Undo Class Reference

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

Inheritance diagram for Undo:

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

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

Protected Member Functions
int	indexOf (int eventid) const
void	removeOldEvents ()
void	removeStartToAndIncluding (int)

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

Additional Inherited Members
Static Public Member Functions inherited from CallBacker
static void	createReceiverForCurrentThread ()
static void	removeReceiverForCurrentThread ()

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::Undo

(

)

~Undo()

virtual Undo::~Undo ( )

virtual

Member Function Documentation

addEvent()

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

Parameters

event	The new event (becomes mine).
description

Returns

the event id.

canReDo()

bool Undo::canReDo

(

)

const

canUnDo()

bool Undo::canUnDo

(

)

const

Note

takes redodesc with userinteraction

currentEventID()

int Undo::currentEventID

(

)

const

firstEventID()

int Undo::firstEventID

(

)

const

getDesc()

BufferString Undo::getDesc

(

int

eventid

)

const

getNextUserInteractionEnd()

int Undo::getNextUserInteractionEnd

(

int

start

)

const

indexOf()

int Undo::indexOf ( int  eventid ) const

protected

isUserInteractionEnd()

bool Undo::isUserInteractionEnd

(

int

eventid

)

const

lastEventID()

int Undo::lastEventID

(

)

const

maxLength()

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.

reDo()

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

reDoDesc()

BufferString Undo::reDoDesc

(

)

const

removeAll()

void Undo::removeAll

(

)

removeAllAfterCurrentEvent()

void Undo::removeAllAfterCurrentEvent

(

)

removeAllBeforeCurrentEvent()

void Undo::removeAllBeforeCurrentEvent

(

)

removeOldEvents()

void Undo::removeOldEvents ( )

protected

removeStartToAndIncluding()

void Undo::removeStartToAndIncluding ( int  )

protected

setDesc()

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

setMaxLength()

void Undo::setMaxLength

(

int

)

setUserInteractionEnd()

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

unDo()

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

unDoDesc()

BufferString Undo::unDoDesc

(

)

const

Member Data Documentation

addlock_

Threads::Lock Undo::addlock_

protected

changenotifier

Notifier<Undo> Undo::changenotifier

currenteventid_

int Undo::currenteventid_

protected

events_

ObjectSet<UndoEvent> Undo::events_

protected

firsteventid_

int Undo::firsteventid_

protected

maxsize_

int Undo::maxsize_

protected

undoredochange

Notifier<Undo> Undo::undoredochange

userendscount_

int Undo::userendscount_

protected