// Copyright 2007, 2008 The Apache Software Foundation

 //

 // 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 org.apache.tapestry5.runtime;

 /**

  * The core methods related to event handling. Events used in this way exist to gather data from user code, by invoking

  * user methods and capturing the response. Return values from methods, if non-null, are passed to a {@link

  * org.apache.tapestry5.ComponentEventCallback}. The {@link ComponentEvent} subinterface extends this by providing

  * access to a context, or set of information related to the event, along with additional data used, at runtime, to

  * match events to user code methods.

  */

 public interface Event

 {

     /**

      * Returns true if the event has been aborted (meaning that the return value from some event handler method was

      * accepted, and processing of the event was terminated).

      *

      * @return true if no further event handler methods should be invoked

      */

     boolean isAborted();

     /**

      * Invoke to identify, to the event, what component and method is being acted upon (used for some kinds of exception

      * reporting).

      *

      * @param methodDescription describes the location (i.e. file name, method name and line number) of the method

      */

     void setMethodDescription(String methodDescription);

     /**

      * Stores a result for the event. Storing a non-null result value may abort the event (at the discretion of the

      * {@link org.apache.tapestry5.ComponentEventCallback}).

      *

      * @param result the result obtained from a method invocations

      * @return true if the event is now aborted

      */

     boolean storeResult(Object result);

 }