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Java example source code file (JComboBox.java)
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The JComboBox.java Java example source code
/*
* Copyright (c) 1997, 2013, 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.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: Swing is not thread safe. For more
* information see <a
* href="package-summary.html#threading">Swing's Threading
* Policy</a>.
* <p>
* <strong>Warning:
* 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 package.
* Please see {@link java.beans.XMLEncoder}.
*
* <p>
* See <a href="http://docs.oracle.com/javase/tutorial/uiswing/components/combobox.html">How to Use Combo Boxes
* in <a href="http://docs.oracle.com/javase/tutorial/">The Java Tutorial
* for further information.
* <p>
* @see ComboBoxModel
* @see DefaultComboBoxModel
*
* @param <E> the type of the elements of this combo box
*
* @beaninfo
* attribute: isContainer false
* description: A combination of a text field and a drop-down list.
*
* @author Arnaud Weber
* @author Mark Davidson
*/
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;
/**
* Creates a <code>JComboBox that takes its items from an
* existing <code>ComboBoxModel. Since the
* <code>ComboBoxModel 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 that provides the
* displayed list of items
* @see DefaultComboBoxModel
*/
public JComboBox(ComboBoxModel<E> aModel) {
super();
setModel(aModel);
init();
}
/**
* Creates a <code>JComboBox 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 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 with a default data model.
* The default data model is an empty list of objects.
* Use <code>addItem 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();
}
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 L&F object
* @see UIDefaults#getUI
*
* @beaninfo
* bound: true
* hidden: true
* attribute: 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() {
setUI((ComboBoxUI)UIManager.getUI(this));
ListCellRenderer<? super E> renderer = getRenderer();
if (renderer instanceof Component) {
SwingUtilities.updateComponentTreeUI((Component)renderer);
}
}
/**
* Returns the name of the L&F class that renders this component.
*
* @return the string "ComboBoxUI"
* @see JComponent#getUIClassID
* @see UIDefaults#getUI
*/
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 uses to obtain
* the list of items.
*
* @param aModel the <code>ComboBoxModel that provides the
* displayed list of items
*
* @beaninfo
* bound: true
* 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.
*
* @return the <code>ComboBoxModel that provides the displayed
* list of items
*/
public ComboBoxModel<E> getModel() {
return dataModel;
}
/*
* Properties
*/
/**
* Sets the <code>lightWeightPopupEnabled property, which
* provides a hint as to whether or not a lightweight
* <code>Component should be used to contain the
* <code>JComboBox, versus a heavyweight
* <code>Component such as a Panel
* or a <code>Window. The decision of lightweight
* versus heavyweight is ultimately up to the
* <code>JComboBox. 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
* property is <code>true, 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
* This method fires a property changed event.
*
* @param aFlag if <code>true, lightweight popups are desired
*
* @beaninfo
* bound: true
* expert: true
* description: Set to <code>false 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
* property.
*
* @return the value of the <code>lightWeightPopupEnabled
* property
* @see #setLightWeightPopupEnabled
*/
public boolean isLightWeightPopupEnabled() {
return lightWeightPopupEnabled;
}
/**
* Determines whether the <code>JComboBox field is editable.
* An editable <code>JComboBox 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
* 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
*
* @beaninfo
* bound: true
* 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 is editable.
* By default, a combo box is not editable.
*
* @return true if the <code>JComboBox is editable, else false
*/
public boolean isEditable() {
return isEditable;
}
/**
* Sets the maximum number of rows the <code>JComboBox 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
* @beaninfo
* bound: true
* 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
* is called, passing the list object and an index of -1.
*
* @param aRenderer the <code>ListCellRenderer that
* displays the selected item
* @see #setEditor
* @beaninfo
* bound: true
* 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 field.
*
* @return the <code>ListCellRenderer 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 field. The editor is used only if the
* receiving <code>JComboBox is editable. If not editable,
* the combo box uses the renderer to paint the selected item.
*
* @param anEditor the <code>ComboBoxEditor that
* displays the selected item
* @see #setRenderer
* @beaninfo
* bound: true
* 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 field.
*
* @return the <code>ComboBoxEditor 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 is in the list, the display area shows
* <code>anObject selected.
* <p>
* If <code>anObject is not 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.
* <p>
* If this constitutes a change in the selected item,
* <code>ItemListeners added to the combo box will be notified with
* one or two <code>ItemEvents.
* If there is a current selected item, an <code>ItemEvent will be
* fired and the state change will be <code>ItemEvent.DESELECTED.
* If <code>anObject is in the list and is not currently selected
* then an <code>ItemEvent will be fired and the state change will
* be <code>ItemEvent.SELECTED.
* <p>
* <code>ActionListeners added to the combo box will be notified
* with an <code>ActionEvent when this method is called.
*
* @param anObject the list object to select; use <code>null to
clear the selection
* @beaninfo
* 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;
}
}
// 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, insertItemAt
* or the data constructors.
*
* @return the current selected Object
* @see #setSelectedItem
*/
public Object getSelectedItem() {
return dataModel.getSelectedItem();
}
/**
* Selects the item at index <code>anIndex.
*
* @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 < -1 or
* <code>anIndex is greater than or equal to size
* @beaninfo
* 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
* 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 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
* @see #getPrototypeDisplayValue
* @since 1.4
* @beaninfo
* bound: true
* attribute: 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 uses a
* mutable data model.
* <p>
* <strong>Warning:
* 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 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 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
* This method works only if the <code>JComboBox 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)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 is an instance of
* <code>MutableComboBoxModel. If not, it throws an exception.
* @exception RuntimeException if <code>dataModel is not an
* instance of <code>MutableComboBoxModel.
*/
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.
*/
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.
* <p>
* <code>aListener will receive one or two ItemEvents when
* the selected item changes.
*
* @param aListener the <code>ItemListener that is to be notified
* @see #setSelectedItem
*/
public void addItemListener(ItemListener aListener) {
listenerList.add(ItemListener.class,aListener);
}
/** Removes an <code>ItemListener.
*
* @param aListener the <code>ItemListener to remove
*/
public void removeItemListener(ItemListener aListener) {
listenerList.remove(ItemListener.class,aListener);
}
/**
* Returns an array of all the <code>ItemListeners added
* to this JComboBox with addItemListener().
*
* @return all of the <code>ItemListeners added or an empty
* array if no listeners have been added
* @since 1.4
*/
public ItemListener[] getItemListeners() {
return listenerList.getListeners(ItemListener.class);
}
/**
* Adds an <code>ActionListener.
* <p>
* The <code>ActionListener will receive an ActionEvent
* when a selection has been made. If the combo box is editable, then
* an <code>ActionEvent will be fired when editing has stopped.
*
* @param l the <code>ActionListener that is to be notified
* @see #setSelectedItem
*/
public void addActionListener(ActionListener l) {
listenerList.add(ActionListener.class,l);
}
/** Removes an <code>ActionListener.
*
* @param l the <code>ActionListener 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>ActionListeners added
* to this JComboBox with addActionListener().
*
* @return all of the <code>ActionListeners added or an empty
* array if no listeners have been added
* @since 1.4
*/
public ActionListener[] getActionListeners() {
return listenerList.getListeners(ActionListener.class);
}
/**
* Adds a <code>PopupMenu 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.
* A custom look and feel may not implement it this way and will
* therefore not receive the notification.
*
* @param l the <code>PopupMenuListener to add
* @since 1.4
*/
public void addPopupMenuListener(PopupMenuListener l) {
listenerList.add(PopupMenuListener.class,l);
}
/**
* Removes a <code>PopupMenuListener.
*
* @param l the <code>PopupMenuListener to remove
* @see #addPopupMenuListener
* @since 1.4
*/
public void removePopupMenuListener(PopupMenuListener l) {
listenerList.remove(PopupMenuListener.class,l);
}
/**
* Returns an array of all the <code>PopupMenuListeners added
* to this JComboBox with addPopupMenuListener().
*
* @return all of the <code>PopupMenuListeners added or an empty
* array if no listeners have been added
* @since 1.4
*/
public PopupMenuListener[] getPopupMenuListeners() {
return listenerList.getListeners(PopupMenuListener.class);
}
/**
* Notifies <code>PopupMenuListeners 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>PopupMenuListeners 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>PopupMenuListeners 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 for the ActionEvent source.
* The new <code>Action replaces any previously set
* <code>Action but does not affect ActionListeners
* independently added with <code>addActionListener.
* If the <code>Action is already a registered
* <code>ActionListener for the ActionEvent source,
* it is not re-registered.
* <p>
* Setting the <code>Action results in immediately changing
* all the properties described in <a href="Action.html#buttonActions">
* Swing Components Supporting <code>Action.
* Subsequently, the combobox's properties are automatically updated
* as the <code>Action's properties change.
* <p>
* This method uses three other methods to set
* and help track the <code>Action's property values.
* It uses the <code>configurePropertiesFromAction method
* to immediately change the combobox's properties.
* To track changes in the <code>Action's property values,
* this method registers the <code>PropertyChangeListener
* returned by <code>createActionPropertyChangeListener. The
* default {@code PropertyChangeListener} invokes the
* {@code actionPropertyChanged} method when a property in the
* {@code Action} changes.
*
* @param a the <code>Action for the JComboBox,
* or <code>null.
* @since 1.3
* @see Action
* @see #getAction
* @see #configurePropertiesFromAction
* @see #createActionPropertyChangeListener
* @see #actionPropertyChanged
* @beaninfo
* bound: true
* attribute: 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 for this
* <code>ActionEvent source, or null if no
* <code>Action is set.
*
* @return the <code>Action for this ActionEvent
* source; or <code>null
* @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. Refer to
* Swing Components Supporting <code>Action for more
* details as to which properties this sets.
*
* @param a the <code>Action from which to get the properties,
* or <code>null
* @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 that is
* responsible for listening for changes from the specified
* <code>Action and updating the appropriate properties.
* <p>
* <b>Warning: 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.
*
* @param a the combobox's action
* @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 for a list of
* the properties this method sets.
*
* @param action the <code>Action 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
*/
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();
}
// 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);
}
}
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.
*
* @return an array of <code>Objects containing one
* element -- the selected item
*/
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) {
Object newItem = getEditor().getItem();
setPopupVisible(false);
getModel().setSelectedItem(newItem);
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
*/
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
* @beaninfo
* bound: true
* preferred: true
* description: Whether the combo box is enabled.
*/
public void setEnabled(boolean b) {
super.setEnabled(b);
firePropertyChange( "enabled", !isEnabled(), isEnabled() );
}
/**
* Initializes the editor with the specified item.
*
* @param anEditor the <code>ComboBoxEditor 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>KeyEvents, looking for the Tab key.
* If the Tab key is found, the popup window is closed.
*
* @param e the <code>KeyEvent containing the keyboard
* key that was pressed
*/
public void processKeyEvent(KeyEvent e) {
if ( e.getKeyCode() == KeyEvent.VK_TAB ) {
hidePopup();
}
super.processKeyEvent(e);
}
/**
* 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.
*
* @beaninfo
* 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 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
*/
public int getItemCount() {
return dataModel.getSize();
}
/**
* Returns the list item at the specified index. If <code>index
* is out of range (less than zero or greater than or equal to size)
* it will return <code>null.
*
* @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 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 currently used by the list
* @see #setKeySelectionManager
*/
protected KeySelectionManager createDefaultKeySelectionManager() {
return new DefaultKeySelectionManager();
}
/**
* The interface that defines a <code>KeySelectionManager.
* To qualify as a <code>KeySelectionManager,
* 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 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 and writeObject in
* <code>JComponent 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.
* 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.
*
* @return a string representation of this <code>JComboBox
*/
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
*/
public AccessibleContext getAccessibleContext() {
if ( accessibleContext == null ) {
accessibleContext = new AccessibleJComboBox();
}
return accessibleContext;
}
/**
* This class implements accessibility support for the
* <code>JComboBox class. It provides an implementation of the
* Java Accessibility API appropriate to Combo Box user-interface elements.
* <p>
* <strong>Warning:
* 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 package.
* Please see {@link java.beans.XMLEncoder}.
*/
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 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
*
* @beaninfo
* 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
*
* @beaninfo
* 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
}
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