Class JScrollBar

All Implemented Interfaces:
Adjustable, ImageObserver, MenuContainer, Serializable, Accessible
Direct Known Subclasses:
JScrollPane.ScrollBar
@JavaBean(defaultProperty="UI",
          description="A component that helps determine the visible content range of an area.")
public class JScrollBar
extends JComponent
implements Adjustable, Accessible

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 JavaBeans™ has been added to the java.beans package. Please see XMLEncoder.

Since:
1.2
See Also:
JScrollPane, Serialized Form

Nested Class Summary

Nested Classes
Modifier and Type Class Description
protected class  JScrollBar.AccessibleJScrollBar

This class implements accessibility support for the JScrollBar class.

Nested classes/interfaces declared in class javax.swing.JComponent

JComponent.AccessibleJComponent

Nested classes/interfaces declared in class java.awt.Container

Container.AccessibleAWTContainer

Nested classes/interfaces declared in class java.awt.Component

Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy

Field Summary

Fields
Modifier and Type Field Description
protected int blockIncrement
protected BoundedRangeModel model

The model that represents the scrollbar's minimum, maximum, extent (aka "visibleAmount") and current value.
protected int orientation
protected int unitIncrement

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_WINDOW

Fields declared in class java.awt.Component

accessibleContext, BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Fields declared in interface java.awt.Adjustable

HORIZONTAL, NO_ORIENTATION, VERTICAL

Fields declared in interface java.awt.image.ImageObserver

ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH

Constructor Summary

Constructors
Constructor Description
JScrollBar()

Creates a vertical scrollbar with the following initial values:
JScrollBar​(int orientation)

Creates a scrollbar with the specified orientation and the following initial values:
JScrollBar​(int orientation, int value, int extent, int min, int max)

Creates a scrollbar with the specified orientation, value, extent, minimum, and maximum.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type Method Description
void addAdjustmentListener​(AdjustmentListener l)

Adds an AdjustmentListener.
protected void fireAdjustmentValueChanged​(int id, int type, int value)

Notify listeners that the scrollbar's model has changed.
AccessibleContext getAccessibleContext()

Gets the AccessibleContext associated with this JScrollBar.
AdjustmentListener[] getAdjustmentListeners()

Returns an array of all the AdjustmentListeners added to this JScrollBar with addAdjustmentListener().
int getBlockIncrement()

For backwards compatibility with java.awt.Scrollbar.
int getBlockIncrement​(int direction)

Returns the amount to change the scrollbar's value by, given a block (usually "page") up/down request.
int getMaximum()

The maximum value of the scrollbar is maximum - extent.
Dimension getMaximumSize()

The scrollbar is flexible along it's scrolling axis and rigid along the other axis.
int getMinimum()

Returns the minimum value supported by the scrollbar (usually zero).
Dimension getMinimumSize()

The scrollbar is flexible along it's scrolling axis and rigid along the other axis.
BoundedRangeModel getModel()

Returns data model that handles the scrollbar's four fundamental properties: minimum, maximum, value, extent.
int getOrientation()

Returns the component's orientation (horizontal or vertical).
ScrollBarUI getUI()

Returns the delegate that implements the look and feel for this component.
String getUIClassID()

Returns the name of the LookAndFeel class for this component.
int getUnitIncrement()

For backwards compatibility with java.awt.Scrollbar.
int getUnitIncrement​(int direction)

Returns the amount to change the scrollbar's value by, given a unit up/down request.
int getValue()

Returns the scrollbar's value.
boolean getValueIsAdjusting()

True if the scrollbar knob is being dragged.
int getVisibleAmount()

Returns the scrollbar's extent, aka its "visibleAmount".
protected String paramString()

Returns a string representation of this JScrollBar.
void removeAdjustmentListener​(AdjustmentListener l)

Removes an AdjustmentEvent listener.
void setBlockIncrement​(int blockIncrement)

Sets the blockIncrement property.
void setEnabled​(boolean x)

Enables the component so that the knob position can be changed.
void setMaximum​(int maximum)

Sets the model's maximum property.
void setMinimum​(int minimum)

Sets the model's minimum property.
void setModel​(BoundedRangeModel newModel)

Sets the model that handles the scrollbar's four fundamental properties: minimum, maximum, value, extent.
void setOrientation​(int orientation)

Set the scrollbar's orientation to either VERTICAL or HORIZONTAL.
void setUI​(ScrollBarUI ui)

Sets the L&F object that renders this component.
void setUnitIncrement​(int unitIncrement)

Sets the unitIncrement property.
void setValue​(int value)

Sets the scrollbar's value.
void setValueIsAdjusting​(boolean b)

Sets the model's valueIsAdjusting property.
void setValues​(int newValue, int newExtent, int newMin, int newMax)

Sets the four BoundedRangeModel properties after forcing the arguments to obey the usual constraints:
void setVisibleAmount​(int extent)

Set the model's extent property.
void updateUI()

Overrides JComponent.updateUI.

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, getNextFocusableComponent, getPopupLocation, getPreferredSize, getRegisteredKeyStrokes, getRootPane, getSize, getToolTipLocation, getToolTipText, getToolTipText, getTopLevelAncestor, getTransferHandler, getVerifyInputWhenFocusTarget, getVetoableChangeListeners, getVisibleRect, getWidth, getX, getY, grabFocus, 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, setFocusTraversalKeys, setFont, setForeground, setInheritsPopupMenu, setInputMap, setInputVerifier, setMaximumSize, setMinimumSize, setNextFocusableComponent, setOpaque, setPreferredSize, setRequestFocusEnabled, setToolTipText, setTransferHandler, setUI, setVerifyInputWhenFocusTarget, setVisible, unregisterKeyboardAction, update

Methods 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, validateTree

Methods 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, 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, 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

Methods declared in class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

model

protected BoundedRangeModel model

The model that represents the scrollbar's minimum, maximum, extent (aka "visibleAmount") and current value.

See Also:
setModel(javax.swing.BoundedRangeModel)

orientation

protected int orientation
See Also:
setOrientation(int)

unitIncrement

protected int unitIncrement
See Also:
setUnitIncrement(int)

blockIncrement

protected int blockIncrement
See Also:
setBlockIncrement(int)

Constructor Detail

JScrollBar

public JScrollBar​(int orientation,
                  int value,
                  int extent,
                  int min,
                  int max)

Creates a scrollbar with the specified orientation, value, extent, minimum, and maximum. The "extent" is the size of the viewable area. It is also known as the "visible amount".

Note: Use setBlockIncrement to set the block increment to a size slightly smaller than the view's extent. That way, when the user jumps the knob to an adjacent position, one or two lines of the original contents remain in view.

Parameters:
orientation - an orientation of the JScrollBar
value - an int giving the current value
extent - an int giving the amount by which the value can "jump"
min - an int giving the minimum value
max - an int giving the maximum value
Throws:
IllegalArgumentException - if orientation is not one of VERTICAL, HORIZONTAL
See Also:
setOrientation(int), setValue(int), setVisibleAmount(int), setMinimum(int), setMaximum(int)

JScrollBar

public JScrollBar​(int orientation)

Creates a scrollbar with the specified orientation and the following initial values: 

minimum = 0
 maximum = 100
 value = 0
 extent = 10
Parameters:
orientation - an orientation of the JScrollBar

JScrollBar

public JScrollBar()

Creates a vertical scrollbar with the following initial values: 

minimum = 0
 maximum = 100
 value = 0
 extent = 10

Method Detail

setUI

@BeanProperty(hidden=true,
              visualUpdate=true,
              description="The UI object that implements the Component\'s LookAndFeel")
public void setUI​(ScrollBarUI ui)

Sets the L&F object that renders this component.

Parameters:
ui - the ScrollBarUI L&F object
Since:
1.4
See Also:
UIDefaults.getUI(javax.swing.JComponent)

getUI

public ScrollBarUI getUI()

Returns the delegate that implements the look and feel for this component.

Overrides:
getUI in class JComponent
Returns:
the scroll bar's current UI.
See Also:
JComponent.setUI(javax.swing.plaf.ComponentUI)

updateUI

public void updateUI()

Overrides JComponent.updateUI.

Overrides:
updateUI in class JComponent
See Also:
JComponent.updateUI()

getUIClassID

@BeanProperty(bound=false)
public String getUIClassID()

Returns the name of the LookAndFeel class for this component.

Overrides:
getUIClassID in class JComponent
Returns:
"ScrollBarUI"
See Also:
JComponent.getUIClassID(), UIDefaults.getUI(javax.swing.JComponent)

getOrientation

public int getOrientation()

Returns the component's orientation (horizontal or vertical).

Specified by:
getOrientation in interface Adjustable
Returns:
VERTICAL or HORIZONTAL
See Also:
setOrientation(int), Adjustable.getOrientation()

setOrientation

@BeanProperty(preferred=true,
              visualUpdate=true,
              enumerationValues={"JScrollBar.VERTICAL","JScrollBar.HORIZONTAL"},
              description="The scrollbar\'s orientation.")
public void setOrientation​(int orientation)

Set the scrollbar's orientation to either VERTICAL or HORIZONTAL.

Parameters:
orientation - an orientation of the JScrollBar
Throws:
IllegalArgumentException - if orientation is not one of VERTICAL, HORIZONTAL
See Also:
getOrientation()

getModel

public BoundedRangeModel getModel()

Returns data model that handles the scrollbar's four fundamental properties: minimum, maximum, value, extent.

Returns:
the data model
See Also:
setModel(javax.swing.BoundedRangeModel)

setModel

@BeanProperty(expert=true,
              description="The scrollbar\'s BoundedRangeModel.")
public void setModel​(BoundedRangeModel newModel)

Sets the model that handles the scrollbar's four fundamental properties: minimum, maximum, value, extent.

Parameters:
newModel - a new model
See Also:
getModel()

getUnitIncrement

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.

Some look and feels implement custom scrolling behavior and ignore this property.

Parameters:
direction - is -1 or 1 for up/down respectively
Returns:
the value of the unitIncrement property
See Also:
setUnitIncrement(int), setValue(int), Scrollable.getScrollableUnitIncrement(java.awt.Rectangle, int, int)

setUnitIncrement

@BeanProperty(preferred=true,
              description="The scrollbar\'s unit increment.")
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.

Some look and feels implement custom scrolling behavior and ignore this property.

Specified by:
setUnitIncrement in interface Adjustable
Parameters:
unitIncrement - the unit increment
See Also:
getUnitIncrement(int)

getBlockIncrement

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.

Some look and feels implement custom scrolling behavior and ignore this property.

Parameters:
direction - is -1 or 1 for up/down respectively
Returns:
the value of the blockIncrement property
See Also:
setBlockIncrement(int), setValue(int), Scrollable.getScrollableBlockIncrement(java.awt.Rectangle, int, int)

setBlockIncrement

@BeanProperty(preferred=true,
              description="The scrollbar\'s block increment.")
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.

Some look and feels implement custom scrolling behavior and ignore this property.

Specified by:
setBlockIncrement in interface Adjustable
Parameters:
blockIncrement - the block increment
See Also:
getBlockIncrement()

getUnitIncrement

public int getUnitIncrement()

For backwards compatibility with java.awt.Scrollbar.

Specified by:
getUnitIncrement in interface Adjustable
Returns:
the unit value increment for the adjustable object
See Also:
Adjustable.getUnitIncrement(), getUnitIncrement(int)

getBlockIncrement

public int getBlockIncrement()

For backwards compatibility with java.awt.Scrollbar.

Specified by:
getBlockIncrement in interface Adjustable
Returns:
the block value increment for the adjustable object
See Also:
Adjustable.getBlockIncrement(), getBlockIncrement(int)

getValue

public int getValue()

Returns the scrollbar's value.

Specified by:
getValue in interface Adjustable
Returns:
the model's value property
See Also:
setValue(int)

setValue

@BeanProperty(bound=false,
              preferred=true,
              description="The scrollbar\'s current value.")
public void setValue​(int value)

Sets the scrollbar's value. This method just forwards the value to the model.

Specified by:
setValue in interface Adjustable
Parameters:
value - the current value, between minimum and maximum - visibleAmount
See Also:
getValue(), BoundedRangeModel.setValue(int)

getVisibleAmount

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.

Specified by:
getVisibleAmount in interface Adjustable
Returns:
the value of the model's extent property
See Also:
setVisibleAmount(int)

setVisibleAmount

@BeanProperty(bound=false,
              preferred=true,
              description="The amount of the view that is currently visible.")
public void setVisibleAmount​(int extent)

Set the model's extent property.

Specified by:
setVisibleAmount in interface Adjustable
Parameters:
extent - the length of the indicator
See Also:
getVisibleAmount(), BoundedRangeModel.setExtent(int)

getMinimum

public int getMinimum()

Returns the minimum value supported by the scrollbar (usually zero).

Specified by:
getMinimum in interface Adjustable
Returns:
the value of the model's minimum property
See Also:
setMinimum(int)

setMinimum

@BeanProperty(bound=false,
              preferred=true,
              description="The scrollbar\'s minimum value.")
public void setMinimum​(int minimum)

Sets the model's minimum property.

Specified by:
setMinimum in interface Adjustable
Parameters:
minimum - the minimum value
See Also:
getMinimum(), BoundedRangeModel.setMinimum(int)

getMaximum

public int getMaximum()

The maximum value of the scrollbar is maximum - extent.

Specified by:
getMaximum in interface Adjustable
Returns:
the value of the model's maximum property
See Also:
setMaximum(int)

setMaximum

@BeanProperty(bound=false,
              preferred=true,
              description="The scrollbar\'s maximum value.")
public void setMaximum​(int maximum)

Sets the model's maximum property. Note that the scrollbar's value can only be set to maximum - extent.

Specified by:
setMaximum in interface Adjustable
Parameters:
maximum - the maximum value
See Also:
getMaximum(), BoundedRangeModel.setMaximum(int)

getValueIsAdjusting

public boolean getValueIsAdjusting()

True if the scrollbar knob is being dragged.

Returns:
the value of the model's valueIsAdjusting property
See Also:
setValueIsAdjusting(boolean)

setValueIsAdjusting

@BeanProperty(bound=false,
              expert=true,
              description="True if the scrollbar thumb is being dragged.")
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.

Parameters:
b - true if the upcoming changes to the value property are part of a series
See Also:
getValueIsAdjusting(), BoundedRangeModel.setValueIsAdjusting(boolean)

setValues

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
Parameters:
newValue - an int giving the current value
newExtent - an int giving the amount by which the value can "jump"
newMin - an int giving the minimum value
newMax - an int giving the maximum value
See Also:
BoundedRangeModel.setRangeProperties(int, int, int, int, boolean), setValue(int), setVisibleAmount(int), setMinimum(int), setMaximum(int)

addAdjustmentListener

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.

Specified by:
addAdjustmentListener in interface Adjustable
Parameters:
l - the AdjustmentLister to add
See Also:
removeAdjustmentListener(java.awt.event.AdjustmentListener), BoundedRangeModel.addChangeListener(javax.swing.event.ChangeListener)

removeAdjustmentListener

public void removeAdjustmentListener​(AdjustmentListener l)

Removes an AdjustmentEvent listener.

Specified by:
removeAdjustmentListener in interface Adjustable
Parameters:
l - the AdjustmentLister to remove
See Also:
addAdjustmentListener(java.awt.event.AdjustmentListener)

getAdjustmentListeners

@BeanProperty(bound=false)
public AdjustmentListener[] getAdjustmentListeners()

Returns an array of all the AdjustmentListeners added to this JScrollBar with addAdjustmentListener().

Returns:
all of the AdjustmentListeners added or an empty array if no listeners have been added
Since:
1.4

fireAdjustmentValueChanged

protected void fireAdjustmentValueChanged​(int id,
                                          int type,
                                          int value)

Notify listeners that the scrollbar's model has changed.

Parameters:
id - an integer indicating the type of event.
type - an integer indicating the adjustment type.
value - the current value of the adjustment
See Also:
addAdjustmentListener(java.awt.event.AdjustmentListener), EventListenerList

getMinimumSize

public Dimension getMinimumSize()

The scrollbar is flexible along it's scrolling axis and rigid along the other axis.

Overrides:
getMinimumSize in class JComponent
Returns:
the value of the minimumSize property
See Also:
JComponent.setMinimumSize(java.awt.Dimension), ComponentUI

getMaximumSize

public Dimension getMaximumSize()

The scrollbar is flexible along it's scrolling axis and rigid along the other axis.

Overrides:
getMaximumSize in class JComponent
Returns:
the value of the maximumSize property
See Also:
JComponent.setMaximumSize(java.awt.Dimension), ComponentUI

setEnabled

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.

Overrides:
setEnabled in class JComponent
Parameters:
x - a boolean value, where true enables the component and false disables it
See Also:
Component.isEnabled(), Component.isLightweight()

paramString

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.

Overrides:
paramString in class JComponent
Returns:
a string representation of this JScrollBar.

getAccessibleContext

@BeanProperty(bound=false)
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.

Specified by:
getAccessibleContext in interface Accessible
Overrides:
getAccessibleContext in class Component
Returns:
an AccessibleJScrollBar that serves as the AccessibleContext of this JScrollBar