Package votorola.g.web.gwt.event

Handling GWT events.

See: Description

Interface Summary

Interface	Description
ChangeHandler	A handler of change events.
PropertyChangeHandler	A handler of property change events.

Class Summary

Class	Description
Change	An event that signals a change.
Change.CoalescingGun	A coalescing scheduler for the dispatch of change events.
CoalescingScheduler	A scheduler wrapper that coalesces multiple scheduling requests.
CoalescingScheduler.Tester	A tester of events and scheduled commands.
CoalescingSchedulerR	A coalescing scheduler that works with a repeating command.
CoalescingSchedulerR.FixedDelay	A phaser that schedules commands with a constant intervening delay.
CoalescingSchedulerR.FixedPeriod	A phaser that schedules commands with a constant period.
CoalescingSchedulerR.Phaser	An adapter that schedules commands for a particular phase only.
CoalescingSchedulerS	A coalescing scheduler that works with an ordinary, non-repeating command.
CoalescingSchedulerS.Phaser	An adapter that schedules commands for a particular phase only.
CoalescingSelectionChangeGun	A coalescing scheduler for the dispatch of selection change events.
DelayedEventGun	A scheduler for the delayed dispatch of events.
HandlerRegistrationCW	A compatability wrapper to get us through GWT's half completed transition from com.google.gwt.event.shared to com.google.web.bindery.event.shared.
PropertyChange	An event that signals a change in the value of a "bound property".
SuppressableSource	An event source that may be suppressed during dispatch.
ValueChange<T>	An implementation of ValueChangeEvent with a public constructor, enabling events to be created and fired through an event bus instead of the global handler manager.

Package votorola.g.web.gwt.event Description

Handling GWT events.

Using a collection as an event source (CAES)

When a HashMap or AbstractList itself is the event source, then events are not dispatched (GWT 2.4 devmode, production mode not tested). Traced (at least in the case of the HashMap) to SimpleEventBus getHandlerList(), where sourceMap.get(source) returns a null list of handlers. This is strange because sourceMap.toString shows the list is there (first entry in sourceMap) and the equivalent line in ensureHandlerList() returns a non-null list earlier when handlers are registered. Maybe a collection works as a key when it's the only key, but fails later when other keys are added?

The user manual says adding a DOCTYPE will enable named entities, but do not add it. Firefox and Chrome will still complain that the template is unreadable owing to undefined entities (not sure why). Instead use numeric entities.

Event class hierarchy

Here is an outline of the most important classes:

    * Event
         * GWTEvent
             - these (excepting DomEvent) are synthetic ("logical")
               and have no native counterparts
             * DomEvent
                 - wraps a NativeEvent
     * NativeEvent
         * Event

Scheduler execution order

Testing indicates that (A) Scheduler executes commands in two groups based on scheduling mode: 1) "finally" commands and then 2) "deferred" and "entry" commands. Further (B) the commands within each of the two groups are executed in the order requested. The grouping together of "deferred" and "entry" (A2), and the ordering behaviour within groups (B) are undocumented in the API. Consider using this warning wherever your code depends on them:

    "scheduling order assumption" (quoted, without a line break)

See Also:

Using the GWT scheduler