Java tutorial
/* * Copyright (c) 2012, 2017, 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 static javafx.scene.control.cell.CellUtils.createComboBox; import javafx.beans.property.BooleanProperty; import javafx.beans.property.ObjectProperty; import javafx.beans.property.SimpleBooleanProperty; import javafx.beans.property.SimpleObjectProperty; import javafx.collections.FXCollections; import javafx.collections.ObservableList; import javafx.scene.control.*; import javafx.util.Callback; import javafx.util.StringConverter; /** * A class containing a {@link ListCell} implementation that draws a * {@link ComboBox} node inside the cell. * * <p>By default, the ComboBoxListCell is rendered as a {@link Label} when not * being edited, and as a ComboBox when in editing mode. The ComboBox will, by * default, stretch to fill the entire list cell. * * <p>To create a ComboBoxListCell, it is necessary to provide zero or more * items that will be shown to the user when the {@link ComboBox} menu is * showing. These items must be of the same type as the ListView items sequence, * such that upon selection, they replace the existing value in the * {@link ListView#itemsProperty() items} list. * * @param <T> The type of the elements contained within the ListView. * @since JavaFX 2.2 */ public class ComboBoxListCell<T> extends ListCell<T> { /*************************************************************************** * * * Static cell factories * * * **************************************************************************/ /** * Creates a ComboBox cell factory for use in {@link ListView} controls. By * default, the ComboBoxCell is rendered as a {@link Label} when not being * edited, and as a ComboBox when in editing mode. The ComboBox will, by * default, stretch to fill the entire list cell. * * @param <T> The type of the elements contained within the ListView. * @param items Zero or more items that will be shown to the user when the * {@link ComboBox} menu is showing. These items must be of the same * type as the ListView items list, such that upon selection, they * replace the existing value in the * {@link ListView#itemsProperty() items} list. * @return A {@link Callback} that will return a ListCell that is able to * work on the type of element contained within the ListView. */ @SafeVarargs public static <T> Callback<ListView<T>, ListCell<T>> forListView(final T... items) { return forListView(FXCollections.observableArrayList(items)); } /** * Creates a ComboBox cell factory for use in {@link ListView} controls. By * default, the ComboBoxCell is rendered as a {@link Label} when not being * edited, and as a ComboBox when in editing mode. The ComboBox will, by * default, stretch to fill the entire list cell. * * @param <T> The type of the elements contained within the ListView. * @param converter A {@link StringConverter} to convert the given item (of * type T) to a String for displaying to the user. * @param items Zero or more items that will be shown to the user when the * {@link ComboBox} menu is showing. These items must be of the same * type as the ListView items list, such that * upon selection, they replace the existing value in the * {@link ListView#itemsProperty() items} list. * @return A {@link Callback} that will return a ListCell that is able to * work on the type of element contained within the ListView. */ @SafeVarargs public static <T> Callback<ListView<T>, ListCell<T>> forListView(final StringConverter<T> converter, final T... items) { return forListView(converter, FXCollections.observableArrayList(items)); } /** * Creates a ComboBox cell factory for use in {@link ListView} controls. By * default, the ComboBoxCell is rendered as a {@link Label} when not being * edited, and as a ComboBox when in editing mode. The ComboBox will, by * default, stretch to fill the entire list cell. * * @param <T> The type of the elements contained within the ListView. * @param items An {@link ObservableList} containing zero or more items that * will be shown to the user when the {@link ComboBox} menu is showing. * These items must be of the same type as the ListView items sequence, * such that upon selection, they replace the existing value in the * {@link ListView#itemsProperty() items} list. * @return A {@link Callback} that will return a ListCell that is able to * work on the type of element contained within the ListView. */ public static <T> Callback<ListView<T>, ListCell<T>> forListView(final ObservableList<T> items) { return forListView(null, items); } /** * Creates a ComboBox cell factory for use in {@link ListView} controls. By * default, the ComboBoxCell is rendered as a {@link Label} when not being * edited, and as a ComboBox when in editing mode. The ComboBox will, by * default, stretch to fill the entire list cell. * * @param <T> The type of the elements contained within the ListView. * @param converter A {@link StringConverter} to convert the given item (of * type T) to a String for displaying to the user. * @param items An {@link ObservableList} containing zero or more items that * will be shown to the user when the {@link ComboBox} menu is showing. * These items must be of the same type as the ListView items sequence, * such that upon selection, they replace the existing value in the * {@link ListView#itemsProperty() items} list. * @return A {@link Callback} that will return a ListCell that is able to * work on the type of element contained within the ListView. */ public static <T> Callback<ListView<T>, ListCell<T>> forListView(final StringConverter<T> converter, final ObservableList<T> items) { return list -> new ComboBoxListCell<T>(converter, items); } /*************************************************************************** * * * Fields * * * **************************************************************************/ private final ObservableList<T> items; private ComboBox<T> comboBox; /*************************************************************************** * * * Constructors * * * **************************************************************************/ /** * Creates a default ComboBoxListCell with an empty items list. */ public ComboBoxListCell() { this(FXCollections.<T>observableArrayList()); } /** * Creates a default {@link ComboBoxListCell} instance with the given items * being used to populate the {@link ComboBox} when it is shown. * * @param items The items to show in the ComboBox popup menu when selected * by the user. */ @SafeVarargs public ComboBoxListCell(T... items) { this(FXCollections.observableArrayList(items)); } /** * Creates a {@link ComboBoxListCell} instance with the given items * being used to populate the {@link ComboBox} when it is shown, and the * {@link StringConverter} being used to convert the item in to a * user-readable form. * * @param converter A {@link StringConverter} that can convert an item of * type T into a user-readable string so that it may then be shown in * the ComboBox popup menu. * @param items The items to show in the ComboBox popup menu when selected * by the user. */ @SafeVarargs public ComboBoxListCell(StringConverter<T> converter, T... items) { this(converter, FXCollections.observableArrayList(items)); } /** * Creates a default {@link ComboBoxListCell} instance with the given items * being used to populate the {@link ComboBox} when it is shown. * * @param items The items to show in the ComboBox popup menu when selected * by the user. */ public ComboBoxListCell(ObservableList<T> items) { this(null, items); } /** * Creates a {@link ComboBoxListCell} instance with the given items * being used to populate the {@link ComboBox} when it is shown, and the * {@link StringConverter} being used to convert the item in to a * user-readable form. * * @param converter A {@link StringConverter} that can convert an item of * type T into a user-readable string so that it may then be shown in * the ComboBox popup menu. * @param items The items to show in the ComboBox popup menu when selected * by the user. */ public ComboBoxListCell(StringConverter<T> converter, ObservableList<T> items) { this.getStyleClass().add("combo-box-list-cell"); this.items = items; setConverter(converter != null ? converter : CellUtils.<T>defaultStringConverter()); } /*************************************************************************** * * * Properties * * * **************************************************************************/ // --- converter private ObjectProperty<StringConverter<T>> converter = new SimpleObjectProperty<StringConverter<T>>(this, "converter"); /** * The {@link StringConverter} property. * @return the {@link StringConverter} property */ public final ObjectProperty<StringConverter<T>> converterProperty() { return converter; } /** * Sets the {@link StringConverter} to be used in this cell. * @param value the {@link StringConverter} to be used in this cell */ public final void setConverter(StringConverter<T> value) { converterProperty().set(value); } /** * Returns the {@link StringConverter} used in this cell. * @return the {@link StringConverter} used in this cell */ public final StringConverter<T> getConverter() { return converterProperty().get(); } // --- comboBox editable private BooleanProperty comboBoxEditable = new SimpleBooleanProperty(this, "comboBoxEditable"); /** * A property representing whether the ComboBox, when shown to the user, * is editable or not. * @return the property representing whether the ComboBox, when shown to * the user, is editable or not */ public final BooleanProperty comboBoxEditableProperty() { return comboBoxEditable; } /** * Configures the ComboBox to be editable (to allow user input outside of the * options provide in the dropdown list). * @param value the editable value for this ComboBox */ public final void setComboBoxEditable(boolean value) { comboBoxEditableProperty().set(value); } /** * Returns true if the ComboBox is editable. * @return true if the ComboBox is editable */ public final boolean isComboBoxEditable() { return comboBoxEditableProperty().get(); } /*************************************************************************** * * * Public API * * * **************************************************************************/ /** * Returns the items to be displayed in the ChoiceBox when it is showing. * @return the items to be displayed in the ChoiceBox when it is showing */ public ObservableList<T> getItems() { return items; } /** {@inheritDoc} */ @Override public void startEdit() { if (!isEditable() || !getListView().isEditable()) { return; } if (comboBox == null) { comboBox = createComboBox(this, items, converterProperty()); comboBox.editableProperty().bind(comboBoxEditableProperty()); } comboBox.getSelectionModel().select(getItem()); super.startEdit(); if (isEditing()) { setText(null); setGraphic(comboBox); } } /** {@inheritDoc} */ @Override public void cancelEdit() { super.cancelEdit(); setText(getConverter().toString(getItem())); setGraphic(null); } /** {@inheritDoc} */ @Override public void updateItem(T item, boolean empty) { super.updateItem(item, empty); CellUtils.updateItem(this, getConverter(), null, null, comboBox); } }