com.vaadin.flow.component.spreadsheet.

java.lang.Object
- com.vaadin.flow.component.spreadsheet.SpreadsheetHistoryManager

All Implemented Interfaces:

Serializable
```
public class SpreadsheetHistoryManager
extends Object
implements Serializable
```
SpreadsheetHistoryManager is an utility class of the Spreadsheet add-on. This class handles remembering any actions done in the Spreadsheet. The purpose is to allow the user to undo and redo any action.

Author:

Vaadin Ltd.

See Also:

Serialized Form

Field Summary

Fields
Modifier and Type	Field	Description
`protected LinkedList<Command>`	`commands`	All executed command in chronological order
`protected int`	`historyIndex`	Current index within the history
`protected Spreadsheet`	`spreadsheet`	Target Spreadsheet component

Constructor Summary

Constructors
Constructor Description

SpreadsheetHistoryManager(Spreadsheet spreadsheet)
Creates a new history manager for the given Spreadsheet.

Method Summary

All Methods
Modifier and Type	Method	Description
`void`	`addCommand(Command command)`	Adds a command to the end of the command history.
`boolean`	`canRedo()`	Determines if redo is possible at the moment.
`boolean`	`canUndo()`	Determines if undo is possible at the moment.
`protected void`	`changeSelection(Command command)`	Applies the cell selection from the given Command.
`void`	`clear()`	Clears the history.
`protected void`	`discardAllAfter(int index)`	Clears all history after the given history index NOT including the command at the given index.
`Command`	`getCommand(int historyIndex)`	Gets the Command at the given history index.
`int`	`getHistoryIndex()`	Gets the current index within the Command history.
`int`	`getHistorySize()`	Gets the current size of the Command history.
`protected void`	`makeSureCorrectSheetActive(Command command)`	Ensures that the correct sheet is active, as recorded in the given Command.
`void`	`redo()`	Does redo if possible.
`void`	`setHistorySize(int historySize)`	Changes the history size.
`void`	`undo()`	Does undo if possible.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - historyIndex
```
protected int historyIndex
```
    Current index within the history
  - commands
```
protected final LinkedList<Command> commands
```
    All executed command in chronological order
  - spreadsheet
```
protected final Spreadsheet spreadsheet
```
    Target Spreadsheet component
- Constructor Detail
  - SpreadsheetHistoryManager
```
public SpreadsheetHistoryManager(Spreadsheet spreadsheet)
```
    Creates a new history manager for the given Spreadsheet.
    
    Parameters:
    
    spreadsheet - Target spreadsheet
- Method Detail
  - clear
```
public void clear()
```
    Clears the history.
  - addCommand
```
public void addCommand(Command command)
```
    Adds a command to the end of the command history. Discards commands after the current position (historyIndex) within the history.
    
    Parameters:
    
    command - Command to add as the latest command in history
  - getCommand
```
public Command getCommand(int historyIndex)
```
    Gets the Command at the given history index.
    
    Parameters:
    
    historyIndex - Index of Command to get, 0-based
    
    Returns:
    
    The command at the index or IndexOutOfBoundsException
  - canRedo
```
public boolean canRedo()
```
    Determines if redo is possible at the moment. In practice tells if there is at least one Command available after the current history index.
    
    Returns:
    
    true if redo() possible, false otherwise.
  - canUndo
```
public boolean canUndo()
```
    Determines if undo is possible at the moment. In practice tells if there is at least one Command available before the current history index.
    
    Returns:
    
    true if undo() possible, false otherwise.
  - redo
```
public void redo()
```
    Does redo if possible. Changes the active sheet to match the one the command belongs to and updates the selection if needed.
  - undo
```
public void undo()
```
    Does undo if possible. Changes the active sheet to match the one that the command belongs to and updates the selection if needed.
  - setHistorySize
```
public void setHistorySize(int historySize)
```
    Changes the history size. Discards possible commands that won't fit the size anymore.
    
    Parameters:
    
    historySize - New size for Command history
  - getHistorySize
```
public int getHistorySize()
```
    Gets the current size of the Command history. The default size is 20 commands.
    
    Returns:
    
    Current size of history.
  - getHistoryIndex
```
public int getHistoryIndex()
```
    Gets the current index within the Command history.
    
    Returns:
    
    Current history index, 0-based
  - makeSureCorrectSheetActive
```
protected void makeSureCorrectSheetActive(Command command)
```
    Ensures that the correct sheet is active, as recorded in the given Command.
    
    Parameters:
    
    command - Command to fetch the sheet from
  - changeSelection
```
protected void changeSelection(Command command)
```
    Applies the cell selection from the given Command.
    
    Parameters:
    
    command - Command to fetch the cell selection from.
  - discardAllAfter
```
protected void discardAllAfter(int index)
```
    Clears all history after the given history index NOT including the command at the given index.
    
    Parameters:
    
    index - History index to start the clearing from.

com.vaadin.flow.component.spreadsheet.

Class SpreadsheetHistoryManager

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

historyIndex

commands

spreadsheet

Constructor Detail

SpreadsheetHistoryManager

Method Detail

clear

addCommand

getCommand

canRedo

canUndo

redo

undo

setHistorySize

getHistorySize

getHistoryIndex

makeSureCorrectSheetActive

changeSelection

discardAllAfter