Undo Class Reference

Class to handle undo/redo information. More...

Inheritance diagram for Undo:

Public Member Functions
	Undo ()
virtual	~Undo ()
void	removeAll ()
int	maxLength () const
void	setMaxLength (int)
int	addEvent (UndoEvent *event, const char *description=0)
int	currentEventID () const
int	firstEventID () const
int	lastEventID () const
void	removeAllAfterCurrentEvent ()
void	removeAllBeforeCurrentEvent ()
bool	isUserInteractionEnd (int eventid) const
void	setUserInteractionEnd (int eventid, bool=true)
int	getNextUserInteractionEnd (int start) const
BufferString	getDesc (int eventid) const
void	setDesc (int eventid, const char *d)
BufferString	unDoDesc () const
BufferString	reDoDesc () const
bool	canUnDo () const
bool	unDo (int nrtimes=1, bool userinteraction=true)
bool	canReDo () const
bool	reDo (int nrtimes=1, bool userinteraction=true)
Public Member Functions inherited from CallBacker
	CallBacker ()
	CallBacker (const CallBacker &)
virtual	~CallBacker ()
bool	attachCB (NotifierAccess &, const CallBack &, bool onlyifnew=false)
bool	attachCB (NotifierAccess *notif, const CallBack &cb, bool onlyifnew=false)
void	detachCB (NotifierAccess &, const CallBack &)
void	detachCB (NotifierAccess *notif, const CallBack &cb)
bool	isNotifierAttached (NotifierAccess *) const
	Only for debugging purposes, don't use. More...

Public Attributes
Notifier< Undo >	changenotifier
Notifier< Undo >	undoredochange

Protected Member Functions
int	indexOf (int eventid) const
void	removeOldEvents ()
void	removeStartToAndIncluding (int)
Protected Member Functions inherited from CallBacker
void	detachAllNotifiers ()
	Call from the destructor of your inherited object. More...

Protected Attributes
int	currenteventid_
int	firsteventid_
int	maxsize_
ObjectSet< UndoEvent >	events_
int	userendscount_
Threads::Lock	addlock_

Detailed Description

Class to handle undo/redo information.

Events that can be undone/redone are added to the Undo. One user operation may involve thousands of changes added to the history, but the user does not want to press undo a thousand times.This is managed by setting a UserInteractionEnd flag on the last event in a chain that the user started. When doing undo, one undo step is consists of all events from the current event until the next event with the UserInteraction flag set.

This means that after all user-driven events, the UserInteractionEnd should be set:

void MyClass::userPushedAButtonCB( CallBacker* )
{
    doSomethingsThatAddThingsOnTheHistory();
    history.setUserInteractionEnd( currentEventID() );
}

Constructor & Destructor Documentation

Undo::Undo

(

)

virtual Undo::~Undo ( )

virtual

Member Function Documentation

int Undo::addEvent	(	UndoEvent *	event,
		const char *	description = 0
	)

Parameters

event

The new event (becomes mine).

Returns

the event id.

bool Undo::canReDo

(

)

const

bool Undo::canUnDo

(

)

const

Note

takes redodesc with userinteraction

int Undo::currentEventID

(

)

const

int Undo::firstEventID

(

)

const

BufferString Undo::getDesc

(

int

eventid

)

const

int Undo::getNextUserInteractionEnd

(

int

start

)

const

int Undo::indexOf ( int  eventid ) const

protected

bool Undo::isUserInteractionEnd

(

int

eventid

)

const

int Undo::lastEventID

(

)

const

int Undo::maxLength

(

)

const

Returns maximum number of userevents.

Note

The actual number of events may be considerably higher since many events may be part of one single user event.

bool Undo::reDo	(	int	nrtimes = 1,
		bool	userinteraction = true
	)

BufferString Undo::reDoDesc

(

)

const

void Undo::removeAll

(

)

void Undo::removeAllAfterCurrentEvent

(

)

void Undo::removeAllBeforeCurrentEvent

(

)

void Undo::removeOldEvents ( )

protected

void Undo::removeStartToAndIncluding ( int  )

protected

void Undo::setDesc	(	int	eventid,
		const char *	d
	)

void Undo::setMaxLength

(

int

)

void Undo::setUserInteractionEnd	(	int	eventid,
		bool	= true
	)

bool Undo::unDo	(	int	nrtimes = 1,
		bool	userinteraction = true
	)

BufferString Undo::unDoDesc

(

)

const

Member Data Documentation

Threads::Lock Undo::addlock_

protected

Notifier<Undo> Undo::changenotifier

int Undo::currenteventid_

protected

ObjectSet<UndoEvent> Undo::events_

protected

int Undo::firsteventid_

protected

int Undo::maxsize_

protected

Notifier<Undo> Undo::undoredochange

int Undo::userendscount_

protected