Class JList<E>
- Type Parameters:
E- the type of the elements of this list
- All Implemented Interfaces:
ImageObserver,MenuContainer,Serializable,Accessible,Scrollable
ListModel, maintains the
contents of the list.
It's easy to display an array or Vector of objects, using the JList
constructor that automatically builds a read-only ListModel instance
for you:
// 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));
}
A ListModel can be supplied directly to a JList by way of a
constructor or the setModel method. The contents need not be static -
the number of items, and the values of items can change over time. A correct
ListModel implementation notifies the set of
javax.swing.event.ListDataListeners that have been added to it, each
time a change occurs. These changes are characterized by a
javax.swing.event.ListDataEvent, which identifies the range of list
indices that have been modified, added, or removed. JList's
ListUI is responsible for keeping the visual representation up to
date with changes, by listening to the model.
Simple, dynamic-content, JList applications can use the
DefaultListModel class to maintain list elements. This class
implements the ListModel interface and also provides a
java.util.Vector-like API. Applications that need a more
custom ListModel implementation may instead wish to subclass
AbstractListModel, which provides basic support for managing and
notifying listeners. For example, a read-only implementation of
AbstractListModel:
// 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; }
};
The selection state of a JList is managed by another separate
model, an instance of ListSelectionModel. JList is
initialized with a selection model on construction, and also contains
methods to query or set this selection model. Additionally, JList
provides convenient methods for easily managing the selection. These methods,
such as setSelectedIndex and getSelectedValue, are cover
methods that take care of the details of interacting with the selection
model. By default, JList's selection model is configured to allow any
combination of items to be selected at a time; selection mode
MULTIPLE_INTERVAL_SELECTION. The selection mode can be changed
on the selection model directly, or via JList's cover method.
Responsibility for updating the selection model in response to user gestures
lies with the list's ListUI.
A correct ListSelectionModel implementation notifies the set of
javax.swing.event.ListSelectionListeners that have been added to it
each time a change to the selection occurs. These changes are characterized
by a javax.swing.event.ListSelectionEvent, which identifies the range
of the selection change.
The preferred way to listen for changes in list selection is to add
ListSelectionListeners directly to the JList. JList
then takes care of listening to the selection model and notifying your
listeners of change.
Responsibility for listening to selection changes in order to keep the list's
visual representation up to date lies with the list's ListUI.
Painting of cells in a JList is handled by a delegate called a
cell renderer, installed on the list as the cellRenderer property.
The renderer provides a 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 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
paint method. A default cell renderer, which uses a JLabel
component to render, is installed by the lists's ListUI. You can
substitute your own renderer using code like this:
// Display an icon and a string for each object in the list.
class MyCellRenderer extends JLabel implements ListCellRenderer<Object> {
static final ImageIcon longIcon = new ImageIcon("long.gif");
static final ImageIcon shortIcon = new ImageIcon("short.gif");
// This is the only method defined by ListCellRenderer.
// We just reconfigure the JLabel each time we're called.
public Component getListCellRendererComponent(
JList<?> list, // the list
Object value, // value to display
int index, // cell index
boolean isSelected, // is the cell selected
boolean cellHasFocus) // does the cell have focus
{
String s = value.toString();
setText(s);
setIcon((s.length() > 10) ? longIcon : shortIcon);
if (isSelected) {
setBackground(list.getSelectionBackground());
setForeground(list.getSelectionForeground());
} else {
setBackground(list.getBackground());
setForeground(list.getForeground());
}
setEnabled(list.isEnabled());
setFont(list.getFont());
setOpaque(true);
return this;
}
}
myList.setCellRenderer(new MyCellRenderer());
Another job for the cell renderer is in helping to determine sizing
information for the list. By default, the list's 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 fixedCellWidth and
fixedCellHeight on the list, or have these values calculated
automatically based on a single prototype value:
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");
JList doesn't implement scrolling directly. To create a list that
scrolls, make it the viewport view of a JScrollPane. For example:
JScrollPane scrollPane = new JScrollPane(myList); // Or in two steps: JScrollPane scrollPane = new JScrollPane(); scrollPane.getViewport().setView(myList);
JList doesn't provide any special handling of double or triple
(or N) mouse clicks, but it's easy to add a MouseListener if you
wish to take action on these events. Use the locationToIndex
method to determine what cell was clicked. For example:
MouseListener mouseListener = new MouseAdapter() {
public void mouseClicked(MouseEvent e) {
if (e.getClickCount() == 2) {
int index = list.locationToIndex(e.getPoint());
System.out.println("Double clicked on Item " + index);
}
}
};
list.addMouseListener(mouseListener);
Warning: Swing is not thread safe. For more information see Swing's Threading Policy.
Warning:
Serialized objects of this class will not be compatible with
future Swing releases. The current serialization support is
appropriate for short term storage or RMI between applications running
the same version of Swing. As of 1.4, support for long term storage
of all JavaBeans
has been added to the java.beans package.
Please see XMLEncoder.
See How to Use Lists in The Java Tutorial for further documentation.
- Since:
- 1.2
- See Also:
-
Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionprotected classThis class implements accessibility support for theJListclass.static final classA subclass ofTransferHandler.DropLocationrepresenting a drop location for aJList.Nested classes/interfaces declared in class javax.swing.JComponent
JComponent.AccessibleJComponentNested classes/interfaces declared in class java.awt.Container
Container.AccessibleAWTContainerNested classes/interfaces declared in class java.awt.Component
Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy -
Field Summary
FieldsModifier and TypeFieldDescriptionstatic final intIndicates a "newspaper style" layout with cells flowing horizontally then vertically.static final intIndicates a vertical layout of cells, in a single column; the default layout.static final intIndicates a "newspaper style" layout with cells flowing vertically then horizontally.Fields declared in class javax.swing.JComponent
listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOWFields declared in class java.awt.Component
accessibleContext, BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENTFields declared in interface java.awt.image.ImageObserver
ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH -
Constructor Summary
ConstructorsConstructorDescriptionJList()Constructs aJListwith an empty, read-only, model.Constructs aJListthat displays the elements in the specified array.Constructs aJListthat displays the elements in the specifiedVector.Constructs aJListthat displays elements from the specified,non-null, model. -
Method Summary
Modifier and TypeMethodDescriptionvoidAdds 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.voidaddSelectionInterval(int anchor, int lead) Sets the selection to be the union of the specified interval with current selection.voidClears the selection; after calling this method,isSelectionEmptywill returntrue.protected ListSelectionModelReturns an instance ofDefaultListSelectionModel; called during construction to initialize the list's selection model property.voidensureIndexIsVisible(int index) Scrolls the list within an enclosing viewport to make the specified cell completely visible.protected voidfireSelectionValueChanged(int firstIndex, int lastIndex, boolean isAdjusting) NotifiesListSelectionListeners added directly to the list of selection changes made to the selection model.Gets theAccessibleContextassociated with thisJList.intReturns the anchor selection index.getCellBounds(int index0, int index1) Returns the bounding rectangle, in the list's coordinate system, for the range of cells specified by the two indices.ListCellRenderer<? super E> Returns the object responsible for painting list items.booleanReturns whether or not automatic drag handling is enabled.final JList.DropLocationReturns the location that this component should visually indicate as the drop location during a DnD operation over the component, ornullif no location is to currently be shown.final DropModeReturns the drop mode for this component.intReturns the smallest list index that is currently visible.intReturns the value of thefixedCellHeightproperty.intReturns the value of thefixedCellWidthproperty.intReturns the largest list index that is currently visible.intReturns the layout orientation property for the list:VERTICALif the layout is a single column of cells,VERTICAL_WRAPif the layout is "newspaper style" with the content flowing vertically then horizontally, orHORIZONTAL_WRAPif the layout is "newspaper style" with the content flowing horizontally then vertically.intReturns the lead selection index.Returns an array of all theListSelectionListeners added to thisJListby way ofaddListSelectionListener.intReturns the largest selected cell index, or-1if the selection is empty.intReturns the smallest selected cell index, or-1if the selection is empty.getModel()Returns the data model that holds the list of items displayed by theJListcomponent.intgetNextMatch(String prefix, int startIndex, Position.Bias bias) Returns the next list element whosetoStringvalue starts with the given prefix.Computes the size of viewport needed to displayvisibleRowCountrows.Returns the "prototypical" cell value -- a value used to calculate a fixed width and height for cells.intgetScrollableBlockIncrement(Rectangle visibleRect, int orientation, int direction) Returns the distance to scroll to expose the next or previous block.booleanReturnstrueif thisJListis displayed in aJViewportand the viewport is taller than the list's preferred height, or if the layout orientation isVERTICAL_WRAPandvisibleRowCount <= 0; otherwise returnsfalse.booleanReturnstrueif thisJListis displayed in aJViewportand the viewport is wider than the list's preferred width, or if the layout orientation isHORIZONTAL_WRAPandvisibleRowCount <= 0; otherwise returnsfalse.intgetScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction) Returns the distance to scroll to expose the next or previous row (for vertical scrolling) or column (for horizontal scrolling).intReturns the smallest selected cell index; the selection when only a single item is selected in the list.int[]Returns an array of all of the selected indices, in increasing order.Returns the value for the smallest selected cell index; the selected value when only a single item is selected in the list.Object[]Deprecated.Returns a list of all the selected items, in increasing order based on their indices in the list.Returns the color used to draw the background of selected items.Returns the color used to draw the foreground of selected items.intReturns the current selection mode for the list.Returns the current selection model.getToolTipText(MouseEvent event) Returns the tooltip text to be used for the given event.getUI()Returns theListUI, the look and feel object that renders this component.Returns"ListUI", theUIDefaultskey used to look up the name of thejavax.swing.plaf.ListUIclass that defines the look and feel for this component.booleanReturns the value of the selection model'sisAdjustingproperty.intReturns the value of thevisibleRowCountproperty.indexToLocation(int index) Returns the origin of the specified item in the list's coordinate system.booleanisSelectedIndex(int index) Returnstrueif the specified index is selected, elsefalse.booleanReturnstrueif nothing is selected, elsefalse.intlocationToIndex(Point location) Returns the cell index closest to the given location in the list's coordinate system.protected StringReturns aStringrepresentation of thisJList.voidRemoves a selection listener from the list.voidremoveSelectionInterval(int index0, int index1) Sets the selection to be the set difference of the specified interval and the current selection.voidsetCellRenderer(ListCellRenderer<? super E> cellRenderer) Sets the delegate that is used to paint each cell in the list.voidsetDragEnabled(boolean b) Turns on or off automatic drag handling.final voidsetDropMode(DropMode dropMode) Sets the drop mode for this component.voidsetFixedCellHeight(int height) Sets a fixed value to be used for the height of every cell in the list.voidsetFixedCellWidth(int width) Sets a fixed value to be used for the width of every cell in the list.voidsetLayoutOrientation(int layoutOrientation) Defines the way list cells are laid out.voidsetListData(E[] listData) Constructs a read-onlyListModelfrom an array of items, and callssetModelwith this model.voidsetListData(Vector<? extends E> listData) Constructs a read-onlyListModelfrom aVectorand callssetModelwith this model.voidSets the model that represents the contents or "value" of the list, notifies property change listeners, and then clears the list's selection.voidsetPrototypeCellValue(E prototypeCellValue) Sets theprototypeCellValueproperty, and then (if the new value isnon-null), computes thefixedCellWidthandfixedCellHeightproperties by requesting the cell renderer component for the given value (and index 0) from the cell renderer, and using that component's preferred size.voidsetSelectedIndex(int index) Selects a single cell.voidsetSelectedIndices(int[] indices) Changes the selection to be the set of indices specified by the given array.voidsetSelectedValue(Object anObject, boolean shouldScroll) Selects the specified object from the list.voidsetSelectionBackground(Color selectionBackground) Sets the color used to draw the background of selected items, which cell renderers can use fill selected cells.voidsetSelectionForeground(Color selectionForeground) Sets the color used to draw the foreground of selected items, which cell renderers can use to render text and graphics.voidsetSelectionInterval(int anchor, int lead) Selects the specified interval.voidsetSelectionMode(int selectionMode) Sets the selection mode for the list.voidsetSelectionModel(ListSelectionModel selectionModel) Sets theselectionModelfor the list to a non-nullListSelectionModelimplementation.voidSets theListUI, the look and feel object that renders this component.voidsetValueIsAdjusting(boolean b) Sets the selection model'svalueIsAdjustingproperty.voidsetVisibleRowCount(int visibleRowCount) Sets thevisibleRowCountproperty, which has different meanings depending on the layout orientation: For aVERTICALlayout orientation, this sets the preferred number of rows to display without requiring scrolling; for other orientations, it affects the wrapping of cells.voidupdateUI()Resets theListUIproperty by setting it to the value provided by the current look and feel.Methods declared in class javax.swing.JComponent
addAncestorListener, addNotify, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, disable, enable, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getAlignmentX, getAlignmentY, getAncestorListeners, getAutoscrolls, getBaseline, getBaselineResizeBehavior, getBorder, getBounds, getClientProperty, getComponentGraphics, getComponentPopupMenu, getConditionForKeyStroke, getDebugGraphicsOptions, getDefaultLocale, getFontMetrics, getGraphics, getHeight, getInheritsPopupMenu, getInputMap, getInputMap, getInputVerifier, getInsets, getInsets, getListeners, getLocation, getMaximumSize, getMinimumSize, getNextFocusableComponent, getPopupLocation, getPreferredSize, getRegisteredKeyStrokes, getRootPane, getSize, getToolTipLocation, getToolTipText, getTopLevelAncestor, getTransferHandler, getVerifyInputWhenFocusTarget, getVetoableChangeListeners, getVisibleRect, getWidth, getX, getY, grabFocus, hide, isDoubleBuffered, isLightweightComponent, isManagingFocus, isOpaque, isOptimizedDrawingEnabled, isPaintingForPrint, isPaintingOrigin, isPaintingTile, isRequestFocusEnabled, isValidateRoot, paint, paintBorder, paintChildren, paintComponent, paintImmediately, paintImmediately, print, printAll, printBorder, printChildren, printComponent, processComponentKeyEvent, processKeyBinding, processKeyEvent, processMouseEvent, processMouseMotionEvent, putClientProperty, registerKeyboardAction, registerKeyboardAction, removeAncestorListener, removeNotify, removeVetoableChangeListener, repaint, repaint, requestDefaultFocus, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, resetKeyboardActions, reshape, revalidate, scrollRectToVisible, setActionMap, setAlignmentX, setAlignmentY, setAutoscrolls, setBackground, setBorder, setComponentPopupMenu, setDebugGraphicsOptions, setDefaultLocale, setDoubleBuffered, setEnabled, setFocusTraversalKeys, setFont, setForeground, setInheritsPopupMenu, setInputMap, setInputVerifier, setMaximumSize, setMinimumSize, setNextFocusableComponent, setOpaque, setPreferredSize, setRequestFocusEnabled, setToolTipText, setTransferHandler, setUI, setVerifyInputWhenFocusTarget, setVisible, unregisterKeyboardAction, updateMethods declared in class java.awt.Container
add, add, add, add, add, addContainerListener, addImpl, addPropertyChangeListener, addPropertyChangeListener, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getComponentZOrder, getContainerListeners, getFocusTraversalKeys, getFocusTraversalPolicy, getLayout, getMousePosition, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusCycleRoot, isFocusTraversalPolicyProvider, isFocusTraversalPolicySet, layout, list, list, locate, minimumSize, paintComponents, preferredSize, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, setComponentZOrder, setFocusCycleRoot, setFocusTraversalPolicy, setFocusTraversalPolicyProvider, setLayout, transferFocusDownCycle, validate, validateTreeMethods declared in class java.awt.Component
action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, bounds, checkImage, checkImage, coalesceEvents, contains, createImage, createImage, createVolatileImage, createVolatileImage, disableEvents, dispatchEvent, enable, enableEvents, enableInputMethods, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getBackground, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getForeground, getGraphicsConfiguration, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocale, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getToolkit, getTreeLock, gotFocus, handleEvent, hasFocus, imageUpdate, inside, isBackgroundSet, isCursorSet, isDisplayable, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isPreferredSizeSet, isShowing, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, postEvent, prepareImage, prepareImage, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, requestFocus, requestFocus, requestFocusInWindow, resize, resize, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setFocusable, setFocusTraversalKeysEnabled, setIgnoreRepaint, setLocale, setLocation, setLocation, setMixingCutoutShape, setName, setSize, setSize, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle
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Field Details
-
VERTICAL
public static final int VERTICALIndicates a vertical layout of cells, in a single column; the default layout.- Since:
- 1.4
- See Also:
-
VERTICAL_WRAP
public static final int VERTICAL_WRAPIndicates a "newspaper style" layout with cells flowing vertically then horizontally.- Since:
- 1.4
- See Also:
-
HORIZONTAL_WRAP
public static final int HORIZONTAL_WRAPIndicates a "newspaper style" layout with cells flowing horizontally then vertically.- Since:
- 1.4
- See Also:
-
-
Constructor Details
-
JList
Constructs aJListthat displays elements from the specified,non-null, model. AllJListconstructors delegate to this one.This constructor registers the list with the
ToolTipManager, allowing for tooltips to be provided by the cell renderers.- Parameters:
dataModel- the model for the list- Throws:
IllegalArgumentException- if the model isnull
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JList
Constructs aJListthat 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 aListModel.Attempts to pass a
nullvalue 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.- Parameters:
listData- the array of Objects to be loaded into the data model,non-null
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JList
Constructs aJListthat displays the elements in the specifiedVector. This constructor creates a read-only model for the givenVector, and then delegates to the constructor that takes aListModel.Attempts to pass a
nullvalue to this method results in undefined behavior and, most likely, exceptions. The created model references the givenVectordirectly. Attempts to modify theVectorafter constructing the list results in undefined behavior.- Parameters:
listData- theVectorto be loaded into the data model,non-null
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JList
public JList()Constructs aJListwith an empty, read-only, model.
-
-
Method Details
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getUI
Returns theListUI, the look and feel object that renders this component.- Overrides:
getUIin classJComponent- Returns:
- the
ListUIobject that renders this component
-
setUI
@BeanProperty(hidden=true, visualUpdate=true, description="The UI object that implements the Component's LookAndFeel.") public void setUI(ListUI ui) Sets theListUI, the look and feel object that renders this component.- Parameters:
ui- theListUIobject- See Also:
-
updateUI
public void updateUI()Resets theListUIproperty 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 callingSwingUtilities.updateComponentTreeUIon it.- Overrides:
updateUIin classJComponent- See Also:
-
getUIClassID
Returns"ListUI", theUIDefaultskey used to look up the name of thejavax.swing.plaf.ListUIclass that defines the look and feel for this component.- Overrides:
getUIClassIDin classJComponent- Returns:
- the string "ListUI"
- See Also:
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getPrototypeCellValue
Returns the "prototypical" cell value -- a value used to calculate a fixed width and height for cells. This can benullif there is no such value.- Returns:
- the value of the
prototypeCellValueproperty - See Also:
-
setPrototypeCellValue
@BeanProperty(visualUpdate=true, description="The cell prototype value, used to compute cell width and height.") public void setPrototypeCellValue(E prototypeCellValue) Sets theprototypeCellValueproperty, and then (if the new value isnon-null), computes thefixedCellWidthandfixedCellHeightproperties by requesting the cell renderer component for the given value (and index 0) from the cell renderer, and using that component's preferred size.This method is useful when the list is too long to allow the
ListUIto compute the width/height of each cell, and there is a single cell value that is known to occupy as much space as any of the others, a so-called prototype.While all three of the
prototypeCellValue,fixedCellHeight, andfixedCellWidthproperties may be modified by this method,PropertyChangeEventnotifications are only sent when theprototypeCellValueproperty changes.To see an example which sets this property, see the class description above.
The default value of this property is
null.This is a JavaBeans bound property.
- Parameters:
prototypeCellValue- the value on which to basefixedCellWidthandfixedCellHeight- See Also:
-
getFixedCellWidth
public int getFixedCellWidth()Returns the value of thefixedCellWidthproperty.- Returns:
- the fixed cell width
- See Also:
-
setFixedCellWidth
@BeanProperty(visualUpdate=true, description="Defines a fixed cell width when greater than zero.") public void setFixedCellWidth(int width) Sets a fixed value to be used for the width of every cell in the list. Ifwidthis -1, cell widths are computed in theListUIby applyinggetPreferredSizeto the cell renderer component for each list element.The default value of this property is
-1.This is a JavaBeans bound property.
- Parameters:
width- the width to be used for all cells in the list- See Also:
-
getFixedCellHeight
public int getFixedCellHeight()Returns the value of thefixedCellHeightproperty.- Returns:
- the fixed cell height
- See Also:
-
setFixedCellHeight
@BeanProperty(visualUpdate=true, description="Defines a fixed cell height when greater than zero.") public void setFixedCellHeight(int height) Sets a fixed value to be used for the height of every cell in the list. Ifheightis -1, cell heights are computed in theListUIby applyinggetPreferredSizeto the cell renderer component for each list element.The default value of this property is
-1.This is a JavaBeans bound property.
- Parameters:
height- the height to be used for all cells in the list- See Also:
-
getCellRenderer
Returns the object responsible for painting list items.- Returns:
- the value of the
cellRendererproperty - See Also:
-
setCellRenderer
@BeanProperty(visualUpdate=true, description="The component used to draw the cells.") public void setCellRenderer(ListCellRenderer<? super E> cellRenderer) Sets the delegate that is used to paint each cell in the list. The job of a cell renderer is discussed in detail in the class level documentation.If the
prototypeCellValueproperty isnon-null, setting the cell renderer also causes thefixedCellWidthandfixedCellHeightproperties to be re-calculated. Only onePropertyChangeEventis generated however - for thecellRendererproperty.The default value of this property is provided by the
ListUIdelegate, i.e. by the look and feel implementation.This is a JavaBeans bound property.
- Parameters:
cellRenderer- theListCellRendererthat paints list cells- See Also:
-
getSelectionForeground
Returns the color used to draw the foreground of selected items.DefaultListCellRendereruses this color to draw the foreground of items in the selected state, as do the renderers installed by mostListUIimplementations.- Returns:
- the color to draw the foreground of selected items
- See Also:
-
setSelectionForeground
@BeanProperty(visualUpdate=true, description="The foreground color of selected cells.") public void setSelectionForeground(Color selectionForeground) Sets the color used to draw the foreground of selected items, which cell renderers can use to render text and graphics.DefaultListCellRendereruses this color to draw the foreground of items in the selected state, as do the renderers installed by mostListUIimplementations.The default value of this property is defined by the look and feel implementation.
This is a JavaBeans bound property.
- Parameters:
selectionForeground- theColorto use in the foreground for selected list items- See Also:
-
getSelectionBackground
Returns the color used to draw the background of selected items.DefaultListCellRendereruses this color to draw the background of items in the selected state, as do the renderers installed by mostListUIimplementations.- Returns:
- the color to draw the background of selected items
- See Also:
-
setSelectionBackground
@BeanProperty(visualUpdate=true, description="The background color of selected cells.") public void setSelectionBackground(Color selectionBackground) Sets the color used to draw the background of selected items, which cell renderers can use fill selected cells.DefaultListCellRendereruses this color to fill the background of items in the selected state, as do the renderers installed by mostListUIimplementations.The default value of this property is defined by the look and feel implementation.
This is a JavaBeans bound property.
- Parameters:
selectionBackground- theColorto use for the background of selected cells- See Also:
-
getVisibleRowCount
public int getVisibleRowCount()Returns the value of thevisibleRowCountproperty. See the documentation forsetVisibleRowCount(int)for details on how to interpret this value.- Returns:
- the value of the
visibleRowCountproperty. - See Also:
-
setVisibleRowCount
@BeanProperty(visualUpdate=true, description="The preferred number of rows to display without requiring scrolling") public void setVisibleRowCount(int visibleRowCount) Sets thevisibleRowCountproperty, which has different meanings depending on the layout orientation: For aVERTICALlayout orientation, this sets the preferred number of rows to display without requiring scrolling; for other orientations, it affects the wrapping of cells.In
VERTICALorientation:
Setting this property affects the return value of thegetPreferredScrollableViewportSize()method, which is used to calculate the preferred size of an enclosing viewport. See that method's documentation for more details.In
HORIZONTAL_WRAPandVERTICAL_WRAPorientations:
This affects how cells are wrapped. See the documentation ofsetLayoutOrientation(int)for more details.The default value of this property is
8.Calling this method with a negative value results in the property being set to
0.This is a JavaBeans bound property.
- Parameters:
visibleRowCount- an integer specifying the preferred number of rows to display without requiring scrolling- See Also:
-
getLayoutOrientation
public int getLayoutOrientation()Returns the layout orientation property for the list:VERTICALif the layout is a single column of cells,VERTICAL_WRAPif the layout is "newspaper style" with the content flowing vertically then horizontally, orHORIZONTAL_WRAPif the layout is "newspaper style" with the content flowing horizontally then vertically.- Returns:
- the value of the
layoutOrientationproperty - Since:
- 1.4
- See Also:
-
setLayoutOrientation
@BeanProperty(visualUpdate=true, enumerationValues={"JList.VERTICAL","JList.HORIZONTAL_WRAP","JList.VERTICAL_WRAP"}, description="Defines the way list cells are laid out.") public void setLayoutOrientation(int layoutOrientation) Defines the way list cells are laid out. Consider aJListwith five cells. Cells can be laid out in one of the following ways:VERTICAL: 0 1 2 3 4 HORIZONTAL_WRAP: 0 1 2 3 4 VERTICAL_WRAP: 0 3 1 4 2A description of these layouts follows:
The default value of this property isDescribes layouts VERTICAL,HORIZONTAL_WRAP, and VERTICAL_WRAP Value Description VERTICALCells are laid out vertically in a single column. HORIZONTAL_WRAPCells are laid out horizontally, wrapping to a new row as necessary. If the visibleRowCountproperty 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 ensurevisibleRowCountrows in the list.VERTICAL_WRAPCells are laid out vertically, wrapping to a new column as necessary. If the visibleRowCountproperty is less than or equal to zero, wrapping is determined by the height of the list; otherwise wrapping is done atvisibleRowCountrows.VERTICAL.- Parameters:
layoutOrientation- the new layout orientation, one of:VERTICAL,HORIZONTAL_WRAPorVERTICAL_WRAP- Throws:
IllegalArgumentException- iflayoutOrientationisn't one of the allowable values- Since:
- 1.4
- See Also:
-
getFirstVisibleIndex
Returns the smallest list index that is currently visible. In a left-to-rightcomponentOrientation, 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,-1is returned. Note that the returned cell may only be partially visible.- Returns:
- the index of the first visible cell
- See Also:
-
getLastVisibleIndex
Returns the largest list index that is currently visible. If nothing is visible or the list is empty,-1is returned. Note that the returned cell may only be partially visible.- Returns:
- the index of the last visible cell
- See Also:
-
ensureIndexIsVisible
public void ensureIndexIsVisible(int index) Scrolls the list within an enclosing viewport to make the specified cell completely visible. This callsscrollRectToVisiblewith the bounds of the specified cell. For this method to work, theJListmust be within aJViewport.If the given index is outside the list's range of cells, this method results in nothing.
- Parameters:
index- the index of the cell to make visible- See Also:
-
setDragEnabled
@BeanProperty(bound=false, description="determines whether automatic drag handling is enabled") public void setDragEnabled(boolean b) Turns on or off automatic drag handling. In order to enable automatic drag handling, this property should be set totrue, and the list'sTransferHandlerneeds to benon-null. The default value of thedragEnabledproperty isfalse.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
ListUI. When automatic drag handling is enabled, most look and feels (including those that subclassBasicLookAndFeel) 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 totruecan therefore have a subtle effect on how selections behave.If a look and feel is used that ignores this property, you can still begin a drag and drop operation by calling
exportAsDragon the list'sTransferHandler.- Parameters:
b- whether or not to enable automatic drag handling- Throws:
HeadlessException- ifbistrueandGraphicsEnvironment.isHeadless()returnstrue- Since:
- 1.4
- See Also:
-
getDragEnabled
public boolean getDragEnabled()Returns whether or not automatic drag handling is enabled.- Returns:
- the value of the
dragEnabledproperty - Since:
- 1.4
- See Also:
-
setDropMode
Sets the drop mode for this component. For backward compatibility, the default for this property isDropMode.USE_SELECTION. Usage of one of the other modes is recommended, however, for an improved user experience.DropMode.ON, for instance, offers similar behavior of showing items as selected, but does so without affecting the actual selection in the list.JListsupports the following drop modes:DropMode.USE_SELECTIONDropMode.ONDropMode.INSERTDropMode.ON_OR_INSERT
TransferHandlerthat accepts drops.- Parameters:
dropMode- the drop mode to use- Throws:
IllegalArgumentException- if the drop mode is unsupported ornull- Since:
- 1.6
- See Also:
-
getDropMode
Returns the drop mode for this component.- Returns:
- the drop mode for this component
- Since:
- 1.6
- See Also:
-
getDropLocation
Returns the location that this component should visually indicate as the drop location during a DnD operation over the component, ornullif no location is to currently be shown.This method is not meant for querying the drop location from a
TransferHandler, as the drop location is only set after theTransferHandler'scanImporthas returned and has allowed for the location to be shown.When this property changes, a property change event with name "dropLocation" is fired by the component.
By default, responsibility for listening for changes to this property and indicating the drop location visually lies with the list's
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.- Returns:
- the drop location
- Since:
- 1.6
- See Also:
-
getNextMatch
Returns the next list element whosetoStringvalue starts with the given prefix.- Parameters:
prefix- the string to test for a matchstartIndex- the index for starting the searchbias- the search direction, either Position.Bias.Forward or Position.Bias.Backward.- Returns:
- the index of the next list element that
starts with the prefix; otherwise
-1 - Throws:
IllegalArgumentException- if prefix isnullor startIndex is out of bounds- Since:
- 1.4
-
getToolTipText
Returns the tooltip text to be used for the given event. This overridesJComponent'sgetToolTipTextto 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 usingsetToolTipTexton your cell renderer component.Note: For
JListto properly display the tooltips of its renderers in this manner,JListmust be a registered component with theToolTipManager. This registration is done automatically in the constructor. However, if at a later pointJListis unregistered, by way of a call tosetToolTipText(null), tips from the renderers will no longer display.- Overrides:
getToolTipTextin classJComponent- Parameters:
event- theMouseEventto fetch the tooltip text for- Returns:
- a string containing the tooltip
- See Also:
-
locationToIndex
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 bygetCellBounds. This method returns-1if the model is emptyThis is a cover method that delegates to the method of the same name in the list's
ListUI. It returns-1if the list has noListUI.- Parameters:
location- the coordinates of the point- Returns:
- the cell index closest to the given location, or
-1
-
indexToLocation
Returns the origin of the specified item in the list's coordinate system. This method returnsnullif the index isn't valid.This is a cover method that delegates to the method of the same name in the list's
ListUI. It returnsnullif the list has noListUI.- Parameters:
index- the cell index- Returns:
- the origin of the cell, or
null
-
getCellBounds
Returns the bounding rectangle, in the list's coordinate system, for the range of cells specified by the two indices. These indices can be supplied in any order.If the smaller index is outside the list's range of cells, this method returns
null. If the smaller index is valid, but the larger index is outside the list's range, the bounds of just the first index is returned. Otherwise, the bounds of the valid range is returned.This is a cover method that delegates to the method of the same name in the list's
ListUI. It returnsnullif the list has noListUI.- Parameters:
index0- the first index in the rangeindex1- the second index in the range- Returns:
- the bounding rectangle for the range of cells, or
null
-
getModel
-
setModel
@BeanProperty(visualUpdate=true, description="The object that contains the data to be drawn by this JList.") public void setModel(ListModel<E> model) Sets the model that represents the contents or "value" of the list, notifies property change listeners, and then clears the list's selection.This is a JavaBeans bound property.
- Parameters:
model- theListModelthat provides the list of items for display- Throws:
IllegalArgumentException- ifmodelisnull- See Also:
-
setListData
Constructs a read-onlyListModelfrom an array of items, and callssetModelwith this model.Attempts to pass a
nullvalue 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.- Parameters:
listData- an array ofEcontaining the items to display in the list- See Also:
-
setListData
Constructs a read-onlyListModelfrom aVectorand callssetModelwith this model.Attempts to pass a
nullvalue to this method results in undefined behavior and, most likely, exceptions. The created model references the givenVectordirectly. Attempts to modify theVectorafter invoking this method results in undefined behavior.- Parameters:
listData- aVectorcontaining the items to display in the list- See Also:
-
createSelectionModel
Returns an instance ofDefaultListSelectionModel; called during construction to initialize the list's selection model property.- Returns:
- a
DefaultListSelectionModel, used to initialize the list's selection model property during construction - See Also:
-
getSelectionModel
Returns the current selection model. The selection model maintains the selection state of the list. See the class level documentation for more details.- Returns:
- the
ListSelectionModelthat maintains the list's selections - See Also:
-
fireSelectionValueChanged
protected void fireSelectionValueChanged(int firstIndex, int lastIndex, boolean isAdjusting) NotifiesListSelectionListeners added directly to the list of selection changes made to the selection model.JListlistens for changes made to the selection in the selection model, and forwards notification to listeners added to the list directly, by calling this method.This method constructs a
ListSelectionEventwith this list as the source, and the specified arguments, and sends it to the registeredListSelectionListeners.- Parameters:
firstIndex- the first index in the range,<= lastIndexlastIndex- the last index in the range,>= firstIndexisAdjusting- whether or not this is one in a series of multiple events, where changes are still being made- See Also:
-
addListSelectionListener
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.JListtakes care of listening for selection state changes in the selection model, and notifies the given listener of each change.ListSelectionEvents sent to the listener have asourceproperty set to this list.- Parameters:
listener- theListSelectionListenerto add- See Also:
-
removeListSelectionListener
Removes a selection listener from the list.- Parameters:
listener- theListSelectionListenerto remove- See Also:
-
getListSelectionListeners
Returns an array of all theListSelectionListeners added to thisJListby way ofaddListSelectionListener.- Returns:
- all of the
ListSelectionListeners on this list, or an empty array if no listeners have been added - Since:
- 1.4
- See Also:
-
setSelectionModel
@BeanProperty(description="The selection model, recording which cells are selected.") public void setSelectionModel(ListSelectionModel selectionModel) Sets theselectionModelfor the list to a non-nullListSelectionModelimplementation. The selection model handles the task of making single selections, selections of contiguous ranges, and non-contiguous selections.This is a JavaBeans bound property.
- Parameters:
selectionModel- theListSelectionModelthat implements the selections- Throws:
IllegalArgumentException- ifselectionModelisnull- See Also:
-
setSelectionMode
@BeanProperty(bound=false, enumerationValues={"ListSelectionModel.SINGLE_SELECTION","ListSelectionModel.SINGLE_INTERVAL_SELECTION","ListSelectionModel.MULTIPLE_INTERVAL_SELECTION"}, description="The selection mode.") public void setSelectionMode(int selectionMode) Sets the selection mode for the list. This is a cover method that sets the selection mode directly on the selection model.The following list describes the accepted selection modes:
ListSelectionModel.SINGLE_SELECTION- Only one list index can be selected at a time. In this mode,setSelectionIntervalandaddSelectionIntervalare equivalent, both replacing the current selection with the index represented by the second argument (the "lead").ListSelectionModel.SINGLE_INTERVAL_SELECTION- Only one contiguous interval can be selected at a time. In this mode,addSelectionIntervalbehaves likesetSelectionInterval(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.ListSelectionModel.MULTIPLE_INTERVAL_SELECTION- In this mode, there's no restriction on what can be selected. This mode is the default.
- Parameters:
selectionMode- the selection mode- Throws:
IllegalArgumentException- if the selection mode isn't one of those allowed- See Also:
-
getSelectionMode
public int getSelectionMode()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.- Returns:
- the current selection mode
- See Also:
-
getAnchorSelectionIndex
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.- Returns:
- the anchor selection index
- See Also:
-
getLeadSelectionIndex
@BeanProperty(bound=false, description="The lead selection index.") public int getLeadSelectionIndex()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.- Returns:
- the lead selection index
- See Also:
-
getMinSelectionIndex
Returns the smallest selected cell index, or-1if the selection is empty. This is a cover method that delegates to the method of the same name on the list's selection model.- Returns:
- the smallest selected cell index, or
-1 - See Also:
-
getMaxSelectionIndex
Returns the largest selected cell index, or-1if the selection is empty. This is a cover method that delegates to the method of the same name on the list's selection model.- Returns:
- the largest selected cell index
- See Also:
-
isSelectedIndex
public boolean isSelectedIndex(int index) Returnstrueif the specified index is selected, elsefalse. This is a cover method that delegates to the method of the same name on the list's selection model.- Parameters:
index- index to be queried for selection state- Returns:
trueif the specified index is selected, elsefalse- See Also:
-
isSelectionEmpty
Returnstrueif nothing is selected, elsefalse. This is a cover method that delegates to the method of the same name on the list's selection model.- Returns:
trueif nothing is selected, elsefalse- See Also:
-
clearSelection
public void clearSelection()Clears the selection; after calling this method,isSelectionEmptywill returntrue. This is a cover method that delegates to the method of the same name on the list's selection model.- See Also:
-
setSelectionInterval
public void setSelectionInterval(int anchor, int lead) Selects the specified interval. Bothanchorandleadindices are included.anchordoesn't have to be less than or equal tolead. This is a cover method that delegates to the method of the same name on the list's selection model.Refer to the documentation of the selection model class being used for details on how values less than
0are handled.- Parameters:
anchor- the first index to selectlead- the last index to select- See Also:
-
addSelectionInterval
public void addSelectionInterval(int anchor, int lead) Sets the selection to be the union of the specified interval with current selection. Both theanchorandleadindices are included.anchordoesn't have to be less than or equal tolead. This is a cover method that delegates to the method of the same name on the list's selection model.Refer to the documentation of the selection model class being used for details on how values less than
0are handled.- Parameters:
anchor- the first index to add to the selectionlead- the last index to add to the selection- See Also:
-
removeSelectionInterval
public void removeSelectionInterval(int index0, int index1) Sets the selection to be the set difference of the specified interval and the current selection. Both theindex0andindex1indices are removed.index0doesn't have to be less than or equal toindex1. This is a cover method that delegates to the method of the same name on the list's selection model.Refer to the documentation of the selection model class being used for details on how values less than
0are handled.- Parameters:
index0- the first index to remove from the selectionindex1- the last index to remove from the selection- See Also:
-
setValueIsAdjusting
public void setValueIsAdjusting(boolean b) Sets the selection model'svalueIsAdjustingproperty. Whentrue, 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 totruewhen the drag is initiated and set tofalsewhen the drag is finished. This allows listeners to update only when a change has been finalized, rather than handling all of the intermediate values.You may want to use this directly if making a series of changes that should be considered part of a single change.
This is a cover method that delegates to the method of the same name on the list's selection model. See the documentation for
ListSelectionModel.setValueIsAdjusting(boolean)for more details.- Parameters:
b- the new value for the property- See Also:
-
getValueIsAdjusting
public boolean getValueIsAdjusting()Returns the value of the selection model'sisAdjustingproperty.This is a cover method that delegates to the method of the same name on the list's selection model.
- Returns:
- the value of the selection model's
isAdjustingproperty. - See Also:
-
getSelectedIndices
public int[] getSelectedIndices()Returns an array of all of the selected indices, in increasing order.- Returns:
- all of the selected indices, in increasing order, or an empty array if nothing is selected
- See Also:
-
setSelectedIndex
@BeanProperty(bound=false, description="The index of the selected cell.") public void setSelectedIndex(int index) 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 usessetSelectionIntervalon the selection model. Refer to the documentation for the selection model class being used for details on how values less than0are handled.- Parameters:
index- the index of the cell to select- See Also:
-
setSelectedIndices
public void setSelectedIndices(int[] indices) 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 usesaddSelectionIntervalon the selection model to add the indices. Refer to the documentation of the selection model class being used for details on how values less than0are handled.- Parameters:
indices- an array of the indices of the cells to select,non-null- Throws:
NullPointerException- if the given array isnull- See Also:
-
getSelectedValues
Deprecated.As of JDK 1.7, replaced bygetSelectedValuesList()Returns an array of all the selected values, in increasing order based on their indices in the list.- Returns:
- the selected values, or an empty array if nothing is selected
- See Also:
-
getSelectedValuesList
Returns a list of all the selected items, in increasing order based on their indices in the list.- Returns:
- the selected items, or an empty list if nothing is selected
- Since:
- 1.7
- See Also:
-
getSelectedIndex
public int getSelectedIndex()Returns the smallest selected cell index; the selection when only a single item is selected in the list. When multiple items are selected, it is simply the smallest selected index. Returns-1if there is no selection.This method is a cover that delegates to
getMinSelectionIndex.- Returns:
- the smallest selected cell index
- See Also:
-
getSelectedValue
Returns the value for the smallest selected cell index; the selected value when only a single item is selected in the list. When multiple items are selected, it is simply the value for the smallest selected index. Returnsnullif there is no selection.This is a convenience method that simply returns the model value for
getMinSelectionIndex.- Returns:
- the first selected value
- See Also:
-
setSelectedValue
Selects the specified object from the list. If the object passed isnull, the selection is cleared.- Parameters:
anObject- the object to selectshouldScroll-trueif the list should scroll to display the selected object, if one exists; otherwisefalse
-
getPreferredScrollableViewportSize
Computes the size of viewport needed to displayvisibleRowCountrows. The value returned by this method depends on the layout orientation:VERTICAL:
This is trivial if bothfixedCellWidthandfixedCellHeighthave been set (either explicitly or by specifying a prototype cell value). The width is simply thefixedCellWidthplus the list's horizontal insets. The height is thefixedCellHeightmultiplied by thevisibleRowCount, plus the list's vertical insets.If either
fixedCellWidthorfixedCellHeighthaven't been specified, heuristics are used. If the model is empty, the width is thefixedCellWidth, if greater than0, or a hard-coded value of256. The height is thefixedCellHeightmultiplied byvisibleRowCount, iffixedCellHeightis greater than0, otherwise it is a hard-coded value of16multiplied byvisibleRowCount.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 height of the cell with index 0 multiplied by the
visibleRowCount, plus the list's vertical insets.VERTICAL_WRAPorHORIZONTAL_WRAP:
This method simply returns the value fromgetPreferredSize. The list'sListUIis expected to overridegetPreferredSizeto return an appropriate value.- Specified by:
getPreferredScrollableViewportSizein interfaceScrollable- Returns:
- a dimension containing the size of the viewport needed
to display
visibleRowCountrows - See Also:
-
getScrollableUnitIncrement
Returns the distance to scroll to expose the next or previous row (for vertical scrolling) or column (for horizontal scrolling).For horizontal scrolling, if the layout orientation is
VERTICAL, then the list's font size is returned (or1if the font isnull).- Specified by:
getScrollableUnitIncrementin interfaceScrollable- Parameters:
visibleRect- the view area visible within the viewportorientation-SwingConstants.HORIZONTALorSwingConstants.VERTICALdirection- less or equal to zero to scroll up/back, greater than zero for down/forward- Returns:
- the "unit" increment for scrolling in the specified direction; always positive
- Throws:
IllegalArgumentException- ifvisibleRectisnull, ororientationisn't one ofSwingConstants.VERTICALorSwingConstants.HORIZONTAL- See Also:
-
getScrollableBlockIncrement
Returns the distance to scroll to expose the next or previous block.For vertical scrolling, the following rules are used:
- if scrolling down, returns the distance to scroll so that the last visible element becomes the first completely visible element
- if scrolling up, returns the distance to scroll so that the first visible element becomes the last completely visible element
- returns
visibleRect.heightif the list is empty
For horizontal scrolling, when the layout orientation is either
VERTICAL_WRAPorHORIZONTAL_WRAP:- if scrolling right, returns the distance to scroll so that the last visible element becomes the first completely visible element
- if scrolling left, returns the distance to scroll so that the first visible element becomes the last completely visible element
- returns
visibleRect.widthif the list is empty
For horizontal scrolling and
VERTICALorientation, returnsvisibleRect.width.Note that the value of
visibleRectmust be the equal tothis.getVisibleRect().- Specified by:
getScrollableBlockIncrementin interfaceScrollable- Parameters:
visibleRect- the view area visible within the viewportorientation-SwingConstants.HORIZONTALorSwingConstants.VERTICALdirection- less or equal to zero to scroll up/back, greater than zero for down/forward- Returns:
- the "block" increment for scrolling in the specified direction; always positive
- Throws:
IllegalArgumentException- ifvisibleRectisnull, ororientationisn't one ofSwingConstants.VERTICALorSwingConstants.HORIZONTAL- See Also:
-
getScrollableTracksViewportWidth
Returnstrueif thisJListis displayed in aJViewportand the viewport is wider than the list's preferred width, or if the layout orientation isHORIZONTAL_WRAPandvisibleRowCount <= 0; otherwise returnsfalse.If
false, then don't track the viewport's width. This allows horizontal scrolling if theJViewportis itself embedded in aJScrollPane.- Specified by:
getScrollableTracksViewportWidthin interfaceScrollable- Returns:
- whether or not an enclosing viewport should force the list's width to match its own
- See Also:
-
getScrollableTracksViewportHeight
Returnstrueif thisJListis displayed in aJViewportand the viewport is taller than the list's preferred height, or if the layout orientation isVERTICAL_WRAPandvisibleRowCount <= 0; otherwise returnsfalse.If
false, then don't track the viewport's height. This allows vertical scrolling if theJViewportis itself embedded in aJScrollPane.- Specified by:
getScrollableTracksViewportHeightin interfaceScrollable- Returns:
- whether or not an enclosing viewport should force the list's height to match its own
- See Also:
-
paramString
Returns aStringrepresentation of thisJList. This method is intended to be used only for debugging purposes, and the content and format of the returnedStringmay vary between implementations. The returnedStringmay be empty, but may not benull.- Overrides:
paramStringin classJComponent- Returns:
- a
Stringrepresentation of thisJList.
-
getAccessibleContext
Gets theAccessibleContextassociated with thisJList. ForJList, theAccessibleContexttakes the form of anAccessibleJList.A new
AccessibleJListinstance is created if necessary.- Specified by:
getAccessibleContextin interfaceAccessible- Overrides:
getAccessibleContextin classComponent- Returns:
- an
AccessibleJListthat serves as theAccessibleContextof thisJList
-
getSelectedValuesList()