1 /*
2 * Copyright (c) 2012, 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.TreeItem;
33 import javafx.scene.control.TreeTableColumn;
34 import javafx.scene.control.TreeTableColumn.CellDataFeatures;
35 import javafx.util.Callback;
36 import com.sun.javafx.property.PropertyReference;
37 import com.sun.javafx.scene.control.Logging;
38 import sun.util.logging.PlatformLogger;
39 import sun.util.logging.PlatformLogger.Level;
40
41
42 /**
43 * A convenience implementation of the Callback interface, designed specifically
44 * for use within the {@link TreeTableColumn}
45 * {@link TreeTableColumn#cellValueFactoryProperty() cell value factory}. An example
46 * of how to use this class is:
47 *
48 * <pre><code>
49 * TreeTableColumn<Person,String> firstNameCol = new TreeTableColumn<Person,String>("First Name");
50 * firstNameCol.setCellValueFactory(new TreeItemPropertyValueFactory<Person,String>("firstName"));
51 * </code></pre>
52 *
53 * In this example, the "firstName" string is used as a reference to an assumed
54 * <code>firstNameProperty()</code> method in the <code>Person</code> class type
55 * (which is the class type of the TreeTableView). Additionally, this method must
56 * return a {@link Property} instance. If a method meeting these requirements
57 * is found, then the {@link javafx.scene.control.TreeTableCell} is populated with this ObservableValue<T>.
58 * In addition, the TreeTableView will automatically add an observer to the
59 * returned value, such that any changes fired will be observed by the TreeTableView,
60 * resulting in the cell immediately updating.
61 *
62 * <p>If no method matching this pattern exists, there is fall-through support
63 * for attempting to call get<property>() or is<property>() (that is,
64 * <code>getFirstName()</code> or <code>isFirstName()</code> in the example
65 * above). If a method matching this pattern exists, the value returned from this method
66 * is wrapped in a {@link ReadOnlyObjectWrapper} and returned to the TreeTableCell.
67 * However, in this situation, this means that the TreeTableCell will not be able
68 * to observe the ObservableValue for changes (as is the case in the first
69 * approach above).
70 *
71 * <p>For reference (and as noted in the TreeTableColumn
72 * {@link TreeTableColumn#cellValueFactory cell value factory} documentation), the
73 * long form of the code above would be the following:
74 *
75 * <pre><code>
76 * TreeTableColumn<Person,String> firstNameCol = new TreeTableColumn<Person,String>("First Name");
77 * firstNameCol.setCellValueFactory(new Callback<CellDataFeatures<Person, String>, ObservableValue<String>>() {
78 * public ObservableValue<String> call(CellDataFeatures<Person, String> p) {
79 * // p.getValue() returns the TreeItem<Person> instance for a particular
80 * // TreeTableView row, and the second getValue() call returns the
81 * // Person instance contained within the TreeItem.
82 * return p.getValue().getValue().firstNameProperty();
83 * }
84 * });
85 * }
86 * </code></pre>
87 *
88 * @see TreeTableColumn
89 * @see javafx.scene.control.TreeTableView
90 * @see javafx.scene.control.TreeTableCell
91 * @see PropertyValueFactory
92 * @see MapValueFactory
93 * @since JavaFX 8.0
94 */
95 public class TreeItemPropertyValueFactory<S,T> implements Callback<TreeTableColumn.CellDataFeatures<S,T>, ObservableValue<T>> {
96
97 private final String property;
98
99 private Class<?> columnClass;
100 private String previousProperty;
101 private PropertyReference<T> propertyRef;
102
103 /**
104 * Creates a default PropertyValueFactory to extract the value from a given
105 * TableView row item reflectively, using the given property name.
106 *
107 * @param property The name of the property with which to attempt to
108 * reflectively extract a corresponding value for in a given object.
109 */
110 public TreeItemPropertyValueFactory(@NamedArg("property") String property) {
111 this.property = property;
112 }
113
114 /** {@inheritDoc} */
115 @Override public ObservableValue<T> call(CellDataFeatures<S, T> param) {
116 TreeItem<S> treeItem = param.getValue();
117 return getCellDataReflectively(treeItem.getValue());
118 }
119
120 /**
121 * Returns the property name provided in the constructor.
122 */
123 public final String getProperty() { return property; }
124
125 private ObservableValue<T> getCellDataReflectively(S rowData) {
126 if (getProperty() == null || getProperty().isEmpty() || rowData == null) return null;
127
128 try {
129 // we attempt to cache the property reference here, as otherwise
130 // performance suffers when working in large data models. For
131 // a bit of reference, refer to RT-13937.
132 if (columnClass == null || previousProperty == null ||
133 ! columnClass.equals(rowData.getClass()) ||
134 ! previousProperty.equals(getProperty())) {
135
136 // create a new PropertyReference
137 this.columnClass = rowData.getClass();
138 this.previousProperty = getProperty();
139 this.propertyRef = new PropertyReference<T>(rowData.getClass(), getProperty());
140 }
141
142 return propertyRef.getProperty(rowData);
143 } catch (IllegalStateException e) {
144 try {
145 // attempt to just get the value
146 T value = propertyRef.get(rowData);
147 return new ReadOnlyObjectWrapper<T>(value);
148 } catch (IllegalStateException e2) {
149 // fall through to logged exception below
150 }
151
152 // log the warning and move on
153 final PlatformLogger logger = Logging.getControlsLogger();
154 if (logger.isLoggable(Level.WARNING)) {
155 logger.finest("Can not retrieve property '" + getProperty() +
156 "' in TreeItemPropertyValueFactory: " + this +
157 " with provided class type: " + rowData.getClass(), e);
158 }
159 }
160
161 return null;
162 }
163 }