Class CheckBoxList<T>

  extended by java.awt.Component
      extended by java.awt.Container
          extended by javax.swing.JComponent
              extended by javax.swing.JList
                  extended by<T>
All Implemented Interfaces:
ImageObserver, MenuContainer, Serializable, Accessible, Scrollable
Direct Known Subclasses:
BasicCheckBoxList, ControlStack

public abstract class CheckBoxList<T>
extends JList

JList subclass that adds a couple of features. First, each entry has a checkbox associated with it that may be selected or deselected by the user. Second, the list entries can be reordered by the user dragging them up or down in the list. A distinctive handle is provided to indicate this option visually. Third, you can overpaint a message below the list items.

The selection model for the checkboxes and the list model giving entry ordering are held externally to this implementation, so must be explicitly managed by clients of this class, and may be modified programmatically.

13 Mar 2013
Mark Taylor
See Also:
Serialized Form

Nested Class Summary
Nested classes/interfaces inherited from class javax.swing.JList
JList.AccessibleJList, JList.DropLocation
Nested classes/interfaces inherited from class javax.swing.JComponent
Nested classes/interfaces inherited from class java.awt.Container
Nested classes/interfaces inherited from class java.awt.Component
Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy
Field Summary
Fields inherited from class javax.swing.JList
Fields inherited from class javax.swing.JComponent
Fields inherited from class java.awt.Component
Fields inherited from interface java.awt.image.ImageObserver
Constructor Summary
CheckBoxList(Class<T> clazz, ListModel model, boolean canSelect, JComponent entryRenderer)
Method Summary
 void addListDataListener(ListDataListener l)
          Adds a listener for list events.
protected abstract  void configureEntryRenderer(JComponent entryRenderer, T item, int index)
          This method is called whenever the list cell needs to be painted.
 T getSelectedValue()
 T getTypedValue(Object value)
          Returns a list cell entry cast to the entry type of this list, or null if it can't be done.
abstract  boolean isChecked(T item)
          Indicates whether the checkbox for a given item is selected.
abstract  void moveItem(int ifrom, int ito)
          Indicates that the user has requested a reordering of the list model.
protected  void paintComponent(Graphics g)
 void removeListDataListener(ListDataListener l)
          Removes a listener previously added.
abstract  void setChecked(T item, boolean isChecked)
          Sets whether the checkbox for a given item is selected.
 void setListMessage(String[] msgLines)
          Sets a message which is overpainted on the blank part of this component.
Methods inherited from class javax.swing.JList
addListSelectionListener, addSelectionInterval, clearSelection, createSelectionModel, ensureIndexIsVisible, fireSelectionValueChanged, getAccessibleContext, getAnchorSelectionIndex, getCellBounds, getCellRenderer, getDragEnabled, getDropLocation, getDropMode, getFirstVisibleIndex, getFixedCellHeight, getFixedCellWidth, getLastVisibleIndex, getLayoutOrientation, getLeadSelectionIndex, getListSelectionListeners, getMaxSelectionIndex, getMinSelectionIndex, getModel, getNextMatch, getPreferredScrollableViewportSize, getPrototypeCellValue, getScrollableBlockIncrement, getScrollableTracksViewportHeight, getScrollableTracksViewportWidth, getScrollableUnitIncrement, getSelectedIndex, getSelectedIndices, getSelectedValues, getSelectionBackground, getSelectionForeground, getSelectionMode, getSelectionModel, getToolTipText, getUI, getUIClassID, getValueIsAdjusting, getVisibleRowCount, indexToLocation, isSelectedIndex, isSelectionEmpty, locationToIndex, paramString, removeListSelectionListener, removeSelectionInterval, setCellRenderer, setDragEnabled, setDropMode, setFixedCellHeight, setFixedCellWidth, setLayoutOrientation, setListData, setListData, setModel, setPrototypeCellValue, setSelectedIndex, setSelectedIndices, setSelectedValue, setSelectionBackground, setSelectionForeground, setSelectionInterval, setSelectionMode, setSelectionModel, setUI, setValueIsAdjusting, setVisibleRowCount, updateUI
Methods inherited from class javax.swing.JComponent
addAncestorListener, addNotify, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, disable, enable, firePropertyChange, 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, isDoubleBuffered, isLightweightComponent, isManagingFocus, isOpaque, isOptimizedDrawingEnabled, isPaintingForPrint, isPaintingTile, isRequestFocusEnabled, isValidateRoot, paint, paintBorder, paintChildren, 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, update
Methods inherited from 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, transferFocusBackward, transferFocusDownCycle, validate, validateTree
Methods inherited from 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, 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, getPeer, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getToolkit, getTreeLock, gotFocus, handleEvent, hasFocus, hide, 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, resize, resize, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setFocusable, setFocusTraversalKeysEnabled, setIgnoreRepaint, setLocale, setLocation, setLocation, setName, setSize, setSize, show, show, size, toString, transferFocus, transferFocusUpCycle
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail


public CheckBoxList(Class<T> clazz,
                    ListModel model,
                    boolean canSelect,
                    JComponent entryRenderer)
Constructor. A renderer component is supplied; when entries need to be displayed the configureEntryRenderer method is called.

clazz - supertype for each entry in the list
model - list model
canSelect - true if list item selection is permitted
entryRenderer - renderer for list entry contents (excluding drag and checkbox decorations)
Method Detail


protected abstract void configureEntryRenderer(JComponent entryRenderer,
                                               T item,
                                               int index)
This method is called whenever the list cell needs to be painted.

entryRenderer - renderer object supplied at construction time
item - list entry
index - index in list at which entry appears


public abstract boolean isChecked(T item)
Indicates whether the checkbox for a given item is selected.

item - list entry
true iff item is selected


public abstract void setChecked(T item,
                                boolean isChecked)
Sets whether the checkbox for a given item is selected. Called when the user interacts with the checkbox. It is up to the concrete implementation to ensure that this is reflected by the isChecked method.

item - list entry
isChecked - whether item should be selected


public abstract void moveItem(int ifrom,
                              int ito)
Indicates that the user has requested a reordering of the list model. It is up to the concrete implementation to ensure that this is reflected in the list model.

ifrom - source list index
ito - destination list index


public T getTypedValue(Object value)
Returns a list cell entry cast to the entry type of this list, or null if it can't be done.

value - list entry
typed list entry, or null


public T getSelectedValue()
getSelectedValue in class JList


public void setListMessage(String[] msgLines)
Sets a message which is overpainted on the blank part of this component. If null or empty, no message is painted.

msgLines - lines of a message to paint


public void addListDataListener(ListDataListener l)
Adds a listener for list events. As well as changes to the underlying ListModel, this will also be messaged when any of the elements becomes checked or unchecked.

l - listener to add


public void removeListDataListener(ListDataListener l)
Removes a listener previously added.

l - listener to remove


protected void paintComponent(Graphics g)
paintComponent in class JComponent

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