/* * Copyright (c) 1997, 2010, 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.awt.*; import java.awt.event.*; import java.util.Vector; import java.util.Locale; import java.util.ArrayList; import java.util.Collections; import java.util.List; import java.beans.PropertyChangeEvent; import java.beans.PropertyChangeListener; import java.beans.Transient; import javax.swing.event.*; import javax.accessibility.*; import javax.swing.plaf.*; import javax.swing.text.Position; import java.io.ObjectOutputStream; import java.io.ObjectInputStream; import java.io.IOException; import java.io.Serializable; import sun.swing.SwingUtilities2; import sun.swing.SwingUtilities2.Section; import static sun.swing.SwingUtilities2.Section.*; /** * A component that displays a list of objects and allows the user to select * one or more items. A separate model, {@code ListModel}, maintains the * contents of the list. *

* It's easy to display an array or Vector of objects, using the {@code JList} * constructor that automatically builds a read-only {@code ListModel} instance * for you: *

 * {@code
 * // Create a JList that displays strings from an array
 *
 * String[] data = {"one", "two", "three", "four"};
 * JList myList = new JList(data);
 *
 * // Create a JList that displays the superclasses of JList.class, by
 * // creating it with a Vector populated with this data
 *
 * Vector> superClasses = new Vector>();
 * Class rootClass = javax.swing.JList.class;
 * for(Class cls = rootClass; cls != null; cls = cls.getSuperclass()) {
 *     superClasses.addElement(cls);
 * }
 * JList> myList = new JList>(superClasses);
 *
 * // The automatically created model is stored in JList's "model"
 * // property, which you can retrieve
 *
 * ListModel> model = myList.getModel();
 * for(int i = 0; i < model.getSize(); i++) {
 *     System.out.println(model.getElementAt(i));
 * }
 * }
 * 
*

* A {@code ListModel} can be supplied directly to a {@code JList} by way of a * constructor or the {@code setModel} method. The contents need not be static - * the number of items, and the values of items can change over time. A correct * {@code ListModel} implementation notifies the set of * {@code javax.swing.event.ListDataListener}s that have been added to it, each * time a change occurs. These changes are characterized by a * {@code javax.swing.event.ListDataEvent}, which identifies the range of list * indices that have been modified, added, or removed. {@code JList}'s * {@code ListUI} is responsible for keeping the visual representation up to * date with changes, by listening to the model. *

* Simple, dynamic-content, {@code JList} applications can use the * {@code DefaultListModel} class to maintain list elements. This class * implements the {@code ListModel} interface and also provides a * java.util.Vector-like API. Applications that need a more * custom ListModel implementation may instead wish to subclass * {@code AbstractListModel}, which provides basic support for managing and * notifying listeners. For example, a read-only implementation of * {@code AbstractListModel}: *

 * {@code
 * // This list model has about 2^16 elements.  Enjoy scrolling.
 *
 * ListModel bigData = new AbstractListModel() {
 *     public int getSize() { return Short.MAX_VALUE; }
 *     public String getElementAt(int index) { return "Index " + index; }
 * };
 * }
 * 
*

* The selection state of a {@code JList} is managed by another separate * model, an instance of {@code ListSelectionModel}. {@code JList} is * initialized with a selection model on construction, and also contains * methods to query or set this selection model. Additionally, {@code JList} * provides convenient methods for easily managing the selection. These methods, * such as {@code setSelectedIndex} and {@code getSelectedValue}, are cover * methods that take care of the details of interacting with the selection * model. By default, {@code JList}'s selection model is configured to allow any * combination of items to be selected at a time; selection mode * {@code MULTIPLE_INTERVAL_SELECTION}. The selection mode can be changed * on the selection model directly, or via {@code JList}'s cover method. * Responsibility for updating the selection model in response to user gestures * lies with the list's {@code ListUI}. *

* A correct {@code ListSelectionModel} implementation notifies the set of * {@code javax.swing.event.ListSelectionListener}s that have been added to it * each time a change to the selection occurs. These changes are characterized * by a {@code javax.swing.event.ListSelectionEvent}, which identifies the range * of the selection change. *

* The preferred way to listen for changes in list selection is to add * {@code ListSelectionListener}s directly to the {@code JList}. {@code JList} * then takes care of listening to the the selection model and notifying your * listeners of change. *

* Responsibility for listening to selection changes in order to keep the list's * visual representation up to date lies with the list's {@code ListUI}. *

* * Painting of cells in a {@code JList} is handled by a delegate called a * cell renderer, installed on the list as the {@code cellRenderer} property. * The renderer provides a {@code java.awt.Component} that is used * like a "rubber stamp" to paint the cells. Each time a cell needs to be * painted, the list's {@code ListUI} asks the cell renderer for the component, * moves it into place, and has it paint the contents of the cell by way of its * {@code paint} method. A default cell renderer, which uses a {@code JLabel} * component to render, is installed by the lists's {@code ListUI}. You can * substitute your own renderer using code like this: *

 * {@code
 *  // Display an icon and a string for each object in the list.
 *
 * class MyCellRenderer extends JLabel implements ListCellRenderer {
 *     final static ImageIcon longIcon = new ImageIcon("long.gif");
 *     final static ImageIcon shortIcon = new ImageIcon("short.gif");
 *
 *     // This is the only method defined by ListCellRenderer.
 *     // We just reconfigure the JLabel each time we're called.
 *
 *     public Component getListCellRendererComponent(
 *       JList list,           // the list
 *       Object value,            // value to display
 *       int index,               // cell index
 *       boolean isSelected,      // is the cell selected
 *       boolean cellHasFocus)    // does the cell have focus
 *     {
 *         String s = value.toString();
 *         setText(s);
 *         setIcon((s.length() > 10) ? longIcon : shortIcon);
 *         if (isSelected) {
 *             setBackground(list.getSelectionBackground());
 *             setForeground(list.getSelectionForeground());
 *         } else {
 *             setBackground(list.getBackground());
 *             setForeground(list.getForeground());
 *         }
 *         setEnabled(list.isEnabled());
 *         setFont(list.getFont());
 *         setOpaque(true);
 *         return this;
 *     }
 * }
 *
 * myList.setCellRenderer(new MyCellRenderer());
 * }
 * 
 * 

* Another job for the cell renderer is in helping to determine sizing * information for the list. By default, the list's {@code ListUI} determines * the size of cells by asking the cell renderer for its preferred * size for each list item. This can be expensive for large lists of items. * To avoid these calculations, you can set a {@code fixedCellWidth} and * {@code fixedCellHeight} on the list, or have these values calculated * automatically based on a single prototype value: * *

 * {@code
 * JList bigDataList = new JList(bigData);
 *
 * // We don't want the JList implementation to compute the width
 * // or height of all of the list cells, so we give it a string
 * // that's as big as we'll need for any cell.  It uses this to
 * // compute values for the fixedCellWidth and fixedCellHeight
 * // properties.
 *
 * bigDataList.setPrototypeCellValue("Index 1234567890");
 * }
 * 
*

* {@code JList} doesn't implement scrolling directly. To create a list that * scrolls, make it the viewport view of a {@code JScrollPane}. For example: *

 * JScrollPane scrollPane = new JScrollPane(myList);
 *
 * // Or in two steps:
 * JScrollPane scrollPane = new JScrollPane();
 * scrollPane.getViewport().setView(myList);
 * 
*

* {@code JList} doesn't provide any special handling of double or triple * (or N) mouse clicks, but it's easy to add a {@code MouseListener} if you * wish to take action on these events. Use the {@code locationToIndex} * method to determine what cell was clicked. For example: *

 * MouseListener mouseListener = new MouseAdapter() {
 *     public void mouseClicked(MouseEvent e) {
 *         if (e.getClickCount() == 2) {
 *             int index = list.locationToIndex(e.getPoint());
 *             System.out.println("Double clicked on Item " + index);
 *          }
 *     }
 * };
 * list.addMouseListener(mouseListener);
 * 
*

* Warning: Swing is not thread safe. For more * information see Swing's Threading * Policy. *

* 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 JavaBeansTM * has been added to the java.beans package. * Please see {@link java.beans.XMLEncoder}. *

* See How to Use Lists * in The Java Tutorial * for further documentation. * Also see the article Advanced JList Programming * in The Swing Connection. *

* @see ListModel * @see AbstractListModel * @see DefaultListModel * @see ListSelectionModel * @see DefaultListSelectionModel * @see ListCellRenderer * @see DefaultListCellRenderer * * @param the type of the elements of this list * * @beaninfo * attribute: isContainer false * description: A component which allows for the selection of one or more objects from a list. * * @author Hans Muller */ public class JList extends JComponent implements Scrollable, Accessible { /** * @see #getUIClassID * @see #readObject */ private static final String uiClassID = "ListUI"; /** * Indicates a vertical layout of cells, in a single column; * the default layout. * @see #setLayoutOrientation * @since 1.4 */ public static final int VERTICAL = 0; /** * Indicates a "newspaper style" layout with cells flowing vertically * then horizontally. * @see #setLayoutOrientation * @since 1.4 */ public static final int VERTICAL_WRAP = 1; /** * Indicates a "newspaper style" layout with cells flowing horizontally * then vertically. * @see #setLayoutOrientation * @since 1.4 */ public static final int HORIZONTAL_WRAP = 2; private int fixedCellWidth = -1; private int fixedCellHeight = -1; private int horizontalScrollIncrement = -1; private E prototypeCellValue; private int visibleRowCount = 8; private Color selectionForeground; private Color selectionBackground; private boolean dragEnabled; private ListSelectionModel selectionModel; private ListModel dataModel; private ListCellRenderer cellRenderer; private ListSelectionListener selectionListener; /** * How to lay out the cells; defaults to VERTICAL. */ private int layoutOrientation; /** * The drop mode for this component. */ private DropMode dropMode = DropMode.USE_SELECTION; /** * The drop location. */ private transient DropLocation dropLocation; /** * A subclass of TransferHandler.DropLocation representing * a drop location for a JList. * * @see #getDropLocation * @since 1.6 */ public static final class DropLocation extends TransferHandler.DropLocation { private final int index; private final boolean isInsert; private DropLocation(Point p, int index, boolean isInsert) { super(p); this.index = index; this.isInsert = isInsert; } /** * Returns the index where dropped data should be placed in the * list. Interpretation of the value depends on the drop mode set on * the associated component. If the drop mode is either * DropMode.USE_SELECTION or DropMode.ON, * the return value is an index of a row in the list. If the drop mode is * DropMode.INSERT, the return value refers to the index * where the data should be inserted. If the drop mode is * DropMode.ON_OR_INSERT, the value of * isInsert() indicates whether the index is an index * of a row, or an insert index. *

* -1 indicates that the drop occurred over empty space, * and no index could be calculated. * * @return the drop index */ public int getIndex() { return index; } /** * Returns whether or not this location represents an insert * location. * * @return whether or not this is an insert location */ public boolean isInsert() { return isInsert; } /** * Returns a string representation of this drop location. * This method is intended to be used for debugging purposes, * and the content and format of the returned string may vary * between implementations. * * @return a string representation of this drop location */ public String toString() { return getClass().getName() + "[dropPoint=" + getDropPoint() + "," + "index=" + index + "," + "insert=" + isInsert + "]"; } } /** * Constructs a {@code JList} that displays elements from the specified, * {@code non-null}, model. All {@code JList} constructors delegate to * this one. *

* This constructor registers the list with the {@code ToolTipManager}, * allowing for tooltips to be provided by the cell renderers. * * @param dataModel the model for the list * @exception IllegalArgumentException if the model is {@code null} */ public JList(ListModel dataModel) { if (dataModel == null) { throw new IllegalArgumentException("dataModel must be non null"); } // Register with the ToolTipManager so that tooltips from the // renderer show through. ToolTipManager toolTipManager = ToolTipManager.sharedInstance(); toolTipManager.registerComponent(this); layoutOrientation = VERTICAL; this.dataModel = dataModel; selectionModel = createSelectionModel(); setAutoscrolls(true); setOpaque(true); updateUI(); } /** * Constructs a JList that displays the elements in * the specified array. This constructor creates a read-only model * for the given array, and then delegates to the constructor that * takes a {@code ListModel}. *

* Attempts to pass a {@code null} value to this method results in * undefined behavior and, most likely, exceptions. The created model * references the given array directly. Attempts to modify the array * after constructing the list results in undefined behavior. * * @param listData the array of Objects to be loaded into the data model, * {@code non-null} */ public JList(final E[] listData) { this ( new AbstractListModel() { public int getSize() { return listData.length; } public E getElementAt(int i) { return listData[i]; } } ); } /** * Constructs a JList that displays the elements in * the specified Vector. This constructor creates a read-only * model for the given {@code Vector}, and then delegates to the constructor * that takes a {@code ListModel}. *

* Attempts to pass a {@code null} value to this method results in * undefined behavior and, most likely, exceptions. The created model * references the given {@code Vector} directly. Attempts to modify the * {@code Vector} after constructing the list results in undefined behavior. * * @param listData the Vector to be loaded into the * data model, {@code non-null} */ public JList(final Vector listData) { this ( new AbstractListModel() { public int getSize() { return listData.size(); } public E getElementAt(int i) { return listData.elementAt(i); } } ); } /** * Constructs a JList with an empty, read-only, model. */ public JList() { this ( new AbstractListModel() { public int getSize() { return 0; } public E getElementAt(int i) { throw new IndexOutOfBoundsException("No Data Model"); } } ); } /** * Returns the {@code ListUI}, the look and feel object that * renders this component. * * @return the ListUI object that renders this component */ public ListUI getUI() { return (ListUI)ui; } /** * Sets the {@code ListUI}, the look and feel object that * renders this component. * * @param ui the ListUI 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(ListUI ui) { super.setUI(ui); } /** * Resets the {@code ListUI} property by setting it to the value provided * by the current look and feel. If the current cell renderer was installed * by the developer (rather than the look and feel itself), this also causes * the cell renderer and its children to be updated, by calling * {@code SwingUtilities.updateComponentTreeUI} on it. * * @see UIManager#getUI * @see SwingUtilities#updateComponentTreeUI */ public void updateUI() { setUI((ListUI)UIManager.getUI(this)); ListCellRenderer renderer = getCellRenderer(); if (renderer instanceof Component) { SwingUtilities.updateComponentTreeUI((Component)renderer); } } /** * Returns {@code "ListUI"}, the UIDefaults key used to look * up the name of the {@code javax.swing.plaf.ListUI} class that defines * the look and feel for this component. * * @return the string "ListUI" * @see JComponent#getUIClassID * @see UIDefaults#getUI */ public String getUIClassID() { return uiClassID; } /* -----private----- * This method is called by setPrototypeCellValue and setCellRenderer * to update the fixedCellWidth and fixedCellHeight properties from the * current value of prototypeCellValue (if it's non null). *

* This method sets fixedCellWidth and fixedCellHeight but does not * generate PropertyChangeEvents for them. * * @see #setPrototypeCellValue * @see #setCellRenderer */ private void updateFixedCellSize() { ListCellRenderer cr = getCellRenderer(); E value = getPrototypeCellValue(); if ((cr != null) && (value != null)) { Component c = cr.getListCellRendererComponent(this, value, 0, false, false); /* The ListUI implementation will add Component c to its private * CellRendererPane however we can't assume that's already * been done here. So we temporarily set the one "inherited" * property that may affect the renderer components preferred size: * its font. */ Font f = c.getFont(); c.setFont(getFont()); Dimension d = c.getPreferredSize(); fixedCellWidth = d.width; fixedCellHeight = d.height; c.setFont(f); } } /** * Returns the "prototypical" cell value -- a value used to calculate a * fixed width and height for cells. This can be {@code null} if there * is no such value. * * @return the value of the {@code prototypeCellValue} property * @see #setPrototypeCellValue */ public E getPrototypeCellValue() { return prototypeCellValue; } /** * Sets the {@code prototypeCellValue} property, and then (if the new value * is {@code non-null}), computes the {@code fixedCellWidth} and * {@code fixedCellHeight} properties by requesting the cell renderer * component for the given value (and index 0) from the cell renderer, and * using that component's preferred size. *

* This method is useful when the list is too long to allow the * {@code ListUI} to compute the width/height of each cell, and there is a * single cell value that is known to occupy as much space as any of the * others, a so-called prototype. *

* While all three of the {@code prototypeCellValue}, * {@code fixedCellHeight}, and {@code fixedCellWidth} properties may be * modified by this method, {@code PropertyChangeEvent} notifications are * only sent when the {@code prototypeCellValue} property changes. *

* To see an example which sets this property, see the * class description above. *

* The default value of this property is null. *

* This is a JavaBeans bound property. * * @param prototypeCellValue the value on which to base * fixedCellWidth and * fixedCellHeight * @see #getPrototypeCellValue * @see #setFixedCellWidth * @see #setFixedCellHeight * @see JComponent#addPropertyChangeListener * @beaninfo * bound: true * attribute: visualUpdate true * description: The cell prototype value, used to compute cell width and height. */ public void setPrototypeCellValue(E prototypeCellValue) { E oldValue = this.prototypeCellValue; this.prototypeCellValue = prototypeCellValue; /* If the prototypeCellValue has changed and is non-null, * then recompute fixedCellWidth and fixedCellHeight. */ if ((prototypeCellValue != null) && !prototypeCellValue.equals(oldValue)) { updateFixedCellSize(); } firePropertyChange("prototypeCellValue", oldValue, prototypeCellValue); } /** * Returns the value of the {@code fixedCellWidth} property. * * @return the fixed cell width * @see #setFixedCellWidth */ public int getFixedCellWidth() { return fixedCellWidth; } /** * Sets a fixed value to be used for the width of every cell in the list. * If {@code width} is -1, cell widths are computed in the {@code ListUI} * by applying getPreferredSize to the cell renderer component * for each list element. *

* The default value of this property is {@code -1}. *

* This is a JavaBeans bound property. * * @param width the width to be used for all cells in the list * @see #setPrototypeCellValue * @see #setFixedCellWidth * @see JComponent#addPropertyChangeListener * @beaninfo * bound: true * attribute: visualUpdate true * description: Defines a fixed cell width when greater than zero. */ public void setFixedCellWidth(int width) { int oldValue = fixedCellWidth; fixedCellWidth = width; firePropertyChange("fixedCellWidth", oldValue, fixedCellWidth); } /** * Returns the value of the {@code fixedCellHeight} property. * * @return the fixed cell height * @see #setFixedCellHeight */ public int getFixedCellHeight() { return fixedCellHeight; } /** * Sets a fixed value to be used for the height of every cell in the list. * If {@code height} is -1, cell heights are computed in the {@code ListUI} * by applying getPreferredSize to the cell renderer component * for each list element. *

* The default value of this property is {@code -1}. *

* This is a JavaBeans bound property. * * @param height the height to be used for for all cells in the list * @see #setPrototypeCellValue * @see #setFixedCellWidth * @see JComponent#addPropertyChangeListener * @beaninfo * bound: true * attribute: visualUpdate true * description: Defines a fixed cell height when greater than zero. */ public void setFixedCellHeight(int height) { int oldValue = fixedCellHeight; fixedCellHeight = height; firePropertyChange("fixedCellHeight", oldValue, fixedCellHeight); } /** * Returns the object responsible for painting list items. * * @return the value of the {@code cellRenderer} property * @see #setCellRenderer */ @Transient public ListCellRenderer getCellRenderer() { return cellRenderer; } /** * Sets the delegate that is used to paint each cell in the list. * The job of a cell renderer is discussed in detail in the * class level documentation. *

* If the {@code prototypeCellValue} property is {@code non-null}, * setting the cell renderer also causes the {@code fixedCellWidth} and * {@code fixedCellHeight} properties to be re-calculated. Only one * PropertyChangeEvent is generated however - * for the cellRenderer property. *

* The default value of this property is provided by the {@code ListUI} * delegate, i.e. by the look and feel implementation. *

* This is a JavaBeans bound property. * * @param cellRenderer the ListCellRenderer * that paints list cells * @see #getCellRenderer * @beaninfo * bound: true * attribute: visualUpdate true * description: The component used to draw the cells. */ public void setCellRenderer(ListCellRenderer cellRenderer) { ListCellRenderer oldValue = this.cellRenderer; this.cellRenderer = cellRenderer; /* If the cellRenderer has changed and prototypeCellValue * was set, then recompute fixedCellWidth and fixedCellHeight. */ if ((cellRenderer != null) && !cellRenderer.equals(oldValue)) { updateFixedCellSize(); } firePropertyChange("cellRenderer", oldValue, cellRenderer); } /** * Returns the color used to draw the foreground of selected items. * {@code DefaultListCellRenderer} uses this color to draw the foreground * of items in the selected state, as do the renderers installed by most * {@code ListUI} implementations. * * @return the color to draw the foreground of selected items * @see #setSelectionForeground * @see DefaultListCellRenderer */ public Color getSelectionForeground() { return selectionForeground; } /** * Sets the color used to draw the foreground of selected items, which * cell renderers can use to render text and graphics. * {@code DefaultListCellRenderer} uses this color to draw the foreground * of items in the selected state, as do the renderers installed by most * {@code ListUI} implementations. *

* The default value of this property is defined by the look and feel * implementation. *

* This is a JavaBeans bound property. * * @param selectionForeground the {@code Color} to use in the foreground * for selected list items * @see #getSelectionForeground * @see #setSelectionBackground * @see #setForeground * @see #setBackground * @see #setFont * @see DefaultListCellRenderer * @beaninfo * bound: true * attribute: visualUpdate true * description: The foreground color of selected cells. */ public void setSelectionForeground(Color selectionForeground) { Color oldValue = this.selectionForeground; this.selectionForeground = selectionForeground; firePropertyChange("selectionForeground", oldValue, selectionForeground); } /** * Returns the color used to draw the background of selected items. * {@code DefaultListCellRenderer} uses this color to draw the background * of items in the selected state, as do the renderers installed by most * {@code ListUI} implementations. * * @return the color to draw the background of selected items * @see #setSelectionBackground * @see DefaultListCellRenderer */ public Color getSelectionBackground() { return selectionBackground; } /** * Sets the color used to draw the background of selected items, which * cell renderers can use fill selected cells. * {@code DefaultListCellRenderer} uses this color to fill the background * of items in the selected state, as do the renderers installed by most * {@code ListUI} implementations. *

* The default value of this property is defined by the look * and feel implementation. *

* This is a JavaBeans bound property. * * @param selectionBackground the {@code Color} to use for the * background of selected cells * @see #getSelectionBackground * @see #setSelectionForeground * @see #setForeground * @see #setBackground * @see #setFont * @see DefaultListCellRenderer * @beaninfo * bound: true * attribute: visualUpdate true * description: The background color of selected cells. */ public void setSelectionBackground(Color selectionBackground) { Color oldValue = this.selectionBackground; this.selectionBackground = selectionBackground; firePropertyChange("selectionBackground", oldValue, selectionBackground); } /** * Returns the value of the {@code visibleRowCount} property. See the * documentation for {@link #setVisibleRowCount} for details on how to * interpret this value. * * @return the value of the {@code visibleRowCount} property. * @see #setVisibleRowCount */ public int getVisibleRowCount() { return visibleRowCount; } /** * Sets the {@code visibleRowCount} property, which has different meanings * depending on the layout orientation: For a {@code VERTICAL} layout * orientation, this sets the preferred number of rows to display without * requiring scrolling; for other orientations, it affects the wrapping of * cells. *

* In {@code VERTICAL} orientation:
* Setting this property affects the return value of the * {@link #getPreferredScrollableViewportSize} method, which is used to * calculate the preferred size of an enclosing viewport. See that method's * documentation for more details. *

* In {@code HORIZONTAL_WRAP} and {@code VERTICAL_WRAP} orientations:
* This affects how cells are wrapped. See the documentation of * {@link #setLayoutOrientation} for more details. *

* The default value of this property is {@code 8}. *

* Calling this method with a negative value results in the property * being set to {@code 0}. *

* This is a JavaBeans bound property. * * @param visibleRowCount an integer specifying the preferred number of * rows to display without requiring scrolling * @see #getVisibleRowCount * @see #getPreferredScrollableViewportSize * @see #setLayoutOrientation * @see JComponent#getVisibleRect * @see JViewport * @beaninfo * bound: true * attribute: visualUpdate true * description: The preferred number of rows to display without * requiring scrolling */ public void setVisibleRowCount(int visibleRowCount) { int oldValue = this.visibleRowCount; this.visibleRowCount = Math.max(0, visibleRowCount); firePropertyChange("visibleRowCount", oldValue, visibleRowCount); } /** * Returns the layout orientation property for the list: {@code VERTICAL} * if the layout is a single column of cells, {@code VERTICAL_WRAP} if the * layout is "newspaper style" with the content flowing vertically then * horizontally, or {@code HORIZONTAL_WRAP} if the layout is "newspaper * style" with the content flowing horizontally then vertically. * * @return the value of the {@code layoutOrientation} property * @see #setLayoutOrientation * @since 1.4 */ public int getLayoutOrientation() { return layoutOrientation; } /** * Defines the way list cells are layed out. Consider a {@code JList} * with five cells. Cells can be layed out in one of the following ways: *

*

     * VERTICAL:          0
     *                    1
     *                    2
     *                    3
     *                    4
     *
     * HORIZONTAL_WRAP:   0  1  2
     *                    3  4
     *
     * VERTICAL_WRAP:     0  3
     *                    1  4
     *                    2
     * 
*

* A description of these layouts follows: * * * *

Value

Description

VERTICAL * Cells are layed out vertically in a single column. *
HORIZONTAL_WRAP * Cells are layed out horizontally, wrapping to a new row as * necessary. If the {@code visibleRowCount} property is less than * or equal to zero, wrapping is determined by the width of the * list; otherwise wrapping is done in such a way as to ensure * {@code visibleRowCount} rows in the list. *
VERTICAL_WRAP * Cells are layed out vertically, wrapping to a new column as * necessary. If the {@code visibleRowCount} property is less than * or equal to zero, wrapping is determined by the height of the * list; otherwise wrapping is done at {@code visibleRowCount} rows. *
*

* The default value of this property is VERTICAL. * * @param layoutOrientation the new layout orientation, one of: * {@code VERTICAL}, {@code HORIZONTAL_WRAP} or {@code VERTICAL_WRAP} * @see #getLayoutOrientation * @see #setVisibleRowCount * @see #getScrollableTracksViewportHeight * @see #getScrollableTracksViewportWidth * @throws IllegalArgumentException if {@code layoutOrientation} isn't one of the * allowable values * @since 1.4 * @beaninfo * bound: true * attribute: visualUpdate true * description: Defines the way list cells are layed out. * enum: VERTICAL JList.VERTICAL * HORIZONTAL_WRAP JList.HORIZONTAL_WRAP * VERTICAL_WRAP JList.VERTICAL_WRAP */ public void setLayoutOrientation(int layoutOrientation) { int oldValue = this.layoutOrientation; switch (layoutOrientation) { case VERTICAL: case VERTICAL_WRAP: case HORIZONTAL_WRAP: this.layoutOrientation = layoutOrientation; firePropertyChange("layoutOrientation", oldValue, layoutOrientation); break; default: throw new IllegalArgumentException("layoutOrientation must be one of: VERTICAL, HORIZONTAL_WRAP or VERTICAL_WRAP"); } } /** * Returns the smallest list index that is currently visible. * In a left-to-right {@code componentOrientation}, the first visible * cell is found closest to the list's upper-left corner. In right-to-left * orientation, it is found closest to the upper-right corner. * If nothing is visible or the list is empty, {@code -1} is returned. * Note that the returned cell may only be partially visible. * * @return the index of the first visible cell * @see #getLastVisibleIndex * @see JComponent#getVisibleRect */ public int getFirstVisibleIndex() { Rectangle r = getVisibleRect(); int first; if (this.getComponentOrientation().isLeftToRight()) { first = locationToIndex(r.getLocation()); } else { first = locationToIndex(new Point((r.x + r.width) - 1, r.y)); } if (first != -1) { Rectangle bounds = getCellBounds(first, first); if (bounds != null) { SwingUtilities.computeIntersection(r.x, r.y, r.width, r.height, bounds); if (bounds.width == 0 || bounds.height == 0) { first = -1; } } } return first; } /** * Returns the largest list index that is currently visible. * If nothing is visible or the list is empty, {@code -1} is returned. * Note that the returned cell may only be partially visible. * * @return the index of the last visible cell * @see #getFirstVisibleIndex * @see JComponent#getVisibleRect */ public int getLastVisibleIndex() { boolean leftToRight = this.getComponentOrientation().isLeftToRight(); Rectangle r = getVisibleRect(); Point lastPoint; if (leftToRight) { lastPoint = new Point((r.x + r.width) - 1, (r.y + r.height) - 1); } else { lastPoint = new Point(r.x, (r.y + r.height) - 1); } int location = locationToIndex(lastPoint); if (location != -1) { Rectangle bounds = getCellBounds(location, location); if (bounds != null) { SwingUtilities.computeIntersection(r.x, r.y, r.width, r.height, bounds); if (bounds.width == 0 || bounds.height == 0) { // Try the top left(LTR) or top right(RTL) corner, and // then go across checking each cell for HORIZONTAL_WRAP. // Try the lower left corner, and then go across checking // each cell for other list layout orientation. boolean isHorizontalWrap = (getLayoutOrientation() == HORIZONTAL_WRAP); Point visibleLocation = isHorizontalWrap ? new Point(lastPoint.x, r.y) : new Point(r.x, lastPoint.y); int last; int visIndex = -1; int lIndex = location; location = -1; do { last = visIndex; visIndex = locationToIndex(visibleLocation); if (visIndex != -1) { bounds = getCellBounds(visIndex, visIndex); if (visIndex != lIndex && bounds != null && bounds.contains(visibleLocation)) { location = visIndex; if (isHorizontalWrap) { visibleLocation.y = bounds.y + bounds.height; if (visibleLocation.y >= lastPoint.y) { // Past visible region, bail. last = visIndex; } } else { visibleLocation.x = bounds.x + bounds.width; if (visibleLocation.x >= lastPoint.x) { // Past visible region, bail. last = visIndex; } } } else { last = visIndex; } } } while (visIndex != -1 && last != visIndex); } } } return location; } /** * Scrolls the list within an enclosing viewport to make the specified * cell completely visible. This calls {@code scrollRectToVisible} with * the bounds of the specified cell. For this method to work, the * {@code JList} must be within a JViewport. *

* If the given index is outside the list's range of cells, this method * results in nothing. * * @param index the index of the cell to make visible * @see JComponent#scrollRectToVisible * @see #getVisibleRect */ public void ensureIndexIsVisible(int index) { Rectangle cellBounds = getCellBounds(index, index); if (cellBounds != null) { scrollRectToVisible(cellBounds); } } /** * Turns on or off automatic drag handling. In order to enable automatic * drag handling, this property should be set to {@code true}, and the * list's {@code TransferHandler} needs to be {@code non-null}. * The default value of the {@code dragEnabled} property is {@code false}. *

* The job of honoring this property, and recognizing a user drag gesture, * lies with the look and feel implementation, and in particular, the list's * {@code ListUI}. When automatic drag handling is enabled, most look and * feels (including those that subclass {@code BasicLookAndFeel}) begin a * drag and drop operation whenever the user presses the mouse button over * an item and then moves the mouse a few pixels. Setting this property to * {@code true} can therefore have a subtle effect on how selections behave. *

* If a look and feel is used that ignores this property, you can still * begin a drag and drop operation by calling {@code exportAsDrag} on the * list's {@code TransferHandler}. * * @param b whether or not to enable automatic drag handling * @exception HeadlessException if * b is true and * GraphicsEnvironment.isHeadless() * returns true * @see java.awt.GraphicsEnvironment#isHeadless * @see #getDragEnabled * @see #setTransferHandler * @see TransferHandler * @since 1.4 * * @beaninfo * description: determines whether automatic drag handling is enabled * bound: false */ public void setDragEnabled(boolean b) { if (b && GraphicsEnvironment.isHeadless()) { throw new HeadlessException(); } dragEnabled = b; } /** * Returns whether or not automatic drag handling is enabled. * * @return the value of the {@code dragEnabled} property * @see #setDragEnabled * @since 1.4 */ public boolean getDragEnabled() { return dragEnabled; } /** * Sets the drop mode for this component. For backward compatibility, * the default for this property is DropMode.USE_SELECTION. * Usage of one of the other modes is recommended, however, for an * improved user experience. DropMode.ON, for instance, * offers similar behavior of showing items as selected, but does so without * affecting the actual selection in the list. *

* JList supports the following drop modes: *

    *
  • DropMode.USE_SELECTION
  • *
  • DropMode.ON
  • *
  • DropMode.INSERT
  • *
  • DropMode.ON_OR_INSERT
  • *
* The drop mode is only meaningful if this component has a * TransferHandler that accepts drops. * * @param dropMode the drop mode to use * @throws IllegalArgumentException if the drop mode is unsupported * or null * @see #getDropMode * @see #getDropLocation * @see #setTransferHandler * @see TransferHandler * @since 1.6 */ public final void setDropMode(DropMode dropMode) { if (dropMode != null) { switch (dropMode) { case USE_SELECTION: case ON: case INSERT: case ON_OR_INSERT: this.dropMode = dropMode; return; } } throw new IllegalArgumentException(dropMode + ": Unsupported drop mode for list"); } /** * Returns the drop mode for this component. * * @return the drop mode for this component * @see #setDropMode * @since 1.6 */ public final DropMode getDropMode() { return dropMode; } /** * Calculates a drop location in this component, representing where a * drop at the given point should insert data. * * @param p the point to calculate a drop location for * @return the drop location, or null */ DropLocation dropLocationForPoint(Point p) { DropLocation location = null; Rectangle rect = null; int index = locationToIndex(p); if (index != -1) { rect = getCellBounds(index, index); } switch(dropMode) { case USE_SELECTION: case ON: location = new DropLocation(p, (rect != null && rect.contains(p)) ? index : -1, false); break; case INSERT: if (index == -1) { location = new DropLocation(p, getModel().getSize(), true); break; } if (layoutOrientation == HORIZONTAL_WRAP) { boolean ltr = getComponentOrientation().isLeftToRight(); if (SwingUtilities2.liesInHorizontal(rect, p, ltr, false) == TRAILING) { index++; // special case for below all cells } else if (index == getModel().getSize() - 1 && p.y >= rect.y + rect.height) { index++; } } else { if (SwingUtilities2.liesInVertical(rect, p, false) == TRAILING) { index++; } } location = new DropLocation(p, index, true); break; case ON_OR_INSERT: if (index == -1) { location = new DropLocation(p, getModel().getSize(), true); break; } boolean between = false; if (layoutOrientation == HORIZONTAL_WRAP) { boolean ltr = getComponentOrientation().isLeftToRight(); Section section = SwingUtilities2.liesInHorizontal(rect, p, ltr, true); if (section == TRAILING) { index++; between = true; // special case for below all cells } else if (index == getModel().getSize() - 1 && p.y >= rect.y + rect.height) { index++; between = true; } else if (section == LEADING) { between = true; } } else { Section section = SwingUtilities2.liesInVertical(rect, p, true); if (section == LEADING) { between = true; } else if (section == TRAILING) { index++; between = true; } } location = new DropLocation(p, index, between); break; default: assert false : "Unexpected drop mode"; } return location; } /** * Called to set or clear the drop location during a DnD operation. * In some cases, the component may need to use it's internal selection * temporarily to indicate the drop location. To help facilitate this, * this method returns and accepts as a parameter a state object. * This state object can be used to store, and later restore, the selection * state. Whatever this method returns will be passed back to it in * future calls, as the state parameter. If it wants the DnD system to * continue storing the same state, it must pass it back every time. * Here's how this is used: *

* Let's say that on the first call to this method the component decides * to save some state (because it is about to use the selection to show * a drop index). It can return a state object to the caller encapsulating * any saved selection state. On a second call, let's say the drop location * is being changed to something else. The component doesn't need to * restore anything yet, so it simply passes back the same state object * to have the DnD system continue storing it. Finally, let's say this * method is messaged with null. This means DnD * is finished with this component for now, meaning it should restore * state. At this point, it can use the state parameter to restore * said state, and of course return null since there's * no longer anything to store. * * @param location the drop location (as calculated by * dropLocationForPoint) or null * if there's no longer a valid drop location * @param state the state object saved earlier for this component, * or null * @param forDrop whether or not the method is being called because an * actual drop occurred * @return any saved state for this component, or null if none */ Object setDropLocation(TransferHandler.DropLocation location, Object state, boolean forDrop) { Object retVal = null; DropLocation listLocation = (DropLocation)location; if (dropMode == DropMode.USE_SELECTION) { if (listLocation == null) { if (!forDrop && state != null) { setSelectedIndices(((int[][])state)[0]); int anchor = ((int[][])state)[1][0]; int lead = ((int[][])state)[1][1]; SwingUtilities2.setLeadAnchorWithoutSelection( getSelectionModel(), lead, anchor); } } else { if (dropLocation == null) { int[] inds = getSelectedIndices(); retVal = new int[][] {inds, {getAnchorSelectionIndex(), getLeadSelectionIndex()}}; } else { retVal = state; } int index = listLocation.getIndex(); if (index == -1) { clearSelection(); getSelectionModel().setAnchorSelectionIndex(-1); getSelectionModel().setLeadSelectionIndex(-1); } else { setSelectionInterval(index, index); } } } DropLocation old = dropLocation; dropLocation = listLocation; firePropertyChange("dropLocation", old, dropLocation); return retVal; } /** * Returns the location that this component should visually indicate * as the drop location during a DnD operation over the component, * or {@code null} if no location is to currently be shown. *

* This method is not meant for querying the drop location * from a {@code TransferHandler}, as the drop location is only * set after the {@code TransferHandler}'s canImport * has returned and has allowed for the location to be shown. *

* When this property changes, a property change event with * name "dropLocation" is fired by the component. *

* By default, responsibility for listening for changes to this property * and indicating the drop location visually lies with the list's * {@code ListUI}, which may paint it directly and/or install a cell * renderer to do so. Developers wishing to implement custom drop location * painting and/or replace the default cell renderer, may need to honor * this property. * * @return the drop location * @see #setDropMode * @see TransferHandler#canImport(TransferHandler.TransferSupport) * @since 1.6 */ public final DropLocation getDropLocation() { return dropLocation; } /** * Returns the next list element whose {@code toString} value * starts with the given prefix. * * @param prefix the string to test for a match * @param startIndex the index for starting the search * @param bias the search direction, either * Position.Bias.Forward or Position.Bias.Backward. * @return the index of the next list element that * starts with the prefix; otherwise {@code -1} * @exception IllegalArgumentException if prefix is {@code null} * or startIndex is out of bounds * @since 1.4 */ public int getNextMatch(String prefix, int startIndex, Position.Bias bias) { ListModel model = getModel(); int max = model.getSize(); if (prefix == null) { throw new IllegalArgumentException(); } if (startIndex < 0 || startIndex >= max) { throw new IllegalArgumentException(); } prefix = prefix.toUpperCase(); // start search from the next element after the selected element int increment = (bias == Position.Bias.Forward) ? 1 : -1; int index = startIndex; do { E element = model.getElementAt(index); if (element != null) { String string; if (element instanceof String) { string = ((String)element).toUpperCase(); } else { string = element.toString(); if (string != null) { string = string.toUpperCase(); } } if (string != null && string.startsWith(prefix)) { return index; } } index = (index + increment + max) % max; } while (index != startIndex); return -1; } /** * Returns the tooltip text to be used for the given event. This overrides * {@code JComponent}'s {@code getToolTipText} to first check the cell * renderer component for the cell over which the event occurred, returning * its tooltip text, if any. This implementation allows you to specify * tooltip text on the cell level, by using {@code setToolTipText} on your * cell renderer component. *

* Note: For JList to properly display the * tooltips of its renderers in this manner, JList must be a * registered component with the ToolTipManager. This registration * is done automatically in the constructor. However, if at a later point * JList is unregistered, by way of a call to * {@code setToolTipText(null)}, tips from the renderers will no longer display. * * @param event the {@code MouseEvent} to fetch the tooltip text for * @see JComponent#setToolTipText * @see JComponent#getToolTipText */ public String getToolTipText(MouseEvent event) { if(event != null) { Point p = event.getPoint(); int index = locationToIndex(p); ListCellRenderer r = getCellRenderer(); Rectangle cellBounds; if (index != -1 && r != null && (cellBounds = getCellBounds(index, index)) != null && cellBounds.contains(p.x, p.y)) { ListSelectionModel lsm = getSelectionModel(); Component rComponent = r.getListCellRendererComponent( this, getModel().getElementAt(index), index, lsm.isSelectedIndex(index), (hasFocus() && (lsm.getLeadSelectionIndex() == index))); if(rComponent instanceof JComponent) { MouseEvent newEvent; p.translate(-cellBounds.x, -cellBounds.y); newEvent = new MouseEvent(rComponent, event.getID(), event.getWhen(), event.getModifiers(), p.x, p.y, event.getXOnScreen(), event.getYOnScreen(), event.getClickCount(), event.isPopupTrigger(), MouseEvent.NOBUTTON); String tip = ((JComponent)rComponent).getToolTipText( newEvent); if (tip != null) { return tip; } } } } return super.getToolTipText(); } /** * --- ListUI Delegations --- */ /** * Returns the cell index closest to the given location in the list's * coordinate system. To determine if the cell actually contains the * specified location, compare the point against the cell's bounds, * as provided by {@code getCellBounds}. This method returns {@code -1} * if the model is empty *

* This is a cover method that delegates to the method of the same name * in the list's {@code ListUI}. It returns {@code -1} if the list has * no {@code ListUI}. * * @param location the coordinates of the point * @return the cell index closest to the given location, or {@code -1} */ public int locationToIndex(Point location) { ListUI ui = getUI(); return (ui != null) ? ui.locationToIndex(this, location) : -1; } /** * Returns the origin of the specified item in the list's coordinate * system. This method returns {@code null} if the index isn't valid. *

* This is a cover method that delegates to the method of the same name * in the list's {@code ListUI}. It returns {@code null} if the list has * no {@code ListUI}. * * @param index the cell index * @return the origin of the cell, or {@code null} */ public Point indexToLocation(int index) { ListUI ui = getUI(); return (ui != null) ? ui.indexToLocation(this, index) : null; } /** * Returns the bounding rectangle, in the list's coordinate system, * for the range of cells specified by the two indices. * These indices can be supplied in any order. *

* If the smaller index is outside the list's range of cells, this method * returns {@code null}. If the smaller index is valid, but the larger * index is outside the list's range, the bounds of just the first index * is returned. Otherwise, the bounds of the valid range is returned. *

* This is a cover method that delegates to the method of the same name * in the list's {@code ListUI}. It returns {@code null} if the list has * no {@code ListUI}. * * @param index0 the first index in the range * @param index1 the second index in the range * @return the bounding rectangle for the range of cells, or {@code null} */ public Rectangle getCellBounds(int index0, int index1) { ListUI ui = getUI(); return (ui != null) ? ui.getCellBounds(this, index0, index1) : null; } /** * --- ListModel Support --- */ /** * Returns the data model that holds the list of items displayed * by the JList component. * * @return the ListModel that provides the displayed * list of items * @see #setModel */ public ListModel getModel() { return dataModel; } /** * Sets the model that represents the contents or "value" of the * list, notifies property change listeners, and then clears the * list's selection. *

* This is a JavaBeans bound property. * * @param model the ListModel that provides the * list of items for display * @exception IllegalArgumentException if model is * null * @see #getModel * @see #clearSelection * @beaninfo * bound: true * attribute: visualUpdate true * description: The object that contains the data to be drawn by this JList. */ public void setModel(ListModel model) { if (model == null) { throw new IllegalArgumentException("model must be non null"); } ListModel oldValue = dataModel; dataModel = model; firePropertyChange("model", oldValue, dataModel); clearSelection(); } /** * Constructs a read-only ListModel from an array of items, * and calls {@code setModel} with this model. *

* Attempts to pass a {@code null} value to this method results in * undefined behavior and, most likely, exceptions. The created model * references the given array directly. Attempts to modify the array * after invoking this method results in undefined behavior. * * @param listData an array of {@code E} containing the items to * display in the list * @see #setModel */ public void setListData(final E[] listData) { setModel ( new AbstractListModel() { public int getSize() { return listData.length; } public E getElementAt(int i) { return listData[i]; } } ); } /** * Constructs a read-only ListModel from a Vector * and calls {@code setModel} with this model. *

* Attempts to pass a {@code null} value to this method results in * undefined behavior and, most likely, exceptions. The created model * references the given {@code Vector} directly. Attempts to modify the * {@code Vector} after invoking this method results in undefined behavior. * * @param listData a Vector containing the items to * display in the list * @see #setModel */ public void setListData(final Vector listData) { setModel ( new AbstractListModel() { public int getSize() { return listData.size(); } public E getElementAt(int i) { return listData.elementAt(i); } } ); } /** * --- ListSelectionModel delegations and extensions --- */ /** * Returns an instance of {@code DefaultListSelectionModel}; called * during construction to initialize the list's selection model * property. * * @return a {@code DefaultListSelecitonModel}, used to initialize * the list's selection model property during construction * @see #setSelectionModel * @see DefaultListSelectionModel */ protected ListSelectionModel createSelectionModel() { return new DefaultListSelectionModel(); } /** * Returns the current selection model. The selection model maintains the * selection state of the list. See the class level documentation for more * details. * * @return the ListSelectionModel that maintains the * list's selections * * @see #setSelectionModel * @see ListSelectionModel */ public ListSelectionModel getSelectionModel() { return selectionModel; } /** * Notifies {@code ListSelectionListener}s added directly to the list * of selection changes made to the selection model. {@code JList} * listens for changes made to the selection in the selection model, * and forwards notification to listeners added to the list directly, * by calling this method. *

* This method constructs a {@code ListSelectionEvent} with this list * as the source, and the specified arguments, and sends it to the * registered {@code ListSelectionListeners}. * * @param firstIndex the first index in the range, {@code <= lastIndex} * @param lastIndex the last index in the range, {@code >= firstIndex} * @param isAdjusting whether or not this is one in a series of * multiple events, where changes are still being made * * @see #addListSelectionListener * @see #removeListSelectionListener * @see javax.swing.event.ListSelectionEvent * @see EventListenerList */ protected void fireSelectionValueChanged(int firstIndex, int lastIndex, boolean isAdjusting) { Object[] listeners = listenerList.getListenerList(); ListSelectionEvent e = null; for (int i = listeners.length - 2; i >= 0; i -= 2) { if (listeners[i] == ListSelectionListener.class) { if (e == null) { e = new ListSelectionEvent(this, firstIndex, lastIndex, isAdjusting); } ((ListSelectionListener)listeners[i+1]).valueChanged(e); } } } /* A ListSelectionListener that forwards ListSelectionEvents from * the selectionModel to the JList ListSelectionListeners. The * forwarded events only differ from the originals in that their * source is the JList instead of the selectionModel itself. */ private class ListSelectionHandler implements ListSelectionListener, Serializable { public void valueChanged(ListSelectionEvent e) { fireSelectionValueChanged(e.getFirstIndex(), e.getLastIndex(), e.getValueIsAdjusting()); } } /** * Adds a listener to the list, to be notified each time a change to the * selection occurs; the preferred way of listening for selection state * changes. {@code JList} takes care of listening for selection state * changes in the selection model, and notifies the given listener of * each change. {@code ListSelectionEvent}s sent to the listener have a * {@code source} property set to this list. * * @param listener the {@code ListSelectionListener} to add * @see #getSelectionModel * @see #getListSelectionListeners */ public void addListSelectionListener(ListSelectionListener listener) { if (selectionListener == null) { selectionListener = new ListSelectionHandler(); getSelectionModel().addListSelectionListener(selectionListener); } listenerList.add(ListSelectionListener.class, listener); } /** * Removes a selection listener from the list. * * @param listener the {@code ListSelectionListener} to remove * @see #addListSelectionListener * @see #getSelectionModel */ public void removeListSelectionListener(ListSelectionListener listener) { listenerList.remove(ListSelectionListener.class, listener); } /** * Returns an array of all the {@code ListSelectionListener}s added * to this {@code JList} by way of {@code addListSelectionListener}. * * @return all of the {@code ListSelectionListener}s on this list, or * an empty array if no listeners have been added * @see #addListSelectionListener * @since 1.4 */ public ListSelectionListener[] getListSelectionListeners() { return listenerList.getListeners(ListSelectionListener.class); } /** * Sets the selectionModel for the list to a * non-null ListSelectionModel * implementation. The selection model handles the task of making single * selections, selections of contiguous ranges, and non-contiguous * selections. *

* This is a JavaBeans bound property. * * @param selectionModel the ListSelectionModel that * implements the selections * @exception IllegalArgumentException if selectionModel * is null * @see #getSelectionModel * @beaninfo * bound: true * description: The selection model, recording which cells are selected. */ public void setSelectionModel(ListSelectionModel selectionModel) { if (selectionModel == null) { throw new IllegalArgumentException("selectionModel must be non null"); } /* Remove the forwarding ListSelectionListener from the old * selectionModel, and add it to the new one, if necessary. */ if (selectionListener != null) { this.selectionModel.removeListSelectionListener(selectionListener); selectionModel.addListSelectionListener(selectionListener); } ListSelectionModel oldValue = this.selectionModel; this.selectionModel = selectionModel; firePropertyChange("selectionModel", oldValue, selectionModel); } /** * Sets the selection mode for the list. This is a cover method that sets * the selection mode directly on the selection model. *

* The following list describes the accepted selection modes: *

    *
  • {@code ListSelectionModel.SINGLE_SELECTION} - * Only one list index can be selected at a time. In this mode, * {@code setSelectionInterval} and {@code addSelectionInterval} are * equivalent, both replacing the current selection with the index * represented by the second argument (the "lead"). *
  • {@code ListSelectionModel.SINGLE_INTERVAL_SELECTION} - * Only one contiguous interval can be selected at a time. * In this mode, {@code addSelectionInterval} behaves like * {@code setSelectionInterval} (replacing the current selection}, * unless the given interval is immediately adjacent to or overlaps * the existing selection, and can be used to grow the selection. *
  • {@code ListSelectionModel.MULTIPLE_INTERVAL_SELECTION} - * In this mode, there's no restriction on what can be selected. * This mode is the default. *
* * @param selectionMode the selection mode * @see #getSelectionMode * @throws IllegalArgumentException if the selection mode isn't * one of those allowed * @beaninfo * description: The selection mode. * enum: SINGLE_SELECTION ListSelectionModel.SINGLE_SELECTION * SINGLE_INTERVAL_SELECTION ListSelectionModel.SINGLE_INTERVAL_SELECTION * MULTIPLE_INTERVAL_SELECTION ListSelectionModel.MULTIPLE_INTERVAL_SELECTION */ public void setSelectionMode(int selectionMode) { getSelectionModel().setSelectionMode(selectionMode); } /** * Returns the current selection mode for the list. This is a cover * method that delegates to the method of the same name on the * list's selection model. * * @return the current selection mode * @see #setSelectionMode */ public int getSelectionMode() { return getSelectionModel().getSelectionMode(); } /** * Returns the anchor selection index. This is a cover method that * delegates to the method of the same name on the list's selection model. * * @return the anchor selection index * @see ListSelectionModel#getAnchorSelectionIndex */ public int getAnchorSelectionIndex() { return getSelectionModel().getAnchorSelectionIndex(); } /** * Returns the lead selection index. This is a cover method that * delegates to the method of the same name on the list's selection model. * * @return the lead selection index * @see ListSelectionModel#getLeadSelectionIndex * @beaninfo * description: The lead selection index. */ public int getLeadSelectionIndex() { return getSelectionModel().getLeadSelectionIndex(); } /** * Returns the smallest selected cell index, or {@code -1} if the selection * is empty. This is a cover method that delegates to the method of the same * name on the list's selection model. * * @return the smallest selected cell index, or {@code -1} * @see ListSelectionModel#getMinSelectionIndex */ public int getMinSelectionIndex() { return getSelectionModel().getMinSelectionIndex(); } /** * Returns the largest selected cell index, or {@code -1} if the selection * is empty. This is a cover method that delegates to the method of the same * name on the list's selection model. * * @return the largest selected cell index * @see ListSelectionModel#getMaxSelectionIndex */ public int getMaxSelectionIndex() { return getSelectionModel().getMaxSelectionIndex(); } /** * Returns {@code true} if the specified index is selected, * else {@code false}. This is a cover method that delegates to the method * of the same name on the list's selection model. * * @param index index to be queried for selection state * @return {@code true} if the specified index is selected, * else {@code false} * @see ListSelectionModel#isSelectedIndex * @see #setSelectedIndex */ public boolean isSelectedIndex(int index) { return getSelectionModel().isSelectedIndex(index); } /** * Returns {@code true} if nothing is selected, else {@code false}. * This is a cover method that delegates to the method of the same * name on the list's selection model. * * @return {@code true} if nothing is selected, else {@code false} * @see ListSelectionModel#isSelectionEmpty * @see #clearSelection */ public boolean isSelectionEmpty() { return getSelectionModel().isSelectionEmpty(); } /** * Clears the selection; after calling this method, {@code isSelectionEmpty} * will return {@code true}. This is a cover method that delegates to the * method of the same name on the list's selection model. * * @see ListSelectionModel#clearSelection * @see #isSelectionEmpty */ public void clearSelection() { getSelectionModel().clearSelection(); } /** * Selects the specified interval. Both {@code anchor} and {@code lead} * indices are included. {@code anchor} doesn't have to be less than or * equal to {@code lead}. This is a cover method that delegates to the * method of the same name on the list's selection model. *

* Refer to the documentation of the selection model class being used * for details on how values less than {@code 0} are handled. * * @param anchor the first index to select * @param lead the last index to select * @see ListSelectionModel#setSelectionInterval * @see DefaultListSelectionModel#setSelectionInterval * @see #createSelectionModel * @see #addSelectionInterval * @see #removeSelectionInterval */ public void setSelectionInterval(int anchor, int lead) { getSelectionModel().setSelectionInterval(anchor, lead); } /** * Sets the selection to be the union of the specified interval with current * selection. Both the {@code anchor} and {@code lead} indices are * included. {@code anchor} doesn't have to be less than or * equal to {@code lead}. This is a cover method that delegates to the * method of the same name on the list's selection model. *

* Refer to the documentation of the selection model class being used * for details on how values less than {@code 0} are handled. * * @param anchor the first index to add to the selection * @param lead the last index to add to the selection * @see ListSelectionModel#addSelectionInterval * @see DefaultListSelectionModel#addSelectionInterval * @see #createSelectionModel * @see #setSelectionInterval * @see #removeSelectionInterval */ public void addSelectionInterval(int anchor, int lead) { getSelectionModel().addSelectionInterval(anchor, lead); } /** * Sets the selection to be the set difference of the specified interval * and the current selection. Both the {@code index0} and {@code index1} * indices are removed. {@code index0} doesn't have to be less than or * equal to {@code index1}. This is a cover method that delegates to the * method of the same name on the list's selection model. *

* Refer to the documentation of the selection model class being used * for details on how values less than {@code 0} are handled. * * @param index0 the first index to remove from the selection * @param index1 the last index to remove from the selection * @see ListSelectionModel#removeSelectionInterval * @see DefaultListSelectionModel#removeSelectionInterval * @see #createSelectionModel * @see #setSelectionInterval * @see #addSelectionInterval */ public void removeSelectionInterval(int index0, int index1) { getSelectionModel().removeSelectionInterval(index0, index1); } /** * Sets the selection model's {@code valueIsAdjusting} property. When * {@code true}, upcoming changes to selection should be considered part * of a single change. This property is used internally and developers * typically need not call this method. For example, when the model is being * updated in response to a user drag, the value of the property is set * to {@code true} when the drag is initiated and set to {@code false} * when the drag is finished. This allows listeners to update only * when a change has been finalized, rather than handling all of the * intermediate values. *

* You may want to use this directly if making a series of changes * that should be considered part of a single change. *

* This is a cover method that delegates to the method of the same name on * the list's selection model. See the documentation for * {@link javax.swing.ListSelectionModel#setValueIsAdjusting} for * more details. * * @param b the new value for the property * @see ListSelectionModel#setValueIsAdjusting * @see javax.swing.event.ListSelectionEvent#getValueIsAdjusting * @see #getValueIsAdjusting */ public void setValueIsAdjusting(boolean b) { getSelectionModel().setValueIsAdjusting(b); } /** * Returns the value of the selection model's {@code isAdjusting} property. *

* This is a cover method that delegates to the method of the same name on * the list's selection model. * * @return the value of the selection model's {@code isAdjusting} property. * * @see #setValueIsAdjusting * @see ListSelectionModel#getValueIsAdjusting */ public boolean getValueIsAdjusting() { return getSelectionModel().getValueIsAdjusting(); } /** * Returns an array of all of the selected indices, in increasing * order. * * @return all of the selected indices, in increasing order, * or an empty array if nothing is selected * @see #removeSelectionInterval * @see #addListSelectionListener */ @Transient public int[] getSelectedIndices() { ListSelectionModel sm = getSelectionModel(); int iMin = sm.getMinSelectionIndex(); int iMax = sm.getMaxSelectionIndex(); if ((iMin < 0) || (iMax < 0)) { return new int[0]; } int[] rvTmp = new int[1+ (iMax - iMin)]; int n = 0; for(int i = iMin; i <= iMax; i++) { if (sm.isSelectedIndex(i)) { rvTmp[n++] = i; } } int[] rv = new int[n]; System.arraycopy(rvTmp, 0, rv, 0, n); return rv; } /** * Selects a single cell. Does nothing if the given index is greater * than or equal to the model size. This is a convenience method that uses * {@code setSelectionInterval} on the selection model. Refer to the * documentation for the selection model class being used for details on * how values less than {@code 0} are handled. * * @param index the index of the cell to select * @see ListSelectionModel#setSelectionInterval * @see #isSelectedIndex * @see #addListSelectionListener * @beaninfo * description: The index of the selected cell. */ public void setSelectedIndex(int index) { if (index >= getModel().getSize()) { return; } getSelectionModel().setSelectionInterval(index, index); } /** * Changes the selection to be the set of indices specified by the given * array. Indices greater than or equal to the model size are ignored. * This is a convenience method that clears the selection and then uses * {@code addSelectionInterval} on the selection model to add the indices. * Refer to the documentation of the selection model class being used for * details on how values less than {@code 0} are handled. * * @param indices an array of the indices of the cells to select, * {@code non-null} * @see ListSelectionModel#addSelectionInterval * @see #isSelectedIndex * @see #addListSelectionListener * @throws NullPointerException if the given array is {@code null} */ public void setSelectedIndices(int[] indices) { ListSelectionModel sm = getSelectionModel(); sm.clearSelection(); int size = getModel().getSize(); for (int i : indices) { if (i < size) { sm.addSelectionInterval(i, i); } } } /** * Returns an array of all the selected values, in increasing order based * on their indices in the list. * * @return the selected values, or an empty array if nothing is selected * @see #isSelectedIndex * @see #getModel * @see #addListSelectionListener * * @deprecated As of JDK 1.7, replaced by {@link #getSelectedValuesList()} */ @Deprecated public Object[] getSelectedValues() { ListSelectionModel sm = getSelectionModel(); ListModel dm = getModel(); int iMin = sm.getMinSelectionIndex(); int iMax = sm.getMaxSelectionIndex(); if ((iMin < 0) || (iMax < 0)) { return new Object[0]; } Object[] rvTmp = new Object[1+ (iMax - iMin)]; int n = 0; for(int i = iMin; i <= iMax; i++) { if (sm.isSelectedIndex(i)) { rvTmp[n++] = dm.getElementAt(i); } } Object[] rv = new Object[n]; System.arraycopy(rvTmp, 0, rv, 0, n); return rv; } /** * Returns a list of all the selected items, in increasing order based * on their indices in the list. * * @return the selected items, or an empty list if nothing is selected * @see #isSelectedIndex * @see #getModel * @see #addListSelectionListener * * @since 1.7 */ public List getSelectedValuesList() { ListSelectionModel sm = getSelectionModel(); ListModel dm = getModel(); int iMin = sm.getMinSelectionIndex(); int iMax = sm.getMaxSelectionIndex(); if ((iMin < 0) || (iMax < 0)) { return Collections.emptyList(); } List selectedItems = new ArrayList(); for(int i = iMin; i <= iMax; i++) { if (sm.isSelectedIndex(i)) { selectedItems.add(dm.getElementAt(i)); } } return selectedItems; } /** * Returns the smallest selected cell index; the selection when only * a single item is selected in the list. When multiple items are selected, * it is simply the smallest selected index. Returns {@code -1} if there is * no selection. *

* This method is a cover that delegates to {@code getMinSelectionIndex}. * * @return the smallest selected cell index * @see #getMinSelectionIndex * @see #addListSelectionListener */ public int getSelectedIndex() { return getMinSelectionIndex(); } /** * Returns the value for the smallest selected cell index; * the selected value when only a single item is selected in the * list. When multiple items are selected, it is simply the value for the * smallest selected index. Returns {@code null} if there is no selection. *

* This is a convenience method that simply returns the model value for * {@code getMinSelectionIndex}. * * @return the first selected value * @see #getMinSelectionIndex * @see #getModel * @see #addListSelectionListener */ public E getSelectedValue() { int i = getMinSelectionIndex(); return (i == -1) ? null : getModel().getElementAt(i); } /** * Selects the specified object from the list. * * @param anObject the object to select * @param shouldScroll {@code true} if the list should scroll to display * the selected object, if one exists; otherwise {@code false} */ public void setSelectedValue(Object anObject,boolean shouldScroll) { if(anObject == null) setSelectedIndex(-1); else if(!anObject.equals(getSelectedValue())) { int i,c; ListModel dm = getModel(); for(i=0,c=dm.getSize();i * {@code VERTICAL}: *
* This is trivial if both {@code fixedCellWidth} and {@code fixedCellHeight} * have been set (either explicitly or by specifying a prototype cell value). * The width is simply the {@code fixedCellWidth} plus the list's horizontal * insets. The height is the {@code fixedCellHeight} multiplied by the * {@code visibleRowCount}, plus the list's vertical insets. *

* If either {@code fixedCellWidth} or {@code fixedCellHeight} haven't been * specified, heuristics are used. If the model is empty, the width is * the {@code fixedCellWidth}, if greater than {@code 0}, or a hard-coded * value of {@code 256}. The height is the {@code fixedCellHeight} multiplied * by {@code visibleRowCount}, if {@code fixedCellHeight} is greater than * {@code 0}, otherwise it is a hard-coded value of {@code 16} multiplied by * {@code visibleRowCount}. *

* If the model isn't empty, the width is the preferred size's width, * typically the width of the widest list element. The height is the * {@code fixedCellHeight} multiplied by the {@code visibleRowCount}, * plus the list's vertical insets. *

* {@code VERTICAL_WRAP} or {@code HORIZONTAL_WRAP}: *
* This method simply returns the value from {@code getPreferredSize}. * The list's {@code ListUI} is expected to override {@code getPreferredSize} * to return an appropriate value. * * @return a dimension containing the size of the viewport needed * to display {@code visibleRowCount} rows * @see #getPreferredScrollableViewportSize * @see #setPrototypeCellValue */ public Dimension getPreferredScrollableViewportSize() { if (getLayoutOrientation() != VERTICAL) { return getPreferredSize(); } Insets insets = getInsets(); int dx = insets.left + insets.right; int dy = insets.top + insets.bottom; int visibleRowCount = getVisibleRowCount(); int fixedCellWidth = getFixedCellWidth(); int fixedCellHeight = getFixedCellHeight(); if ((fixedCellWidth > 0) && (fixedCellHeight > 0)) { int width = fixedCellWidth + dx; int height = (visibleRowCount * fixedCellHeight) + dy; return new Dimension(width, height); } else if (getModel().getSize() > 0) { int width = getPreferredSize().width; int height; Rectangle r = getCellBounds(0, 0); if (r != null) { height = (visibleRowCount * r.height) + dy; } else { // Will only happen if UI null, shouldn't matter what we return height = 1; } return new Dimension(width, height); } else { fixedCellWidth = (fixedCellWidth > 0) ? fixedCellWidth : 256; fixedCellHeight = (fixedCellHeight > 0) ? fixedCellHeight : 16; return new Dimension(fixedCellWidth, fixedCellHeight * visibleRowCount); } } /** * Returns the distance to scroll to expose the next or previous * row (for vertical scrolling) or column (for horizontal scrolling). *

* For horizontal scrolling, if the layout orientation is {@code VERTICAL}, * then the list's font size is returned (or {@code 1} if the font is * {@code null}). * * @param visibleRect the view area visible within the viewport * @param orientation {@code SwingConstants.HORIZONTAL} or * {@code SwingConstants.VERTICAL} * @param direction less or equal to zero to scroll up/back, * greater than zero for down/forward * @return the "unit" increment for scrolling in the specified direction; * always positive * @see #getScrollableBlockIncrement * @see Scrollable#getScrollableUnitIncrement * @throws IllegalArgumentException if {@code visibleRect} is {@code null}, or * {@code orientation} isn't one of {@code SwingConstants.VERTICAL} or * {@code SwingConstants.HORIZONTAL} */ public int getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction) { checkScrollableParameters(visibleRect, orientation); if (orientation == SwingConstants.VERTICAL) { int row = locationToIndex(visibleRect.getLocation()); if (row == -1) { return 0; } else { /* Scroll Down */ if (direction > 0) { Rectangle r = getCellBounds(row, row); return (r == null) ? 0 : r.height - (visibleRect.y - r.y); } /* Scroll Up */ else { Rectangle r = getCellBounds(row, row); /* The first row is completely visible and it's row 0. * We're done. */ if ((r.y == visibleRect.y) && (row == 0)) { return 0; } /* The first row is completely visible, return the * height of the previous row or 0 if the first row * is the top row of the list. */ else if (r.y == visibleRect.y) { Point loc = r.getLocation(); loc.y--; int prevIndex = locationToIndex(loc); Rectangle prevR = getCellBounds(prevIndex, prevIndex); if (prevR == null || prevR.y >= r.y) { return 0; } return prevR.height; } /* The first row is partially visible, return the * height of hidden part. */ else { return visibleRect.y - r.y; } } } } else if (orientation == SwingConstants.HORIZONTAL && getLayoutOrientation() != JList.VERTICAL) { boolean leftToRight = getComponentOrientation().isLeftToRight(); int index; Point leadingPoint; if (leftToRight) { leadingPoint = visibleRect.getLocation(); } else { leadingPoint = new Point(visibleRect.x + visibleRect.width -1, visibleRect.y); } index = locationToIndex(leadingPoint); if (index != -1) { Rectangle cellBounds = getCellBounds(index, index); if (cellBounds != null && cellBounds.contains(leadingPoint)) { int leadingVisibleEdge; int leadingCellEdge; if (leftToRight) { leadingVisibleEdge = visibleRect.x; leadingCellEdge = cellBounds.x; } else { leadingVisibleEdge = visibleRect.x + visibleRect.width; leadingCellEdge = cellBounds.x + cellBounds.width; } if (leadingCellEdge != leadingVisibleEdge) { if (direction < 0) { // Show remainder of leading cell return Math.abs(leadingVisibleEdge - leadingCellEdge); } else if (leftToRight) { // Hide rest of leading cell return leadingCellEdge + cellBounds.width - leadingVisibleEdge; } else { // Hide rest of leading cell return leadingVisibleEdge - cellBounds.x; } } // ASSUME: All cells are the same width return cellBounds.width; } } } Font f = getFont(); return (f != null) ? f.getSize() : 1; } /** * Returns the distance to scroll to expose the next or previous block. *

* For vertical scrolling, the following rules are used: *

    *
  • if scrolling down, returns the distance to scroll so that the last * visible element becomes the first completely visible element *
  • if scrolling up, returns the distance to scroll so that the first * visible element becomes the last completely visible element *
  • returns {@code visibleRect.height} if the list is empty *
*

* For horizontal scrolling, when the layout orientation is either * {@code VERTICAL_WRAP} or {@code HORIZONTAL_WRAP}: *

    *
  • if scrolling right, returns the distance to scroll so that the * last visible element becomes * the first completely visible element *
  • if scrolling left, returns the distance to scroll so that the first * visible element becomes the last completely visible element *
  • returns {@code visibleRect.width} if the list is empty *
*

* For horizontal scrolling and {@code VERTICAL} orientation, * returns {@code visibleRect.width}. *

* Note that the value of {@code visibleRect} must be the equal to * {@code this.getVisibleRect()}. * * @param visibleRect the view area visible within the viewport * @param orientation {@code SwingConstants.HORIZONTAL} or * {@code SwingConstants.VERTICAL} * @param direction less or equal to zero to scroll up/back, * greater than zero for down/forward * @return the "block" increment for scrolling in the specified direction; * always positive * @see #getScrollableUnitIncrement * @see Scrollable#getScrollableBlockIncrement * @throws IllegalArgumentException if {@code visibleRect} is {@code null}, or * {@code orientation} isn't one of {@code SwingConstants.VERTICAL} or * {@code SwingConstants.HORIZONTAL} */ public int getScrollableBlockIncrement(Rectangle visibleRect, int orientation, int direction) { checkScrollableParameters(visibleRect, orientation); if (orientation == SwingConstants.VERTICAL) { int inc = visibleRect.height; /* Scroll Down */ if (direction > 0) { // last cell is the lowest left cell int last = locationToIndex(new Point(visibleRect.x, visibleRect.y+visibleRect.height-1)); if (last != -1) { Rectangle lastRect = getCellBounds(last,last); if (lastRect != null) { inc = lastRect.y - visibleRect.y; if ( (inc == 0) && (last < getModel().getSize()-1) ) { inc = lastRect.height; } } } } /* Scroll Up */ else { int newFirst = locationToIndex(new Point(visibleRect.x, visibleRect.y-visibleRect.height)); int first = getFirstVisibleIndex(); if (newFirst != -1) { if (first == -1) { first = locationToIndex(visibleRect.getLocation()); } Rectangle newFirstRect = getCellBounds(newFirst,newFirst); Rectangle firstRect = getCellBounds(first,first); if ((newFirstRect != null) && (firstRect!=null)) { while ( (newFirstRect.y + visibleRect.height < firstRect.y + firstRect.height) && (newFirstRect.y < firstRect.y) ) { newFirst++; newFirstRect = getCellBounds(newFirst,newFirst); } inc = visibleRect.y - newFirstRect.y; if ( (inc <= 0) && (newFirstRect.y > 0)) { newFirst--; newFirstRect = getCellBounds(newFirst,newFirst); if (newFirstRect != null) { inc = visibleRect.y - newFirstRect.y; } } } } } return inc; } else if (orientation == SwingConstants.HORIZONTAL && getLayoutOrientation() != JList.VERTICAL) { boolean leftToRight = getComponentOrientation().isLeftToRight(); int inc = visibleRect.width; /* Scroll Right (in ltr mode) or Scroll Left (in rtl mode) */ if (direction > 0) { // position is upper right if ltr, or upper left otherwise int x = visibleRect.x + (leftToRight ? (visibleRect.width - 1) : 0); int last = locationToIndex(new Point(x, visibleRect.y)); if (last != -1) { Rectangle lastRect = getCellBounds(last,last); if (lastRect != null) { if (leftToRight) { inc = lastRect.x - visibleRect.x; } else { inc = visibleRect.x + visibleRect.width - (lastRect.x + lastRect.width); } if (inc < 0) { inc += lastRect.width; } else if ( (inc == 0) && (last < getModel().getSize()-1) ) { inc = lastRect.width; } } } } /* Scroll Left (in ltr mode) or Scroll Right (in rtl mode) */ else { // position is upper left corner of the visibleRect shifted // left by the visibleRect.width if ltr, or upper right shifted // right by the visibleRect.width otherwise int x = visibleRect.x + (leftToRight ? -visibleRect.width : visibleRect.width - 1 + visibleRect.width); int first = locationToIndex(new Point(x, visibleRect.y)); if (first != -1) { Rectangle firstRect = getCellBounds(first,first); if (firstRect != null) { // the right of the first cell int firstRight = firstRect.x + firstRect.width; if (leftToRight) { if ((firstRect.x < visibleRect.x - visibleRect.width) && (firstRight < visibleRect.x)) { inc = visibleRect.x - firstRight; } else { inc = visibleRect.x - firstRect.x; } } else { int visibleRight = visibleRect.x + visibleRect.width; if ((firstRight > visibleRight + visibleRect.width) && (firstRect.x > visibleRight)) { inc = firstRect.x - visibleRight; } else { inc = firstRight - visibleRight; } } } } } return inc; } return visibleRect.width; } /** * Returns {@code true} if this {@code JList} is displayed in a * {@code JViewport} and the viewport is wider than the list's * preferred width, or if the layout orientation is {@code HORIZONTAL_WRAP} * and {@code visibleRowCount <= 0}; otherwise returns {@code false}. *

* If {@code false}, then don't track the viewport's width. This allows * horizontal scrolling if the {@code JViewport} is itself embedded in a * {@code JScrollPane}. * * @return whether or not an enclosing viewport should force the list's * width to match its own * @see Scrollable#getScrollableTracksViewportWidth */ public boolean getScrollableTracksViewportWidth() { if (getLayoutOrientation() == HORIZONTAL_WRAP && getVisibleRowCount() <= 0) { return true; } Container parent = SwingUtilities.getUnwrappedParent(this); if (parent instanceof JViewport) { return parent.getWidth() > getPreferredSize().width; } return false; } /** * Returns {@code true} if this {@code JList} is displayed in a * {@code JViewport} and the viewport is taller than the list's * preferred height, or if the layout orientation is {@code VERTICAL_WRAP} * and {@code visibleRowCount <= 0}; otherwise returns {@code false}. *

* If {@code false}, then don't track the viewport's height. This allows * vertical scrolling if the {@code JViewport} is itself embedded in a * {@code JScrollPane}. * * @return whether or not an enclosing viewport should force the list's * height to match its own * @see Scrollable#getScrollableTracksViewportHeight */ public boolean getScrollableTracksViewportHeight() { if (getLayoutOrientation() == VERTICAL_WRAP && getVisibleRowCount() <= 0) { return true; } Container parent = SwingUtilities.getUnwrappedParent(this); if (parent instanceof JViewport) { return parent.getHeight() > getPreferredSize().height; } return false; } /* * See {@code readObject} and {@code 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 {@code String} representation of this {@code JList}. * This method is intended to be used only for debugging purposes, * and the content and format of the returned {@code String} may vary * between implementations. The returned {@code String} may be empty, * but may not be {@code null}. * * @return a {@code String} representation of this {@code JList}. */ protected String paramString() { String selectionForegroundString = (selectionForeground != null ? selectionForeground.toString() : ""); String selectionBackgroundString = (selectionBackground != null ? selectionBackground.toString() : ""); return super.paramString() + ",fixedCellHeight=" + fixedCellHeight + ",fixedCellWidth=" + fixedCellWidth + ",horizontalScrollIncrement=" + horizontalScrollIncrement + ",selectionBackground=" + selectionBackgroundString + ",selectionForeground=" + selectionForegroundString + ",visibleRowCount=" + visibleRowCount + ",layoutOrientation=" + layoutOrientation; } /** * --- Accessibility Support --- */ /** * Gets the {@code AccessibleContext} associated with this {@code JList}. * For {@code JList}, the {@code AccessibleContext} takes the form of an * {@code AccessibleJList}. *

* A new {@code AccessibleJList} instance is created if necessary. * * @return an {@code AccessibleJList} that serves as the * {@code AccessibleContext} of this {@code JList} */ public AccessibleContext getAccessibleContext() { if (accessibleContext == null) { accessibleContext = new AccessibleJList(); } return accessibleContext; } /** * This class implements accessibility support for the * {@code JList} class. It provides an implementation of the * Java Accessibility API appropriate to list user-interface * elements. *

* 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 JavaBeansTM * has been added to the java.beans package. * Please see {@link java.beans.XMLEncoder}. */ protected class AccessibleJList extends AccessibleJComponent implements AccessibleSelection, PropertyChangeListener, ListSelectionListener, ListDataListener { int leadSelectionIndex; public AccessibleJList() { super(); JList.this.addPropertyChangeListener(this); JList.this.getSelectionModel().addListSelectionListener(this); JList.this.getModel().addListDataListener(this); leadSelectionIndex = JList.this.getLeadSelectionIndex(); } /** * Property Change Listener change method. Used to track changes * to the DataModel and ListSelectionModel, in order to re-set * listeners to those for reporting changes there via the Accessibility * PropertyChange mechanism. * * @param e PropertyChangeEvent */ public void propertyChange(PropertyChangeEvent e) { String name = e.getPropertyName(); Object oldValue = e.getOldValue(); Object newValue = e.getNewValue(); // re-set listData listeners if (name.compareTo("model") == 0) { if (oldValue != null && oldValue instanceof ListModel) { ((ListModel) oldValue).removeListDataListener(this); } if (newValue != null && newValue instanceof ListModel) { ((ListModel) newValue).addListDataListener(this); } // re-set listSelectionModel listeners } else if (name.compareTo("selectionModel") == 0) { if (oldValue != null && oldValue instanceof ListSelectionModel) { ((ListSelectionModel) oldValue).removeListSelectionListener(this); } if (newValue != null && newValue instanceof ListSelectionModel) { ((ListSelectionModel) newValue).addListSelectionListener(this); } firePropertyChange( AccessibleContext.ACCESSIBLE_SELECTION_PROPERTY, Boolean.valueOf(false), Boolean.valueOf(true)); } } /** * List Selection Listener value change method. Used to fire * the property change * * @param e ListSelectionEvent * */ public void valueChanged(ListSelectionEvent e) { int oldLeadSelectionIndex = leadSelectionIndex; leadSelectionIndex = JList.this.getLeadSelectionIndex(); if (oldLeadSelectionIndex != leadSelectionIndex) { Accessible oldLS, newLS; oldLS = (oldLeadSelectionIndex >= 0) ? getAccessibleChild(oldLeadSelectionIndex) : null; newLS = (leadSelectionIndex >= 0) ? getAccessibleChild(leadSelectionIndex) : null; firePropertyChange(AccessibleContext.ACCESSIBLE_ACTIVE_DESCENDANT_PROPERTY, oldLS, newLS); } firePropertyChange(AccessibleContext.ACCESSIBLE_VISIBLE_DATA_PROPERTY, Boolean.valueOf(false), Boolean.valueOf(true)); firePropertyChange(AccessibleContext.ACCESSIBLE_SELECTION_PROPERTY, Boolean.valueOf(false), Boolean.valueOf(true)); // Process the State changes for Multiselectable AccessibleStateSet s = getAccessibleStateSet(); ListSelectionModel lsm = JList.this.getSelectionModel(); if (lsm.getSelectionMode() != ListSelectionModel.SINGLE_SELECTION) { if (!s.contains(AccessibleState.MULTISELECTABLE)) { s.add(AccessibleState.MULTISELECTABLE); firePropertyChange(AccessibleContext.ACCESSIBLE_STATE_PROPERTY, null, AccessibleState.MULTISELECTABLE); } } else { if (s.contains(AccessibleState.MULTISELECTABLE)) { s.remove(AccessibleState.MULTISELECTABLE); firePropertyChange(AccessibleContext.ACCESSIBLE_STATE_PROPERTY, AccessibleState.MULTISELECTABLE, null); } } } /** * List Data Listener interval added method. Used to fire the visible data property change * * @param e ListDataEvent * */ public void intervalAdded(ListDataEvent e) { firePropertyChange(AccessibleContext.ACCESSIBLE_VISIBLE_DATA_PROPERTY, Boolean.valueOf(false), Boolean.valueOf(true)); } /** * List Data Listener interval removed method. Used to fire the visible data property change * * @param e ListDataEvent * */ public void intervalRemoved(ListDataEvent e) { firePropertyChange(AccessibleContext.ACCESSIBLE_VISIBLE_DATA_PROPERTY, Boolean.valueOf(false), Boolean.valueOf(true)); } /** * List Data Listener contents changed method. Used to fire the visible data property change * * @param e ListDataEvent * */ public void contentsChanged(ListDataEvent e) { firePropertyChange(AccessibleContext.ACCESSIBLE_VISIBLE_DATA_PROPERTY, Boolean.valueOf(false), Boolean.valueOf(true)); } // AccessibleContext methods /** * Get the state set of this object. * * @return an instance of AccessibleState containing the current state * of the object * @see AccessibleState */ public AccessibleStateSet getAccessibleStateSet() { AccessibleStateSet states = super.getAccessibleStateSet(); if (selectionModel.getSelectionMode() != ListSelectionModel.SINGLE_SELECTION) { states.add(AccessibleState.MULTISELECTABLE); } return states; } /** * Get the role of this object. * * @return an instance of AccessibleRole describing the role of the * object * @see AccessibleRole */ public AccessibleRole getAccessibleRole() { return AccessibleRole.LIST; } /** * Returns the Accessible child contained at * the local coordinate Point, if one exists. * Otherwise returns null. * * @return the Accessible at the specified * location, if it exists */ public Accessible getAccessibleAt(Point p) { int i = locationToIndex(p); if (i >= 0) { return new AccessibleJListChild(JList.this, i); } else { return null; } } /** * 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() { return getModel().getSize(); } /** * Return the nth Accessible child of the object. * * @param i zero-based index of child * @return the nth Accessible child of the object */ public Accessible getAccessibleChild(int i) { if (i >= getModel().getSize()) { return null; } else { return new AccessibleJListChild(JList.this, i); } } /** * 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; } // AccessibleSelection methods /** * Returns the number of items currently selected. * If no items are selected, the return value will be 0. * * @return the number of items currently selected. */ public int getAccessibleSelectionCount() { return JList.this.getSelectedIndices().length; } /** * Returns an Accessible representing the specified selected item * in the object. If there isn't a selection, or there are * fewer items selected than the integer passed in, the return * value will be null. * * @param i the zero-based index of selected items * @return an Accessible containing the selected item */ public Accessible getAccessibleSelection(int i) { int len = getAccessibleSelectionCount(); if (i < 0 || i >= len) { return null; } else { return getAccessibleChild(JList.this.getSelectedIndices()[i]); } } /** * Returns true if the current child of this object is selected. * * @param i the zero-based index of the child in this Accessible * object. * @see AccessibleContext#getAccessibleChild */ public boolean isAccessibleChildSelected(int i) { return isSelectedIndex(i); } /** * Adds the specified selected item in the object to the object's * selection. If the object supports multiple selections, * the specified item is added to any existing selection, otherwise * it replaces any existing selection in the object. If the * specified item is already selected, this method has no effect. * * @param i the zero-based index of selectable items */ public void addAccessibleSelection(int i) { JList.this.addSelectionInterval(i, i); } /** * Removes the specified selected item in 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 selectable items */ public void removeAccessibleSelection(int i) { JList.this.removeSelectionInterval(i, i); } /** * Clears the selection in the object, so that nothing in the * object is selected. */ public void clearAccessibleSelection() { JList.this.clearSelection(); } /** * Causes every selected item in the object to be selected * if the object supports multiple selections. */ public void selectAllAccessibleSelection() { JList.this.addSelectionInterval(0, getAccessibleChildrenCount() -1); } /** * This class implements accessibility support appropriate * for list children. */ protected class AccessibleJListChild extends AccessibleContext implements Accessible, AccessibleComponent { private JList parent = null; private int indexInParent; private Component component = null; private AccessibleContext accessibleContext = null; private ListModel listModel; private ListCellRenderer cellRenderer = null; public AccessibleJListChild(JList parent, int indexInParent) { this.parent = parent; this.setAccessibleParent(parent); this.indexInParent = indexInParent; if (parent != null) { listModel = parent.getModel(); cellRenderer = parent.getCellRenderer(); } } private Component getCurrentComponent() { return getComponentAtIndex(indexInParent); } private AccessibleContext getCurrentAccessibleContext() { Component c = getComponentAtIndex(indexInParent); if (c instanceof Accessible) { return c.getAccessibleContext(); } else { return null; } } private Component getComponentAtIndex(int index) { if (index < 0 || index >= listModel.getSize()) { return null; } if ((parent != null) && (listModel != null) && cellRenderer != null) { E value = listModel.getElementAt(index); boolean isSelected = parent.isSelectedIndex(index); boolean isFocussed = parent.isFocusOwner() && (index == parent.getLeadSelectionIndex()); return cellRenderer.getListCellRendererComponent( parent, value, index, isSelected, isFocussed); } else { return null; } } // Accessible Methods /** * Get the AccessibleContext for this object. In the * implementation of the Java Accessibility API for this class, * returns this object, which is its own AccessibleContext. * * @return this object */ public AccessibleContext getAccessibleContext() { return this; } // AccessibleContext methods public String getAccessibleName() { AccessibleContext ac = getCurrentAccessibleContext(); if (ac != null) { return ac.getAccessibleName(); } else { return null; } } public void setAccessibleName(String s) { AccessibleContext ac = getCurrentAccessibleContext(); if (ac != null) { ac.setAccessibleName(s); } } public String getAccessibleDescription() { AccessibleContext ac = getCurrentAccessibleContext(); if (ac != null) { return ac.getAccessibleDescription(); } else { return null; } } public void setAccessibleDescription(String s) { AccessibleContext ac = getCurrentAccessibleContext(); if (ac != null) { ac.setAccessibleDescription(s); } } public AccessibleRole getAccessibleRole() { AccessibleContext ac = getCurrentAccessibleContext(); if (ac != null) { return ac.getAccessibleRole(); } else { return null; } } public AccessibleStateSet getAccessibleStateSet() { AccessibleContext ac = getCurrentAccessibleContext(); AccessibleStateSet s; if (ac != null) { s = ac.getAccessibleStateSet(); } else { s = new AccessibleStateSet(); } s.add(AccessibleState.SELECTABLE); if (parent.isFocusOwner() && (indexInParent == parent.getLeadSelectionIndex())) { s.add(AccessibleState.ACTIVE); } if (parent.isSelectedIndex(indexInParent)) { s.add(AccessibleState.SELECTED); } if (this.isShowing()) { s.add(AccessibleState.SHOWING); } else if (s.contains(AccessibleState.SHOWING)) { s.remove(AccessibleState.SHOWING); } if (this.isVisible()) { s.add(AccessibleState.VISIBLE); } else if (s.contains(AccessibleState.VISIBLE)) { s.remove(AccessibleState.VISIBLE); } s.add(AccessibleState.TRANSIENT); // cell-rendered return s; } public int getAccessibleIndexInParent() { return indexInParent; } public int getAccessibleChildrenCount() { AccessibleContext ac = getCurrentAccessibleContext(); if (ac != null) { return ac.getAccessibleChildrenCount(); } else { return 0; } } public Accessible getAccessibleChild(int i) { AccessibleContext ac = getCurrentAccessibleContext(); if (ac != null) { Accessible accessibleChild = ac.getAccessibleChild(i); ac.setAccessibleParent(this); return accessibleChild; } else { return null; } } public Locale getLocale() { AccessibleContext ac = getCurrentAccessibleContext(); if (ac != null) { return ac.getLocale(); } else { return null; } } public void addPropertyChangeListener(PropertyChangeListener l) { AccessibleContext ac = getCurrentAccessibleContext(); if (ac != null) { ac.addPropertyChangeListener(l); } } public void removePropertyChangeListener(PropertyChangeListener l) { AccessibleContext ac = getCurrentAccessibleContext(); if (ac != null) { ac.removePropertyChangeListener(l); } } public AccessibleAction getAccessibleAction() { return getCurrentAccessibleContext().getAccessibleAction(); } /** * Get the AccessibleComponent associated with this object. In the * implementation of the Java Accessibility API for this class, * return this object, which is responsible for implementing the * AccessibleComponent interface on behalf of itself. * * @return this object */ public AccessibleComponent getAccessibleComponent() { return this; // to override getBounds() } public AccessibleSelection getAccessibleSelection() { return getCurrentAccessibleContext().getAccessibleSelection(); } public AccessibleText getAccessibleText() { return getCurrentAccessibleContext().getAccessibleText(); } public AccessibleValue getAccessibleValue() { return getCurrentAccessibleContext().getAccessibleValue(); } // AccessibleComponent methods public Color getBackground() { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { return ((AccessibleComponent) ac).getBackground(); } else { Component c = getCurrentComponent(); if (c != null) { return c.getBackground(); } else { return null; } } } public void setBackground(Color c) { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { ((AccessibleComponent) ac).setBackground(c); } else { Component cp = getCurrentComponent(); if (cp != null) { cp.setBackground(c); } } } public Color getForeground() { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { return ((AccessibleComponent) ac).getForeground(); } else { Component c = getCurrentComponent(); if (c != null) { return c.getForeground(); } else { return null; } } } public void setForeground(Color c) { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { ((AccessibleComponent) ac).setForeground(c); } else { Component cp = getCurrentComponent(); if (cp != null) { cp.setForeground(c); } } } public Cursor getCursor() { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { return ((AccessibleComponent) ac).getCursor(); } else { Component c = getCurrentComponent(); if (c != null) { return c.getCursor(); } else { Accessible ap = getAccessibleParent(); if (ap instanceof AccessibleComponent) { return ((AccessibleComponent) ap).getCursor(); } else { return null; } } } } public void setCursor(Cursor c) { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { ((AccessibleComponent) ac).setCursor(c); } else { Component cp = getCurrentComponent(); if (cp != null) { cp.setCursor(c); } } } public Font getFont() { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { return ((AccessibleComponent) ac).getFont(); } else { Component c = getCurrentComponent(); if (c != null) { return c.getFont(); } else { return null; } } } public void setFont(Font f) { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { ((AccessibleComponent) ac).setFont(f); } else { Component c = getCurrentComponent(); if (c != null) { c.setFont(f); } } } public FontMetrics getFontMetrics(Font f) { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { return ((AccessibleComponent) ac).getFontMetrics(f); } else { Component c = getCurrentComponent(); if (c != null) { return c.getFontMetrics(f); } else { return null; } } } public boolean isEnabled() { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { return ((AccessibleComponent) ac).isEnabled(); } else { Component c = getCurrentComponent(); if (c != null) { return c.isEnabled(); } else { return false; } } } public void setEnabled(boolean b) { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { ((AccessibleComponent) ac).setEnabled(b); } else { Component c = getCurrentComponent(); if (c != null) { c.setEnabled(b); } } } public boolean isVisible() { int fi = parent.getFirstVisibleIndex(); int li = parent.getLastVisibleIndex(); // The UI incorrectly returns a -1 for the last // visible index if the list is smaller than the // viewport size. if (li == -1) { li = parent.getModel().getSize() - 1; } return ((indexInParent >= fi) && (indexInParent <= li)); } public void setVisible(boolean b) { } public boolean isShowing() { return (parent.isShowing() && isVisible()); } public boolean contains(Point p) { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { Rectangle r = ((AccessibleComponent) ac).getBounds(); return r.contains(p); } else { Component c = getCurrentComponent(); if (c != null) { Rectangle r = c.getBounds(); return r.contains(p); } else { return getBounds().contains(p); } } } public Point getLocationOnScreen() { if (parent != null) { Point listLocation = parent.getLocationOnScreen(); Point componentLocation = parent.indexToLocation(indexInParent); if (componentLocation != null) { componentLocation.translate(listLocation.x, listLocation.y); return componentLocation; } else { return null; } } else { return null; } } public Point getLocation() { if (parent != null) { return parent.indexToLocation(indexInParent); } else { return null; } } public void setLocation(Point p) { if ((parent != null) && (parent.contains(p))) { ensureIndexIsVisible(indexInParent); } } public Rectangle getBounds() { if (parent != null) { return parent.getCellBounds(indexInParent,indexInParent); } else { return null; } } public void setBounds(Rectangle r) { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { ((AccessibleComponent) ac).setBounds(r); } } public Dimension getSize() { Rectangle cellBounds = this.getBounds(); if (cellBounds != null) { return cellBounds.getSize(); } else { return null; } } public void setSize (Dimension d) { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { ((AccessibleComponent) ac).setSize(d); } else { Component c = getCurrentComponent(); if (c != null) { c.setSize(d); } } } public Accessible getAccessibleAt(Point p) { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { return ((AccessibleComponent) ac).getAccessibleAt(p); } else { return null; } } public boolean isFocusTraversable() { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { return ((AccessibleComponent) ac).isFocusTraversable(); } else { Component c = getCurrentComponent(); if (c != null) { return c.isFocusTraversable(); } else { return false; } } } public void requestFocus() { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { ((AccessibleComponent) ac).requestFocus(); } else { Component c = getCurrentComponent(); if (c != null) { c.requestFocus(); } } } public void addFocusListener(FocusListener l) { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { ((AccessibleComponent) ac).addFocusListener(l); } else { Component c = getCurrentComponent(); if (c != null) { c.addFocusListener(l); } } } public void removeFocusListener(FocusListener l) { AccessibleContext ac = getCurrentAccessibleContext(); if (ac instanceof AccessibleComponent) { ((AccessibleComponent) ac).removeFocusListener(l); } else { Component c = getCurrentComponent(); if (c != null) { c.removeFocusListener(l); } } } // TIGER - 4733624 /** * Returns the icon for the element renderer, as the only item * of an array of AccessibleIcons or a null array * if the renderer component contains no icons. * * @return an array containing the accessible icon * or a null array if none * @since 1.3 */ public AccessibleIcon [] getAccessibleIcon() { AccessibleContext ac = getCurrentAccessibleContext(); if (ac != null) { return ac.getAccessibleIcon(); } else { return null; } } } // inner class AccessibleJListChild } // inner class AccessibleJList }