Java tutorial
/* * Copyright (c) 1997, 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 javax.swing; import java.beans.JavaBean; import java.beans.BeanProperty; import java.beans.PropertyChangeEvent; import java.beans.PropertyChangeListener; import java.beans.Transient; import java.util.*; import java.awt.*; import java.awt.event.*; import java.io.Serializable; import java.io.ObjectOutputStream; import java.io.IOException; import javax.swing.event.*; import javax.swing.plaf.*; import javax.accessibility.*; /** * A component that combines a button or editable field and a drop-down list. * The user can select a value from the drop-down list, which appears at the * user's request. If you make the combo box editable, then the combo box * includes an editable field into which the user can type a value. * <p> * <strong>Warning:</strong> Swing is not thread safe. For more * information see <a * href="package-summary.html#threading">Swing's Threading * Policy</a>. * <p> * <strong>Warning:</strong> * Serialized objects of this class will not be compatible with * future Swing releases. The current serialization support is * appropriate for short term storage or RMI between applications running * the same version of Swing. As of 1.4, support for long term storage * of all JavaBeans™ * has been added to the <code>java.beans</code> package. * Please see {@link java.beans.XMLEncoder}. * * <p> * See <a href="https://docs.oracle.com/javase/tutorial/uiswing/components/combobox.html">How to Use Combo Boxes</a> * in <a href="https://docs.oracle.com/javase/tutorial/"><em>The Java Tutorial</em></a> * for further information. * * @see ComboBoxModel * @see DefaultComboBoxModel * * @param <E> the type of the elements of this combo box * * @author Arnaud Weber * @author Mark Davidson * @since 1.2 */ @JavaBean(defaultProperty = "UI", description = "A combination of a text field and a drop-down list.") @SwingContainer(false) @SuppressWarnings("serial") // Same-version serialization only public class JComboBox<E> extends JComponent implements ItemSelectable, ListDataListener, ActionListener, Accessible { /** * @see #getUIClassID * @see #readObject */ private static final String uiClassID = "ComboBoxUI"; /** * This protected field is implementation specific. Do not access directly * or override. Use the accessor methods instead. * * @see #getModel * @see #setModel */ protected ComboBoxModel<E> dataModel; /** * This protected field is implementation specific. Do not access directly * or override. Use the accessor methods instead. * * @see #getRenderer * @see #setRenderer */ protected ListCellRenderer<? super E> renderer; /** * This protected field is implementation specific. Do not access directly * or override. Use the accessor methods instead. * * @see #getEditor * @see #setEditor */ protected ComboBoxEditor editor; /** * This protected field is implementation specific. Do not access directly * or override. Use the accessor methods instead. * * @see #getMaximumRowCount * @see #setMaximumRowCount */ protected int maximumRowCount = 8; /** * This protected field is implementation specific. Do not access directly * or override. Use the accessor methods instead. * * @see #isEditable * @see #setEditable */ protected boolean isEditable = false; /** * This protected field is implementation specific. Do not access directly * or override. Use the accessor methods instead. * * @see #setKeySelectionManager * @see #getKeySelectionManager */ protected KeySelectionManager keySelectionManager = null; /** * This protected field is implementation specific. Do not access directly * or override. Use the accessor methods instead. * * @see #setActionCommand * @see #getActionCommand */ protected String actionCommand = "comboBoxChanged"; /** * This protected field is implementation specific. Do not access directly * or override. Use the accessor methods instead. * * @see #setLightWeightPopupEnabled * @see #isLightWeightPopupEnabled */ protected boolean lightWeightPopupEnabled = JPopupMenu.getDefaultLightWeightPopupEnabled(); /** * This protected field is implementation specific. Do not access directly * or override. */ protected Object selectedItemReminder = null; private E prototypeDisplayValue; // Flag to ensure that infinite loops do not occur with ActionEvents. private boolean firingActionEvent = false; // Flag to ensure the we don't get multiple ActionEvents on item selection. private boolean selectingItem = false; // Flag to indicate UI update is in progress private transient boolean updateInProgress; /** * Creates a <code>JComboBox</code> that takes its items from an * existing <code>ComboBoxModel</code>. Since the * <code>ComboBoxModel</code> is provided, a combo box created using * this constructor does not create a default combo box model and * may impact how the insert, remove and add methods behave. * * @param aModel the <code>ComboBoxModel</code> that provides the * displayed list of items * @see DefaultComboBoxModel */ public JComboBox(ComboBoxModel<E> aModel) { super(); setModel(aModel); init(); } /** * Creates a <code>JComboBox</code> that contains the elements * in the specified array. By default the first item in the array * (and therefore the data model) becomes selected. * * @param items an array of objects to insert into the combo box * @see DefaultComboBoxModel */ public JComboBox(E[] items) { super(); setModel(new DefaultComboBoxModel<E>(items)); init(); } /** * Creates a <code>JComboBox</code> that contains the elements * in the specified Vector. By default the first item in the vector * (and therefore the data model) becomes selected. * * @param items an array of vectors to insert into the combo box * @see DefaultComboBoxModel */ public JComboBox(Vector<E> items) { super(); setModel(new DefaultComboBoxModel<E>(items)); init(); } /** * Creates a <code>JComboBox</code> with a default data model. * The default data model is an empty list of objects. * Use <code>addItem</code> to add items. By default the first item * in the data model becomes selected. * * @see DefaultComboBoxModel */ public JComboBox() { super(); setModel(new DefaultComboBoxModel<E>()); init(); } private void init() { installAncestorListener(); setUIProperty("opaque", true); updateUI(); } /** * Registers ancestor listener so that it will receive * {@code AncestorEvents} when it or any of its ancestors * move or are made visible or invisible. * Events are also sent when the component or its ancestors are added * or removed from the containment hierarchy. */ protected void installAncestorListener() { addAncestorListener(new AncestorListener() { public void ancestorAdded(AncestorEvent event) { hidePopup(); } public void ancestorRemoved(AncestorEvent event) { hidePopup(); } public void ancestorMoved(AncestorEvent event) { if (event.getSource() != JComboBox.this) hidePopup(); } }); } /** * Sets the L&F object that renders this component. * * @param ui the <code>ComboBoxUI</code> L&F object * @see UIDefaults#getUI */ @BeanProperty(hidden = true, visualUpdate = true, description = "The UI object that implements the Component's LookAndFeel.") public void setUI(ComboBoxUI ui) { super.setUI(ui); } /** * Resets the UI property to a value from the current look and feel. * * @see JComponent#updateUI */ public void updateUI() { if (!updateInProgress) { updateInProgress = true; try { setUI((ComboBoxUI) UIManager.getUI(this)); ListCellRenderer<? super E> renderer = getRenderer(); if (renderer instanceof Component) { SwingUtilities.updateComponentTreeUI((Component) renderer); } } finally { updateInProgress = false; } } } /** * Returns the name of the L&F class that renders this component. * * @return the string "ComboBoxUI" * @see JComponent#getUIClassID * @see UIDefaults#getUI */ @BeanProperty(bound = false) public String getUIClassID() { return uiClassID; } /** * Returns the L&F object that renders this component. * * @return the ComboBoxUI object that renders this component */ public ComboBoxUI getUI() { return (ComboBoxUI) ui; } /** * Sets the data model that the <code>JComboBox</code> uses to obtain * the list of items. * * @param aModel the <code>ComboBoxModel</code> that provides the * displayed list of items */ @BeanProperty(description = "Model that the combo box uses to get data to display.") public void setModel(ComboBoxModel<E> aModel) { ComboBoxModel<E> oldModel = dataModel; if (oldModel != null) { oldModel.removeListDataListener(this); } dataModel = aModel; dataModel.addListDataListener(this); // set the current selected item. selectedItemReminder = dataModel.getSelectedItem(); firePropertyChange("model", oldModel, dataModel); } /** * Returns the data model currently used by the <code>JComboBox</code>. * * @return the <code>ComboBoxModel</code> that provides the displayed * list of items */ public ComboBoxModel<E> getModel() { return dataModel; } /* * Properties */ /** * Sets the <code>lightWeightPopupEnabled</code> property, which * provides a hint as to whether or not a lightweight * <code>Component</code> should be used to contain the * <code>JComboBox</code>, versus a heavyweight * <code>Component</code> such as a <code>Panel</code> * or a <code>Window</code>. The decision of lightweight * versus heavyweight is ultimately up to the * <code>JComboBox</code>. Lightweight windows are more * efficient than heavyweight windows, but lightweight * and heavyweight components do not mix well in a GUI. * If your application mixes lightweight and heavyweight * components, you should disable lightweight popups. * The default value for the <code>lightWeightPopupEnabled</code> * property is <code>true</code>, unless otherwise specified * by the look and feel. Some look and feels always use * heavyweight popups, no matter what the value of this property. * <p> * See the article <a href="http://www.oracle.com/technetwork/articles/java/mixing-components-433992.html">Mixing Heavy and Light Components</a> * This method fires a property changed event. * * @param aFlag if <code>true</code>, lightweight popups are desired */ @BeanProperty(expert = true, description = "Set to <code>false</code> to require heavyweight popups.") public void setLightWeightPopupEnabled(boolean aFlag) { boolean oldFlag = lightWeightPopupEnabled; lightWeightPopupEnabled = aFlag; firePropertyChange("lightWeightPopupEnabled", oldFlag, lightWeightPopupEnabled); } /** * Gets the value of the <code>lightWeightPopupEnabled</code> * property. * * @return the value of the <code>lightWeightPopupEnabled</code> * property * @see #setLightWeightPopupEnabled */ public boolean isLightWeightPopupEnabled() { return lightWeightPopupEnabled; } /** * Determines whether the <code>JComboBox</code> field is editable. * An editable <code>JComboBox</code> allows the user to type into the * field or selected an item from the list to initialize the field, * after which it can be edited. (The editing affects only the field, * the list item remains intact.) A non editable <code>JComboBox</code> * displays the selected item in the field, * but the selection cannot be modified. * * @param aFlag a boolean value, where true indicates that the * field is editable */ @BeanProperty(preferred = true, description = "If true, the user can type a new value in the combo box.") public void setEditable(boolean aFlag) { boolean oldFlag = isEditable; isEditable = aFlag; firePropertyChange("editable", oldFlag, isEditable); } /** * Returns true if the <code>JComboBox</code> is editable. * By default, a combo box is not editable. * * @return true if the <code>JComboBox</code> is editable, else false */ public boolean isEditable() { return isEditable; } /** * Sets the maximum number of rows the <code>JComboBox</code> displays. * If the number of objects in the model is greater than count, * the combo box uses a scrollbar. * * @param count an integer specifying the maximum number of items to * display in the list before using a scrollbar */ @BeanProperty(preferred = true, description = "The maximum number of rows the popup should have") public void setMaximumRowCount(int count) { int oldCount = maximumRowCount; maximumRowCount = count; firePropertyChange("maximumRowCount", oldCount, maximumRowCount); } /** * Returns the maximum number of items the combo box can display * without a scrollbar * * @return an integer specifying the maximum number of items that are * displayed in the list before using a scrollbar */ public int getMaximumRowCount() { return maximumRowCount; } /** * Sets the renderer that paints the list items and the item selected from the list in * the JComboBox field. The renderer is used if the JComboBox is not * editable. If it is editable, the editor is used to render and edit * the selected item. * <p> * The default renderer displays a string or an icon. * Other renderers can handle graphic images and composite items. * <p> * To display the selected item, * <code>aRenderer.getListCellRendererComponent</code> * is called, passing the list object and an index of -1. * * @param aRenderer the <code>ListCellRenderer</code> that * displays the selected item * @see #setEditor */ @BeanProperty(expert = true, description = "The renderer that paints the item selected in the list.") public void setRenderer(ListCellRenderer<? super E> aRenderer) { ListCellRenderer<? super E> oldRenderer = renderer; renderer = aRenderer; firePropertyChange("renderer", oldRenderer, renderer); invalidate(); } /** * Returns the renderer used to display the selected item in the * <code>JComboBox</code> field. * * @return the <code>ListCellRenderer</code> that displays * the selected item. */ public ListCellRenderer<? super E> getRenderer() { return renderer; } /** * Sets the editor used to paint and edit the selected item in the * <code>JComboBox</code> field. The editor is used only if the * receiving <code>JComboBox</code> is editable. If not editable, * the combo box uses the renderer to paint the selected item. * * @param anEditor the <code>ComboBoxEditor</code> that * displays the selected item * @see #setRenderer */ @BeanProperty(expert = true, description = "The editor that combo box uses to edit the current value") public void setEditor(ComboBoxEditor anEditor) { ComboBoxEditor oldEditor = editor; if (editor != null) { editor.removeActionListener(this); } editor = anEditor; if (editor != null) { editor.addActionListener(this); } firePropertyChange("editor", oldEditor, editor); } /** * Returns the editor used to paint and edit the selected item in the * <code>JComboBox</code> field. * * @return the <code>ComboBoxEditor</code> that displays the selected item */ public ComboBoxEditor getEditor() { return editor; } // // Selection // /** * Sets the selected item in the combo box display area to the object in * the argument. * If <code>anObject</code> is in the list, the display area shows * <code>anObject</code> selected. * <p> * If <code>anObject</code> is <i>not</i> in the list and the combo box is * uneditable, it will not change the current selection. For editable * combo boxes, the selection will change to <code>anObject</code>. * <p> * If this constitutes a change in the selected item, * <code>ItemListener</code>s added to the combo box will be notified with * one or two <code>ItemEvent</code>s. * If there is a current selected item, an <code>ItemEvent</code> will be * fired and the state change will be <code>ItemEvent.DESELECTED</code>. * If <code>anObject</code> is in the list and is not currently selected * then an <code>ItemEvent</code> will be fired and the state change will * be <code>ItemEvent.SELECTED</code>. * <p> * <code>ActionListener</code>s added to the combo box will be notified * with an <code>ActionEvent</code> when this method is called. * * @param anObject the list object to select; use <code>null</code> to clear the selection */ @BeanProperty(bound = false, preferred = true, description = "Sets the selected item in the JComboBox.") public void setSelectedItem(Object anObject) { Object oldSelection = selectedItemReminder; Object objectToSelect = anObject; if (oldSelection == null || !oldSelection.equals(anObject)) { if (anObject != null && !isEditable()) { // For non editable combo boxes, an invalid selection // will be rejected. boolean found = false; for (int i = 0; i < dataModel.getSize(); i++) { E element = dataModel.getElementAt(i); if (anObject.equals(element)) { found = true; objectToSelect = element; break; } } if (!found) { return; } getEditor().setItem(anObject); } // Must toggle the state of this flag since this method // call may result in ListDataEvents being fired. selectingItem = true; dataModel.setSelectedItem(objectToSelect); selectingItem = false; if (selectedItemReminder != dataModel.getSelectedItem()) { // in case a users implementation of ComboBoxModel // doesn't fire a ListDataEvent when the selection // changes. selectedItemChanged(); } } fireActionEvent(); } /** * Returns the current selected item. * <p> * If the combo box is editable, then this value may not have been added * to the combo box with <code>addItem</code>, <code>insertItemAt</code> * or the data constructors. * * @return the current selected Object * @see #setSelectedItem */ public Object getSelectedItem() { return dataModel.getSelectedItem(); } /** * Selects the item at index <code>anIndex</code>. * * @param anIndex an integer specifying the list item to select, * where 0 specifies the first item in the list and -1 indicates no selection * @exception IllegalArgumentException if <code>anIndex</code> < -1 or * <code>anIndex</code> is greater than or equal to size */ @BeanProperty(bound = false, preferred = true, description = "The item at index is selected.") public void setSelectedIndex(int anIndex) { int size = dataModel.getSize(); if (anIndex == -1) { setSelectedItem(null); } else if (anIndex < -1 || anIndex >= size) { throw new IllegalArgumentException("setSelectedIndex: " + anIndex + " out of bounds"); } else { setSelectedItem(dataModel.getElementAt(anIndex)); } } /** * Returns the first item in the list that matches the given item. * The result is not always defined if the <code>JComboBox</code> * allows selected items that are not in the list. * Returns -1 if there is no selected item or if the user specified * an item which is not in the list. * @return an integer specifying the currently selected list item, * where 0 specifies * the first item in the list; * or -1 if no item is selected or if * the currently selected item is not in the list */ @Transient public int getSelectedIndex() { Object sObject = dataModel.getSelectedItem(); int i, c; E obj; for (i = 0, c = dataModel.getSize(); i < c; i++) { obj = dataModel.getElementAt(i); if (obj != null && obj.equals(sObject)) return i; } return -1; } /** * Returns the "prototypical display" value - an Object used * for the calculation of the display height and width. * * @return the value of the <code>prototypeDisplayValue</code> property * @see #setPrototypeDisplayValue * @since 1.4 */ public E getPrototypeDisplayValue() { return prototypeDisplayValue; } /** * Sets the prototype display value used to calculate the size of the display * for the UI portion. * <p> * If a prototype display value is specified, the preferred size of * the combo box is calculated by configuring the renderer with the * prototype display value and obtaining its preferred size. Specifying * the preferred display value is often useful when the combo box will be * displaying large amounts of data. If no prototype display value has * been specified, the renderer must be configured for each value from * the model and its preferred size obtained, which can be * relatively expensive. * * @param prototypeDisplayValue the prototype display value * @see #getPrototypeDisplayValue * @since 1.4 */ @BeanProperty(visualUpdate = true, description = "The display prototype value, used to compute display width and height.") public void setPrototypeDisplayValue(E prototypeDisplayValue) { Object oldValue = this.prototypeDisplayValue; this.prototypeDisplayValue = prototypeDisplayValue; firePropertyChange("prototypeDisplayValue", oldValue, prototypeDisplayValue); } /** * Adds an item to the item list. * This method works only if the <code>JComboBox</code> uses a * mutable data model. * <p> * <strong>Warning:</strong> * Focus and keyboard navigation problems may arise if you add duplicate * String objects. A workaround is to add new objects instead of String * objects and make sure that the toString() method is defined. * For example: * <pre> * comboBox.addItem(makeObj("Item 1")); * comboBox.addItem(makeObj("Item 1")); * ... * private Object makeObj(final String item) { * return new Object() { public String toString() { return item; } }; * } * </pre> * * @param item the item to add to the list * @see MutableComboBoxModel */ public void addItem(E item) { checkMutableComboBoxModel(); ((MutableComboBoxModel<E>) dataModel).addElement(item); } /** * Inserts an item into the item list at a given index. * This method works only if the <code>JComboBox</code> uses a * mutable data model. * * @param item the item to add to the list * @param index an integer specifying the position at which * to add the item * @see MutableComboBoxModel */ public void insertItemAt(E item, int index) { checkMutableComboBoxModel(); ((MutableComboBoxModel<E>) dataModel).insertElementAt(item, index); } /** * Removes an item from the item list. * This method works only if the <code>JComboBox</code> uses a * mutable data model. * * @param anObject the object to remove from the item list * @see MutableComboBoxModel */ public void removeItem(Object anObject) { checkMutableComboBoxModel(); ((MutableComboBoxModel) dataModel).removeElement(anObject); } /** * Removes the item at <code>anIndex</code> * This method works only if the <code>JComboBox</code> uses a * mutable data model. * * @param anIndex an int specifying the index of the item to remove, * where 0 * indicates the first item in the list * @see MutableComboBoxModel */ public void removeItemAt(int anIndex) { checkMutableComboBoxModel(); ((MutableComboBoxModel<E>) dataModel).removeElementAt(anIndex); } /** * Removes all items from the item list. */ public void removeAllItems() { checkMutableComboBoxModel(); MutableComboBoxModel<E> model = (MutableComboBoxModel<E>) dataModel; int size = model.getSize(); if (model instanceof DefaultComboBoxModel) { ((DefaultComboBoxModel) model).removeAllElements(); } else { for (int i = 0; i < size; ++i) { E element = model.getElementAt(0); model.removeElement(element); } } selectedItemReminder = null; if (isEditable()) { editor.setItem(null); } } /** * Checks that the <code>dataModel</code> is an instance of * <code>MutableComboBoxModel</code>. If not, it throws an exception. * @exception RuntimeException if <code>dataModel</code> is not an * instance of <code>MutableComboBoxModel</code>. */ void checkMutableComboBoxModel() { if (!(dataModel instanceof MutableComboBoxModel)) throw new RuntimeException("Cannot use this method with a non-Mutable data model."); } /** * Causes the combo box to display its popup window. * @see #setPopupVisible */ public void showPopup() { setPopupVisible(true); } /** * Causes the combo box to close its popup window. * @see #setPopupVisible */ public void hidePopup() { setPopupVisible(false); } /** * Sets the visibility of the popup. * * @param v if {@code true} shows the popup, otherwise, hides the popup. */ public void setPopupVisible(boolean v) { getUI().setPopupVisible(this, v); } /** * Determines the visibility of the popup. * * @return true if the popup is visible, otherwise returns false */ public boolean isPopupVisible() { return getUI().isPopupVisible(this); } /** Selection **/ /** * Adds an <code>ItemListener</code>. * <p> * <code>aListener</code> will receive one or two <code>ItemEvent</code>s when * the selected item changes. * * @param aListener the <code>ItemListener</code> that is to be notified * @see #setSelectedItem */ public void addItemListener(ItemListener aListener) { listenerList.add(ItemListener.class, aListener); } /** Removes an <code>ItemListener</code>. * * @param aListener the <code>ItemListener</code> to remove */ public void removeItemListener(ItemListener aListener) { listenerList.remove(ItemListener.class, aListener); } /** * Returns an array of all the <code>ItemListener</code>s added * to this JComboBox with addItemListener(). * * @return all of the <code>ItemListener</code>s added or an empty * array if no listeners have been added * @since 1.4 */ @BeanProperty(bound = false) public ItemListener[] getItemListeners() { return listenerList.getListeners(ItemListener.class); } /** * Adds an <code>ActionListener</code>. * <p> * The <code>ActionListener</code> will receive an <code>ActionEvent</code> * when a selection has been made. If the combo box is editable, then * an <code>ActionEvent</code> will be fired when editing has stopped. * * @param l the <code>ActionListener</code> that is to be notified * @see #setSelectedItem */ public void addActionListener(ActionListener l) { listenerList.add(ActionListener.class, l); } /** Removes an <code>ActionListener</code>. * * @param l the <code>ActionListener</code> to remove */ public void removeActionListener(ActionListener l) { if ((l != null) && (getAction() == l)) { setAction(null); } else { listenerList.remove(ActionListener.class, l); } } /** * Returns an array of all the <code>ActionListener</code>s added * to this JComboBox with addActionListener(). * * @return all of the <code>ActionListener</code>s added or an empty * array if no listeners have been added * @since 1.4 */ @BeanProperty(bound = false) public ActionListener[] getActionListeners() { return listenerList.getListeners(ActionListener.class); } /** * Adds a <code>PopupMenu</code> listener which will listen to notification * messages from the popup portion of the combo box. * <p> * For all standard look and feels shipped with Java, the popup list * portion of combo box is implemented as a <code>JPopupMenu</code>. * A custom look and feel may not implement it this way and will * therefore not receive the notification. * * @param l the <code>PopupMenuListener</code> to add * @since 1.4 */ public void addPopupMenuListener(PopupMenuListener l) { listenerList.add(PopupMenuListener.class, l); } /** * Removes a <code>PopupMenuListener</code>. * * @param l the <code>PopupMenuListener</code> to remove * @see #addPopupMenuListener * @since 1.4 */ public void removePopupMenuListener(PopupMenuListener l) { listenerList.remove(PopupMenuListener.class, l); } /** * Returns an array of all the <code>PopupMenuListener</code>s added * to this JComboBox with addPopupMenuListener(). * * @return all of the <code>PopupMenuListener</code>s added or an empty * array if no listeners have been added * @since 1.4 */ @BeanProperty(bound = false) public PopupMenuListener[] getPopupMenuListeners() { return listenerList.getListeners(PopupMenuListener.class); } /** * Notifies <code>PopupMenuListener</code>s that the popup portion of the * combo box will become visible. * <p> * This method is public but should not be called by anything other than * the UI delegate. * @see #addPopupMenuListener * @since 1.4 */ public void firePopupMenuWillBecomeVisible() { Object[] listeners = listenerList.getListenerList(); PopupMenuEvent e = null; for (int i = listeners.length - 2; i >= 0; i -= 2) { if (listeners[i] == PopupMenuListener.class) { if (e == null) e = new PopupMenuEvent(this); ((PopupMenuListener) listeners[i + 1]).popupMenuWillBecomeVisible(e); } } } /** * Notifies <code>PopupMenuListener</code>s that the popup portion of the * combo box has become invisible. * <p> * This method is public but should not be called by anything other than * the UI delegate. * @see #addPopupMenuListener * @since 1.4 */ public void firePopupMenuWillBecomeInvisible() { Object[] listeners = listenerList.getListenerList(); PopupMenuEvent e = null; for (int i = listeners.length - 2; i >= 0; i -= 2) { if (listeners[i] == PopupMenuListener.class) { if (e == null) e = new PopupMenuEvent(this); ((PopupMenuListener) listeners[i + 1]).popupMenuWillBecomeInvisible(e); } } } /** * Notifies <code>PopupMenuListener</code>s that the popup portion of the * combo box has been canceled. * <p> * This method is public but should not be called by anything other than * the UI delegate. * @see #addPopupMenuListener * @since 1.4 */ public void firePopupMenuCanceled() { Object[] listeners = listenerList.getListenerList(); PopupMenuEvent e = null; for (int i = listeners.length - 2; i >= 0; i -= 2) { if (listeners[i] == PopupMenuListener.class) { if (e == null) e = new PopupMenuEvent(this); ((PopupMenuListener) listeners[i + 1]).popupMenuCanceled(e); } } } /** * Sets the action command that should be included in the event * sent to action listeners. * * @param aCommand a string containing the "command" that is sent * to action listeners; the same listener can then * do different things depending on the command it * receives */ public void setActionCommand(String aCommand) { actionCommand = aCommand; } /** * Returns the action command that is included in the event sent to * action listeners. * * @return the string containing the "command" that is sent * to action listeners. */ public String getActionCommand() { return actionCommand; } private Action action; private PropertyChangeListener actionPropertyChangeListener; /** * Sets the <code>Action</code> for the <code>ActionEvent</code> source. * The new <code>Action</code> replaces any previously set * <code>Action</code> but does not affect <code>ActionListeners</code> * independently added with <code>addActionListener</code>. * If the <code>Action</code> is already a registered * <code>ActionListener</code> for the <code>ActionEvent</code> source, * it is not re-registered. * <p> * Setting the <code>Action</code> results in immediately changing * all the properties described in <a href="Action.html#buttonActions"> * Swing Components Supporting <code>Action</code></a>. * Subsequently, the combobox's properties are automatically updated * as the <code>Action</code>'s properties change. * <p> * This method uses three other methods to set * and help track the <code>Action</code>'s property values. * It uses the <code>configurePropertiesFromAction</code> method * to immediately change the combobox's properties. * To track changes in the <code>Action</code>'s property values, * this method registers the <code>PropertyChangeListener</code> * returned by <code>createActionPropertyChangeListener</code>. The * default {@code PropertyChangeListener} invokes the * {@code actionPropertyChanged} method when a property in the * {@code Action} changes. * * @param a the <code>Action</code> for the <code>JComboBox</code>, * or <code>null</code>. * @since 1.3 * @see Action * @see #getAction * @see #configurePropertiesFromAction * @see #createActionPropertyChangeListener * @see #actionPropertyChanged */ @BeanProperty(visualUpdate = true, description = "the Action instance connected with this ActionEvent source") public void setAction(Action a) { Action oldValue = getAction(); if (action == null || !action.equals(a)) { action = a; if (oldValue != null) { removeActionListener(oldValue); oldValue.removePropertyChangeListener(actionPropertyChangeListener); actionPropertyChangeListener = null; } configurePropertiesFromAction(action); if (action != null) { // Don't add if it is already a listener if (!isListener(ActionListener.class, action)) { addActionListener(action); } // Reverse linkage: actionPropertyChangeListener = createActionPropertyChangeListener(action); action.addPropertyChangeListener(actionPropertyChangeListener); } firePropertyChange("action", oldValue, action); } } private boolean isListener(Class<?> c, ActionListener a) { boolean isListener = false; Object[] listeners = listenerList.getListenerList(); for (int i = listeners.length - 2; i >= 0; i -= 2) { if (listeners[i] == c && listeners[i + 1] == a) { isListener = true; } } return isListener; } /** * Returns the currently set <code>Action</code> for this * <code>ActionEvent</code> source, or <code>null</code> if no * <code>Action</code> is set. * * @return the <code>Action</code> for this <code>ActionEvent</code> * source; or <code>null</code> * @since 1.3 * @see Action * @see #setAction */ public Action getAction() { return action; } /** * Sets the properties on this combobox to match those in the specified * <code>Action</code>. Refer to <a href="Action.html#buttonActions"> * Swing Components Supporting <code>Action</code></a> for more * details as to which properties this sets. * * @param a the <code>Action</code> from which to get the properties, * or <code>null</code> * @since 1.3 * @see Action * @see #setAction */ protected void configurePropertiesFromAction(Action a) { AbstractAction.setEnabledFromAction(this, a); AbstractAction.setToolTipTextFromAction(this, a); setActionCommandFromAction(a); } /** * Creates and returns a <code>PropertyChangeListener</code> that is * responsible for listening for changes from the specified * <code>Action</code> and updating the appropriate properties. * <p> * <b>Warning:</b> If you subclass this do not create an anonymous * inner class. If you do the lifetime of the combobox will be tied to * that of the <code>Action</code>. * * @param a the combobox's action * @return the {@code PropertyChangeListener} * @since 1.3 * @see Action * @see #setAction */ protected PropertyChangeListener createActionPropertyChangeListener(Action a) { return new ComboBoxActionPropertyChangeListener(this, a); } /** * Updates the combobox's state in response to property changes in * associated action. This method is invoked from the * {@code PropertyChangeListener} returned from * {@code createActionPropertyChangeListener}. Subclasses do not normally * need to invoke this. Subclasses that support additional {@code Action} * properties should override this and * {@code configurePropertiesFromAction}. * <p> * Refer to the table at <a href="Action.html#buttonActions"> * Swing Components Supporting <code>Action</code></a> for a list of * the properties this method sets. * * @param action the <code>Action</code> associated with this combobox * @param propertyName the name of the property that changed * @since 1.6 * @see Action * @see #configurePropertiesFromAction */ protected void actionPropertyChanged(Action action, String propertyName) { if (propertyName == Action.ACTION_COMMAND_KEY) { setActionCommandFromAction(action); } else if (propertyName == "enabled") { AbstractAction.setEnabledFromAction(this, action); } else if (Action.SHORT_DESCRIPTION == propertyName) { AbstractAction.setToolTipTextFromAction(this, action); } } private void setActionCommandFromAction(Action a) { setActionCommand((a != null) ? (String) a.getValue(Action.ACTION_COMMAND_KEY) : null); } private static class ComboBoxActionPropertyChangeListener extends ActionPropertyChangeListener<JComboBox<?>> { ComboBoxActionPropertyChangeListener(JComboBox<?> b, Action a) { super(b, a); } protected void actionPropertyChanged(JComboBox<?> cb, Action action, PropertyChangeEvent e) { if (AbstractAction.shouldReconfigure(e)) { cb.configurePropertiesFromAction(action); } else { cb.actionPropertyChanged(action, e.getPropertyName()); } } } /** * Notifies all listeners that have registered interest for * notification on this event type. * @param e the event of interest * * @see EventListenerList */ protected void fireItemStateChanged(ItemEvent e) { // Guaranteed to return a non-null array Object[] listeners = listenerList.getListenerList(); // Process the listeners last to first, notifying // those that are interested in this event for (int i = listeners.length - 2; i >= 0; i -= 2) { if (listeners[i] == ItemListener.class) { // Lazily create the event: // if (changeEvent == null) // changeEvent = new ChangeEvent(this); ((ItemListener) listeners[i + 1]).itemStateChanged(e); } } } /** * Notifies all listeners that have registered interest for * notification on this event type. * * @see EventListenerList */ @SuppressWarnings("deprecation") protected void fireActionEvent() { if (!firingActionEvent) { // Set flag to ensure that an infinite loop is not created firingActionEvent = true; ActionEvent e = null; // Guaranteed to return a non-null array Object[] listeners = listenerList.getListenerList(); long mostRecentEventTime = EventQueue.getMostRecentEventTime(); int modifiers = 0; AWTEvent currentEvent = EventQueue.getCurrentEvent(); if (currentEvent instanceof InputEvent) { modifiers = ((InputEvent) currentEvent).getModifiers(); } else if (currentEvent instanceof ActionEvent) { modifiers = ((ActionEvent) currentEvent).getModifiers(); } try { // Process the listeners last to first, notifying // those that are interested in this event for (int i = listeners.length - 2; i >= 0; i -= 2) { if (listeners[i] == ActionListener.class) { // Lazily create the event: if (e == null) e = new ActionEvent(this, ActionEvent.ACTION_PERFORMED, getActionCommand(), mostRecentEventTime, modifiers); ((ActionListener) listeners[i + 1]).actionPerformed(e); } } } finally { firingActionEvent = false; } } } /** * This protected method is implementation specific. Do not access directly * or override. */ protected void selectedItemChanged() { if (selectedItemReminder != null) { fireItemStateChanged( new ItemEvent(this, ItemEvent.ITEM_STATE_CHANGED, selectedItemReminder, ItemEvent.DESELECTED)); } // set the new selected item. selectedItemReminder = dataModel.getSelectedItem(); if (selectedItemReminder != null) { fireItemStateChanged( new ItemEvent(this, ItemEvent.ITEM_STATE_CHANGED, selectedItemReminder, ItemEvent.SELECTED)); } } /** * Returns an array containing the selected item. * This method is implemented for compatibility with * <code>ItemSelectable</code>. * * @return an array of <code>Objects</code> containing one * element -- the selected item */ @BeanProperty(bound = false) public Object[] getSelectedObjects() { Object selectedObject = getSelectedItem(); if (selectedObject == null) return new Object[0]; else { Object[] result = new Object[1]; result[0] = selectedObject; return result; } } /** * This method is public as an implementation side effect. * do not call or override. */ public void actionPerformed(ActionEvent e) { setPopupVisible(false); getModel().setSelectedItem(getEditor().getItem()); String oldCommand = getActionCommand(); setActionCommand("comboBoxEdited"); fireActionEvent(); setActionCommand(oldCommand); } /** * This method is public as an implementation side effect. * do not call or override. */ public void contentsChanged(ListDataEvent e) { Object oldSelection = selectedItemReminder; Object newSelection = dataModel.getSelectedItem(); if (oldSelection == null || !oldSelection.equals(newSelection)) { selectedItemChanged(); if (!selectingItem) { fireActionEvent(); } } } /** * This method is public as an implementation side effect. * do not call or override. */ public void intervalAdded(ListDataEvent e) { if (selectedItemReminder != dataModel.getSelectedItem()) { selectedItemChanged(); } } /** * This method is public as an implementation side effect. * do not call or override. */ public void intervalRemoved(ListDataEvent e) { contentsChanged(e); } /** * Selects the list item that corresponds to the specified keyboard * character and returns true, if there is an item corresponding * to that character. Otherwise, returns false. * * @param keyChar a char, typically this is a keyboard key * typed by the user * @return {@code true} if there is an item corresponding to that character. * Otherwise, returns {@code false}. */ public boolean selectWithKeyChar(char keyChar) { int index; if (keySelectionManager == null) keySelectionManager = createDefaultKeySelectionManager(); index = keySelectionManager.selectionForKey(keyChar, getModel()); if (index != -1) { setSelectedIndex(index); return true; } else return false; } /** * Enables the combo box so that items can be selected. When the * combo box is disabled, items cannot be selected and values * cannot be typed into its field (if it is editable). * * @param b a boolean value, where true enables the component and * false disables it */ @BeanProperty(preferred = true, description = "The enabled state of the component.") public void setEnabled(boolean b) { super.setEnabled(b); firePropertyChange("enabled", !isEnabled(), isEnabled()); } /** * Initializes the editor with the specified item. * * @param anEditor the <code>ComboBoxEditor</code> that displays * the list item in the * combo box field and allows it to be edited * @param anItem the object to display and edit in the field */ public void configureEditor(ComboBoxEditor anEditor, Object anItem) { anEditor.setItem(anItem); } /** * Handles <code>KeyEvent</code>s, looking for the Tab key. * If the Tab key is found, the popup window is closed. * * @param e the <code>KeyEvent</code> containing the keyboard * key that was pressed */ public void processKeyEvent(KeyEvent e) { if (e.getKeyCode() == KeyEvent.VK_TAB) { hidePopup(); } super.processKeyEvent(e); } /** * {@inheritDoc} */ @Override protected boolean processKeyBinding(KeyStroke ks, KeyEvent e, int condition, boolean pressed) { if (super.processKeyBinding(ks, e, condition, pressed)) { return true; } if (!isEditable() || condition != WHEN_FOCUSED || getEditor() == null || !Boolean.TRUE.equals(getClientProperty("JComboBox.isTableCellEditor"))) { return false; } Component editorComponent = getEditor().getEditorComponent(); if (editorComponent instanceof JComponent) { JComponent component = (JComponent) editorComponent; return component.processKeyBinding(ks, e, WHEN_FOCUSED, pressed); } return false; } /** * Sets the object that translates a keyboard character into a list * selection. Typically, the first selection with a matching first * character becomes the selected item. * * @param aManager a key selection manager */ @BeanProperty(bound = false, expert = true, description = "The objects that changes the selection when a key is pressed.") public void setKeySelectionManager(KeySelectionManager aManager) { keySelectionManager = aManager; } /** * Returns the list's key-selection manager. * * @return the <code>KeySelectionManager</code> currently in use */ public KeySelectionManager getKeySelectionManager() { return keySelectionManager; } /* Accessing the model */ /** * Returns the number of items in the list. * * @return an integer equal to the number of items in the list */ @BeanProperty(bound = false) public int getItemCount() { return dataModel.getSize(); } /** * Returns the list item at the specified index. If <code>index</code> * is out of range (less than zero or greater than or equal to size) * it will return <code>null</code>. * * @param index an integer indicating the list position, where the first * item starts at zero * @return the item at that list position; or * <code>null</code> if out of range */ public E getItemAt(int index) { return dataModel.getElementAt(index); } /** * Returns an instance of the default key-selection manager. * * @return the <code>KeySelectionManager</code> currently used by the list * @see #setKeySelectionManager */ protected KeySelectionManager createDefaultKeySelectionManager() { return new DefaultKeySelectionManager(); } /** * The interface that defines a <code>KeySelectionManager</code>. * To qualify as a <code>KeySelectionManager</code>, * the class needs to implement the method * that identifies the list index given a character and the * combo box data model. */ public interface KeySelectionManager { /** Given <code>aKey</code> and the model, returns the row * that should become selected. Return -1 if no match was * found. * * @param aKey a char value, usually indicating a keyboard key that * was pressed * @param aModel a ComboBoxModel -- the component's data model, containing * the list of selectable items * @return an int equal to the selected row, where 0 is the * first item and -1 is none. */ int selectionForKey(char aKey, ComboBoxModel<?> aModel); } class DefaultKeySelectionManager implements KeySelectionManager, Serializable { public int selectionForKey(char aKey, ComboBoxModel<?> aModel) { int i, c; int currentSelection = -1; Object selectedItem = aModel.getSelectedItem(); String v; String pattern; if (selectedItem != null) { for (i = 0, c = aModel.getSize(); i < c; i++) { if (selectedItem == aModel.getElementAt(i)) { currentSelection = i; break; } } } pattern = ("" + aKey).toLowerCase(); aKey = pattern.charAt(0); for (i = ++currentSelection, c = aModel.getSize(); i < c; i++) { Object elem = aModel.getElementAt(i); if (elem != null && elem.toString() != null) { v = elem.toString().toLowerCase(); if (v.length() > 0 && v.charAt(0) == aKey) return i; } } for (i = 0; i < currentSelection; i++) { Object elem = aModel.getElementAt(i); if (elem != null && elem.toString() != null) { v = elem.toString().toLowerCase(); if (v.length() > 0 && v.charAt(0) == aKey) return i; } } return -1; } } /** * See <code>readObject</code> and <code>writeObject</code> in * <code>JComponent</code> for more * information about serialization in Swing. */ private void writeObject(ObjectOutputStream s) throws IOException { s.defaultWriteObject(); if (getUIClassID().equals(uiClassID)) { byte count = JComponent.getWriteObjCounter(this); JComponent.setWriteObjCounter(this, --count); if (count == 0 && ui != null) { ui.installUI(this); } } } /** * Returns a string representation of this <code>JComboBox</code>. * This method is intended to be used only for debugging purposes, * and the content and format of the returned string may vary between * implementations. The returned string may be empty but may not * be <code>null</code>. * * @return a string representation of this <code>JComboBox</code> */ protected String paramString() { String selectedItemReminderString = (selectedItemReminder != null ? selectedItemReminder.toString() : ""); String isEditableString = (isEditable ? "true" : "false"); String lightWeightPopupEnabledString = (lightWeightPopupEnabled ? "true" : "false"); return super.paramString() + ",isEditable=" + isEditableString + ",lightWeightPopupEnabled=" + lightWeightPopupEnabledString + ",maximumRowCount=" + maximumRowCount + ",selectedItemReminder=" + selectedItemReminderString; } /////////////////// // Accessibility support /////////////////// /** * Gets the AccessibleContext associated with this JComboBox. * For combo boxes, the AccessibleContext takes the form of an * AccessibleJComboBox. * A new AccessibleJComboBox instance is created if necessary. * * @return an AccessibleJComboBox that serves as the * AccessibleContext of this JComboBox */ @BeanProperty(bound = false) public AccessibleContext getAccessibleContext() { if (accessibleContext == null) { accessibleContext = new AccessibleJComboBox(); } return accessibleContext; } /** * This class implements accessibility support for the * <code>JComboBox</code> class. It provides an implementation of the * Java Accessibility API appropriate to Combo Box user-interface elements. * <p> * <strong>Warning:</strong> * Serialized objects of this class will not be compatible with * future Swing releases. The current serialization support is * appropriate for short term storage or RMI between applications running * the same version of Swing. As of 1.4, support for long term storage * of all JavaBeans™ * has been added to the <code>java.beans</code> package. * Please see {@link java.beans.XMLEncoder}. */ @SuppressWarnings("serial") // Same-version serialization only protected class AccessibleJComboBox extends AccessibleJComponent implements AccessibleAction, AccessibleSelection { private JList<?> popupList; // combo box popup list private Accessible previousSelectedAccessible = null; /** * Returns an AccessibleJComboBox instance * @since 1.4 */ public AccessibleJComboBox() { // set the combo box editor's accessible name and description JComboBox.this.addPropertyChangeListener(new AccessibleJComboBoxPropertyChangeListener()); setEditorNameAndDescription(); // Get the popup list Accessible a = getUI().getAccessibleChild(JComboBox.this, 0); if (a instanceof javax.swing.plaf.basic.ComboPopup) { // Listen for changes to the popup menu selection. popupList = ((javax.swing.plaf.basic.ComboPopup) a).getList(); popupList.addListSelectionListener(new AccessibleJComboBoxListSelectionListener()); } // Listen for popup menu show/hide events JComboBox.this.addPopupMenuListener(new AccessibleJComboBoxPopupMenuListener()); } /* * JComboBox PropertyChangeListener */ private class AccessibleJComboBoxPropertyChangeListener implements PropertyChangeListener { public void propertyChange(PropertyChangeEvent e) { if (e.getPropertyName() == "editor") { // set the combo box editor's accessible name // and description setEditorNameAndDescription(); } } } /* * Sets the combo box editor's accessible name and descripton */ private void setEditorNameAndDescription() { ComboBoxEditor editor = JComboBox.this.getEditor(); if (editor != null) { Component comp = editor.getEditorComponent(); if (comp instanceof Accessible) { AccessibleContext ac = comp.getAccessibleContext(); if (ac != null) { // may be null ac.setAccessibleName(getAccessibleName()); ac.setAccessibleDescription(getAccessibleDescription()); } } } } /* * Listener for combo box popup menu * TIGER - 4669379 4894434 */ private class AccessibleJComboBoxPopupMenuListener implements PopupMenuListener { /** * This method is called before the popup menu becomes visible */ public void popupMenuWillBecomeVisible(PopupMenuEvent e) { // save the initial selection if (popupList == null) { return; } int selectedIndex = popupList.getSelectedIndex(); if (selectedIndex < 0) { return; } previousSelectedAccessible = popupList.getAccessibleContext().getAccessibleChild(selectedIndex); } /** * This method is called before the popup menu becomes invisible * Note that a JPopupMenu can become invisible any time */ public void popupMenuWillBecomeInvisible(PopupMenuEvent e) { // ignore } /** * This method is called when the popup menu is canceled */ public void popupMenuCanceled(PopupMenuEvent e) { // ignore } } /* * Handles changes to the popup list selection. * TIGER - 4669379 4894434 4933143 */ private class AccessibleJComboBoxListSelectionListener implements ListSelectionListener { public void valueChanged(ListSelectionEvent e) { if (popupList == null) { return; } // Get the selected popup list item. int selectedIndex = popupList.getSelectedIndex(); if (selectedIndex < 0) { return; } Accessible selectedAccessible = popupList.getAccessibleContext().getAccessibleChild(selectedIndex); if (selectedAccessible == null) { return; } // Fire a FOCUSED lost PropertyChangeEvent for the // previously selected list item. PropertyChangeEvent pce; if (previousSelectedAccessible != null) { pce = new PropertyChangeEvent(previousSelectedAccessible, AccessibleContext.ACCESSIBLE_STATE_PROPERTY, AccessibleState.FOCUSED, null); firePropertyChange(AccessibleContext.ACCESSIBLE_STATE_PROPERTY, null, pce); } // Fire a FOCUSED gained PropertyChangeEvent for the // currently selected list item. pce = new PropertyChangeEvent(selectedAccessible, AccessibleContext.ACCESSIBLE_STATE_PROPERTY, null, AccessibleState.FOCUSED); firePropertyChange(AccessibleContext.ACCESSIBLE_STATE_PROPERTY, null, pce); // Fire the ACCESSIBLE_ACTIVE_DESCENDANT_PROPERTY event // for the combo box. firePropertyChange(AccessibleContext.ACCESSIBLE_ACTIVE_DESCENDANT_PROPERTY, previousSelectedAccessible, selectedAccessible); // Save the previous selection. previousSelectedAccessible = selectedAccessible; } } /** * Returns the number of accessible children in the object. If all * of the children of this object implement Accessible, than this * method should return the number of children of this object. * * @return the number of accessible children in the object. */ public int getAccessibleChildrenCount() { // Always delegate to the UI if it exists if (ui != null) { return ui.getAccessibleChildrenCount(JComboBox.this); } else { return super.getAccessibleChildrenCount(); } } /** * Returns the nth Accessible child of the object. * The child at index zero represents the popup. * If the combo box is editable, the child at index one * represents the editor. * * @param i zero-based index of child * @return the nth Accessible child of the object */ public Accessible getAccessibleChild(int i) { // Always delegate to the UI if it exists if (ui != null) { return ui.getAccessibleChild(JComboBox.this, i); } else { return super.getAccessibleChild(i); } } /** * Get the role of this object. * * @return an instance of AccessibleRole describing the role of the * object * @see AccessibleRole */ public AccessibleRole getAccessibleRole() { return AccessibleRole.COMBO_BOX; } /** * Gets the state set of this object. The AccessibleStateSet of * an object is composed of a set of unique AccessibleStates. * A change in the AccessibleStateSet of an object will cause a * PropertyChangeEvent to be fired for the ACCESSIBLE_STATE_PROPERTY * property. * * @return an instance of AccessibleStateSet containing the * current state set of the object * @see AccessibleStateSet * @see AccessibleState * @see #addPropertyChangeListener * */ public AccessibleStateSet getAccessibleStateSet() { // TIGER - 4489748 AccessibleStateSet ass = super.getAccessibleStateSet(); if (ass == null) { ass = new AccessibleStateSet(); } if (JComboBox.this.isPopupVisible()) { ass.add(AccessibleState.EXPANDED); } else { ass.add(AccessibleState.COLLAPSED); } return ass; } /** * Get the AccessibleAction associated with this object. In the * implementation of the Java Accessibility API for this class, * return this object, which is responsible for implementing the * AccessibleAction interface on behalf of itself. * * @return this object */ public AccessibleAction getAccessibleAction() { return this; } /** * Return a description of the specified action of the object. * * @param i zero-based index of the actions */ public String getAccessibleActionDescription(int i) { if (i == 0) { return UIManager.getString("ComboBox.togglePopupText"); } else { return null; } } /** * Returns the number of Actions available in this object. The * default behavior of a combo box is to have one action. * * @return 1, the number of Actions in this object */ public int getAccessibleActionCount() { return 1; } /** * Perform the specified Action on the object * * @param i zero-based index of actions * @return true if the action was performed; else false. */ public boolean doAccessibleAction(int i) { if (i == 0) { setPopupVisible(!isPopupVisible()); return true; } else { return false; } } /** * Get the AccessibleSelection associated with this object. In the * implementation of the Java Accessibility API for this class, * return this object, which is responsible for implementing the * AccessibleSelection interface on behalf of itself. * * @return this object */ public AccessibleSelection getAccessibleSelection() { return this; } /** * Returns the number of Accessible children currently selected. * If no children are selected, the return value will be 0. * * @return the number of items currently selected. * @since 1.3 */ public int getAccessibleSelectionCount() { Object o = JComboBox.this.getSelectedItem(); if (o != null) { return 1; } else { return 0; } } /** * Returns an Accessible representing the specified selected child * in the popup. If there isn't a selection, or there are * fewer children selected than the integer passed in, the return * value will be null. * <p>Note that the index represents the i-th selected child, which * is different from the i-th child. * * @param i the zero-based index of selected children * @return the i-th selected child * @see #getAccessibleSelectionCount * @since 1.3 */ public Accessible getAccessibleSelection(int i) { // Get the popup Accessible a = JComboBox.this.getUI().getAccessibleChild(JComboBox.this, 0); if (a != null && a instanceof javax.swing.plaf.basic.ComboPopup) { // get the popup list JList<?> list = ((javax.swing.plaf.basic.ComboPopup) a).getList(); // return the i-th selection in the popup list AccessibleContext ac = list.getAccessibleContext(); if (ac != null) { AccessibleSelection as = ac.getAccessibleSelection(); if (as != null) { return as.getAccessibleSelection(i); } } } return null; } /** * Determines if the current child of this object is selected. * * @return true if the current child of this object is selected; * else false * @param i the zero-based index of the child in this Accessible * object. * @see AccessibleContext#getAccessibleChild * @since 1.3 */ public boolean isAccessibleChildSelected(int i) { return JComboBox.this.getSelectedIndex() == i; } /** * Adds the specified Accessible child of the object to the object's * selection. If the object supports multiple selections, * the specified child is added to any existing selection, otherwise * it replaces any existing selection in the object. If the * specified child is already selected, this method has no effect. * * @param i the zero-based index of the child * @see AccessibleContext#getAccessibleChild * @since 1.3 */ public void addAccessibleSelection(int i) { // TIGER - 4856195 clearAccessibleSelection(); JComboBox.this.setSelectedIndex(i); } /** * Removes the specified child of the object from the object's * selection. If the specified item isn't currently selected, this * method has no effect. * * @param i the zero-based index of the child * @see AccessibleContext#getAccessibleChild * @since 1.3 */ public void removeAccessibleSelection(int i) { if (JComboBox.this.getSelectedIndex() == i) { clearAccessibleSelection(); } } /** * Clears the selection in the object, so that no children in the * object are selected. * @since 1.3 */ public void clearAccessibleSelection() { JComboBox.this.setSelectedIndex(-1); } /** * Causes every child of the object to be selected * if the object supports multiple selections. * @since 1.3 */ public void selectAllAccessibleSelection() { // do nothing since multiple selection is not supported } // public Accessible getAccessibleAt(Point p) { // Accessible a = getAccessibleChild(1); // if ( a != null ) { // return a; // the editor // } // else { // return getAccessibleChild(0); // the list // } // } private EditorAccessibleContext editorAccessibleContext = null; private class AccessibleEditor implements Accessible { public AccessibleContext getAccessibleContext() { if (editorAccessibleContext == null) { Component c = JComboBox.this.getEditor().getEditorComponent(); if (c instanceof Accessible) { editorAccessibleContext = new EditorAccessibleContext((Accessible) c); } } return editorAccessibleContext; } } /* * Wrapper class for the AccessibleContext implemented by the * combo box editor. Delegates all method calls except * getAccessibleIndexInParent to the editor. The * getAccessibleIndexInParent method returns the selected * index in the combo box. */ private class EditorAccessibleContext extends AccessibleContext { private AccessibleContext ac; private EditorAccessibleContext() { } /* * @param a the AccessibleContext implemented by the * combo box editor */ EditorAccessibleContext(Accessible a) { this.ac = a.getAccessibleContext(); } /** * Gets the accessibleName property of this object. The accessibleName * property of an object is a localized String that designates the purpose * of the object. For example, the accessibleName property of a label * or button might be the text of the label or button itself. In the * case of an object that doesn't display its name, the accessibleName * should still be set. For example, in the case of a text field used * to enter the name of a city, the accessibleName for the en_US locale * could be 'city.' * * @return the localized name of the object; null if this * object does not have a name * * @see #setAccessibleName */ public String getAccessibleName() { return ac.getAccessibleName(); } /** * Sets the localized accessible name of this object. Changing the * name will cause a PropertyChangeEvent to be fired for the * ACCESSIBLE_NAME_PROPERTY property. * * @param s the new localized name of the object. * * @see #getAccessibleName * @see #addPropertyChangeListener */ @BeanProperty(preferred = true, description = "Sets the accessible name for the component.") public void setAccessibleName(String s) { ac.setAccessibleName(s); } /** * Gets the accessibleDescription property of this object. The * accessibleDescription property of this object is a short localized * phrase describing the purpose of the object. For example, in the * case of a 'Cancel' button, the accessibleDescription could be * 'Ignore changes and close dialog box.' * * @return the localized description of the object; null if * this object does not have a description * * @see #setAccessibleDescription */ public String getAccessibleDescription() { return ac.getAccessibleDescription(); } /** * Sets the accessible description of this object. Changing the * name will cause a PropertyChangeEvent to be fired for the * ACCESSIBLE_DESCRIPTION_PROPERTY property. * * @param s the new localized description of the object * * @see #setAccessibleName * @see #addPropertyChangeListener */ @BeanProperty(preferred = true, description = "Sets the accessible description for the component.") public void setAccessibleDescription(String s) { ac.setAccessibleDescription(s); } /** * Gets the role of this object. The role of the object is the generic * purpose or use of the class of this object. For example, the role * of a push button is AccessibleRole.PUSH_BUTTON. The roles in * AccessibleRole are provided so component developers can pick from * a set of predefined roles. This enables assistive technologies to * provide a consistent interface to various tweaked subclasses of * components (e.g., use AccessibleRole.PUSH_BUTTON for all components * that act like a push button) as well as distinguish between subclasses * that behave differently (e.g., AccessibleRole.CHECK_BOX for check boxes * and AccessibleRole.RADIO_BUTTON for radio buttons). * <p>Note that the AccessibleRole class is also extensible, so * custom component developers can define their own AccessibleRole's * if the set of predefined roles is inadequate. * * @return an instance of AccessibleRole describing the role of the object * @see AccessibleRole */ public AccessibleRole getAccessibleRole() { return ac.getAccessibleRole(); } /** * Gets the state set of this object. The AccessibleStateSet of an object * is composed of a set of unique AccessibleStates. A change in the * AccessibleStateSet of an object will cause a PropertyChangeEvent to * be fired for the ACCESSIBLE_STATE_PROPERTY property. * * @return an instance of AccessibleStateSet containing the * current state set of the object * @see AccessibleStateSet * @see AccessibleState * @see #addPropertyChangeListener */ public AccessibleStateSet getAccessibleStateSet() { return ac.getAccessibleStateSet(); } /** * Gets the Accessible parent of this object. * * @return the Accessible parent of this object; null if this * object does not have an Accessible parent */ public Accessible getAccessibleParent() { return ac.getAccessibleParent(); } /** * Sets the Accessible parent of this object. This is meant to be used * only in the situations where the actual component's parent should * not be treated as the component's accessible parent and is a method * that should only be called by the parent of the accessible child. * * @param a - Accessible to be set as the parent */ public void setAccessibleParent(Accessible a) { ac.setAccessibleParent(a); } /** * Gets the 0-based index of this object in its accessible parent. * * @return the 0-based index of this object in its parent; -1 if this * object does not have an accessible parent. * * @see #getAccessibleParent * @see #getAccessibleChildrenCount * @see #getAccessibleChild */ public int getAccessibleIndexInParent() { return JComboBox.this.getSelectedIndex(); } /** * Returns the number of accessible children of the object. * * @return the number of accessible children of the object. */ public int getAccessibleChildrenCount() { return ac.getAccessibleChildrenCount(); } /** * Returns the specified Accessible child of the object. The Accessible * children of an Accessible object are zero-based, so the first child * of an Accessible child is at index 0, the second child is at index 1, * and so on. * * @param i zero-based index of child * @return the Accessible child of the object * @see #getAccessibleChildrenCount */ public Accessible getAccessibleChild(int i) { return ac.getAccessibleChild(i); } /** * Gets the locale of the component. If the component does not have a * locale, then the locale of its parent is returned. * * @return this component's locale. If this component does not have * a locale, the locale of its parent is returned. * * @exception IllegalComponentStateException * If the Component does not have its own locale and has not yet been * added to a containment hierarchy such that the locale can be * determined from the containing parent. */ public Locale getLocale() throws IllegalComponentStateException { return ac.getLocale(); } /** * Adds a PropertyChangeListener to the listener list. * The listener is registered for all Accessible properties and will * be called when those properties change. * * @see #ACCESSIBLE_NAME_PROPERTY * @see #ACCESSIBLE_DESCRIPTION_PROPERTY * @see #ACCESSIBLE_STATE_PROPERTY * @see #ACCESSIBLE_VALUE_PROPERTY * @see #ACCESSIBLE_SELECTION_PROPERTY * @see #ACCESSIBLE_TEXT_PROPERTY * @see #ACCESSIBLE_VISIBLE_DATA_PROPERTY * * @param listener The PropertyChangeListener to be added */ public void addPropertyChangeListener(PropertyChangeListener listener) { ac.addPropertyChangeListener(listener); } /** * Removes a PropertyChangeListener from the listener list. * This removes a PropertyChangeListener that was registered * for all properties. * * @param listener The PropertyChangeListener to be removed */ public void removePropertyChangeListener(PropertyChangeListener listener) { ac.removePropertyChangeListener(listener); } /** * Gets the AccessibleAction associated with this object that supports * one or more actions. * * @return AccessibleAction if supported by object; else return null * @see AccessibleAction */ public AccessibleAction getAccessibleAction() { return ac.getAccessibleAction(); } /** * Gets the AccessibleComponent associated with this object that has a * graphical representation. * * @return AccessibleComponent if supported by object; else return null * @see AccessibleComponent */ public AccessibleComponent getAccessibleComponent() { return ac.getAccessibleComponent(); } /** * Gets the AccessibleSelection associated with this object which allows its * Accessible children to be selected. * * @return AccessibleSelection if supported by object; else return null * @see AccessibleSelection */ public AccessibleSelection getAccessibleSelection() { return ac.getAccessibleSelection(); } /** * Gets the AccessibleText associated with this object presenting * text on the display. * * @return AccessibleText if supported by object; else return null * @see AccessibleText */ public AccessibleText getAccessibleText() { return ac.getAccessibleText(); } /** * Gets the AccessibleEditableText associated with this object * presenting editable text on the display. * * @return AccessibleEditableText if supported by object; else return null * @see AccessibleEditableText */ public AccessibleEditableText getAccessibleEditableText() { return ac.getAccessibleEditableText(); } /** * Gets the AccessibleValue associated with this object that supports a * Numerical value. * * @return AccessibleValue if supported by object; else return null * @see AccessibleValue */ public AccessibleValue getAccessibleValue() { return ac.getAccessibleValue(); } /** * Gets the AccessibleIcons associated with an object that has * one or more associated icons * * @return an array of AccessibleIcon if supported by object; * otherwise return null * @see AccessibleIcon */ public AccessibleIcon[] getAccessibleIcon() { return ac.getAccessibleIcon(); } /** * Gets the AccessibleRelationSet associated with an object * * @return an AccessibleRelationSet if supported by object; * otherwise return null * @see AccessibleRelationSet */ public AccessibleRelationSet getAccessibleRelationSet() { return ac.getAccessibleRelationSet(); } /** * Gets the AccessibleTable associated with an object * * @return an AccessibleTable if supported by object; * otherwise return null * @see AccessibleTable */ public AccessibleTable getAccessibleTable() { return ac.getAccessibleTable(); } /** * Support for reporting bound property changes. If oldValue and * newValue are not equal and the PropertyChangeEvent listener list * is not empty, then fire a PropertyChange event to each listener. * In general, this is for use by the Accessible objects themselves * and should not be called by an application program. * @param propertyName The programmatic name of the property that * was changed. * @param oldValue The old value of the property. * @param newValue The new value of the property. * @see java.beans.PropertyChangeSupport * @see #addPropertyChangeListener * @see #removePropertyChangeListener * @see #ACCESSIBLE_NAME_PROPERTY * @see #ACCESSIBLE_DESCRIPTION_PROPERTY * @see #ACCESSIBLE_STATE_PROPERTY * @see #ACCESSIBLE_VALUE_PROPERTY * @see #ACCESSIBLE_SELECTION_PROPERTY * @see #ACCESSIBLE_TEXT_PROPERTY * @see #ACCESSIBLE_VISIBLE_DATA_PROPERTY */ public void firePropertyChange(String propertyName, Object oldValue, Object newValue) { ac.firePropertyChange(propertyName, oldValue, newValue); } } } // innerclass AccessibleJComboBox }