Java tutorial
/* * Copyright 2008 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.GwtEvent; /** * Represents a open event. * * @param <T> the type being opened */ public class OpenEvent<T> extends GwtEvent<OpenHandler<T>> { /** * Handler type. */ private static Type<OpenHandler<?>> TYPE; /** * Fires a open event on all registered handlers in the handler manager.If no * such handlers exist, this method will do nothing. * * @param <T> the target type * @param source the source of the handlers * @param target the target */ public static <T> void fire(HasOpenHandlers<T> source, T target) { if (TYPE != null) { OpenEvent<T> event = new OpenEvent<T>(target); source.fireEvent(event); } } /** * Gets the type associated with this event. * * @return returns the handler type */ public static Type<OpenHandler<?>> getType() { if (TYPE == null) { TYPE = new Type<OpenHandler<?>>(); } return TYPE; } private final T target; /** * Creates a new open event. * * @param target the ui object being opened */ protected OpenEvent(T target) { this.target = target; } @SuppressWarnings("unchecked") @Override public final Type<OpenHandler<T>> getAssociatedType() { return (Type) TYPE; } /** * Gets the target. * * @return the target */ public T getTarget() { return target; } // Because of type erasure, our static type is // wild carded, yet the "real" type should use our I param. @Override protected void dispatch(OpenHandler<T> handler) { handler.onOpen(this); } }