TSE3::Cmd::CommandHistory Class Reference

History of which Command objects have been executed. More...

#include <CommandHistory.h>

Inheritance diagram for TSE3::Cmd::CommandHistory:

[legend]Collaboration diagram for TSE3::Cmd::CommandHistory:

[legend]List of all members.

Public Member Functions
	CommandHistory (int limit=defaultLimit)
void	add (Command *command)
bool	undos () const
void	undo ()
Command *	undoCommand (size_t pos)
bool	redos () const
void	redo ()
Command *	redoCommand (size_t pos)
int	limit () const
void	setLimit (int limit)
void	clear ()
void	clearUndos ()
void	clearRedos ()
Static Public Attributes
const int	defaultLimit = 20

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Detailed Description

History of which Command objects have been executed.

The history of which Command objects have been executed. Once a Command has been executed, it should be placed into the CommandHistory so that an undo/redo mechanism can be operated by the user.

In the TSE3 system there could be be one CommandHistroy object per TSE3::Song or one global CommandHistory.

When the availablity of either undos or redos changes, a notification is sent.

The CommandHistory class has a size limit facility. When either the undo or redo list goes over a certain threshold (see limit) will be deleted. This can be set to 'infinite'.

Author:

Pete Goodliffe

Version:

3.00

See also:

Command

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Constructor & Destructor Documentation

TSE3::Cmd::CommandHistory::CommandHistory (  int  limit = defaultLimit  )

Create a CommandHistory with the given limit size. This limit defaults to the value of defaultLimit. Parameters: limit  CommandHistory size limit

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Member Function Documentation

void TSE3::Cmd::CommandHistory::add (  Command *  command  )

Adds a Command to the CommandHistory. The Command must have been executed. Placing it in the CommandHistory ties it's lifetime to that of the CommandHistory object. Adding a Command will wipe any redos that may have been possible. Parameters: command  New Command to add

bool TSE3::Cmd::CommandHistory::undos (   )  const

Returns whether there are any Command objects that can be undone. When this information changes a notification will be sent. Returns: True if there are any undos

void TSE3::Cmd::CommandHistory::undo (   )

Undoes the last Command, and places it on the redo list.

Command* TSE3::Cmd::CommandHistory::undoCommand (  size_t  pos  )

Returns the command places down in the undo history. For example, undoCommand(0) returns the next Command to be undone. If there is no command to be undone at this pos then returns zero. Parameters: pos  Index into undo history Returns: Command at this position

bool TSE3::Cmd::CommandHistory::redos (   )  const

Returns whether there are any Command objects that can be redone. When this information changes a notification will be sent. Returns: True if there are any redos

void TSE3::Cmd::CommandHistory::redo (   )

Redoes the last undone Command.

Command* TSE3::Cmd::CommandHistory::redoCommand (  size_t  pos  )

Returns the command places down in the redo history. For example, redoCommand(0) returns the next Command to be redone. If there is no command to be redone at this pos then returns zero. Parameters: pos  Index into redo history Returns: Command at this position

int TSE3::Cmd::CommandHistory::limit (   )  const

Returns the value of the history size limit. This is the number of Command objects that are stored. If the value is -1 then the number of undos is unlimited. Clearly, if the value is 0 then undo is effectively 'off'. Returns: CommandHistory size limit

void TSE3::Cmd::CommandHistory::setLimit (  int  limit  )

Sets the CommandHistory limit value. If there are more Command objects than the new limit currently in the CommandHistory, they will be removed. Parameters: limit  New CommandHistory size limit

void TSE3::Cmd::CommandHistory::clear (   )  [inline]

Clears all undo and redo actions in the CommandHistory. See also: clearUndos clearRedos

void TSE3::Cmd::CommandHistory::clearUndos (   )

Clears all undo actions in the CommandHistory. See also: clear clearRedos

void TSE3::Cmd::CommandHistory::clearRedos (   )

Clears all redo actions in the CommandHistory. See also: clear clearUndos

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Member Data Documentation

const int TSE3::Cmd::CommandHistory::defaultLimit = 20 [static]

The default CommandHistory limit size.

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

• /home/pete/Work/TSE3.svn/tse3/src/tse3/cmd/CommandHistory.h

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