1 /*
2 * Copyright (c) 2011, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package javafx.scene.control.cell;
27
28 import javafx.beans.NamedArg;
29 import javafx.beans.property.Property;
30 import javafx.beans.property.ReadOnlyObjectWrapper;
31 import javafx.beans.value.ObservableValue;
32 import javafx.scene.control.TableCell;
33 import javafx.scene.control.TableColumn;
34 import javafx.scene.control.TableColumn.CellDataFeatures;
35 import javafx.scene.control.TableView;
36 import javafx.util.Callback;
37
38 import sun.util.logging.PlatformLogger;
39 import sun.util.logging.PlatformLogger.Level;
40 import com.sun.javafx.property.PropertyReference;
41 import com.sun.javafx.scene.control.Logging;
42
43
44 /**
45 * A convenience implementation of the Callback interface, designed specifically
46 * for use within the {@link TableColumn}
47 * {@link TableColumn#cellValueFactoryProperty() cell value factory}. An example
48 * of how to use this class is:
49 *
50 * <pre><code>
51 * TableColumn<Person,String> firstNameCol = new TableColumn<Person,String>("First Name");
52 * firstNameCol.setCellValueFactory(new PropertyValueFactory<Person,String>("firstName"));
53 * </code></pre>
54 *
55 * In this example, the "firstName" string is used as a reference to an assumed
56 * <code>firstNameProperty()</code> method in the <code>Person</code> class type
57 * (which is the class type of the TableView
58 * {@link TableView#itemsProperty() items} list). Additionally, this method must
59 * return a {@link Property} instance. If a method meeting these requirements
60 * is found, then the {@link TableCell} is populated with this
61 * {@literal ObservableValue<T>}.
62 * In addition, the TableView will automatically add an observer to the
63 * returned value, such that any changes fired will be observed by the TableView,
64 * resulting in the cell immediately updating.
65 *
66 * <p>If no method matching this pattern exists, there is fall-through support
67 * for attempting to call get<property>() or is<property>() (that is,
68 * <code>getFirstName()</code> or <code>isFirstName()</code> in the example
69 * above). If a method matching this pattern exists, the value returned from this method
70 * is wrapped in a {@link ReadOnlyObjectWrapper} and returned to the TableCell.
71 * However, in this situation, this means that the TableCell will not be able
72 * to observe the ObservableValue for changes (as is the case in the first
73 * approach above).
74 *
75 * <p>For reference (and as noted in the TableColumn
76 * {@link TableColumn#cellValueFactory cell value factory} documentation), the
77 * long form of the code above would be the following:
78 *
79 * <pre><code>
80 * TableColumn<Person,String> firstNameCol = new TableColumn<Person,String>("First Name");
81 * firstNameCol.setCellValueFactory(new Callback<CellDataFeatures<Person, String>, ObservableValue<String>>() {
82 * public ObservableValue<String> call(CellDataFeatures<Person, String> p) {
83 * // p.getValue() returns the Person instance for a particular TableView row
84 * return p.getValue().firstNameProperty();
85 * }
86 * });
87 * }
88 * </code></pre>
89 *
90 * @see TableColumn
91 * @see TableView
92 * @see TableCell
93 * @see TreeItemPropertyValueFactory
94 * @see MapValueFactory
95 * @param <S> The type of the class contained within the TableView.items list.
96 * @param <T> The type of the class contained within the TableColumn cells.
97 * @since JavaFX 2.0
98 */
99 public class PropertyValueFactory<S,T> implements Callback<CellDataFeatures<S,T>, ObservableValue<T>> {
100
101 private final String property;
102
103 private Class<?> columnClass;
104 private String previousProperty;
105 private PropertyReference<T> propertyRef;
106
107 /**
108 * Creates a default PropertyValueFactory to extract the value from a given
109 * TableView row item reflectively, using the given property name.
110 *
111 * @param property The name of the property with which to attempt to
112 * reflectively extract a corresponding value for in a given object.
113 */
114 public PropertyValueFactory(@NamedArg("property") String property) {
115 this.property = property;
116 }
117
118 /** {@inheritDoc} */
119 @Override public ObservableValue<T> call(CellDataFeatures<S,T> param) {
120 return getCellDataReflectively(param.getValue());
121 }
122
123 /**
124 * Returns the property name provided in the constructor.
125 * @return the property name provided in the constructor
126 */
127 public final String getProperty() { return property; }
128
129 private ObservableValue<T> getCellDataReflectively(S rowData) {
130 if (getProperty() == null || getProperty().isEmpty() || rowData == null) return null;
131
132 try {
133 // we attempt to cache the property reference here, as otherwise
134 // performance suffers when working in large data models. For
135 // a bit of reference, refer to RT-13937.
136 if (columnClass == null || previousProperty == null ||
137 ! columnClass.equals(rowData.getClass()) ||
138 ! previousProperty.equals(getProperty())) {
139
140 // create a new PropertyReference
141 this.columnClass = rowData.getClass();
142 this.previousProperty = getProperty();
143 this.propertyRef = new PropertyReference<T>(rowData.getClass(), getProperty());
144 }
145
146 if (propertyRef.hasProperty()) {
147 return propertyRef.getProperty(rowData);
148 } else {
149 T value = propertyRef.get(rowData);
150 return new ReadOnlyObjectWrapper<T>(value);
151 }
152 } catch (IllegalStateException e) {
153 // log the warning and move on
154 final PlatformLogger logger = Logging.getControlsLogger();
155 if (logger.isLoggable(Level.WARNING)) {
156 logger.finest("Can not retrieve property '" + getProperty() +
157 "' in PropertyValueFactory: " + this +
158 " with provided class type: " + rowData.getClass(), e);
159 }
160 }
161
162 return null;
163 }
164 }