/**
* 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.dispatch.annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Annotation to generate Event and Handler classes.
*
* If you type:
*
*
*
* {@literal @}GenEvent
* public class FooChanged {
* Foo foo;
* boolean originator;
* }
*
*
*
* gwt-platform will generate two classes, {@code FooChangedEvent} and {@code FooChangedHandler}.
*
* {@code FooChangedEvent} will have fields, getters, and a constructor for foo and
* originator, plus static {@code getType()}, instance dispatch, etc., for it to
* function correctly as a {@link com.google.gwt.event.shared.GwtEvent}.
*
* {@code FooChangedHandler} will be an interface with a {@code onFooChanged} method that takes
* a {@code FooChangedEvent} parameter.
*
* Notes:
*
* There is no naming requirement for your class name. It will be appended with
* Event and Handler.
*
* Using @{@link Order}:
*
* The order the the fields can be optionally specified using the @{@link Order}
* annotation. If @{@link Order} is not used, then the order of the parameters to the
* constructor and to fire() is undefined.
*
* If you type:
*
*
*
* {@literal @}GenEvent
* public class FooChanged {
* {@literal @}Order(1) Foo foo;
* {@literal @}Order(2) int bar;
* {@literal @}Order(3) boolean originator;
* }
*
*
* The following constructor and {@code fire} methods will be generated:
*
*
*
* ...
* FooChangedEvent(Foo foo, int bar, boolean originator)
* ...
* public static void fire(HasEventBus source, Foo foo, int bar, boolean originator)
* ...
*
*
* Omitting the @{@link Order} annotations would yield:
*
*
*
* ...
* FooChangedEvent(int bar, Foo foo, boolean originator)
* ...
* public static void fire(HasEventBus source, int bar, Foo foo, boolean originator)
* ...
*
*
*
*
* Using @{@link Optional}:
*
* If @{@link Optional} is used together with @{@link GenEvent}, an additional fire method is generated.
* If you type:
*
*
*
* {@literal @}GenEvent
* public class FooChanged {
* {@literal @}Optional @Order(1) Foo foo;
* {@literal @}Order(2) int bar;
* {@literal @}Optional @Order(3) boolean originator;
* }
*
*
* The following constructors and {@code fire} methods will be generated:
*
*
*
* ...
* FooChangedEvent(int bar)
* FooChangedEvent(Foo foo, int bar, boolean originator)
* ...
* public static void fire(HasEventBus source, int bar)
* public static void fire(HasEventBus source, Foo foo, int bar, boolean originator)
* ...
*
*
*
*
* @author Brendan Doherty
* @author Florian Sauter
* @author Stephen Haberman (concept)
*/
@Target({ElementType.TYPE})
@Retention(RetentionPolicy.SOURCE)
@Inherited
public @interface GenEvent {
}
