| /* |
| * Copyright 2010 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.gwt.event.logical.shared; |
| |
| import com.google.gwt.event.shared.EventHandler; |
| import com.google.gwt.event.shared.GwtEvent; |
| |
| /** |
| * Fired when the event source is attached to the browser's document |
| * or detached from it. |
| */ |
| public class AttachEvent extends GwtEvent<AttachEvent.Handler> { |
| |
| /** |
| * Implemented by objects that handle {@link AttachEvent}. |
| */ |
| public interface Handler extends EventHandler { |
| void onAttachOrDetach(AttachEvent event); |
| } |
| |
| /** |
| * The event type. |
| */ |
| static Type<AttachEvent.Handler> TYPE; |
| |
| /** |
| * Fires an {@link AttachEvent} on all registered handlers in the handler |
| * source. |
| * |
| * @param <S> The handler source type |
| * @param source the source of the handlers |
| * @param attached whether to announce an attach or detach |
| */ |
| public static <S extends HasAttachHandlers> void fire(S source, |
| boolean attached) { |
| if (TYPE != null) { |
| AttachEvent event = new AttachEvent(attached); |
| source.fireEvent(event); |
| } |
| } |
| |
| /** |
| * Ensures the existence of the handler hook and then returns it. |
| * |
| * @return returns a handler hook |
| */ |
| public static Type<AttachEvent.Handler> getType() { |
| if (TYPE == null) { |
| TYPE = new Type<AttachEvent.Handler>(); |
| } |
| return TYPE; |
| } |
| |
| private final boolean attached; |
| |
| /** |
| * Construct a new {@link AttachEvent}. |
| * |
| * @param attached true if the source has been attached |
| */ |
| protected AttachEvent(boolean attached) { |
| this.attached = attached; |
| } |
| |
| @Override |
| public final Type<AttachEvent.Handler> getAssociatedType() { |
| return TYPE; |
| } |
| |
| /** |
| * Returns true if this event announces that the source has been attached, |
| * false if it has been detached. |
| */ |
| public boolean isAttached() { |
| return attached; |
| } |
| |
| @Override |
| public String toDebugString() { |
| assertLive(); |
| return super.toDebugString() + " attached = " + attached; |
| } |
| |
| @Override |
| protected void dispatch(AttachEvent.Handler handler) { |
| handler.onAttachOrDetach(this); |
| } |
| } |