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1   /**
2    * This file Copyright (c) 2015 Magnolia International
3    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
4    *
5    *
6    * This file is dual-licensed under both the Magnolia
7    * Network Agreement and the GNU General Public License.
8    * You may elect to use one or the other of these licenses.
9    *
10   * This file is distributed in the hope that it will be
11   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
12   * implied warranty of MERCHANTABILITY or FITNESS FOR A
13   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
14   * Redistribution, except as permitted by whichever of the GPL
15   * or MNA you select, is prohibited.
16   *
17   * 1. For the GPL license (GPL), you can redistribute and/or
18   * modify this file under the terms of the GNU General
19   * Public License, Version 3, as published by the Free Software
20   * Foundation.  You should have received a copy of the GNU
21   * General Public License, Version 3 along with this program;
22   * if not, write to the Free Software Foundation, Inc., 51
23   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
24   *
25   * 2. For the Magnolia Network Agreement (MNA), this file
26   * and the accompanying materials are made available under the
27   * terms of the MNA which accompanies this distribution, and
28   * is available at http://www.magnolia-cms.com/mna.html
29   *
30   * Any modifications to this file must keep this entire header
31   * intact.
32   *
33   */
34  package info.magnolia.resourceloader.util;
35  
36  import static info.magnolia.resourceloader.util.Functions.always;
37  
38  import info.magnolia.resourceloader.Resource;
39  import info.magnolia.resourceloader.ResourceVisitor;
40  
41  import com.google.common.base.Function;
42  import com.google.common.base.Predicate;
43  import com.google.common.base.Predicates;
44  
45  /**
46   * A {@link ResourceVisitor} constructed with {@link Predicate}s and a {@link Function} to determine its behavior.
47   */
48  public class PredicatedResourceVisitor implements ResourceVisitor {
49      /**
50       * Visits everything and applies the given {@link Function} to everything.
51       * @see Functions which provides a couple of helpful predicates and functions to use with Resource.
52       * @see VoidFunction
53       */
54      public static PredicatedResourceVisitor with(Function<Resource, Void> function) {
55          return with(always(), always(), always(), function);
56      }
57  
58      /**
59       * Visits according to the given {@code visitAndApply} predicate and applies the given {@link Function} according to {@code visitAndApply}.
60       * @see Functions which provides a couple of helpful predicates and functions to use with Resource.
61       * @see VoidFunction
62       */
63      public static PredicatedResourceVisitor with(Predicate<Resource> visitAndApply, Function<Resource, Void> function) {
64          return with(visitAndApply, visitAndApply, visitAndApply, function);
65      }
66  
67      /**
68       * Visits according to the given {@code visitDirectory} predicate and applies the given {@link Function} according to {@code applyFunction}.
69       * @see Functions which provides a couple of helpful predicates and functions to use with Resource.
70       * @see VoidFunction
71       */
72      public static PredicatedResourceVisitor with(Predicate<Resource> visitDirectory, Predicate<Resource> applyFunction, Function<Resource, Void> function) {
73          return new PredicatedResourceVisitor(visitDirectory, applyFunction, applyFunction, function);
74      }
75  
76      /**
77       * Visits according to the given {@code visitDirectory} predicate and applies the given {@link Function} according to {@code applyToDirectory} and {@code applyToFile} depending on the resource's type.
78       * @see Functions which provides a couple of helpful predicates and functions to use with Resource.
79       * @see VoidFunction
80       */
81      public static PredicatedResourceVisitor with(Predicate<Resource> visitDirectory, Predicate<Resource> applyToDirectory, Predicate<Resource> applyToFile, Function<Resource, Void> function) {
82          return new PredicatedResourceVisitor(visitDirectory, applyToDirectory, applyToFile, function);
83      }
84  
85      /**
86       * Traverses all directories, and applies the given {@link Function} to all files, according to {@code applyToFile}. Does not apply the function to directory resources.
87       * @see Functions which provides a couple of helpful predicates and functions to use with Resource.
88       * @see VoidFunction
89       */
90      public static PredicatedResourceVisitor onAllMatchingFiles(Predicate<Resource> applyToFile, Function<Resource, Void> function) {
91          return new PredicatedResourceVisitor(Functions.always(), Functions.never(), applyToFile, function);
92      }
93  
94      private final Predicate<Resource> visitDirectory;
95      private final Predicate<Resource> applyToDirectory;
96      private final Predicate<Resource> applyToFile;
97      private final Function<Resource, Void> function;
98  
99      private PredicatedResourceVisitor(Predicate<Resource> visitDirectory, Predicate<Resource> applyToDirectory, Predicate<Resource> applyToFile, Function<Resource, Void> function) {
100         this.visitDirectory = Predicates.or(Functions.pathEquals("/"), visitDirectory);
101         this.applyToDirectory = applyToDirectory;
102         this.applyToFile = applyToFile;
103         this.function = function;
104     }
105 
106     @Override
107     public boolean visitDirectory(Resource resource) {
108         if (applyToDirectory.apply(resource)) {
109             function.apply(resource);
110         }
111         return visitDirectory.apply(resource);
112     }
113 
114     @Override
115     public void visitFile(Resource resource) {
116         if (applyToFile.apply(resource)) {
117             function.apply(resource);
118         }
119     }
120 }