pycross.utils.undo.CommandManager Class Reference

Stack-like Undo / Redo history manager: lets the app manage undoable actions. More...

Public Member Functions
def	__init__ (self, histsize=1e4, cyclic=True, on_update=None, on_pop_undo=None, on_push_undo=None, on_pop_redo=None, on_push_redo=None)
	Constructor. More...
def	canundo (self)
	Checks if there are undoable operations in the Undo stack. More...
def	canredo (self)
	Checks if there are redoable operations in the Redo stack. More...
def	undoable (self, pos=-1)
	Returns an operation from the Undo stack. More...
def	redoable (self, pos=-1)
	Returns an operation from the Redo stack. More...
def	do (self, command)
	Executes the given command, adding it to the Undo stack so it can be undone later. More...
def	undo (self, n=1)
	Undoes a given number of operations stored in the Undo stack. More...
def	redo (self, n=1)
	Redoes a given number of operations stored in the Redo stack. More...

Public Attributes
	histsize
	int Undo / Redo history size More...
	cyclic
	bool if True (default) the Undo / Redo stack will automatically remove the oldest operation when the threshold size is reached More...
	on_update
	callable callback fired when the Undo or Redo stack is updated More...
	on_pop_undo
	callable callback fired when an operation is removed from the Undo stack More...
	on_push_undo
	callable callback fired when an operation is added to the Undo stack More...
	on_pop_redo
	callable callback fired when an operation is removed from the Redo stack More...
	on_push_redo
	callable callback fired when an operation is added to the Redo stack More...

Private Member Functions
def	_push_undo_command (self, command)
	Stores (appends) a new command in the Undo stack. More...
def	_pop_undo_command (self)
	Removes the latest operation from the Undo stack and returns it. More...
def	_push_redo_command (self, command)
	Stores (appends) a command in the Redo stack. More...
def	_pop_redo_command (self)
	Removes the latest operation from the Redo stack and returns it. More...

Private Attributes
	_undo_commands
	list Undo stack More...
	_redo_commands
	list Redo stack More...

Detailed Description

Stack-like Undo / Redo history manager: lets the app manage undoable actions.

Constructor & Destructor Documentation

__init__()

def pycross.utils.undo.CommandManager.__init__	(		self,
			histsize = 1e4,
			cyclic = True,
			on_update = None,
			on_pop_undo = None,
			on_push_undo = None,
			on_pop_redo = None,
			on_push_redo = None
	)

Constructor.

Parameters

histsize	int Undo / Redo history size (max number of operations stored in each stack); default is 10k
cyclic	bool if True (default) the Undo / Redo stack will automatically remove the oldest operation when the threshold size is reached; if False, the HistoryOverflowError excetion will be raised.
on_update	callable callback fired when the Undo or Redo stack is updated
on_pop_undo	callable callback fired when an operation is removed from the Undo stack
on_push_undo	callable callback fired when an operation is added to the Undo stack
on_pop_redo	callable callback fired when an operation is removed from the Redo stack
on_push_redo	callable callback fired when an operation is added to the Redo stack

Member Function Documentation

_pop_redo_command()

def pycross.utils.undo.CommandManager._pop_redo_command (   self )

private

Removes the latest operation from the Redo stack and returns it.

Returns

Operation the removed command

_pop_undo_command()

def pycross.utils.undo.CommandManager._pop_undo_command (   self )

private

Removes the latest operation from the Undo stack and returns it.

Returns

Operation the removed command

_push_redo_command()

def pycross.utils.undo.CommandManager._push_redo_command (   self,   command  )

private

Stores (appends) a command in the Redo stack.

The Redo stack adds operations removed from the Undo stack (so they can be redone later). If the max stack size is reached, the history will remove the oldest operation if CommandManager::cyclic is True or raise the HistoryOverflowError error.

Parameters

command

Operation the command to store

_push_undo_command()

def pycross.utils.undo.CommandManager._push_undo_command (   self,   command  )

private

Stores (appends) a new command in the Undo stack.

If the max stack size is reached, the history will remove the oldest operation if CommandManager::cyclic is True or raise the HistoryOverflowError error.

Parameters

command

Operation the new command to store

canredo()

def pycross.utils.undo.CommandManager.canredo

(

self

)

Checks if there are redoable operations in the Redo stack.

Returns

bool whether there are redoable operations in the Redo stack

See also

CommandManager::canundo()

canundo()

def pycross.utils.undo.CommandManager.canundo

(

self

)

Checks if there are undoable operations in the Undo stack.

Returns

bool whether there are undoable operations in the Undo stack

See also

CommandManager::canredo()

do()

def pycross.utils.undo.CommandManager.do	(		self,
			command
	)

Executes the given command, adding it to the Undo stack so it can be undone later.

Parameters

command

Operation the command to execute

redo()

def pycross.utils.undo.CommandManager.redo	(		self,
			n = 1
	)

Redoes a given number of operations stored in the Redo stack.

Parameters

n	int number of operations to redo (rewinding the stack)

Returns

bool True on success, False on failure to redo

redoable()

def pycross.utils.undo.CommandManager.redoable	(		self,
			pos = -1
	)

Returns an operation from the Redo stack.

Parameters

pos	int index of the operation

Returns

Command redoable operation

undo()

def pycross.utils.undo.CommandManager.undo	(		self,
			n = 1
	)

Undoes a given number of operations stored in the Undo stack.

Parameters

n	int number of operations to undo (rewinding the stack)

Returns

bool True on success, False on failure to undo

undoable()

def pycross.utils.undo.CommandManager.undoable	(		self,
			pos = -1
	)

Returns an operation from the Undo stack.

Parameters

pos	int index of the operation

Returns

Command undoable operation

Member Data Documentation

_redo_commands

pycross.utils.undo.CommandManager._redo_commands

private

list Redo stack

_undo_commands

pycross.utils.undo.CommandManager._undo_commands

private

list Undo stack

cyclic

pycross.utils.undo.CommandManager.cyclic

bool if True (default) the Undo / Redo stack will automatically remove the oldest operation when the threshold size is reached

histsize

pycross.utils.undo.CommandManager.histsize

int Undo / Redo history size

on_pop_redo

pycross.utils.undo.CommandManager.on_pop_redo

callable callback fired when an operation is removed from the Redo stack

on_pop_undo

pycross.utils.undo.CommandManager.on_pop_undo

callable callback fired when an operation is removed from the Undo stack

on_push_redo

pycross.utils.undo.CommandManager.on_push_redo

callable callback fired when an operation is added to the Redo stack

on_push_undo

pycross.utils.undo.CommandManager.on_push_undo

callable callback fired when an operation is added to the Undo stack

on_update

pycross.utils.undo.CommandManager.on_update

callable callback fired when the Undo or Redo stack is updated

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

• pycross/utils/undo.py