Class HistoryManager

Represents to customizes the undo redo functionalities.

Inheritance

System.Object

HistoryManager

Implements

IUndoRedo

System.ComponentModel.INotifyPropertyChanged

Namespace: Syncfusion.UI.Xaml.Diagram

Assembly: Syncfusion.SfDiagram.WPF.dll

Syntax

public class HistoryManager : Object, IUndoRedo, INotifyPropertyChanged

Constructors

HistoryManager()

Declaration

public HistoryManager()

Properties

RedoStack

Gets the list of undo history entries.

Declaration

public Stack<HistoryEntry> RedoStack { get; }

Property Value

Type	Description
System.Collections.Generic.Stack<HistoryEntry>	The list of data that is used when performing Undo Operations. The default value is an empty list.

Remarks

This property is used to add, remove, and modify the data in the undo list of the diagram's HistoryManager.

StackLimit

Gets or sets the numerical value that is used to limit the maximum number of history entries in the Undo and Redo stacks.

Declaration

public int StackLimit { get; set; }

Property Value

Type	Description
System.Int32	This value represents the maximum number of history entries that can be stored in the undo and redo stack. The default value is 0, which means you can store an unlimited number of entries.

State

Gets or sets state for UndoRedo.

Declaration

public UndoRedoState State { get; set; }

Property Value

Type
UndoRedoState

UndoStack

Gets the list of undo history entries.

Declaration

public Stack<HistoryEntry> UndoStack { get; }

Property Value

Type	Description
System.Collections.Generic.Stack<HistoryEntry>	The list of data that is used when performing Undo Operations. The default value is an empty list.

Remarks

This property is used to add, remove, and modify the data in the undo list of the diagram's HistoryManager.

Methods

BeginComposite()

Starts grouping the actions that will be undone/restored as a whole.

Declaration

public void BeginComposite()

BeginComposite(IUndoRedo, Object)

Starts grouping the actions that will be undone/restored as a whole.

Declaration

public void BeginComposite(IUndoRedo source, object data)

Parameters

Type	Name	Description
IUndoRedo	source	The instance of source.
System.Object	data	Specified the data(Instance of CompositeTransactions with the TransactionState as start) to log in the Stack.

CanLogData(IUndoRedo, Object)

canLog in the history list, which takes a history entry as argument and returns whether the specific entry can be added or not.

Declaration

public virtual bool CanLogData(IUndoRedo source, object data)

Parameters

Type	Name	Description
IUndoRedo	source	The instance of IUndoRedo.
System.Object	data	Specified the data to log in the Stack.

Returns

Type
System.Boolean

CanRedo(Object)

Specifies a method to perform redo operation.

Declaration

public bool CanRedo(object data)

Parameters

Type	Name	Description
System.Object	data

Returns

Type	Description
System.Boolean	Returns true, when the state as idle in redo operation. Otherwise, false.

CanUndo(Object)

Specifies a method to perform undo operation.

Declaration

public bool CanUndo(object data)

Parameters

Type	Name	Description
System.Object	data

Returns

Type	Description
System.Boolean	Returns true, when the state as idle in undo operation. Otherwise, false.

EndComposite()

Closes grouping the actions that will be undone/restored as a whole

Declaration

public void EndComposite()

EndComposite(IUndoRedo, Object)

Closes grouping the actions that will be undone/restored as a whole

Declaration

public void EndComposite(IUndoRedo source, object data)

Parameters

Type	Name	Description
IUndoRedo	source	The instance of source.
System.Object	data	Specified the data(Instance of CompositeTransactions with the TransactionState as end) to log in the Stack.

LogData(IUndoRedo, Object)

Specifies a method to log the requied data with instance of source to stack for UndoRedo.

Declaration

public bool LogData(IUndoRedo source, object data)

Parameters

Type	Name	Description
IUndoRedo	source	The instance of IUndoRedo.
System.Object	data	Specified the data to log in the Stack.

Returns

Type
System.Boolean

OnPropertyChanged(String)

Declaration

protected virtual void OnPropertyChanged(string name)

Parameters

Type	Name	Description
System.String	name

Redo(Object)

Specifies a method to invoke when perform redo operation.

Declaration

public object Redo(object data)

Parameters

Type	Name	Description
System.Object	data

Returns

Type
System.Object

Undo(Object)

Specifies a method to invoke when perform undo operation.

Declaration

public object Undo(object data)

Parameters

Type	Name	Description
System.Object	data

Returns

Type
System.Object

Events

PropertyChanged

Declaration

public event PropertyChangedEventHandler PropertyChanged

Event Type

Type
System.ComponentModel.PropertyChangedEventHandler

Implements

IUndoRedo

System.ComponentModel.INotifyPropertyChanged