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javax.swing
public class: JScrollBar [javadoc | source]
java.lang.Object
   java.awt.Component
      java.awt.Container
         javax.swing.JComponent
            javax.swing.JScrollBar

All Implemented Interfaces:
    Accessible, Adjustable, HasGetTransferHandler, Serializable, MenuContainer, ImageObserver

Direct Known Subclasses:
    ScrollBar

An implementation of a scrollbar. The user positions the knob in the scrollbar to determine the contents of the viewing area. The program typically adjusts the display so that the end of the scrollbar represents the end of the displayable contents, or 100% of the contents. The start of the scrollbar is the beginning of the displayable contents, or 0%. The position of the knob within those bounds then translates to the corresponding percentage of the displayable contents.

Typically, as the position of the knob in the scrollbar changes a corresponding change is made to the position of the JViewport on the underlying view, changing the contents of the JViewport.

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

Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeansTM has been added to the java.beans package. Please see java.beans.XMLEncoder .

Nested Class Summary:
protected class  JScrollBar.AccessibleJScrollBar  This class implements accessibility support for the JScrollBar class. It provides an implementation of the Java Accessibility API appropriate to scroll bar user-interface elements.

Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeansTM has been added to the java.beans package. Please see {@link java.beans.XMLEncoder}. 

Field Summary
protected  BoundedRangeModel model    The model that represents the scrollbar's minimum, maximum, extent (aka "visibleAmount") and current value. 
protected  int orientation     
protected  int unitIncrement     
protected  int blockIncrement     
Fields inherited from javax.swing.JComponent:
DEBUG_GRAPHICS_LOADED,  ui,  listenerList,  paintingChild,  WHEN_FOCUSED,  WHEN_ANCESTOR_OF_FOCUSED_COMPONENT,  WHEN_IN_FOCUSED_WINDOW,  UNDEFINED_CONDITION,  TOOL_TIP_TEXT_KEY,  focusController,  accessibleContext
Fields inherited from java.awt.Container:
layoutMgr,  containerListener,  listeningChildren,  listeningBoundsChildren,  descendantsCount,  preserveBackgroundColor,  INCLUDE_SELF,  SEARCH_HEAVYWEIGHTS,  modalComp,  modalAppContext
Fields inherited from java.awt.Component:
peer,  parent,  appContext,  x,  y,  width,  height,  foreground,  background,  font,  peerFont,  cursor,  locale,  bufferStrategy,  ignoreRepaint,  visible,  enabled,  dropTarget,  popups,  focusTraversalKeys,  LOCK,  minSize,  minSizeSet,  prefSize,  prefSizeSet,  maxSize,  maxSizeSet,  componentOrientation,  newEventsOnly,  componentListener,  focusListener,  hierarchyListener,  hierarchyBoundsListener,  keyListener,  mouseListener,  mouseMotionListener,  mouseWheelListener,  inputMethodListener,  windowClosingException,  actionListenerK,  adjustmentListenerK,  componentListenerK,  containerListenerK,  focusListenerK,  itemListenerK,  keyListenerK,  mouseListenerK,  mouseMotionListenerK,  mouseWheelListenerK,  textListenerK,  ownedWindowK,  windowListenerK,  inputMethodListenerK,  hierarchyListenerK,  hierarchyBoundsListenerK,  windowStateListenerK,  windowFocusListenerK,  eventMask,  isInc,  incRate,  TOP_ALIGNMENT,  CENTER_ALIGNMENT,  BOTTOM_ALIGNMENT,  LEFT_ALIGNMENT,  RIGHT_ALIGNMENT,  isPacked,  backgroundEraseDisabled,  eventCache,  accessibleContext
Constructor:
 public JScrollBar() 
 public JScrollBar(int orientation) 
 public JScrollBar(int orientation,
    int value,
    int extent,
    int min,
    int max) 
Method from javax.swing.JScrollBar Summary:
addAdjustmentListener,   fireAdjustmentValueChanged,   getAccessibleContext,   getAdjustmentListeners,   getBlockIncrement,   getBlockIncrement,   getMaximum,   getMaximumSize,   getMinimum,   getMinimumSize,   getModel,   getOrientation,   getUI,   getUIClassID,   getUnitIncrement,   getUnitIncrement,   getValue,   getValueIsAdjusting,   getVisibleAmount,   paramString,   removeAdjustmentListener,   setBlockIncrement,   setEnabled,   setMaximum,   setMinimum,   setModel,   setOrientation,   setUI,   setUnitIncrement,   setValue,   setValueIsAdjusting,   setValues,   setVisibleAmount,   updateUI
Methods from javax.swing.JComponent:
_paintImmediately,   addAncestorListener,   addNotify,   addVetoableChangeListener,   alwaysOnTop,   checkIfChildObscuredBySibling,   clientPropertyChanged,   compWriteObjectNotify,   componentInputMapChanged,   computeVisibleRect,   computeVisibleRect,   contains,   createToolTip,   disable,   dndDone,   dropLocationForPoint,   enable,   firePropertyChange,   firePropertyChange,   firePropertyChange,   fireVetoableChange,   getAccessibleContext,   getActionForKeyStroke,   getActionMap,   getActionMap,   getAlignmentX,   getAlignmentY,   getAncestorListeners,   getAutoscrolls,   getBaseline,   getBaselineResizeBehavior,   getBorder,   getBounds,   getClientProperty,   getComponentGraphics,   getComponentPopupMenu,   getConditionForKeyStroke,   getCreatedDoubleBuffer,   getDebugGraphicsOptions,   getDefaultLocale,   getFontMetrics,   getGraphics,   getGraphicsInvoked,   getHeight,   getInheritsPopupMenu,   getInputMap,   getInputMap,   getInputMap,   getInputVerifier,   getInsets,   getInsets,   getListeners,   getLocation,   getManagingFocusBackwardTraversalKeys,   getManagingFocusForwardTraversalKeys,   getMaximumSize,   getMinimumSize,   getNextFocusableComponent,   getPopupLocation,   getPreferredSize,   getRegisteredKeyStrokes,   getRootPane,   getSize,   getToolTipLocation,   getToolTipText,   getToolTipText,   getTopLevelAncestor,   getTransferHandler,   getUIClassID,   getVerifyInputWhenFocusTarget,   getVetoableChangeListeners,   getVisibleRect,   getWidth,   getWriteObjCounter,   getX,   getY,   grabFocus,   isDoubleBuffered,   isLightweightComponent,   isManagingFocus,   isOpaque,   isOptimizedDrawingEnabled,   isPainting,   isPaintingForPrint,   isPaintingOrigin,   isPaintingTile,   isRequestFocusEnabled,   isValidateRoot,   paint,   paintBorder,   paintChildren,   paintComponent,   paintForceDoubleBuffered,   paintImmediately,   paintImmediately,   paintToOffscreen,   paramString,   print,   printAll,   printBorder,   printChildren,   printComponent,   processComponentKeyEvent,   processKeyBinding,   processKeyBindings,   processKeyBindingsForAllComponents,   processKeyEvent,   processMouseEvent,   processMouseMotionEvent,   putClientProperty,   rectangleIsObscured,   registerKeyboardAction,   registerKeyboardAction,   removeAncestorListener,   removeNotify,   removeVetoableChangeListener,   repaint,   repaint,   requestDefaultFocus,   requestFocus,   requestFocus,   requestFocusInWindow,   requestFocusInWindow,   resetKeyboardActions,   reshape,   revalidate,   safelyGetGraphics,   safelyGetGraphics,   scrollRectToVisible,   setActionMap,   setAlignmentX,   setAlignmentY,   setAutoscrolls,   setBackground,   setBorder,   setComponentPopupMenu,   setCreatedDoubleBuffer,   setDebugGraphicsOptions,   setDefaultLocale,   setDoubleBuffered,   setDropLocation,   setEnabled,   setFocusTraversalKeys,   setFont,   setForeground,   setInheritsPopupMenu,   setInputMap,   setInputVerifier,   setMaximumSize,   setMinimumSize,   setNextFocusableComponent,   setOpaque,   setPaintingChild,   setPreferredSize,   setRequestFocusEnabled,   setToolTipText,   setTransferHandler,   setUI,   setUIProperty,   setVerifyInputWhenFocusTarget,   setVisible,   setWriteObjCounter,   shouldDebugGraphics,   superProcessMouseMotionEvent,   unregisterKeyboardAction,   update,   updateUI
Methods from java.awt.Container:
add,   add,   add,   add,   add,   addContainerListener,   addImpl,   addNotify,   addPropertyChangeListener,   addPropertyChangeListener,   adjustDecendantsOnParent,   adjustDescendants,   adjustListeningChildren,   applyComponentOrientation,   areFocusTraversalKeysSet,   canContainFocusOwner,   checkGD,   clearCurrentFocusCycleRootOnHide,   clearMostRecentFocusOwnerOnHide,   containsFocus,   countComponents,   countHierarchyMembers,   createChildHierarchyEvents,   createHierarchyEvents,   decreaseComponentCount,   deliverEvent,   dispatchEventImpl,   dispatchEventToSelf,   doLayout,   eventEnabled,   findComponentAt,   findComponentAt,   findComponentAt,   findComponentAtImpl,   getAccessibleAt,   getAccessibleChild,   getAccessibleChildrenCount,   getAlignmentX,   getAlignmentY,   getComponent,   getComponentAt,   getComponentAt,   getComponentCount,   getComponentZOrder,   getComponents,   getComponentsSync,   getComponents_NoClientCode,   getContainerListeners,   getDropTargetEventTarget,   getFocusTraversalKeys,   getFocusTraversalPolicy,   getHeavyweightContainer,   getInsets,   getLayout,   getListeners,   getMaximumSize,   getMinimumSize,   getMouseEventTarget,   getMousePosition,   getOpaqueShape,   getPreferredSize,   getTraversalRoot,   hasHeavyweightDescendants,   hasLightweightDescendants,   increaseComponentCount,   initializeFocusTraversalKeys,   insets,   invalidate,   invalidateParent,   invalidateTree,   isAncestorOf,   isFocusCycleRoot,   isFocusCycleRoot,   isFocusTraversalPolicyProvider,   isFocusTraversalPolicySet,   isRecursivelyVisibleUpToHeavyweightContainer,   isSameOrAncestorOf,   isValidateRoot,   layout,   lightweightPaint,   lightweightPrint,   list,   list,   locate,   minimumSize,   mixOnHiding,   mixOnReshaping,   mixOnShowing,   mixOnValidating,   mixOnZOrderChanging,   numListening,   paint,   paintComponents,   paintHeavyweightComponents,   paramString,   postProcessKeyEvent,   postsOldMouseEvents,   preProcessKeyEvent,   preferredSize,   print,   printComponents,   printHeavyweightComponents,   processContainerEvent,   processEvent,   proxyEnableEvents,   recursiveApplyCurrentShape,   recursiveApplyCurrentShape,   recursiveApplyCurrentShape,   recursiveSubtractAndApplyShape,   recursiveSubtractAndApplyShape,   recursiveSubtractAndApplyShape,   remove,   remove,   removeAll,   removeContainerListener,   removeNotify,   setComponentZOrder,   setFocusCycleRoot,   setFocusTraversalKeys,   setFocusTraversalPolicy,   setFocusTraversalPolicyProvider,   setFont,   setLayout,   transferFocusDownCycle,   update,   updateGraphicsData,   validate,   validateTree,   validateUnconditionally
Methods from java.awt.Component:
action,   add,   addComponentListener,   addFocusListener,   addHierarchyBoundsListener,   addHierarchyListener,   addInputMethodListener,   addKeyListener,   addMouseListener,   addMouseMotionListener,   addMouseWheelListener,   addNotify,   addPropertyChangeListener,   addPropertyChangeListener,   adjustListeningChildrenOnParent,   applyComponentOrientation,   applyCompoundShape,   applyCurrentShape,   areBoundsValid,   areFocusTraversalKeysSet,   areInputMethodsEnabled,   autoProcessMouseWheel,   bounds,   canBeFocusOwner,   canBeFocusOwnerRecursively,   checkGD,   checkImage,   checkImage,   checkTreeLock,   checkWindowClosingException,   clearCurrentFocusCycleRootOnHide,   clearMostRecentFocusOwnerOnHide,   coalesceEvents,   constructComponentName,   contains,   contains,   containsFocus,   countHierarchyMembers,   createBufferStrategy,   createBufferStrategy,   createHierarchyEvents,   createImage,   createImage,   createVolatileImage,   createVolatileImage,   deliverEvent,   disable,   disableEvents,   dispatchEvent,   dispatchEventImpl,   dispatchMouseWheelToAncestor,   doLayout,   enable,   enable,   enableEvents,   enableInputMethods,   eventEnabled,   eventTypeEnabled,   findUnderMouseInWindow,   firePropertyChange,   firePropertyChange,   firePropertyChange,   firePropertyChange,   firePropertyChange,   firePropertyChange,   firePropertyChange,   firePropertyChange,   firePropertyChange,   getAccessControlContext,   getAccessibleContext,   getAccessibleIndexInParent,   getAccessibleStateSet,   getAlignmentX,   getAlignmentY,   getBackBuffer,   getBackground,   getBaseline,   getBaselineResizeBehavior,   getBounds,   getBounds,   getBoundsOp,   getBufferStrategy,   getColorModel,   getComponentAt,   getComponentAt,   getComponentListeners,   getComponentOrientation,   getContainer,   getContainingWindow,   getCursor,   getCursor_NoClientCode,   getDropTarget,   getFocusCycleRootAncestor,   getFocusListeners,   getFocusTraversalKeys,   getFocusTraversalKeysEnabled,   getFocusTraversalKeys_NoIDCheck,   getFont,   getFontMetrics,   getFont_NoClientCode,   getForeground,   getGraphics,   getGraphicsConfiguration,   getGraphicsConfiguration_NoClientCode,   getGraphics_NoClientCode,   getHWPeerAboveMe,   getHeight,   getHierarchyBoundsListeners,   getHierarchyListeners,   getIgnoreRepaint,   getInputContext,   getInputMethodListeners,   getInputMethodRequests,   getKeyListeners,   getListeners,   getLocale,   getLocation,   getLocation,   getLocationOnScreen,   getLocationOnScreen_NoTreeLock,   getLocationOnWindow,   getMaximumSize,   getMinimumSize,   getMouseListeners,   getMouseMotionListeners,   getMousePosition,   getMouseWheelListeners,   getName,   getNativeContainer,   getNextFocusCandidate,   getNormalShape,   getObjectLock,   getOpaqueShape,   getParent,   getParent_NoClientCode,   getPeer,   getPreferredSize,   getPropertyChangeListeners,   getPropertyChangeListeners,   getSiblingIndexAbove,   getSiblingIndexBelow,   getSize,   getSize,   getToolkit,   getToolkitImpl,   getTraversalRoot,   getTreeLock,   getWidth,   getX,   getY,   gotFocus,   handleEvent,   hasFocus,   hide,   imageUpdate,   initializeFocusTraversalKeys,   inside,   invalidate,   invalidateIfValid,   invalidateParent,   isAutoFocusTransferOnDisposal,   isBackgroundSet,   isCoalescingEnabled,   isCursorSet,   isDisplayable,   isDoubleBuffered,   isEnabled,   isEnabledImpl,   isFocusCycleRoot,   isFocusOwner,   isFocusTraversable,   isFocusTraversableOverridden,   isFocusable,   isFontSet,   isForegroundSet,   isInstanceOf,   isLightweight,   isMaximumSizeSet,   isMinimumSizeSet,   isMixingNeeded,   isNonOpaqueForMixing,   isOpaque,   isPreferredSizeSet,   isRecursivelyVisible,   isSameOrAncestorOf,   isShowing,   isValid,   isVisible,   isVisible_NoClientCode,   keyDown,   keyUp,   layout,   lightweightPaint,   lightweightPrint,   list,   list,   list,   list,   list,   locate,   location,   lostFocus,   minimumSize,   mixOnHiding,   mixOnReshaping,   mixOnShowing,   mixOnValidating,   mixOnZOrderChanging,   mouseDown,   mouseDrag,   mouseEnter,   mouseExit,   mouseMove,   mouseUp,   move,   nextFocus,   numListening,   paint,   paintAll,   paintHeavyweightComponents,   paramString,   pointRelativeToComponent,   postEvent,   postsOldMouseEvents,   preferredSize,   prepareImage,   prepareImage,   print,   printAll,   printHeavyweightComponents,   processComponentEvent,   processEvent,   processFocusEvent,   processHierarchyBoundsEvent,   processHierarchyEvent,   processInputMethodEvent,   processKeyEvent,   processMouseEvent,   processMouseMotionEvent,   processMouseWheelEvent,   relocateComponent,   remove,   removeComponentListener,   removeFocusListener,   removeHierarchyBoundsListener,   removeHierarchyListener,   removeInputMethodListener,   removeKeyListener,   removeMouseListener,   removeMouseMotionListener,   removeMouseWheelListener,   removeNotify,   removePropertyChangeListener,   removePropertyChangeListener,   repaint,   repaint,   repaint,   repaint,   requestFocus,   requestFocus,   requestFocus,   requestFocus,   requestFocusHelper,   requestFocusHelper,   requestFocusInWindow,   requestFocusInWindow,   requestFocusInWindow,   requestFocusInWindow,   reshape,   resize,   resize,   revalidate,   setAutoFocusTransferOnDisposal,   setBackground,   setBounds,   setBounds,   setBoundsOp,   setComponentOrientation,   setCursor,   setDropTarget,   setEnabled,   setFocusTraversalKeys,   setFocusTraversalKeysEnabled,   setFocusTraversalKeys_NoIDCheck,   setFocusable,   setFont,   setForeground,   setGraphicsConfiguration,   setIgnoreRepaint,   setLocale,   setLocation,   setLocation,   setMaximumSize,   setMinimumSize,   setName,   setPreferredSize,   setRequestFocusController,   setSize,   setSize,   setVisible,   show,   show,   size,   subtractAndApplyShape,   subtractAndApplyShapeBelowMe,   toString,   transferFocus,   transferFocus,   transferFocusBackward,   transferFocusBackward,   transferFocusUpCycle,   update,   updateCursorImmediately,   updateGraphicsData,   updateZOrder,   validate
Methods from java.lang.Object:
clone,   equals,   finalize,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait
Method from javax.swing.JScrollBar Detail:
 public  void addAdjustmentListener(AdjustmentListener l) 
    Adds an AdjustmentListener. Adjustment listeners are notified each time the scrollbar's model changes. Adjustment events are provided for backwards compatibility with java.awt.Scrollbar.

    Note that the AdjustmentEvents type property will always have a placeholder value of AdjustmentEvent.TRACK because all changes to a BoundedRangeModels value are considered equivalent. To change the value of a BoundedRangeModel one just sets its value property, i.e. model.setValue(123). No information about the origin of the change, e.g. it's a block decrement, is provided. We don't try fabricate the origin of the change here.

 protected  void fireAdjustmentValueChanged(int id,
    int type,
    int value) 
    Notify listeners that the scrollbar's model has changed.
 public AccessibleContext getAccessibleContext() 
    Gets the AccessibleContext associated with this JScrollBar. For JScrollBar, the AccessibleContext takes the form of an AccessibleJScrollBar. A new AccessibleJScrollBar instance is created if necessary.
 public AdjustmentListener[] getAdjustmentListeners() 
    Returns an array of all the AdjustmentListeners added to this JScrollBar with addAdjustmentListener().
 public int getBlockIncrement() 
    For backwards compatibility with java.awt.Scrollbar.
 public int getBlockIncrement(int direction) 
    Returns the amount to change the scrollbar's value by, given a block (usually "page") up/down request. A ScrollBarUI implementation typically calls this method when the user clicks above or below the scrollbar "knob" to change the value up or down by large amount. Subclasses my override this method to compute a value, e.g. the change required to scroll up or down one paragraph in a text document.

    The JScrollPane component creates scrollbars (by default) that override this method and delegate to the viewports Scrollable view, if it has one. The Scrollable interface provides a more specialized version of this method.

 public int getMaximum() 
    The maximum value of the scrollbar is maximum - extent.
 public Dimension getMaximumSize() 
    The scrollbar is flexible along it's scrolling axis and rigid along the other axis.
 public int getMinimum() 
    Returns the minimum value supported by the scrollbar (usually zero).
 public Dimension getMinimumSize() 
    The scrollbar is flexible along it's scrolling axis and rigid along the other axis.
 public BoundedRangeModel getModel() 
    Returns data model that handles the scrollbar's four fundamental properties: minimum, maximum, value, extent.
 public int getOrientation() 
    Returns the component's orientation (horizontal or vertical).
 public ScrollBarUI getUI() 
    Returns the delegate that implements the look and feel for this component.
 public String getUIClassID() 
    Returns the name of the LookAndFeel class for this component.
 public int getUnitIncrement() 
    For backwards compatibility with java.awt.Scrollbar.
 public int getUnitIncrement(int direction) 
    Returns the amount to change the scrollbar's value by, given a unit up/down request. A ScrollBarUI implementation typically calls this method when the user clicks on a scrollbar up/down arrow and uses the result to update the scrollbar's value. Subclasses my override this method to compute a value, e.g. the change required to scroll up or down one (variable height) line text or one row in a table.

    The JScrollPane component creates scrollbars (by default) that override this method and delegate to the viewports Scrollable view, if it has one. The Scrollable interface provides a more specialized version of this method.

 public int getValue() 
    Returns the scrollbar's value.
 public boolean getValueIsAdjusting() 
    True if the scrollbar knob is being dragged.
 public int getVisibleAmount() 
    Returns the scrollbar's extent, aka its "visibleAmount". In many scrollbar look and feel implementations the size of the scrollbar "knob" or "thumb" is proportional to the extent.
 protected String paramString() 
    Returns a string representation of this JScrollBar. This method is intended to be used only for debugging purposes, and the content and format of the returned string may vary between implementations. The returned string may be empty but may not be null.
 public  void removeAdjustmentListener(AdjustmentListener l) 
    Removes an AdjustmentEvent listener.
 public  void setBlockIncrement(int blockIncrement) 
    Sets the blockIncrement property.

    Note, that if the argument is equal to the value of Integer.MIN_VALUE, the most look and feels will not provide the scrolling to the right/down.

 public  void setEnabled(boolean x) 
    Enables the component so that the knob position can be changed. When the disabled, the knob position cannot be changed.
 public  void setMaximum(int maximum) 
    Sets the model's maximum property. Note that the scrollbar's value can only be set to maximum - extent.
 public  void setMinimum(int minimum) 
    Sets the model's minimum property.
 public  void setModel(BoundedRangeModel newModel) 
    Sets the model that handles the scrollbar's four fundamental properties: minimum, maximum, value, extent.
 public  void setOrientation(int orientation) 
    Set the scrollbar's orientation to either VERTICAL or HORIZONTAL.
 public  void setUI(ScrollBarUI ui) 
    Sets the L&F object that renders this component.
 public  void setUnitIncrement(int unitIncrement) 
    Sets the unitIncrement property.

    Note, that if the argument is equal to the value of Integer.MIN_VALUE, the most look and feels will not provide the scrolling to the right/down.

 public  void setValue(int value) 
    Sets the scrollbar's value. This method just forwards the value to the model.
 public  void setValueIsAdjusting(boolean b) 
    Sets the model's valueIsAdjusting property. Scrollbar look and feel implementations should set this property to true when a knob drag begins, and to false when the drag ends. The scrollbar model will not generate ChangeEvents while valueIsAdjusting is true.
 public  void setValues(int newValue,
    int newExtent,
    int newMin,
    int newMax) 
    Sets the four BoundedRangeModel properties after forcing the arguments to obey the usual constraints:
    minimum <= value <= value+extent <= maximum
    

 public  void setVisibleAmount(int extent) 
    Set the model's extent property.
 public  void updateUI() 
    Overrides JComponent.updateUI.