Class ConfigurationEvent

  • All Implemented Interfaces:
    java.io.Serializable

    public class ConfigurationEvent
    extends Event

    An event class for reporting updates on a configuration object.

    Event objects of this type are used for "raw" events, i.e. unfiltered modifications of any kind. A level with semantically higher events (e.g. for property changes) may be built on top of this fundamental event mechanism.

    Each event can contain the following data:

    • A source object, which is usually the configuration object that was modified.
    • The event's type. This is an object that corresponds to constant declarations in specific event classes. It describes what exactly has happened.
    • If available, the name of the property whose modification caused the event.
    • If available, the value of the property that caused this event.
    • A flag whether this event was generated before or after the update of the source configuration. A modification of a configuration typically causes two events: one event before and one event after the modification is performed. This allows event listeners to react at the correct point of time.

    The following standard events are generated by typical configuration implementations (the constants for the event types are defined in this class:

    ADD_PROPERTY
    This event is triggered for each call of the addProperty() method of a configuration object. It contains the name of the property, to which new data is added, and the value object that is added to this property (this may be an array or a list if multiple values are added).
    SET_PROPERTY
    Calling the setProperty() method triggers this event. The event object stores the name of the affected property and its new value.
    CLEAR_PROPERTY
    If a property is removed from a configuration (by calling the clearProperty() method), an event of this type is fired. In this case the event object only stores the name of the removed property, the value is null.
    CLEAR
    This event is fired when the whole configuration is cleared. The corresponding event object contains no additional data.
    Since:
    1.3
    See Also:
    Serialized Form
    • Field Detail

      • ANY

        public static final EventType<ConfigurationEvent> ANY
        Constant for the common super type of all configuration update events.
        Since:
        2.0
      • ADD_PROPERTY

        public static final EventType<ConfigurationEvent> ADD_PROPERTY
        Constant for the event type for an add property operation.
        Since:
        2.0
      • SET_PROPERTY

        public static final EventType<ConfigurationEvent> SET_PROPERTY
        Constant for the event type for a set property operation.
        Since:
        2.0
      • CLEAR_PROPERTY

        public static final EventType<ConfigurationEvent> CLEAR_PROPERTY
        Constant for the event type for a clear property operation.
        Since:
        2.0
      • ANY_HIERARCHICAL

        public static final EventType<ConfigurationEvent> ANY_HIERARCHICAL
        Constant for the common base event type for all hierarchical update events. Events derived from this type are generated by some specific methods of hierarchical configurations.
        Since:
        2.0
      • ADD_NODES

        public static final EventType<ConfigurationEvent> ADD_NODES
        Constant for the event type for an add nodes operation.
        Since:
        2.0
      • CLEAR_TREE

        public static final EventType<ConfigurationEvent> CLEAR_TREE
        Constant for the event type for a clear tree operation.
        Since:
        2.0
      • SUBNODE_CHANGED

        public static final EventType<ConfigurationEvent> SUBNODE_CHANGED
        Constant for the event type indicating a change on a sub configuration.
        Since:
        2.0
      • serialVersionUID

        private static final long serialVersionUID
        The serial version UID.
        See Also:
        Constant Field Values
      • propertyName

        private final java.lang.String propertyName
        Stores the property name.
      • propertyValue

        private final java.lang.Object propertyValue
        Stores the property value.
      • beforeUpdate

        private final boolean beforeUpdate
        Stores the before update flag.
    • Constructor Detail

      • ConfigurationEvent

        public ConfigurationEvent​(java.lang.Object source,
                                  EventType<? extends ConfigurationEvent> type,
                                  java.lang.String propertyName,
                                  java.lang.Object propertyValue,
                                  boolean beforeUpdate)
        Creates a new instance of ConfigurationEvent and initializes it.
        Parameters:
        source - the event source
        type - the event's type
        propertyName - the name of the affected property
        propertyValue - the value of the affected property
        beforeUpdate - the before update flag
    • Method Detail

      • getPropertyName

        public java.lang.String getPropertyName()
        Gets the name of the affected property. This can be null if no property change has lead to this event.
        Returns:
        the name of the property
      • getPropertyValue

        public java.lang.Object getPropertyValue()
        Gets the value of the affected property if available.
        Returns:
        the value of the property; can be null
      • isBeforeUpdate

        public boolean isBeforeUpdate()
        Returns a flag if this event was generated before or after an update.
        Returns:
        true if this event was generated before an update; false otherwise