UndoHistory (Apache JMeter API)

java.lang.Object
- org.apache.jmeter.gui.UndoHistory

All Implemented Interfaces:

Serializable, EventListener, TreeModelListener
```
public class UndoHistory
extends Object
implements TreeModelListener, Serializable
```
This class serves storing Test Tree state and navigating through it to give the undo/redo ability for test plan changes

Since:

2.12

See Also:
Serialized Form

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static interface UndoHistory.HistoryListener
Interface to be implemented by components interested in UndoHistory

Nested Classes
Modifier and Type	Class and Description
`static interface`	`UndoHistory.HistoryListener` Interface to be implemented by components interested in UndoHistory

Constructor Summary

Constructors
Constructor and Description

UndoHistory()

Constructors
Constructor and Description
`UndoHistory()`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`add(JMeterTreeModel treeModel, String comment)` Add tree model copy to the history This method relies on the rule that the record in history made AFTER change has been made to test plan
`boolean`	`canRedo()`
`boolean`	`canUndo()`
`void`	`clear()` Clears the undo history
`void`	`moveInHistory(int offset, JMeterTreeModel acceptorModel)` Goes through undo history, changing GUI
`void`	`registerHistoryListener(UndoHistory.HistoryListener listener)` Register HistoryListener
`void`	`treeNodesChanged(TreeModelEvent tme)` Record the changes in the node as the undo step
`void`	`treeNodesInserted(TreeModelEvent tme)` Record adding nodes as the undo step
`void`	`treeNodesRemoved(TreeModelEvent tme)` Record deleting nodes as the undo step
`void`	`treeStructureChanged(TreeModelEvent tme)` Record some other change

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

- Constructor Detail
  - UndoHistory
```
public UndoHistory()
```
- Method Detail
  - clear
```
public void clear()
```
    Clears the undo history
  - add
```
public void add(JMeterTreeModel treeModel,
       String comment)
```
    Add tree model copy to the history
    This method relies on the rule that the record in history made AFTER change has been made to test plan
    
    Parameters:
    treeModel - JMeterTreeModel
    comment - String
  - moveInHistory
```
public void moveInHistory(int offset,
                 JMeterTreeModel acceptorModel)
```
    Goes through undo history, changing GUI
    
    Parameters:
    offset - the direction to go to, usually -1 for undo or 1 for redo
    acceptorModel - TreeModel to accept the changes
  - canRedo
```
public boolean canRedo()
```
    Returns:
    true if remaing items
  - canUndo
```
public boolean canUndo()
```
    Returns:
    true if not at first element
  - treeNodesChanged
```
public void treeNodesChanged(TreeModelEvent tme)
```
    Record the changes in the node as the undo step
    
    Specified by:
    
    treeNodesChanged in interface TreeModelListener
    
    Parameters:
    tme - TreeModelEvent with event details
  - treeNodesInserted
```
public void treeNodesInserted(TreeModelEvent tme)
```
    Record adding nodes as the undo step
    
    Specified by:
    
    treeNodesInserted in interface TreeModelListener
    
    Parameters:
    tme - TreeModelEvent with event details
  - treeNodesRemoved
```
public void treeNodesRemoved(TreeModelEvent tme)
```
    Record deleting nodes as the undo step
    
    Specified by:
    
    treeNodesRemoved in interface TreeModelListener
    
    Parameters:
    tme - TreeModelEvent with event details
  - treeStructureChanged
```
public void treeStructureChanged(TreeModelEvent tme)
```
    Record some other change
    
    Specified by:
    
    treeStructureChanged in interface TreeModelListener
    
    Parameters:
    tme - TreeModelEvent with event details
  - registerHistoryListener
```
public void registerHistoryListener(UndoHistory.HistoryListener listener)
```
    Register HistoryListener
    
    Parameters:
    listener - to add to our listeners

Class UndoHistory

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

UndoHistory

Method Detail

clear

add

moveInHistory

canRedo

canUndo

treeNodesChanged

treeNodesInserted

treeNodesRemoved

treeStructureChanged

registerHistoryListener