JDK8/Java8源码在线阅读
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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.
* <p>
* 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:
* <pre>
* {@code
* // Create a JList that displays strings from an array
*
* String[] data = {"one", "two", "three", "four"};
* JList<String> myList = new JList<String>(data);
*
* // Create a JList that displays the superclasses of JList.class, by
* // creating it with a Vector populated with this data
*
* Vector<Class<?>> superClasses = new Vector<Class<?>>();
* Class<JList> rootClass = javax.swing.JList.class;
* for(Class<?> cls = rootClass; cls != null; cls = cls.getSuperclass()) {
* superClasses.addElement(cls);
* }
* JList<Class<?>> myList = new JList<Class<?>>(superClasses);
*
* // The automatically created model is stored in JList's "model"
* // property, which you can retrieve
*
* ListModel<Class<?>> model = myList.getModel();
* for(int i = 0; i < model.getSize(); i++) {
* System.out.println(model.getElementAt(i));
* }
* }
* </pre>
* <p>
* 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.
* <p>
* 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
* <code>java.util.Vector</code>-like API. Applications that need a more
* custom <code>ListModel</code> 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}:
* <pre>
* {@code
* // This list model has about 2^16 elements. Enjoy scrolling.
*
* ListModel<String> bigData = new AbstractListModel<String>() {
* public int getSize() { return Short.MAX_VALUE; }
* public String getElementAt(int index) { return "Index " + index; }
* };
* }
* </pre>
* <p>
* 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}.
* <p>
* 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.
* <p>
* 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.
* <p>
* 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}.
* <p>
* <a name="renderer"></a>
* 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:
* <pre>
* {@code
* // Display an icon and a string for each object in the list.
*
* class MyCellRenderer extends JLabel implements ListCellRenderer<Object> {
* 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());
* }
* </pre>
* <p>
* 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:
* <a name="prototype_example"></a>
* <pre>
* {@code
* JList<String> bigDataList = new JList<String>(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");
* }
* </pre>
* <p>
* {@code JList} doesn't implement scrolling directly. To create a list that
* scrolls, make it the viewport view of a {@code JScrollPane}. For example:
* <pre>
* JScrollPane scrollPane = new JScrollPane(myList);
*
* // Or in two steps:
* JScrollPane scrollPane = new JScrollPane();
* scrollPane.getViewport().setView(myList);
* </pre>
* <p>
* {@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:
* <pre>
* 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);
* </pre>
* <p>
* <strong>Warning:</strong> Swing is not thread safe. For more
* information see <a
* href="package-summary.html#threading">Swing's Threading
* Policy</a>.
* <p>
* <strong>Warning:</strong>
* Serialized objects of this class will not be compatible with
* future Swing releases. The current serialization support is
* appropriate for short term storage or RMI between applications running
* the same version of Swing. As of 1.4, support for long term storage
* of all JavaBeans™
* has been added to the <code>java.beans</code> package.
* Please see {@link java.beans.XMLEncoder}.
* <p>
* See <a href="https://docs.oracle.com/javase/tutorial/uiswing/components/list.html">How to Use Lists</a>
* in <a href="https://docs.oracle.com/javase/tutorial/"><em>The Java Tutorial</em></a>
* for further documentation.
* <p>
* @see ListModel
* @see AbstractListModel
* @see DefaultListModel
* @see ListSelectionModel
* @see DefaultListSelectionModel
* @see ListCellRenderer
* @see DefaultListCellRenderer
*
* @param <E> 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<E> 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<E> dataModel;
private ListCellRenderer<? super E> cellRenderer;
private ListSelectionListener selectionListener;
/**
* How to lay out the cells; defaults to <code>VERTICAL</code>.
*/
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 <code>TransferHandler.DropLocation</code> representing
* a drop location for a <code>JList</code>.
*
* @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
* <code>DropMode.USE_SELECTION</code> or <code>DropMode.ON</code>,
* the return value is an index of a row in the list. If the drop mode is
* <code>DropMode.INSERT</code>, the return value refers to the index
* where the data should be inserted. If the drop mode is
* <code>DropMode.ON_OR_INSERT</code>, the value of
* <code>isInsert()</code> indicates whether the index is an index
* of a row, or an insert index.
* <p>
* <code>-1</code> 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.
* <p>
* 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<E> 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 <code>JList</code> 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}.
* <p>
* 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<E>() {
public int getSize() { return listData.length; }
public E getElementAt(int i) { return listData[i]; }
}
);
}
/**
* Constructs a <code>JList</code> that displays the elements in
* the specified <code>Vector</code>. This constructor creates a read-only
* model for the given {@code Vector}, and then delegates to the constructor
* that takes a {@code ListModel}.
* <p>
* 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 <code>Vector</code> to be loaded into the
* data model, {@code non-null}
*/
public JList(final Vector<? extends E> listData) {
this (
new AbstractListModel<E>() {
public int getSize() { return listData.size(); }
public E getElementAt(int i) { return listData.elementAt(i); }
}
);
}
/**
* Constructs a <code>JList</code> with an empty, read-only, model.
*/
public JList() {
this (
new AbstractListModel<E>() {
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 <code>ListUI</code> 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 <code>ListUI</code> 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<? super E> renderer = getCellRenderer();
if (renderer instanceof Component) {
SwingUtilities.updateComponentTreeUI((Component)renderer);
}
}
/**
* Returns {@code "ListUI"}, the <code>UIDefaults</code> 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).
* <p>
* This method sets fixedCellWidth and fixedCellHeight but does <b>not</b>
* generate PropertyChangeEvents for them.
*
* @see #setPrototypeCellValue
* @see #setCellRenderer
*/
private void updateFixedCellSize()
{
ListCellRenderer<? super E> 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.
* <p>
* 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.
* <p>
* 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.
* <p>
* To see an example which sets this property, see the
* <a href="#prototype_example">class description</a> above.
* <p>
* The default value of this property is <code>null</code>.
* <p>
* This is a JavaBeans bound property.
*
* @param prototypeCellValue the value on which to base
* <code>fixedCellWidth</code> and
* <code>fixedCellHeight</code>
* @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 <code>getPreferredSize</code> to the cell renderer component
* for each list element.
* <p>
* The default value of this property is {@code -1}.
* <p>
* 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 <code>getPreferredSize</code> to the cell renderer component
* for each list element.
* <p>
* The default value of this property is {@code -1}.
* <p>
* 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<? super E> 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
* <a href="#renderer">class level documentation</a>.
* <p>
* 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
* <code>PropertyChangeEvent</code> is generated however -
* for the <code>cellRenderer</code> property.
* <p>
* The default value of this property is provided by the {@code ListUI}
* delegate, i.e. by the look and feel implementation.
* <p>
* This is a JavaBeans bound property.
*
* @param cellRenderer the <code>ListCellRenderer</code>
* that paints list cells
* @see #getCellRenderer
* @beaninfo
* bound: true
* attribute: visualUpdate true
* description: The component used to draw the cells.
*/
public void setCellRenderer(ListCellRenderer<? super E> cellRenderer) {
ListCellRenderer<? super E> 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.
* <p>
* The default value of this property is defined by the look and feel
* implementation.
* <p>
* 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.
* <p>
* The default value of this property is defined by the look
* and feel implementation.
* <p>
* 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.
* <p>
* In {@code VERTICAL} orientation:<br>
* 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.
* <p>
* In {@code HORIZONTAL_WRAP} and {@code VERTICAL_WRAP} orientations:<br>
* This affects how cells are wrapped. See the documentation of
* {@link #setLayoutOrientation} for more details.
* <p>
* The default value of this property is {@code 8}.
* <p>
* Calling this method with a negative value results in the property
* being set to {@code 0}.
* <p>
* 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:
*
* <pre>
* VERTICAL: 0
* 1
* 2
* 3
* 4
*
* HORIZONTAL_WRAP: 0 1 2
* 3 4
*
* VERTICAL_WRAP: 0 3
* 1 4
* 2
* </pre>
* <p>
* A description of these layouts follows:
*
* <table border="1"
* summary="Describes layouts VERTICAL, HORIZONTAL_WRAP, and VERTICAL_WRAP">
* <tr><th><p style="text-align:left">Value</p></th><th><p style="text-align:left">Description</p></th></tr>
* <tr><td><code>VERTICAL</code>
* <td>Cells are layed out vertically in a single column.
* <tr><td><code>HORIZONTAL_WRAP</code>
* <td>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.
* <tr><td><code>VERTICAL_WRAP</code>
* <td>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.
* </table>
* <p>
* The default value of this property is <code>VERTICAL</code>.
*
* @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 <code>JViewport</code>.
* <p>
* 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}.
* <p>
* 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.
* <p>
* 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
* <code>b</code> is <code>true</code> and
* <code>GraphicsEnvironment.isHeadless()</code>
* returns <code>true</code>
* @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 <code>DropMode.USE_SELECTION</code>.
* Usage of one of the other modes is recommended, however, for an
* improved user experience. <code>DropMode.ON</code>, for instance,
* offers similar behavior of showing items as selected, but does so without
* affecting the actual selection in the list.
* <p>
* <code>JList</code> supports the following drop modes:
* <ul>
* <li><code>DropMode.USE_SELECTION</code></li>
* <li><code>DropMode.ON</code></li>
* <li><code>DropMode.INSERT</code></li>
* <li><code>DropMode.ON_OR_INSERT</code></li>
* </ul>
* The drop mode is only meaningful if this component has a
* <code>TransferHandler</code> that accepts drops.
*
* @param dropMode the drop mode to use
* @throws IllegalArgumentException if the drop mode is unsupported
* or <code>null</code>
* @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 <code>null</code>
*/
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:
* <p>
* 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 <code>null</code>. 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 <code>null</code> since there's
* no longer anything to store.
*
* @param location the drop location (as calculated by
* <code>dropLocationForPoint</code>) or <code>null</code>
* if there's no longer a valid drop location
* @param state the state object saved earlier for this component,
* or <code>null</code>
* @param forDrop whether or not the method is being called because an
* actual drop occurred
* @return any saved state for this component, or <code>null</code> 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.
* <p>
* 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 <code>canImport</code>
* has returned and has allowed for the location to be shown.
* <p>
* When this property changes, a property change event with
* name "dropLocation" is fired by the component.
* <p>
* 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<E> 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.
* <p>
* <strong>Note:</strong> For <code>JList</code> to properly display the
* tooltips of its renderers in this manner, <code>JList</code> must be a
* registered component with the <code>ToolTipManager</code>. This registration
* is done automatically in the constructor. However, if at a later point
* <code>JList</code> 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<? super E> 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
* <p>
* 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.
* <p>
* 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.
* <p>
* 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.
* <p>
* 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 <code>JList</code> component.
*
* @return the <code>ListModel</code> that provides the displayed
* list of items
* @see #setModel
*/
public ListModel<E> 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.
* <p>
* This is a JavaBeans bound property.
*
* @param model the <code>ListModel</code> that provides the
* list of items for display
* @exception IllegalArgumentException if <code>model</code> is
* <code>null</code>
* @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<E> model) {
if (model == null) {
throw new IllegalArgumentException("model must be non null");
}
ListModel<E> oldValue = dataModel;
dataModel = model;
firePropertyChange("model", oldValue, dataModel);
clearSelection();
}
/**
* Constructs a read-only <code>ListModel</code> from an array of items,
* and calls {@code setModel} with this model.
* <p>
* 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<E>() {
public int getSize() { return listData.length; }
public E getElementAt(int i) { return listData[i]; }
}
);
}
/**
* Constructs a read-only <code>ListModel</code> from a <code>Vector</code>
* and calls {@code setModel} with this model.
* <p>
* 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 <code>Vector</code> containing the items to
* display in the list
* @see #setModel
*/
public void setListData(final Vector<? extends E> listData) {
setModel (
new AbstractListModel<E>() {
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 <code>ListSelectionModel</code> 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.
* <p>
* 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 <code>selectionModel</code> for the list to a
* non-<code>null</code> <code>ListSelectionModel</code>
* implementation. The selection model handles the task of making single
* selections, selections of contiguous ranges, and non-contiguous
* selections.
* <p>
* This is a JavaBeans bound property.
*
* @param selectionModel the <code>ListSelectionModel</code> that
* implements the selections
* @exception IllegalArgumentException if <code>selectionModel</code>
* is <code>null</code>
* @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.
* <p>
* The following list describes the accepted selection modes:
* <ul>
* <li>{@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").
* <li>{@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.
* <li>{@code ListSelectionModel.MULTIPLE_INTERVAL_SELECTION} -
* In this mode, there's no restriction on what can be selected.
* This mode is the default.
* </ul>
*
* @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.
* <p>
* 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.
* <p>
* 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.
* <p>
* 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.
* <p>
* You may want to use this directly if making a series of changes
* that should be considered part of a single change.
* <p>
* 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.
* <p>
* 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<E> 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<E> getSelectedValuesList() {
ListSelectionModel sm = getSelectionModel();
ListModel<E> dm = getModel();
int iMin = sm.getMinSelectionIndex();
int iMax = sm.getMaxSelectionIndex();
if ((iMin < 0) || (iMax < 0)) {
return Collections.emptyList();
}
List<E> selectedItems = new ArrayList<E>();
for(int i = iMin; i <= iMax; i++) {
if (sm.isSelectedIndex(i)) {
selectedItems.add(dm.getElementAt(i));
}
}
return selectedItems;
}
/**
* Returns the smallest selected cell index; <i>the selection</i> 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.
* <p>
* 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;
* <i>the selected value</i> 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.
* <p>
* 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<E> dm = getModel();
for(i=0,c=dm.getSize();i<c;i++)
if(anObject.equals(dm.getElementAt(i))){
setSelectedIndex(i);
if(shouldScroll)
ensureIndexIsVisible(i);
repaint(); /** FIX-ME setSelectedIndex does not redraw all the time with the basic l&f**/
return;
}
setSelectedIndex(-1);
}
repaint(); /** FIX-ME setSelectedIndex does not redraw all the time with the basic l&f**/
}
/**
* --- The Scrollable Implementation ---
*/
private void checkScrollableParameters(Rectangle visibleRect, int orientation) {
if (visibleRect == null) {
throw new IllegalArgumentException("visibleRect must be non-null");
}
switch (orientation) {
case SwingConstants.VERTICAL:
case SwingConstants.HORIZONTAL:
break;
default:
throw new IllegalArgumentException("orientation must be one of: VERTICAL, HORIZONTAL");
}
}
/**
* Computes the size of viewport needed to display {@code visibleRowCount}
* rows. The value returned by this method depends on the layout
* orientation:
* <p>
* <b>{@code VERTICAL}:</b>
* <br>
* 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.
* <p>
* 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}.
* <p>
* 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.
* <p>
* <b>{@code VERTICAL_WRAP} or {@code HORIZONTAL_WRAP}:</b>
* <br>
* 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).
* <p>
* 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.
* <p>
* For vertical scrolling, the following rules are used:
* <ul>
* <li>if scrolling down, returns the distance to scroll so that the last
* visible element becomes the first completely visible element
* <li>if scrolling up, returns the distance to scroll so that the first
* visible element becomes the last completely visible element
* <li>returns {@code visibleRect.height} if the list is empty
* </ul>
* <p>
* For horizontal scrolling, when the layout orientation is either
* {@code VERTICAL_WRAP} or {@code HORIZONTAL_WRAP}:
* <ul>
* <li>if scrolling right, returns the distance to scroll so that the
* last visible element becomes
* the first completely visible element
* <li>if scrolling left, returns the distance to scroll so that the first
* visible element becomes the last completely visible element
* <li>returns {@code visibleRect.width} if the list is empty
* </ul>
* <p>
* For horizontal scrolling and {@code VERTICAL} orientation,
* returns {@code visibleRect.width}.
* <p>
* 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}.
* <p>
* 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}.
* <p>
* 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}.
* <p>
* 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.
* <p>
* <strong>Warning:</strong>
* Serialized objects of this class will not be compatible with
* future Swing releases. The current serialization support is
* appropriate for short term storage or RMI between applications running
* the same version of Swing. As of 1.4, support for long term storage
* of all JavaBeans™
* has been added to the <code>java.beans</code> package.
* Please see {@link java.beans.XMLEncoder}.
*/
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 <code>Accessible</code> child contained at
* the local coordinate <code>Point</code>, if one exists.
* Otherwise returns <code>null</code>.
*
* @return the <code>Accessible</code> 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 <code>null</code>.
*
* @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<E> parent = null;
private int indexInParent;
private Component component = null;
private AccessibleContext accessibleContext = null;
private ListModel<E> listModel;
private ListCellRenderer<? super E> cellRenderer = null;
public AccessibleJListChild(JList<E> 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;
}
}
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