org.bushe.swing.event

Class ContainerEventServiceFinder

java.lang.Object

org.bushe.swing.event.ContainerEventServiceFinder

public class ContainerEventServiceFinder
extends Object

This class finds a component's container event service, and creates one if necessary and possible.

A Container EventService is, unlike the EventBus, an EventService that is container specific, in other words, it is shared only amongst components within a container. For example, a Form component can supply an EventService used only by components in the form. The Form's components can publish value change events on their Container's Event Service. The Form's Model and Validator may listen to these events to collect data and show errors, respectively.

Most importantly, Container EventService's cuts down event traffic, avoid naming and listener clashes, promotes componentization, and splits events usage into logical subsets.

The finder will walk up a component's hierarchy searching for a parent that implements ContainerEventServiceSupplier. If it find one, it returns it. If it doesn't find one, the top level JComponent (specifically, the highest parent in the hierarchy, typically a JRootPane) has a client property added to it (if not already set) that has the value of a new SwingEventService, which is then returned. The EventBus is never returned.

Field Summary

Fields

Modifier and Type	Field and Description
static String	CLIENT_PROPERTY_KEY_TOP_LEVEL_EVENT_SERVICE The client property used to put a new SwingEventService on top-level components.

Constructor Summary

Constructors

Constructor and Description
ContainerEventServiceFinder()

Method Summary

Methods

Modifier and Type	Method and Description
static EventService	getEventService(Component component) Walks the component's parents until it find an ContainerEventServiceSupplier and returns the supplier's EventService.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

CLIENT_PROPERTY_KEY_TOP_LEVEL_EVENT_SERVICE

public static final String CLIENT_PROPERTY_KEY_TOP_LEVEL_EVENT_SERVICE

The client property used to put a new SwingEventService on top-level components.

See Also:

Constant Field Values

Constructor Detail

ContainerEventServiceFinder

public ContainerEventServiceFinder()

Method Detail

getEventService

public static EventService getEventService(Component component)

Walks the component's parents until it find an ContainerEventServiceSupplier and returns the supplier's EventService. If the component in the tree is a JPopupMenu, then the menu's invoker is walked.

Parameters:

component - any component

Returns:

the ContainerEventService of the nearest parent