Model::UndoCommand Class Reference

Inheritance diagram for Model::UndoCommand:

Public Member Functions
	UndoCommand (Node *target, const QString &text)
virtual	~UndoCommand ()
virtual Node *	insertedNode () const
	Returns the node that this command inserted into the tree, or nullptr if no node was inserted. More...
bool	isUndone () const
	Returns whether the command has been undone since it was applied. More...
virtual Node *	owned () const
	Returns the node owned by this command or nullptr if no node is owned. More...
virtual void	redo ()
virtual Node *	removedNode () const
	Returns the node that this command removed from the tree, or nullptr if no node was removed. More...
Node *	target () const
virtual void	undo ()

Private Attributes
Node *	target_
bool	undone

Constructor & Destructor Documentation

UndoCommand()

Model::UndoCommand::UndoCommand	(	Node *	target,
		const QString &	text
	)

~UndoCommand()

Model::UndoCommand::~UndoCommand ( )

virtual

Member Function Documentation

insertedNode()

Node * Model::UndoCommand::insertedNode ( ) const

virtual

Returns the node that this command inserted into the tree, or nullptr if no node was inserted.

The default implementaion returns nullptr. Reimplement this in commands that own a node.

Reimplemented in Model::NodeOwningCommand.

isUndone()

bool Model::UndoCommand::isUndone ( ) const

inline

Returns whether the command has been undone since it was applied.

If a command is undone after it was originally executed, this will return true. If a command which was undone is redone this will return false.

This is used for memory management. If a command is destroyed (leaves the undo stack) it may need to delete objects associated with it. A command can leave the stack for two reasons:

• It is at the bottom of the stack and the stack is full. Therefore this command needs to be deleted to free up space for new commands. In this case isUndone will return false.
• The command has been undone and a new command has been pushed on top of the stack. In this case the current command is deleted and isUndone is true.

owned()

Node * Model::UndoCommand::owned ( ) const

virtual

Returns the node owned by this command or nullptr if no node is owned.

Nodes which are owned should be deleted by the command when it is deleted.

Reimplemented in Model::NodeOwningCommand.

redo()

void Model::UndoCommand::redo ( )

virtual

Reimplemented in Model::NodeOwningCommand, Model::SetModificationTarget, Model::NoteNodeChange, Model::NameChange, Model::ListRemove, Model::ListPut, Model::ListInsert, Model::FieldSet< T >, Model::FieldSet< QString >, and Model::CompositeNodeChangeChild.

removedNode()

Node * Model::UndoCommand::removedNode ( ) const

virtual

Returns the node that this command removed from the tree, or nullptr if no node was removed.

The default implementaion returns nullptr. Reimplement this in commands that own a node.

Reimplemented in Model::NodeOwningCommand.

target()

Node * Model::UndoCommand::target ( ) const

inline

undo()

void Model::UndoCommand::undo ( )

virtual

Reimplemented in Model::NodeOwningCommand, Model::SetModificationTarget, Model::NoteNodeChange, Model::NameChange, Model::ListRemove, Model::ListPut, Model::ListInsert, Model::FieldSet< T >, Model::FieldSet< QString >, and Model::CompositeNodeChangeChild.

Member Data Documentation

target_

Node* Model::UndoCommand::target_

private

undone

bool Model::UndoCommand::undone

private