HierarchyListener (Java SE 10 & JDK 10 )
Keywords: java.awt.event.HierarchyListener interface

Module java.desktop
Package java.awt.event

## Interface HierarchyListener

- All Superinterfaces:
    `EventListener`
  All Known Implementing Classes:
    `AWTEventMulticaster`

      public interface HierarchyListener
      extends EventListener

  The listener interface for receiving hierarchy changed events. The class that is interested in processing a hierarchy changed event should implement this interface. The listener object created from that class is then registered with a Component using the Component's `addHierarchyListener` method. When the hierarchy to which the Component belongs changes, the `hierarchyChanged` method in the listener object is invoked, and the `HierarchyEvent` is passed to it.

  Hierarchy events are provided for notification purposes ONLY; The AWT will automatically handle changes to the hierarchy internally so that GUI layout, displayability, and visibility work properly regardless of whether a program registers a `HierarchyListener` or not.

  Since:
    1.3
  See Also:
    `HierarchyEvent`

- - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `void` | `hierarchyChanged​(HierarchyEvent e)` | Called when the hierarchy has been changed.

- - ### Method Detail

    - #### hierarchyChanged

          void hierarchyChanged​(HierarchyEvent e)

      Called when the hierarchy has been changed. To discern the actual type of change, call `HierarchyEvent.getChangeFlags()`.
      Parameters:
        `e` - the event to be processed
      See Also:
        `HierarchyEvent.getChangeFlags()`