IlvActionHistory Class Reference

A repository of user actions. More...

#include <ilviews/base/action.h>

Inheritance diagram for IlvActionHistory:

Public Member Functions
	IlvActionHistory (IlUInt max=8)
	Constructor. More...
virtual	~IlvActionHistory ()
	Destructor.
virtual void	add (IlvAction *action)
	Adds an action or a command and executes it (if necessary). More...
void	addProperty (const IlSymbol *key, IlAny value)
	Adds a property. More...
virtual IlvAction *	canRepeat ()
	Specifies whether the last executed action can be repeated. More...
IlvAction *	getAction (IlUInt i) const
	Returns the i th action stored in the history. More...
IlvValueInterface *const *	getCurrentSelection (IlUInt &c)
	Simplifies access to the current selection in the attached document. More...
IlvAction *	getLast () const
	Shortcut method for getAction(0). More...
IlUInt	getLength () const
	Returns the number of actions stored in the history. More...
IlUInt	getMaxLength () const
	Returns the maximum number of commands that can be stored in the history. More...
IlAny	getProperty (const IlSymbol *key) const
	Gets a property value. More...
IlvActionSelectionHandler *	getSelectionHandler () const
	Returns the selection handler attached to this history. More...
IlBoolean	hasProperty (const IlSymbol *key) const
	Checks if a property exists. More...
virtual void	purge (IlUInt n=(IlUInt)-1)
	Purges the history of recorded actions or commands. More...
IlBoolean	recordValueChanges () const
	Indicates whether changes to objects should be recorded as commands. More...
IlBoolean	removeProperty (const IlSymbol *key)
	Removes a property. More...
virtual void	repeatLast ()
	Repeats the last action stored in the history. More...
IlBoolean	replaceProperty (const IlSymbol *key, IlAny value)
	Replaces a property. More...
virtual void	setMaxLength (IlUInt maxLength)
	Sets the maximum number of commands that can be stored in the history. More...
void	setRecordValueChanges (IlBoolean b)
	Enables or disables command recording when objects are modified. More...
void	setSelectionHandler (IlvActionSelectionHandler *handler)
	Attaches a selection handler to a history. More...
Public Member Functions inherited from IlvObservable
	IlvObservable ()
	Empty constructor. More...
virtual void	notify (IlAny arg=0)
	Notification method, to be called in methods that modify the state of the object whenever required. More...
Public Member Functions inherited from IlvSmartData
	IlvSmartData ()
	Constructor. More...
	IlvSmartData (const IlvSmartData &data)
	Copy constructor. More...
virtual	~IlvSmartData ()
	Destructor.
void	decrRef ()
	Decrements the reference counter of the object and deletes this object when the counter reaches 0. More...
void	incrRef ()
	Increments the reference counter.
int	refCount ()
	Returns the number of references to this object. More...

Detailed Description

A repository of user actions.

Library: views

The class IlvActionHistory defines a repository of user actions. It allows you to implement user feedback, smart repeat, and other advanced input features based on the analysis of the recorded user actions.

See Also

IlvAction, IlvCommand, IlvCommandHistory.

Constructor & Destructor Documentation

IlvActionHistory::IlvActionHistory

(

IlUInt

max = 8

)

Constructor.

Parameters

max	The maximum number of actions that can be recorded in the history.

Member Function Documentation

virtual void IlvActionHistory::add ( IlvAction *  action )

virtual

Adds an action or a command and executes it (if necessary).

If the total number of actions exceeds the maximum number of actions that can be stored in the history, the least recently executed actions are deleted with the delete operator. This means actions added to an action history must be dynamically allocated with the new operator for the action history to keep track of more than one action.

Parameters

action

The action to be added to the history.

Reimplemented in IlvCommandHistory.

void IlvActionHistory::addProperty	(	const IlSymbol *	key,
		IlAny	value
	)

Adds a property.

Parameters

key	The name of the property to be added.
value	The value of the property.

virtual IlvAction* IlvActionHistory::canRepeat ( )

virtual

Specifies whether the last executed action can be repeated.

Returns

The last executed action if it can be repeated, or 0 if it cannot.

IlvAction* IlvActionHistory::getAction

(

IlUInt

i

)

const

Returns the i ^th action stored in the history.

h.getAction(0) returns the last executed action. h.getAction(h.getLength()-1) returns the earliest executed action still stored in the history.

Parameters

i	The index of the action to be retrieved.

IlvValueInterface* const* IlvActionHistory::getCurrentSelection

(

IlUInt &

c

)

Simplifies access to the current selection in the attached document.

This method delegates its implementation to the attached IlvActionSelectionHandler object, if any.

IlvAction* IlvActionHistory::getLast

(

)

const

Shortcut method for getAction(0).

Returns

A pointer to the last action.

IlUInt IlvActionHistory::getLength

(

)

const

Returns the number of actions stored in the history.

Returns

The number of actions stored in the history.

IlUInt IlvActionHistory::getMaxLength

(

)

const

Returns the maximum number of commands that can be stored in the history.

Returns

The maximum length of the history stack.

IlAny IlvActionHistory::getProperty

(

const IlSymbol *

key

)

const

Gets a property value.

Parameters

key	The name of the property to be retrieved.

Returns

The value of this property or 0 if there is none.

IlvActionSelectionHandler* IlvActionHistory::getSelectionHandler

(

)

const

Returns the selection handler attached to this history.

Returns

The selection handler of this history.

IlBoolean IlvActionHistory::hasProperty

(

const IlSymbol *

key

)

const

Checks if a property exists.

Properties can be added to the history through commands or other objects, therefore allowing you to implement smart repeat features.

Parameters

key	The name of the property to be tested.

Returns

IlTrue if this property exists, and IlFalse if it does not.

virtual void IlvActionHistory::purge ( IlUInt  n = (IlUInt)-1 )

virtual

Purges the history of recorded actions or commands.

Parameters

n	The number of actions to be removed from the history.

IlBoolean IlvActionHistory::recordValueChanges

(

)

const

Indicates whether changes to objects should be recorded as commands.

Returns

IlTrue if changes on objects are recorder as commands and IlFalse otherwise.

IlBoolean IlvActionHistory::removeProperty

(

const IlSymbol *

key

)

Removes a property.

Parameters

key	The name of the property to be removed.

virtual void IlvActionHistory::repeatLast ( )

virtual

Repeats the last action stored in the history.

This is performed by duplicating the last action, executing it, and adding it to the history.

IlBoolean IlvActionHistory::replaceProperty	(	const IlSymbol *	key,
		IlAny	value
	)

Replaces a property.

Parameters

key	The name of the property to be replaced.
value	The new value of the property.

virtual void IlvActionHistory::setMaxLength ( IlUInt  maxLength )

virtual

Sets the maximum number of commands that can be stored in the history.

Parameters

maxLength

The maximum length of the history stack.

void IlvActionHistory::setRecordValueChanges

(

IlBoolean

b

)

Enables or disables command recording when objects are modified.

Parameters

b	When set to IlTrue (the default), calls to changeValue() should record changes in the attached history. Otherwise, they should consider that the recording has already been carried out and therefore should not record commands.

void IlvActionHistory::setSelectionHandler

(

IlvActionSelectionHandler *

handler

)

Attaches a selection handler to a history.

Parameters

handler

The selection handler to attach to this history. If this parameter is set to 0, the handler is detached.