subscriber to start with.
sourceValue	The names of the attributes observed by the subscription.
subscriberValue	The names of the attributes to be notified in the subscriber.
type	The types of the expected values pushed in subscriber.
mode	The modes of the subscriptions.
subscribers	The subscribers also observing the object.

static const IlvValueTypeClass* IlvAccessible::GetType ( IlSymbol *  name )

static

Returns the type instance from a name.

Parameters

name	The name of the type that is requested.

Returns

A pointer to the type instance that corresponds to the name name.

virtual const IlvValueTypeClass* IlvAccessible::getValueType ( const IlSymbol *  s ) const

virtual

Returns the type of a given attribute.

Returns

The type of this object accessor, or IlvValueNoType if the accessor does not exist.

Parameters

s	The name of the accessor.

Reimplemented in IlvGroup.

virtual IlBoolean IlvAccessible::isOutputValue ( const IlSymbol *  value ) const

virtual

Indicates whether value designates an accessor that can generate notifying values.

Returns

IlTrue if value designates an accessor that can generate notifying values, that is, a value for which pushValue calls may be issued. The default implementation returns IlFalse. Subclasses such as IlvAccessorHolder redefine this method.

Parameters

value

Name of the accessor.

See Also

pushValue.

Reimplemented in IlvSubGroupNode, IlvGroup, and IlvAccessorHolder.

virtual void IlvAccessible::pullValues ( IlvValue *  vals, IlUShort  c  ) const

virtual

Propagates value queries to the subscribers to this object.

Must be called to propagate value queries to the subscribers to this object. When pullValue or pullValues is called, every IlvAccessible object subscribed to the value identified by val with a mode of IlvValueSubscriptionQuery is notified through a call to the subscriber queryValue or queryValues methods. The value name is equal to the subscriberValue passed to the subscribe method when the subscription was made. The first method returns the last value returned by the queryValue methods of the subscribers. The second method returns whether the object considered the call successful.

Parameters

vals	The pulled values.
c	The number of values.

Returns

Whether the object considered the call successful, or the last value returned by the queryValue methods of the subscribers.

virtual IlBoolean IlvAccessible::pushValues ( const IlvValue *  vals, IlUShort  c  ) const

virtual

Propagates value changes to the subscribers to this object.

Must be called to propagate value changes to the subscribers to this object. When pushValue or pushValues is called, every IlvAccessible object subscribed to the value identified by v with a mode of IlvValueSubscriptionChange is notified through a call to the subscriber changeValue or changeValues methods. The value name is equal to the subscriberValue passed to the subscribe method when the subscription was made, with a data value equal to the data contained in val. The method returns IlTrue if at least one of the changeValue methods of the subscribers returns IlTrue, and IlFalse otherwise.

Returns

Whether the object considered the call successful.

Parameters

vals	The pushed values.
c	The number of values.

virtual IlvValue& IlvAccessible::queryValue ( IlvValue &  value ) const

virtual

Queries the value designated by value from the object. Both the value and the value type are stored in value.

Parameters

value

The queried value name.

Returns

The value passed in argument, set to the object value.

Reimplemented in IlvSubGroupNode, IlvGroup, IlvGraphicNode, IlvGroupMediator, and IlvAccessorHolder.

virtual void IlvAccessible::queryValues ( IlvValue *  v, IlUShort  c  ) const

virtual

Queries several values in a single call. The default implementation calls queryValue for each value.

Parameters

v	The array of value names to be queried
c	The number of values to be queried.

Reimplemented in IlvSubGroupNode, IlvGroup, IlvGroupMediator, and IlvAccessorHolder.

static IlBoolean IlvAccessible::StringToValue ( const char *  s, IlSymbol *  type, IlvValue &  v, IlvDisplay *  display  )

static

Converts the character string s to an IlvValue with the type type.

See below.

static IlBoolean IlvAccessible::StringToValue ( const char *  s, const IlvValueTypeClass *  typeClass, IlvValue &  v, IlvDisplay *  d  )

static

Converts the character string s to an IlvValue with the type type.

Returns

IlTrue if the conversion was successful, and IlFalse otherwise.

Parameters

s	Input string.
typeClass	Type of the value to convert the string into.
v	Resulting value.
d	Display used to convert resources such as colors, fonts, and so on.

virtual void IlvAccessible::subscribe ( IlvAccessible *  subscriber, IlSymbol *  sourceValue, IlSymbol *  subscriberValue, IlvValueTypeClass *  type, IlvValueSubscriptionMode  mode = IlvValueSubscriptionChange  )

virtual

Subscribes the subscriber object to the value sourceValue of this object.

After this subscription, every call to this object pushValue method with a value name of sourceValue will cause the subscriber changeValue method to be called with the value name subscriberValue, and with the value data passed to the initial pushValue call of the value source. The type parameter specifies the type of the sourceValue and subscriberValue values. An IlvAccessible object can subscribe several times to another IlvAccessible object for different source values and/or subscriber values, but it may not subscribe several times to the same object and subscriber values. The mode argument specifies whether the subscriber wants to be notified of value changes (this is the default mode IlvValueSubscriptionChange), or if it wants to be notified of value queries (mode IlvValueSubscriptionQuery). In this last case, the source object notifies its subscribers of calls to pullValue instead of pushValue by calling queryValue instead of changeValue.

Parameters

subscriber	The object to be notified of accesses to sourceValue.
sourceValue	The name of the attribute to be observed by the subscription.
subscriberValue	The name of the attribute to be notified in the subscriber.
type	The expected value type to be pushed to the subscriber.
mode	The type of access to sourceValue to be reported to subscriber.

See Also

IlvValueSubscriptionMode

Reimplemented in IlvSubGroupNode, and IlvGroup.

virtual void IlvAccessible::unSubscribe ( IlvAccessible *  subscriber, IlSymbol *  sourceValue = 0, IlSymbol *  subscriberValue = 0  )

virtual

Cancels subscriptions previously made.

Cancels the subscription of the subscriber object to the specified sourceValue and subscriberValue. If sourceValue is 0, the subscriptions of subscriber to all source values are cancelled. If subscriberValue is 0, the subscriptions of subscriber for all subscriber values are removed. If both are 0, all subscriptions of subscriber to this source object are cancelled.

Parameters

subscriber	The object that is to be notified of accesses to sourceValue.
sourceValue	The name of the attribute to be observed by the subscription.
subscriberValue	The name of the attribute to be notified in the subscriber.

Reimplemented in IlvSubGroupNode, and IlvGroup.

static IlBoolean IlvAccessible::ValuesAreEqual ( IlvValue &  v1, IlvValue &  v2, IlBoolean  compareNames = IlTrue  )

static

Compares two values.

The actual comparison depends on the type of the values: scalar types are compared using their == operators, strings are compared using the strcmp function, and resource values (such as IlvColors) are compared using their pointers (that is, two distinct instances of IlvColor representing the same RGB values will still be considered as different).

Returns

IlTrue if the values are equal, and IlFalse if they differ.

Parameters

v1	First value.
v2	Second value.
compareNames	Specifies whether names should also be identical.