| /* |
| * Copyright 2011 Google 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.google.web.bindery.event.shared; |
| |
| import com.google.web.bindery.event.shared.Event.Type; |
| |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.Set; |
| |
| /** |
| * Wraps an EventBus to hold on to any HandlerRegistrations, so that they can |
| * easily all be cleared at once. |
| */ |
| public class ResettableEventBus extends EventBus { |
| private final EventBus wrapped; |
| private final Set<HandlerRegistration> registrations = new HashSet<HandlerRegistration>(); |
| |
| public ResettableEventBus(EventBus wrappedBus) { |
| this.wrapped = wrappedBus; |
| } |
| |
| @Override |
| public <H> HandlerRegistration addHandler(Type<H> type, H handler) { |
| HandlerRegistration rtn = wrapped.addHandler(type, handler); |
| return doRegisterHandler(rtn); |
| } |
| |
| @Override |
| public <H> HandlerRegistration addHandlerToSource(Event.Type<H> type, Object source, H handler) { |
| HandlerRegistration rtn = wrapped.addHandlerToSource(type, source, handler); |
| return doRegisterHandler(rtn); |
| } |
| |
| @Override |
| public void fireEvent(Event<?> event) { |
| wrapped.fireEvent(event); |
| } |
| |
| @Override |
| public void fireEventFromSource(Event<?> event, Object source) { |
| wrapped.fireEventFromSource(event, source); |
| } |
| |
| /** |
| * Remove all handlers that have been added through this wrapper. |
| */ |
| public void removeHandlers() { |
| Iterator<HandlerRegistration> it = registrations.iterator(); |
| while (it.hasNext()) { |
| HandlerRegistration r = it.next(); |
| |
| /* |
| * must remove before we call removeHandler. Might have come from nested |
| * ResettableEventBus |
| */ |
| it.remove(); |
| |
| r.removeHandler(); |
| } |
| } |
| |
| /** |
| * Visible for testing. |
| */ |
| protected int getRegistrationSize() { |
| return registrations.size(); |
| } |
| |
| private HandlerRegistration doRegisterHandler(final HandlerRegistration registration) { |
| registrations.add(registration); |
| return new HandlerRegistration() { |
| public void removeHandler() { |
| doUnregisterHandler(registration); |
| } |
| }; |
| } |
| |
| private void doUnregisterHandler(HandlerRegistration registration) { |
| if (registrations.contains(registration)) { |
| registration.removeHandler(); |
| registrations.remove(registration); |
| } |
| } |
| } |