PsiTreeChangeListener (Unofficial IntelliJ Community Edition API docs)

All Superinterfaces:

java.util.EventListener

All Known Implementing Classes:

ExternalPSIChangeListener, FileEditorPsiTreeChangeListener, NavBarListener, ProjectTreeBuilder.ProjectTreeBuilderPsiListener, ProjectViewPsiTreeChangeListener, PsiToDocumentSynchronizer, PsiTreeAnyChangeAbstractAdapter, PsiTreeChangeAdapter
```
public interface PsiTreeChangeListener
extends java.util.EventListener
```
Listener for receiving notifications about all changes in the PSI tree of a project.
Try to avoid processing PSI events at all cost! See PsiTreeChangeEvent documentation for more details.

See Also:

PsiManager.addPsiTreeChangeListener(PsiTreeChangeListener), PsiManager.removePsiTreeChangeListener(PsiTreeChangeListener)

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`void`	`beforeChildAddition(PsiTreeChangeEvent event)` Invoked just before adding a child to the tree. Parent element is returned by `event.getParent()`. Added child is returned by `event.getChild`.
`void`	`beforeChildMovement(PsiTreeChangeEvent event)` Invoked just before movement of a child in the tree by changing its parent or by changing its position in the same parent. Child to be moved is returned by `event.getChild()`. The old parent is returned by `event.getOldParent()`. The new parent is returned by `event.getNewParent()`.
`void`	`beforeChildRemoval(PsiTreeChangeEvent event)` Invoked just before removal of a child from the tree. Child to be removed is returned by `event.getChild()`. Parent element is returned by `event.getParent()`.
`void`	`beforeChildrenChange(PsiTreeChangeEvent event)` Invoked before a mass change of children of the specified node. The parent the nodes of which are changing is returned by `event.getParent()`.
`void`	`beforeChildReplacement(PsiTreeChangeEvent event)` Invoked just before replacement of a child in the tree by another element. Child to be replaced is returned by `event.getOldChild()`. Parent element is returned by `event.getParent()`.
`void`	`beforePropertyChange(PsiTreeChangeEvent event)` Invoked just before changing of some property of an element. Element, whose property is to be changed is returned by `event.getElement()`. The property name is returned by `event.getPropertyName()`. The old property value is returned by `event.getOldValue()`.
`void`	`childAdded(PsiTreeChangeEvent event)` Invoked just after adding of a new child to the tree. The added child is returned by `event.getChild()`. Parent element is returned by `event.getParent()`.
`void`	`childMoved(PsiTreeChangeEvent event)` Invoked just after movement of a child in the tree by changing its parent or by changing its position in the same parent. The moved child is returned by `event.getChild()`. The old parent is returned by `event.getOldParent()`. The new parent is returned by `event.getNewParent()`.
`void`	`childRemoved(PsiTreeChangeEvent event)` Invoked just after removal of a child from the tree. The removed child is returned by `event.getChild()`.
`void`	`childrenChanged(PsiTreeChangeEvent event)` Invoked after a mass change of children of the specified node. The parent the nodes of which have changed is returned by `event.getParent()`.
`void`	`childReplaced(PsiTreeChangeEvent event)` Invoked just after replacement of a child in the tree by another element. The replaced child is returned by `event.getOldChild()`.
`void`	`propertyChanged(PsiTreeChangeEvent event)` Invoked just after changing of some property of an element. Element, whose property has changed is returned by `event.getElement()`. The property name is returned by `event.getPropertyName()`. The old property value is returned by `event.getOldValue()`. The new property value is returned by `event.getNewValue()`.

- Method Detail
  - beforeChildAddition
```
void beforeChildAddition(PsiTreeChangeEvent event)
```
    Invoked just before adding a child to the tree.
    Parent element is returned by event.getParent().
    Added child is returned by event.getChild.
    
    Parameters:
    
    event - the event object describing the change.
  - beforeChildRemoval
```
void beforeChildRemoval(PsiTreeChangeEvent event)
```
    Invoked just before removal of a child from the tree.
    Child to be removed is returned by event.getChild().
    Parent element is returned by event.getParent().
    
    Parameters:
    
    event - the event object describing the change.
  - beforeChildReplacement
```
void beforeChildReplacement(PsiTreeChangeEvent event)
```
    Invoked just before replacement of a child in the tree by another element.
    Child to be replaced is returned by event.getOldChild().
    Parent element is returned by event.getParent().
    
    Parameters:
    
    event - the event object describing the change.
  - beforeChildMovement
```
void beforeChildMovement(PsiTreeChangeEvent event)
```
    Invoked just before movement of a child in the tree by changing its parent or by changing its position in the same parent.
    Child to be moved is returned by event.getChild().
    The old parent is returned by event.getOldParent().
    The new parent is returned by event.getNewParent().
    
    Parameters:
    
    event - the event object describing the change.
  - beforeChildrenChange
```
void beforeChildrenChange(PsiTreeChangeEvent event)
```
    Invoked before a mass change of children of the specified node.
    The parent the nodes of which are changing is returned by event.getParent().
    
    Parameters:
    
    event - the event object describing the change.
  - beforePropertyChange
```
void beforePropertyChange(PsiTreeChangeEvent event)
```
    Invoked just before changing of some property of an element.
    Element, whose property is to be changed is returned by event.getElement().
    The property name is returned by event.getPropertyName().
    The old property value is returned by event.getOldValue().
    
    Parameters:
    
    event - the event object describing the change.
  - childAdded
```
void childAdded(PsiTreeChangeEvent event)
```
    Invoked just after adding of a new child to the tree.
    The added child is returned by event.getChild().
    Parent element is returned by event.getParent().
    
    Parameters:
    
    event - the event object describing the change.
  - childRemoved
```
void childRemoved(PsiTreeChangeEvent event)
```
    Invoked just after removal of a child from the tree.
    The removed child is returned by event.getChild(). Note that only equals(), hashCode(), isValid() methods can be safely invoked for this element, because it's not valid anymore.
    Parent element is returned by event.getParent().
    
    Parameters:
    
    event - the event object describing the change.
  - childReplaced
```
void childReplaced(PsiTreeChangeEvent event)
```
    Invoked just after replacement of a child in the tree by another element.
    The replaced child is returned by event.getOldChild(). Note that only equals(), hashCode(), isValid() methods can be safely invoked for this element, because it's not valid anymore.
    The new child is returned by event.getNewChild().
    Parent element is returned by event.getParent().
    
    Parameters:
    
    event - the event object describing the change.
  - childrenChanged
```
void childrenChanged(PsiTreeChangeEvent event)
```
    Invoked after a mass change of children of the specified node.
    The parent the nodes of which have changed is returned by event.getParent().
    
    Parameters:
    
    event - the event object describing the change.
  - childMoved
```
void childMoved(PsiTreeChangeEvent event)
```
    Invoked just after movement of a child in the tree by changing its parent or by changing its position in the same parent.
    The moved child is returned by event.getChild().
    The old parent is returned by event.getOldParent().
    The new parent is returned by event.getNewParent().
    
    Parameters:
    
    event - the event object describing the change.
  - propertyChanged
```
void propertyChanged(PsiTreeChangeEvent event)
```
    Invoked just after changing of some property of an element.
    Element, whose property has changed is returned by event.getElement().
    The property name is returned by event.getPropertyName().
    The old property value is returned by event.getOldValue().
    The new property value is returned by event.getNewValue().
    
    Parameters:
    
    event - the event object describing the change.

Interface PsiTreeChangeListener

Method Summary

Method Detail

beforeChildAddition

beforeChildRemoval

beforeChildReplacement

beforeChildMovement

beforeChildrenChange

beforePropertyChange

childAdded

childRemoved

childReplaced

childrenChanged

childMoved

propertyChanged