Mediator between a 'Business Graphic Object' and its corresponding object in the application. More...

#include <ilviews/protos/grouplin.h>

Inheritance diagram for IlvGroupMediator:

Public Member Functions
	IlvGroupMediator (IlvGroup *presentation, IlAny object=0)
	Links an object of the application domain with its representation. More...

IlBoolean	changeValue (const IlvValue &val)
	Changes the object's value. Both the name and the new value are contained in val. More...

IlBoolean	changeValues (const IlvValue *values, IlUShort count)
	Updates the object when the user has changed the presentation. More...

void	getAccessors (const IlSymbol const , const IlvValueTypeClass const **, IlUInt &) const
	Returns the names of all the accessors known by this object. More...

const char *	getName () const
	Returns the object name. More...

IlAny	getObject () const
	Returns the object linked to the current presentation. More...

IlvGroup *	getPresentation () const
	Returns the presentation currently linked to the object. More...

void	lock ()
	Locks the mediator. More...

IlBoolean	locked ()
	Guard against update loops that could occur if the representation attribute does not match the attribute of the object it represents. More...

IlvValue &	queryValue (IlvValue &val) const
	Queries the value designated by value from the object. Both the value and the value type are stored in value. More...

void	queryValues (IlvValue *values, IlUShort count) const
	Updates the presentation from the object values. More...

virtual void	setObject (IlAny arg, IlBoolean refresh=IlTrue)
	Sets the object to link to the presentation. More...

virtual void	setPresentation (IlvGroup *group, IlBoolean refresh=IlTrue)
	Sets the presentation that will allow the user to edit the object. More...

void	unlock ()
	Releases the lock. More...

virtual void	update (const IlSymbol const symbs=0, IlUInt count=0)
	Synchronizes the presentation with the object values. More...

Public Member Functions inherited from IlvAccessible
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...

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 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...

Additional Inherited Members
Static Public Member Functions inherited from IlvAccessible
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

Mediator between a 'Business Graphic Object' and its corresponding object in the application.

Library: ilvproto
The IlvGroupMediator class allows you to link an application object to its corresponding presentation in a graphical user interface (GUI). The presentation is implemented as an IlvGroup. This class reads the values exported from the group and keeps synchronized its object and the group implementing its user interface. Synchronization is used to refer to the following:

When, through accessors interpreting the user actions, one of the public attributes of the group is changed, the IlvGroupMediator is notified and updates the object to reflect the changes by calling the changeValues() method.
When the object changes and these changes need to be propagated to the presentation so that the user can see the changes, the IlvGroupMediator will call its queryValues() method, which updates the values with data corresponding to the internal state of the object.
Finally, whenever attributes change in the object, the application calls the update() method to ensure that the presentation reflects these changes.

See the samples in the Views directory: samples/protos/inspector

See also: IlvGroup

Constructor & Destructor Documentation

§ IlvGroupMediator()

IlvGroupMediator::IlvGroupMediator	(	IlvGroup *	presentation,
		IlAny	object = `0`
	)

Links an object of the application domain with its representation.

Creates an instance of IlvGroupMediator by linking its presentation with its object. presentation implements the presentation under the form of an IlvGroup while object is an object of the application domain.

Parameters

presentation	A group that implements the visual appearance of an object. This group will usually require attributes that match the attributes of its attached object.
object	Any reference to an applicative object that must be presented to the user.
object	A reference to any kind of object of the application represented by the presentation.

Member Function Documentation

§ changeValue()

IlBoolean IlvGroupMediator::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 from IlvAccessible.

§ changeValues()

IlBoolean IlvGroupMediator::changeValues	(	const IlvValue *	values,
		IlUShort	count
	)

virtual

Updates the object when the user has changed the presentation.

This method must be overloaded. The implementation should read the values changed, update the internal state of the object to reflect these new values, and propagate these changes to other potential observers of the object. This method should start with if(locked()) return IlTrue; to avoid possible feedback loops between the object and its representation. You may also want to use the lock() method to lock the IlvGroupMediator class before propagating the changes, and then use the unlock() method when you have finished (to avoid unnecessary updates of the presentation).

Parameters

values	Values that have changed in the `IlvGroup` and should be reflected in the application object.
count	Number of values.

Returns: IlTrue if the change was successful.

Reimplemented from IlvAccessible.

§ getAccessors()

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

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.

Implements IlvAccessible.

§ getName()

const char* IlvGroupMediator::getName ( ) const

virtual

Returns the object name.

Returns: The object name. This pointer must not be freed.

Implements IlvAccessible.

§ getObject()

IlAny IlvGroupMediator::getObject ( ) const

Returns the object linked to the current presentation.

Returns: The object linked to the current presentation.

See also: setObject().

§ getPresentation()

IlvGroup* IlvGroupMediator::getPresentation ( ) const

Returns the presentation currently linked to the object.

Returns: The presentation currently linked to the object.

§ lock()

void IlvGroupMediator::lock ( )

Locks the mediator.

Locks the IlvGroupMediator so that further changes will not be propagated to the object. This avoids infinite update loops between the object and its representation.

§ locked()

IlBoolean IlvGroupMediator::locked ( )

Guard against update loops that could occur if the representation attribute does not match the attribute of the object it represents.

Returns: IlTrue if the lock on the object has been set. This implies that changes are not propagated to the object or the group.

§ queryValue()

IlvValue& IlvGroupMediator::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 from IlvAccessible.

§ queryValues()

void IlvGroupMediator::queryValues	(	IlvValue *	values,
		IlUShort	count
	)		const

virtual

Updates the presentation from the object values.

This method must be overloaded. The implementation should fill the values array with values representing the internal state of the object.

Parameters

values	Values to be changed in the `IlvGroup`.
count	Number of values.

Reimplemented from IlvAccessible.

§ setObject()

virtual void IlvGroupMediator::setObject	(	IlAny	arg,
		IlBoolean	refresh = `IlTrue`
	)

virtual

Sets the object to link to the presentation.

Parameters

arg	The object that is linked to the presentation.
refresh	Can be set to `IlFalse` if you don't want an immediate refresh.

§ setPresentation()

virtual void IlvGroupMediator::setPresentation	(	IlvGroup *	group,
		IlBoolean	refresh = `IlTrue`
	)

virtual

Sets the presentation that will allow the user to edit the object.

Parameters

group	The presentation that is linked to this object.
refresh	Can be set to `IlFalse` if you don't want an immediate refresh.

Reimplemented in IlvProtoMediator.

§ unlock()

void IlvGroupMediator::unlock ( )

Releases the lock.

Releases the lock on the object, allowing further changes to be propagated.

§ update()

virtual void IlvGroupMediator::update	(	const IlSymbol const	symbs = `0`,
		IlUInt	count = `0`
	)

virtual

Synchronizes the presentation with the object values.

Use this method whenever the object is changed from the application and the presentation is to be updated to reflect these changes. The optional list of symbols indicates what attributes have changed. It can be used to minimize refreshes of the representation.

Parameters

symbs	Array of attribute names that should be queried from the object and changed in the group serving as presentation. If symbs is `0`, all attributes that are notifying in the `IlvGroup` are queried from the object and changed in the presentation.
count	Size of the symbs array.

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

§ IlvGroupMediator()

Member Function Documentation

§ changeValue()

§ changeValues()

§ getAccessors()

§ getName()

§ getObject()

§ getPresentation()

§ lock()

§ locked()

§ queryValue()

§ queryValues()

§ setObject()

§ setPresentation()

§ unlock()

§ update()