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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  
20  package org.apache.myfaces.tobago.facelets;
21  
22  import org.apache.myfaces.tobago.component.Attributes;
23  import org.apache.myfaces.tobago.component.Position;
24  import org.apache.myfaces.tobago.layout.Measure;
25  
26  import javax.el.ValueExpression;
27  import javax.faces.component.UIComponent;
28  import javax.faces.view.facelets.FaceletContext;
29  import javax.faces.view.facelets.MetaRule;
30  import javax.faces.view.facelets.Metadata;
31  import javax.faces.view.facelets.MetadataTarget;
32  import javax.faces.view.facelets.TagAttribute;
33  
34  public class PositionRule extends MetaRule {
35    
36    public static final PositionRule INSTANCE = new PositionRule();
37  
38    public Metadata applyRule(String name, TagAttribute attribute, MetadataTarget metadataTarget) {
39      if (Attributes.LEFT.equals(name)) {
40        return new LeftMapper(attribute);
41      }
42      if (Attributes.TOP.equals(name)) {
43        return new TopMapper(attribute);
44      }
45      return null;
46    }
47  
48    static final class LeftMapper extends Metadata {
49      private final TagAttribute attribute;
50  
51      LeftMapper(TagAttribute attribute) {
52        this.attribute = attribute;
53      }
54  
55      public void applyMetadata(FaceletContext ctx, Object instance) {
56        if (attribute.isLiteral()) {
57          ((Position) instance).setLeft(Measure.parse(attribute.getValue()));
58        } else {
59          ValueExpression expression = attribute.getValueExpression(ctx, Object.class);
60          ((UIComponent) instance).setValueExpression(Attributes.LEFT, expression);
61        }
62      }
63    }
64  
65    static final class TopMapper extends Metadata {
66      private final TagAttribute attribute;
67  
68      TopMapper(TagAttribute attribute) {
69        this.attribute = attribute;
70      }
71  
72      public void applyMetadata(FaceletContext ctx, Object instance) {
73        if (attribute.isLiteral()) {
74           ((Position) instance).setTop(Measure.parse(attribute.getValue()));
75        } else {
76          ValueExpression expression = attribute.getValueExpression(ctx, Object.class);
77          ((UIComponent) instance).setValueExpression(Attributes.TOP, expression);
78        }
79      }
80    }
81  }