/* * Copyright (c) 2011, 2018, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javafx.scene.control.cell; import javafx.beans.NamedArg; import javafx.beans.property.Property; import javafx.beans.property.ReadOnlyObjectWrapper; import javafx.beans.value.ObservableValue; import javafx.scene.control.TableCell; import javafx.scene.control.TableColumn; import javafx.scene.control.TableColumn.CellDataFeatures; import javafx.scene.control.TableView; import javafx.util.Callback; import com.sun.javafx.logging.PlatformLogger; import com.sun.javafx.logging.PlatformLogger.Level; import com.sun.javafx.property.PropertyReference; import com.sun.javafx.scene.control.Logging; /** * A convenience implementation of the Callback interface, designed specifically * for use within the {@link TableColumn} * {@link TableColumn#cellValueFactoryProperty() cell value factory}. An example * of how to use this class is: * * 

 * TableColumn<Person,String> firstNameCol = new TableColumn<Person,String>("First Name");
 * firstNameCol.setCellValueFactory(new PropertyValueFactory<Person,String>("firstName"));
 *
* *

* In this example, {@code Person} is the class type of the {@code TableView} * {@link TableView#itemsProperty() items} list. * The class {@code Person} must be declared public. * {@code PropertyValueFactory} uses the constructor argument, * {@code "firstName"}, to assume that {@code Person} has a public method * {@code firstNameProperty} with no formal parameters and a return type of * {@code ObservableValue}. *

*

* If such a method exists, then it is invoked, and additionally assumed * to return an instance of {@code Property}. The return value is used * to populate the {@link TableCell}. In addition, the {@code TableView} adds * an observer to the return value, such that any changes fired will be observed * by the {@code TableView}, resulting in the cell immediately updating. *

*

* If no such method exists, then {@code PropertyValueFactory} * assumes that {@code Person} has a public method {@code getFirstName} or * {@code isFirstName} with no formal parameters and a return type of * {@code String}. If such a method exists, then it is invoked, and its return * value is wrapped in a {@link ReadOnlyObjectWrapper} * and returned to the {@code TableCell}. In this situation, * the {@code TableCell} will not be able to observe changes to the property, * unlike in the first approach above. *

* *

For reference (and as noted in the TableColumn * {@link TableColumn#cellValueFactoryProperty()} cell value factory} documentation), the * long form of the code above would be the following: *

* * 

 * TableColumn<Person,String> firstNameCol = new TableColumn<Person,String>("First Name");
 * firstNameCol.setCellValueFactory(new Callback<CellDataFeatures<Person, String>, ObservableValue<String>>() {
 *     public ObservableValue<String> call(CellDataFeatures<Person, String> p) {
 *         // p.getValue() returns the Person instance for a particular TableView row
 *         return p.getValue().firstNameProperty();
 *     }
 *  });
 * }
 *
* *

Deploying an Application as a Module

*

* If the referenced class is in a named module, then it must be reflectively * accessible to the {@code javafx.base} module. * A class is reflectively accessible if the module * {@link Module#isOpen(String,Module) opens} the containing package to at * least the {@code javafx.base} module. * Otherwise the {@link #call call(TableColumn.CellDataFeatures)} method * will log a warning and return {@code null}. *

*

* For example, if the {@code Person} class is in the {@code com.foo} package * in the {@code foo.app} module, the {@code module-info.java} might * look like this: *

* 
{@code module foo.app {
    opens com.foo to javafx.base;
}}
* *

* Alternatively, a class is reflectively accessible if the module * {@link Module#isExported(String) exports} the containing package * unconditionally. *

* * @see TableColumn * @see TableView * @see TableCell * @see TreeItemPropertyValueFactory * @see MapValueFactory * @param The type of the class contained within the TableView.items list. * @param The type of the class contained within the TableColumn cells. * @since JavaFX 2.0 */ public class PropertyValueFactory implements Callback, ObservableValue> { private final String property; private Class columnClass; private String previousProperty; private PropertyReference propertyRef; /** * Creates a default PropertyValueFactory to extract the value from a given * TableView row item reflectively, using the given property name. * * @param property The name of the property with which to attempt to * reflectively extract a corresponding value for in a given object. */ public PropertyValueFactory(@NamedArg("property") String property) { this.property = property; } /** {@inheritDoc} */ @Override public ObservableValue call(CellDataFeatures param) { return getCellDataReflectively(param.getValue()); } /** * Returns the property name provided in the constructor. * @return the property name provided in the constructor */ public final String getProperty() { return property; } private ObservableValue getCellDataReflectively(S rowData) { if (getProperty() == null || getProperty().isEmpty() || rowData == null) return null; try { // we attempt to cache the property reference here, as otherwise // performance suffers when working in large data models. For // a bit of reference, refer to RT-13937. if (columnClass == null || previousProperty == null || ! columnClass.equals(rowData.getClass()) || ! previousProperty.equals(getProperty())) { // create a new PropertyReference this.columnClass = rowData.getClass(); this.previousProperty = getProperty(); this.propertyRef = new PropertyReference(rowData.getClass(), getProperty()); } if (propertyRef != null) { if (propertyRef.hasProperty()) { return propertyRef.getProperty(rowData); } else { T value = propertyRef.get(rowData); return new ReadOnlyObjectWrapper(value); } } } catch (RuntimeException e) { // log the warning and move on final PlatformLogger logger = Logging.getControlsLogger(); if (logger.isLoggable(Level.WARNING)) { logger.warning("Can not retrieve property '" + getProperty() + "' in PropertyValueFactory: " + this + " with provided class type: " + rowData.getClass(), e); } propertyRef = null; } return null; } }