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ACT_ActionStack Class Reference

A stack with actions that implements undo/redo capabilities. More...

#include <ACT_ActionStack.h>

List of all members.

Public Methods
	ACT_ActionStack (unsigned int maxStackDepth=1)
	Constructs an action stack. More...
	~ACT_ActionStack ()
	Destructs an action stack.
virtual unsigned int	getStackDepth ()const
	Returns the current depth of the stack. More...
virtual unsigned int	getMaxStackDepth ()const
	Returns the current maximum depth of the stack. More...
virtual void	setMaxStackDepth (unsigned int maxStackDepth)
	Sets new maximum depth of the stack. More...
virtual void	push (ACT_Action &action)
	Pushes an action on the stack. More...
virtual ACT_Action*	peekUndo ()
	Returns pointer to the current undo item. More...
virtual ACT_Action*	peekRedo ()
	Returns pointer to the current redo item. More...
virtual void	flush ()
	Flushes the action stack. More...
virtual bool	canUndo ()const
	Returns whether we can undo the current action. More...
virtual void	undo ()
	Undos the current action. More...
virtual bool	canRedo ()const
	Returns whether we can redo the current action. More...
virtual void	redo ()
	Redos the current action. More...
Protected Methods
virtual unsigned int	popBack (unsigned int numActions=1)
	Removes numItem actions from the back of the stack. More...
virtual unsigned int	popFront (unsigned int numActions=1)
	Removes numItem actions from the front of the stack. More...
virtual bool	getUndoIndex (unsigned int &index)const
	Returns the index of the current undo action. More...
virtual bool	getRedoIndex (unsigned int &index)const
	Returns the index of the current redo action. More...
Protected Attributes
unsigned int	m_maxStackDepth
	The maximum depth of this stack.
unsigned int	m_undoIndex
	The index of the current undo action in the stack.
bool	m_undoIndexValid
	Is the index of the current undo action in the stack valid.
unsigned int	m_redoIndex
	The index of the current redo action in the stack.
bool	m_redoIndexValid
	Is the index of the current redo action in the stack valid.
deque<ACT_Action*>	m_stack
	The stack with actions.

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Detailed Description

A stack with actions that implements undo/redo capabilities.

A stack can grow to a maximum number of actions by pushing actions on the stack. By calling undo and redo the apply and undo members of the actions on the stack are called. In addition, this will move the stackIndex up and down the stack. When a new action is pushed onto the stack, the actions above the current action are removed from the stack. Actions pushed onto the stack are applied if they are not applied already.

Todo:

implement error handling (e.g. memory errors)

Author(s):

Maarten Gribnau

Date:

March 31, 2001

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Constructor & Destructor Documentation

ACT_ActionStack::ACT_ActionStack ( unsigned int maxStackDepth = 1 )

Constructs an action stack. Author(s): Maarten Gribnau Date: March 31, 2001 Version: Id:

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Member Function Documentation

bool ACT_ActionStack::canRedo ( ) const [virtual]

Returns whether we can redo the current action. Returns: Indication of the possibility to redo.

bool ACT_ActionStack::canUndo ( ) const [virtual]

Returns whether we can undo the current action. Returns: Indication of the possibility to undo.

void ACT_ActionStack::flush ( ) [virtual]

Flushes the action stack. All actions are removed from the stack and their reference counts decreased.

unsigned int ACT_ActionStack::getMaxStackDepth ( ) const [virtual]

Returns the current maximum depth of the stack. Returns: the maximum stack depth.

bool ACT_ActionStack::getRedoIndex ( unsigned int & index ) const [protected, virtual]

Returns the index of the current redo action. Parameters: index   The index of the action. Returns: Indication as to whether the index is valid (==true).

unsigned int ACT_ActionStack::getStackDepth ( ) const [virtual]

Returns the current depth of the stack. Returns: the current stack depth.

bool ACT_ActionStack::getUndoIndex ( unsigned int & index ) const [protected, virtual]

Returns the index of the current undo action. Parameters: index   The index of the action. Returns: Indication as to whether the index is valid (==true).

ACT_Action * ACT_ActionStack::peekRedo ( ) [virtual]

Returns pointer to the current redo item. Returns: The action scheduled for redo (0 if there is none).

ACT_Action * ACT_ActionStack::peekUndo ( ) [virtual]

Returns pointer to the current undo item. Returns: The action scheduled for undo (0 if there is none).

unsigned int ACT_ActionStack::popBack ( unsigned int numActions = 1 ) [protected, virtual]

Removes numItem actions from the back of the stack. Parameters: numActions   number of items to remove. Returns: the number of actions removed.

unsigned int ACT_ActionStack::popFront ( unsigned int numActions = 1 ) [protected, virtual]

Removes numItem actions from the front of the stack. Parameters: numActions   number of items to remove. Returns: the number of actions removed.

void ACT_ActionStack::push ( ACT_Action & action ) [virtual]

Pushes an action on the stack. If the action has not been applied yet, it will be applied here. This will increase the reference count of the action. If there is not enough capacity, the action at the bottom of the stack is removed (and its reference count decreased). Parameters: action   the action that is pushed onto the stack.

void ACT_ActionStack::redo ( ) [virtual]

Redos the current action. This will move the action index up (if the stack depth allows it).

void ACT_ActionStack::setMaxStackDepth ( unsigned int maxStackDepth ) [virtual]

Sets new maximum depth of the stack. Parameters: maxStackDepth   The new stack depth.

void ACT_ActionStack::undo ( ) [virtual]

Undos the current action. This will move the current undo index down (if the stack depth allows it).

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The documentation for this class was generated from the following files:

• ACT_ActionStack.h
• ACT_ActionStack.cpp

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