com.yworks.yfiles.graph

Class CompositeUndoUnit

java.lang.Object

com.yworks.yfiles.graph.CompositeUndoUnit

All Implemented Interfaces:

IUndoUnit, IDisposable, AutoCloseable

public class CompositeUndoUnit
extends Object
implements IUndoUnit

A group of IUndoUnits that are undone/redone as a single unit.

Clients can use this class to build an IUndoUnit that groups together multiple IUndoUnits. The IUndoUnits added to this unit are undone/redone in the order in which they were added. This implementation will try to merge or replace units that are added.

Constructor Summary

Constructors

Constructor and Description
CompositeUndoUnit() Creates a new instance with null names.
CompositeUndoUnit(String undoName, String redoName) Creates a new instance using the provided names.

Method Summary

Modifier and Type	Method and Description
void	add(IUndoUnit unit) Adds a new IUndoUnit to the queue.
boolean	canRedo() Determines whether a call to redo() can be made.
boolean	canUndo() Determines whether a call to undo() can be made.
void	clear() Clears the internal collection of units.
void	dispose() Disposes this unit and all of its contents.
String	getRedoName() Returns the current redo name.
String	getUndoName() Returns the current redo name.
boolean	isDisposed() Determines whether this instance has been disposed..
void	redo() Redoes the next IUndoUnit.
boolean	removeUnit(IUndoUnit unit) Tries to remove a given unit from this compound unit.
void	setRedoName(String value) Returns the current redo name.
void	setUndoName(String value) Returns the current redo name.
int	size() Yields the number of units that are contained in this compound unit.
String	toString()
boolean	tryMergeUnit(IUndoUnit unit) Implements the IUndoUnit interface.
boolean	tryReplaceUnit(IUndoUnit unit) Implements the IUndoUnit interface.
void	undo() Undoes the next IUndoUnit.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.yworks.yfiles.utils.IDisposable

close

Constructor Detail

CompositeUndoUnit

public CompositeUndoUnit()

Creates a new instance with null names.

CompositeUndoUnit

public CompositeUndoUnit(String undoName,
                         String redoName)

Creates a new instance using the provided names.

Method Detail

add

public void add(IUndoUnit unit)

Adds a new IUndoUnit to the queue.

Parameters:

unit - The unit of work to add.

canRedo

public boolean canRedo()

Determines whether a call to redo() can be made.

canUndo

public boolean canUndo()

Determines whether a call to undo() can be made.

clear

public void clear()

Clears the internal collection of units.

dispose

public final void dispose()

Disposes this unit and all of its contents.

This unit cannot be used anymore after this has been invoked.

Specified by:

dispose in interface IDisposable

getRedoName

public final String getRedoName()

Returns the current redo name.

Specified by:

getRedoName in interface IUndoUnit

Returns:

The RedoName.

See Also:

setRedoName(String)

getUndoName

public final String getUndoName()

Returns the current redo name.

Specified by:

getUndoName in interface IUndoUnit

Returns:

The UndoName.

See Also:

setUndoName(String)

isDisposed

public final boolean isDisposed()

Determines whether this instance has been disposed..

An instance that has been disposed cannot be undone or redone.

Returns:

The Disposed.

redo

public void redo()

Redoes the next IUndoUnit.

Specified by:

redo in interface IUndoUnit

Throws:

UnsupportedOperationException - If an undo operation is already in progress.

RuntimeException - If canRedo() would yield false.

See Also:

IUndoUnit.getRedoName()

removeUnit

public boolean removeUnit(IUndoUnit unit)

Tries to remove a given unit from this compound unit.

This method will throw an exception if this unit has been undone or an undo or redo is in progress or this unit has already been disposed. This method will not automatically Dispose removed units.

Parameters:

unit - The unit to remove.

Returns:

true iff the unit has been removed from this instance.

setRedoName

public final void setRedoName(String value)

Returns the current redo name.

Parameters:

value - The RedoName to set.

See Also:

getRedoName()

setUndoName

public final void setUndoName(String value)

Returns the current redo name.

Parameters:

value - The UndoName to set.

See Also:

getUndoName()

size

public final int size()

Yields the number of units that are contained in this compound unit.

Returns:

The Count.

toString

public String toString()

Overrides:

toString in class Object

tryMergeUnit

public final boolean tryMergeUnit(IUndoUnit unit)

Implements the IUndoUnit interface.

This implementation will always yield false.

Specified by:

tryMergeUnit in interface IUndoUnit

Parameters:

unit - The unit to incorporate that happened after this unit.

Returns:

Whether the state change of unit has been incorporated into this unit and unit can be disposed of.

tryReplaceUnit

public final boolean tryReplaceUnit(IUndoUnit unit)

Implements the IUndoUnit interface.

This implementation will always yield false.

Specified by:

tryReplaceUnit in interface IUndoUnit

Parameters:

unit - The unit to incorporate that happened before this unit.

Returns:

Whether the state change of this unit has been incorporated into the given unit and this can be disposed of.

undo

public void undo()

Undoes the next IUndoUnit.

Specified by:

undo in interface IUndoUnit

Throws:

UnsupportedOperationException - If an undo operation is already in progress.

RuntimeException - If canUndo() would yield false.

See Also:

IUndoUnit.getUndoName()