1 /* 2 * Copyright (c) 2011, 2017, 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 * <p> 56 * In this example, {@code Person} is the class type of the {@code TableView} 57 * {@link TableView#itemsProperty() items} list. 58 * The class {@code Person} must be declared public. 59 * {@code PropertyValueFactory} 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 TableCell}. In addition, the {@code TableView} adds 68 * an observer to the return value, such that any changes fired will be observed 69 * by the {@code TableView}, resulting in the cell immediately updating. 70 * </p> 71 * <p> 72 * If no such method exists, then {@code PropertyValueFactory} 73 * assumes that {@code Person} has a public method {@code getFirstName} or 74 * {@code isFirstName} with no formal parameters and a return type of 75 * {@code String}. If such a method exists, then it is invoked, and its return 76 * value is wrapped in a {@link ReadOnlyObjectWrapper} 77 * and returned to the {@code TableCell}. In this situation, 78 * the {@code TableCell} will not be able to observe changes to the property, 79 * unlike in the first approach above. 80 * </p> 81 * 82 * <p>For reference (and as noted in the TableColumn 83 * {@link TableColumn#cellValueFactory cell value factory} documentation), the 84 * long form of the code above would be the following: 85 * </p> 86 * 87 * <pre><code> 88 * TableColumn<Person,String> firstNameCol = new TableColumn<Person,String>("First Name"); 89 * firstNameCol.setCellValueFactory(new Callback<CellDataFeatures<Person, String>, ObservableValue<String>>() { 90 * public ObservableValue<String> call(CellDataFeatures<Person, String> p) { 91 * // p.getValue() returns the Person instance for a particular TableView row 92 * return p.getValue().firstNameProperty(); 93 * } 94 * }); 95 * } 96 * </code></pre> 97 * 98 * <p><b>Deploying an Application as a Module</b></p> 99 * <p> 100 * If the referenced class is in a named module, then it must be reflectively 101 * accessible to the {@code javafx.base} module. 102 * A class is reflectively accessible if the module 103 * {@link Module#isOpen(String,Module) opens} the containing package to at 104 * least the {@code javafx.base} module. 105 * Otherwise the {@link #call call(TableColumn.CellDataFeatures)} method 106 * will log a warning and return {@code null}. 107 * </p> 108 * <p> 109 * For example, if the {@code Person} class is in the {@code com.foo} package 110 * in the {@code foo.app} module, the {@code module-info.java} might 111 * look like this: 112 * </p> 113 * 114 <pre>{@code module foo.app { 115 opens com.foo to javafx.base; 116 }}</pre> 117 * 118 * <p> 119 * Alternatively, a class is reflectively accessible if the module 120 * {@link Module#isExported(String) exports} the containing package 121 * unconditionally. 122 * </p> 123 * 124 * @see TableColumn 125 * @see TableView 126 * @see TableCell 127 * @see TreeItemPropertyValueFactory 128 * @see MapValueFactory 129 * @param <S> The type of the class contained within the TableView.items list. 130 * @param <T> The type of the class contained within the TableColumn cells. 131 * @since JavaFX 2.0 132 */ 133 public class PropertyValueFactory<S,T> implements Callback<CellDataFeatures<S,T>, ObservableValue<T>> { 134 135 private final String property; 136 137 private Class<?> columnClass; 138 private String previousProperty; 139 private PropertyReference<T> propertyRef; 140 141 /** 142 * Creates a default PropertyValueFactory to extract the value from a given 143 * TableView row item reflectively, using the given property name. 144 * 145 * @param property The name of the property with which to attempt to 146 * reflectively extract a corresponding value for in a given object. 147 */ 148 public PropertyValueFactory(@NamedArg("property") String property) { 149 this.property = property; 150 } 151 152 /** {@inheritDoc} */ 153 @Override public ObservableValue<T> call(CellDataFeatures<S,T> param) { 154 return getCellDataReflectively(param.getValue()); 155 } 156 157 /** 158 * Returns the property name provided in the constructor. 159 * @return the property name provided in the constructor 160 */ 161 public final String getProperty() { return property; } 162 163 private ObservableValue<T> getCellDataReflectively(S rowData) { 164 if (getProperty() == null || getProperty().isEmpty() || rowData == null) return null; 165 166 try { 167 // we attempt to cache the property reference here, as otherwise 168 // performance suffers when working in large data models. For 169 // a bit of reference, refer to RT-13937. 170 if (columnClass == null || previousProperty == null || 171 ! columnClass.equals(rowData.getClass()) || 172 ! previousProperty.equals(getProperty())) { 173 174 // create a new PropertyReference 175 this.columnClass = rowData.getClass(); 176 this.previousProperty = getProperty(); 177 this.propertyRef = new PropertyReference<T>(rowData.getClass(), getProperty()); 178 } 179 180 if (propertyRef != null) { 181 if (propertyRef.hasProperty()) { 182 return propertyRef.getProperty(rowData); 183 } else { 184 T value = propertyRef.get(rowData); 185 return new ReadOnlyObjectWrapper<T>(value); 186 } 187 } 188 } catch (RuntimeException e) { 189 // log the warning and move on 190 final PlatformLogger logger = Logging.getControlsLogger(); 191 if (logger.isLoggable(Level.WARNING)) { 192 logger.warning("Can not retrieve property '" + getProperty() + 193 "' in PropertyValueFactory: " + this + 194 " with provided class type: " + rowData.getClass(), e); 195 } 196 propertyRef = null; 197 } 198 199 return null; 200 } 201 }