Class HistoryManager

Represents to customizes the undo redo functionalities.

Inheritance
System.Object
HistoryManager
Implements
System.ComponentModel.INotifyPropertyChanged
Namespace: Syncfusion.UI.Xaml.Diagram
Assembly: Syncfusion.SfDiagram.UWP.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

System.ComponentModel.INotifyPropertyChanged

Extension Methods