| 1 | // Copyright 2004-2007 Jean-Francois Poilpret |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | |
| 15 | package net.sourceforge.hiveevents; |
| 16 | |
| 17 | import java.util.ArrayList; |
| 18 | import java.util.List; |
| 19 | |
| 20 | /** |
| 21 | * Chain of event filters. Allows to daisy chain several filters (makes it |
| 22 | * easier to build complex filters). |
| 23 | * |
| 24 | * @author Jean-Francois Poilpret |
| 25 | */ |
| 26 | public class FiltersChain<T> implements Filter<T> |
| 27 | { |
| 28 | /** |
| 29 | * Create a chain of filters. |
| 30 | */ |
| 31 | static public<T> Filter<T> create(Filter<T>... filters) |
| 32 | { |
| 33 | FiltersChain<T> chain = new FiltersChain<T>(); |
| 34 | for (Filter<T> filter: filters) |
| 35 | { |
| 36 | chain.addFilter(filter); |
| 37 | } |
| 38 | return chain; |
| 39 | } |
| 40 | |
| 41 | /** |
| 42 | * Add a filter at the end of the chain. |
| 43 | */ |
| 44 | public void addFilter(Filter<T> filter) |
| 45 | { |
| 46 | _filters.add(filter); |
| 47 | } |
| 48 | |
| 49 | /** |
| 50 | * Checks if an event passes through ALL the filters in the chain. |
| 51 | * If one only filter does not allow the event to pass, then the event will |
| 52 | * NOT pass. |
| 53 | */ |
| 54 | public boolean passEvent(T event) |
| 55 | { |
| 56 | for (Filter<T> filter: _filters) |
| 57 | { |
| 58 | if (!filter.passEvent(event)) |
| 59 | { |
| 60 | return false; |
| 61 | } |
| 62 | } |
| 63 | return true; |
| 64 | } |
| 65 | |
| 66 | private final List<Filter<T>> _filters = new ArrayList<Filter<T>>(); |
| 67 | } |