com.gwtplatform.mvp.client.proxy.RevealContentHandler Maven / Gradle / Ivy
/**
* Copyright 2011 ArcBees Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.gwtplatform.mvp.client.proxy;
import com.google.gwt.core.client.Scheduler;
import com.google.gwt.event.shared.EventHandler;
import com.google.gwt.user.client.Command;
import com.google.web.bindery.event.shared.EventBus;
import com.gwtplatform.mvp.client.Presenter;
/**
* This is the handler class for {@link RevealContentEvent}. It should be used
* by any {@link Proxy} class of a {@link Presenter} that accepts child
* presenters. When this handler is triggered, the proxy should first set
* the content appropriately in the presenter, and then reveal the presenter.
*
* @param The Presenter's type.
* @author Philippe Beaudoin
*/
public class RevealContentHandler> implements EventHandler {
private final EventBus eventBus;
private final ProxyImpl proxy;
public RevealContentHandler(final EventBus eventBus,
final ProxyImpl proxy) {
this.eventBus = eventBus;
this.proxy = proxy;
}
/**
* This is the dispatched method. Reveals
*
* @param revealContentEvent The event containing the presenter that wants to
* bet set as content.
*/
public final void onRevealContent(final RevealContentEvent revealContentEvent) {
proxy.getPresenter(new NotifyingAsyncCallback(eventBus) {
@Override
public void success(final T presenter) {
// Deferring is needed because the event bus enqueues and delays handler
// registration when events are currently being processed.
// (see {@link com.google.gwt.event.shared.HandlerManager@addHandler()})
// So if a presenter registers a handler in its onBind() method and a
// child fires the event in its onReveal() method, then the event might
// get lost because the handler is not officially registered yet.
Scheduler.get().scheduleDeferred(new Command() {
@Override
public void execute() {
presenter.forceReveal();
presenter.setInSlot(revealContentEvent.getAssociatedType(),
revealContentEvent.getContent());
}
});
}
});
}
}