001package votorola.g.web.gwt; // Copyright 2012, Michael Allan. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Votorola Software"), to deal in the Votorola Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicence, and/or sell copies of the Votorola Software, and to permit persons to whom the Votorola Software is furnished to do so, subject to the following conditions: The preceding copyright notice and this permission notice shall be included in all copies or substantial portions of the Votorola Software. THE VOTOROLA SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE VOTOROLA SOFTWARE OR THE USE OR OTHER DEALINGS IN THE VOTOROLA SOFTWARE. 002 003import com.google.gwt.user.client.rpc.AsyncCallback; 004import votorola.g.hold.*; 005 006 007/** A wrapper that disables an asynchronous callback when a spool is unwinding. 008 */ 009public final class SpooledAsyncCallback<T> implements AsyncCallback<T> 010{ 011 012 013 /** Creates an SpooledAsyncCallback. 014 * 015 * @param spool the spool to use. 016 * @param callback the callback to guard. 017 */ 018 public static <T> SpooledAsyncCallback<T> wrap( final Spool spool, 019 final AsyncCallback<T> callback ) 020 { 021 return new SpooledAsyncCallback<T>( spool, callback ); 022 } 023 024 025 026 private SpooledAsyncCallback( Spool _spool, AsyncCallback<T> _callback ) 027 { 028 spool = _spool; 029 callback = _callback; 030 } 031 032 033 034 // - A s y n c - C a l l b a c k ------------------------------------------------------ 035 036 037 public void onFailure( final Throwable x ) 038 { 039 if( !spool.isUnwinding() ) callback.onFailure( x ); 040 } 041 042 043 044 public void onSuccess( final T result ) 045 { 046 if( !spool.isUnwinding() ) callback.onSuccess( result ); 047 } 048 049 050 051//// P r i v a t e /////////////////////////////////////////////////////////////////////// 052 053 054 private final AsyncCallback<T> callback; 055 056 057 058 private final Spool spool; 059 060 061}