1 /*
2 * Copyright (c) 2012, 2018, 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.TreeTableCell;
34 import javafx.scene.control.TreeTableColumn;
35 import javafx.scene.control.TreeTableColumn.CellDataFeatures;
36 import javafx.scene.control.TreeTableView;
37 import javafx.util.Callback;
38 import com.sun.javafx.property.PropertyReference;
39 import com.sun.javafx.scene.control.Logging;
40 import com.sun.javafx.logging.PlatformLogger;
41 import com.sun.javafx.logging.PlatformLogger.Level;
42
43
44 /**
45 * A convenience implementation of the Callback interface, designed specifically
46 * for use within the {@link TreeTableColumn}
47 * {@link TreeTableColumn#cellValueFactoryProperty() cell value factory}. An example
48 * of how to use this class is:
49 *
50 * <pre><code>
51 * TreeTableColumn<Person,String> firstNameCol = new TreeTableColumn<Person,String>("First Name");
52 * firstNameCol.setCellValueFactory(new TreeItemPropertyValueFactory<Person,String>("firstName"));
53 * </code></pre>
54 *
55 * <p>
56 * In this example, {@code Person} is the class type of the {@link TreeItem}
57 * instances used in the {@link TreeTableView}.
58 * The class {@code Person} must be declared public.
59 * {@code TreeItemPropertyValueFactory} uses the constructor argument,
60 * {@code "firstName"}, to assume that {@code Person} has a public method
61 * {@code firstNameProperty} with no formal parameters and a return type of
62 * {@code ObservableValue<String>}.
63 * </p>
64 * <p>
65 * If such a method exists, then it is invoked, and additionally assumed
66 * to return an instance of {@code Property<String>}. The return value is used
67 * to populate the {@link TreeTableCell}. In addition, the {@code TreeTableView}
68 * adds an observer to the return value, such that any changes fired will be
69 * observed by the {@code TreeTableView}, resulting in the cell immediately
70 * updating.
71 * </p>
72 * <p>
73 * If no such method exists, then {@code TreeItemPropertyValueFactory}
74 * assumes that {@code Person} has a public method {@code getFirstName} or
75 * {@code isFirstName} with no formal parameters and a return type of
76 * {@code String}. If such a method exists, then it is invoked, and its return
77 * value is wrapped in a {@link ReadOnlyObjectWrapper}
78 * and returned to the {@code TreeTableCell}. In this situation,
79 * the {@code TreeTableCell} will not be able to observe changes to the property,
80 * unlike in the first approach above.
81 * </p>
82 *
83 * <p>For reference (and as noted in the TreeTableColumn
84 * {@link TreeTableColumn#cellValueFactoryProperty() cell value factory} documentation), the
85 * long form of the code above would be the following:
86 * </p>
87 *
88 * <pre><code>
89 * TreeTableColumn<Person,String> firstNameCol = new TreeTableColumn<Person,String>("First Name");
90 * {@literal
91 * firstNameCol.setCellValueFactory(new Callback<CellDataFeatures<Person, String>, ObservableValue<String>>() {
92 * public ObservableValue<String> call(CellDataFeatures<Person, String> p) {
93 * // p.getValue() returns the TreeItem<Person> instance for a particular
94 * // TreeTableView row, and the second getValue() call returns the
95 * // Person instance contained within the TreeItem.
96 * return p.getValue().getValue().firstNameProperty();
97 * }
98 * });
99 * }
100 * }
101 * </code></pre>
102 *
103 * <p><b>Deploying an Application as a Module</b></p>
104 * <p>
105 * If the referenced class is in a named module, then it must be reflectively
106 * accessible to the {@code javafx.base} module.
107 * A class is reflectively accessible if the module
108 * {@link Module#isOpen(String,Module) opens} the containing package to at
109 * least the {@code javafx.base} module.
110 * Otherwise the {@link #call call(TreeTableColumn.CellDataFeatures)} method
111 * will log a warning and return {@code null}.
112 * </p>
113 * <p>
114 * For example, if the {@code Person} class is in the {@code com.foo} package
115 * in the {@code foo.app} module, the {@code module-info.java} might
116 * look like this:
117 * </p>
118 *
119 <pre>{@code module foo.app {
120 opens com.foo to javafx.base;
121 }}</pre>
122 *
123 * <p>
124 * Alternatively, a class is reflectively accessible if the module
125 * {@link Module#isExported(String) exports} the containing package
126 * unconditionally.
127 * </p>
128 *
129 * @see TreeTableColumn
130 * @see TreeTableView
131 * @see TreeTableCell
132 * @see PropertyValueFactory
133 * @see MapValueFactory
134 * @since JavaFX 8.0
135 */
136 public class TreeItemPropertyValueFactory<S,T> implements Callback<TreeTableColumn.CellDataFeatures<S,T>, ObservableValue<T>> {
137
138 private final String property;
139
140 private Class<?> columnClass;
141 private String previousProperty;
142 private PropertyReference<T> propertyRef;
143
144 /**
145 * Creates a default PropertyValueFactory to extract the value from a given
146 * TableView row item reflectively, using the given property name.
147 *
148 * @param property The name of the property with which to attempt to
149 * reflectively extract a corresponding value for in a given object.
150 */
151 public TreeItemPropertyValueFactory(@NamedArg("property") String property) {
152 this.property = property;
153 }
154
155 /** {@inheritDoc} */
156 @Override public ObservableValue<T> call(CellDataFeatures<S, T> param) {
157 TreeItem<S> treeItem = param.getValue();
158 return getCellDataReflectively(treeItem.getValue());
159 }
160
161 /**
162 * Returns the property name provided in the constructor.
163 * @return the property name provided in the constructor
164 */
165 public final String getProperty() { return property; }
166
167 private ObservableValue<T> getCellDataReflectively(S rowData) {
168 if (getProperty() == null || getProperty().isEmpty() || rowData == null) return null;
169
170 try {
171 // we attempt to cache the property reference here, as otherwise
172 // performance suffers when working in large data models. For
173 // a bit of reference, refer to RT-13937.
174 if (columnClass == null || previousProperty == null ||
175 ! columnClass.equals(rowData.getClass()) ||
176 ! previousProperty.equals(getProperty())) {
177
178 // create a new PropertyReference
179 this.columnClass = rowData.getClass();
180 this.previousProperty = getProperty();
181 this.propertyRef = new PropertyReference<T>(rowData.getClass(), getProperty());
182 }
183
184 if (propertyRef != null) {
185 return propertyRef.getProperty(rowData);
186 }
187 } catch (RuntimeException e) {
188 try {
189 // attempt to just get the value
190 T value = propertyRef.get(rowData);
191 return new ReadOnlyObjectWrapper<T>(value);
192 } catch (RuntimeException e2) {
193 // fall through to logged exception below
194 }
195
196 // log the warning and move on
197 final PlatformLogger logger = Logging.getControlsLogger();
198 if (logger.isLoggable(Level.WARNING)) {
199 logger.warning("Can not retrieve property '" + getProperty() +
200 "' in TreeItemPropertyValueFactory: " + this +
201 " with provided class type: " + rowData.getClass(), e);
202 }
203 propertyRef = null;
204 }
205
206 return null;
207 }
208 }