Module java.desktop

Class ContainerEvent

All Implemented Interfaces:

public class ContainerEvent extends ComponentEvent
A low-level event which indicates that a container's contents changed because a component was added or removed.

Container events are provided for notification purposes ONLY; The AWT will automatically handle changes to the containers contents internally so that the program works properly regardless of whether the program is receiving these events or not.

This low-level event is generated by a container object (such as a Panel) when a component is added to it or removed from it. The event is passed to every ContainerListener or ContainerAdapter object which registered to receive such events using the component's addContainerListener method. (ContainerAdapter objects implement the ContainerListener interface.) Each such listener object gets this ContainerEvent when the event occurs.

An unspecified behavior will be caused if the id parameter of any particular ContainerEvent instance is not in the range from CONTAINER_FIRST to CONTAINER_LAST.

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  • Field Details


      public static final int CONTAINER_FIRST
      The first number in the range of ids used for container events.
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      public static final int CONTAINER_LAST
      The last number in the range of ids used for container events.
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      public static final int COMPONENT_ADDED
      This event indicates that a component was added to the container.
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      public static final int COMPONENT_REMOVED
      This event indicates that a component was removed from the container.
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  • Constructor Details

    • ContainerEvent

      public ContainerEvent(Component source, int id, Component child)
      Constructs a ContainerEvent object.

      This method throws an IllegalArgumentException if source is null.

      source - The Component object (container) that originated the event
      id - An integer indicating the type of event. For information on allowable values, see the class description for ContainerEvent
      child - the component that was added or removed
      IllegalArgumentException - if source is null
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  • Method Details

    • getContainer

      public Container getContainer()
      Returns the originator of the event.
      the Container object that originated the event, or null if the object is not a Container.
    • getChild

      public Component getChild()
      Returns the component that was affected by the event.
      the Component object that was added or removed
    • paramString

      public String paramString()
      Returns a parameter string identifying this event. This method is useful for event-logging and for debugging.
      paramString in class ComponentEvent
      a string identifying the event and its attributes