java.lang.Object
- javax.swing.plaf.ComponentUI
- - javax.swing.plaf.ScrollBarUI
  - - javax.swing.plaf.basic.BasicScrollBarUI

All Implemented Interfaces:

LayoutManager, SwingConstants

Direct Known Subclasses:

MetalScrollBarUI, SynthScrollBarUI
```
public class BasicScrollBarUI
extends ScrollBarUI
implements LayoutManager, SwingConstants
```
Implementation of ScrollBarUI for the Basic Look and Feel

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`protected class`	`BasicScrollBarUI.ArrowButtonListener`	Listener for cursor keys.
`protected class`	`BasicScrollBarUI.ModelListener`	A listener to listen for model changes.
`class`	`BasicScrollBarUI.PropertyChangeHandler`	Property change handler
`protected class`	`BasicScrollBarUI.ScrollListener`	Listener for scrolling events initiated in the `ScrollPane`.
`protected class`	`BasicScrollBarUI.TrackListener`	Track mouse drags.

Field Summary

Fields
Modifier and Type	Field	Description
`protected BasicScrollBarUI.ArrowButtonListener`	`buttonListener`	Button listener
`protected JButton`	`decrButton`	Decrement button
`protected static int`	`DECREASE_HIGHLIGHT`	Decrease highlight
`protected int`	`decrGap`	Distance between the decrement button and the track.
`protected JButton`	`incrButton`	Increment button
`protected static int`	`INCREASE_HIGHLIGHT`	Increase highlight
`protected int`	`incrGap`	Distance between the increment button and the track.
`protected boolean`	`isDragging`	Dragging
`protected Dimension`	`maximumThumbSize`	Maximum thumb size
`protected Dimension`	`minimumThumbSize`	Minimum thumb size
`protected BasicScrollBarUI.ModelListener`	`modelListener`	Model listener
`protected static int`	`NO_HIGHLIGHT`	No highlight
`protected PropertyChangeListener`	`propertyChangeListener`	Property change listener
`protected JScrollBar`	`scrollbar`	Scrollbar
`protected int`	`scrollBarWidth`	Hint as to what width (when vertical) or height (when horizontal) should be.
`protected BasicScrollBarUI.ScrollListener`	`scrollListener`	Scroll listener
`protected Timer`	`scrollTimer`	Scroll timer
`protected Color`	`thumbColor`	Thumb color
`protected Color`	`thumbDarkShadowColor`	Thumb dark shadow color
`protected Color`	`thumbHighlightColor`	Thumb highlight color
`protected Color`	`thumbLightShadowColor`	Thumb light shadow color
`protected Rectangle`	`thumbRect`	Thumb rectangle
`protected Color`	`trackColor`	Track color
`protected int`	`trackHighlight`	Track highlight
`protected Color`	`trackHighlightColor`	Track highlight color
`protected BasicScrollBarUI.TrackListener`	`trackListener`	Track listener
`protected Rectangle`	`trackRect`	Track rectangle

Fields declared in interface javax.swing.SwingConstants
BOTTOM, CENTER, EAST, HORIZONTAL, LEADING, LEFT, NEXT, NORTH, NORTH_EAST, NORTH_WEST, PREVIOUS, RIGHT, SOUTH, SOUTH_EAST, SOUTH_WEST, TOP, TRAILING, VERTICAL, WEST

Constructor Summary

Constructors
Constructor Description

BasicScrollBarUI()

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected void`	`configureScrollBarColors()`	Configures the scroll bar colors.
`protected BasicScrollBarUI.ArrowButtonListener`	`createArrowButtonListener()`	Creates an arrow button listener.
`protected JButton`	`createDecreaseButton(int orientation)`	Creates a decrease button.
`protected JButton`	`createIncreaseButton(int orientation)`	Creates an increase button.
`protected BasicScrollBarUI.ModelListener`	`createModelListener()`	Creates a model listener.
`protected PropertyChangeListener`	`createPropertyChangeListener()`	Creates a property change listener.
`protected BasicScrollBarUI.ScrollListener`	`createScrollListener()`	Creates a scroll listener.
`protected BasicScrollBarUI.TrackListener`	`createTrackListener()`	Creates a track listener.
`static ComponentUI`	`createUI(JComponent c)`	Creates the UI.
`Dimension`	`getMaximumSize(JComponent c)`	Returns the specified component's maximum size appropriate for the look and feel.
`protected Dimension`	`getMaximumThumbSize()`	Returns the largest acceptable size for the thumb.
`protected Dimension`	`getMinimumThumbSize()`	Returns the smallest acceptable size for the thumb.
`Dimension`	`getPreferredSize(JComponent c)`	A vertical scrollbar's preferred width is the maximum of preferred widths of the (non `null`) increment/decrement buttons, and the minimum width of the thumb.
`boolean`	`getSupportsAbsolutePositioning()`	Indicates whether the user can absolutely position the thumb with a mouse gesture (usually the middle mouse button).
`protected Rectangle`	`getThumbBounds()`	Return the current size/location of the thumb.
`protected Rectangle`	`getTrackBounds()`	Returns the current bounds of the track, i.e. the space in between the increment and decrement buttons, less the insets.
`protected void`	`installComponents()`	Installs the components.
`protected void`	`installDefaults()`	Installs the defaults.
`protected void`	`installKeyboardActions()`	Installs the keyboard actions.
`protected void`	`installListeners()`	Installs the listeners.
`void`	`installUI(JComponent c)`	Installs the UI.
`boolean`	`isThumbRollover()`	Returns true if the mouse is currently over the thumb.
`protected void`	`layoutHScrollbar(JScrollBar sb)`	Laysouts a vertical scroll bar.
`protected void`	`layoutVScrollbar(JScrollBar sb)`	Laysouts a vertical scroll bar.
`protected void`	`paintDecreaseHighlight(Graphics g)`	Paints the decrease highlight.
`protected void`	`paintIncreaseHighlight(Graphics g)`	Paints the increase highlight.
`protected void`	`paintThumb(Graphics g, JComponent c, Rectangle thumbBounds)`	Paints the thumb.
`protected void`	`paintTrack(Graphics g, JComponent c, Rectangle trackBounds)`	Paints the track.
`protected void`	`scrollByBlock(int direction)`	Scrolls by block.
`protected void`	`scrollByUnit(int direction)`	Scrolls by unit.
`protected void`	`setThumbBounds(int x, int y, int width, int height)`	Set the bounds of the thumb and force a repaint that includes the old thumbBounds and the new one.
`protected void`	`setThumbRollover(boolean active)`	Sets whether or not the mouse is currently over the thumb.
`protected void`	`uninstallComponents()`	Uninstalls the components.
`protected void`	`uninstallDefaults()`	Uninstalls the defaults.
`protected void`	`uninstallKeyboardActions()`	Uninstalls the keyboard actions.
`protected void`	`uninstallListeners()`	Uninstall the listeners.
`void`	`uninstallUI(JComponent c)`	Uninstalls the UI.

Methods declared in class javax.swing.plaf.ComponentUI
contains, getAccessibleChild, getAccessibleChildrenCount, getBaseline, getBaselineResizeBehavior, getMinimumSize, paint, update

Methods declared in interface java.awt.LayoutManager
addLayoutComponent, layoutContainer, minimumLayoutSize, preferredLayoutSize, removeLayoutComponent

Methods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - minimumThumbSize
```
protected Dimension minimumThumbSize
```
    Minimum thumb size
  - maximumThumbSize
```
protected Dimension maximumThumbSize
```
    Maximum thumb size
  - thumbHighlightColor
```
protected Color thumbHighlightColor
```
    Thumb highlight color
  - thumbLightShadowColor
```
protected Color thumbLightShadowColor
```
    Thumb light shadow color
  - thumbDarkShadowColor
```
protected Color thumbDarkShadowColor
```
    Thumb dark shadow color
  - thumbColor
```
protected Color thumbColor
```
    Thumb color
  - trackColor
```
protected Color trackColor
```
    Track color
  - trackHighlightColor
```
protected Color trackHighlightColor
```
    Track highlight color
  - scrollbar
```
protected JScrollBar scrollbar
```
    Scrollbar
  - incrButton
```
protected JButton incrButton
```
    Increment button
  - decrButton
```
protected JButton decrButton
```
    Decrement button
  - isDragging
```
protected boolean isDragging
```
    Dragging
  - trackListener
```
protected BasicScrollBarUI.TrackListener trackListener
```
    Track listener
  - buttonListener
```
protected BasicScrollBarUI.ArrowButtonListener buttonListener
```
    Button listener
  - modelListener
```
protected BasicScrollBarUI.ModelListener modelListener
```
    Model listener
  - thumbRect
```
protected Rectangle thumbRect
```
    Thumb rectangle
  - trackRect
```
protected Rectangle trackRect
```
    Track rectangle
  - trackHighlight
```
protected int trackHighlight
```
    Track highlight
  - NO_HIGHLIGHT
```
protected static final int NO_HIGHLIGHT
```
    No highlight
    
    See Also:
    
    Constant Field Values
  - DECREASE_HIGHLIGHT
```
protected static final int DECREASE_HIGHLIGHT
```
    Decrease highlight
    
    See Also:
    
    Constant Field Values
  - INCREASE_HIGHLIGHT
```
protected static final int INCREASE_HIGHLIGHT
```
    Increase highlight
    
    See Also:
    
    Constant Field Values
  - scrollListener
```
protected BasicScrollBarUI.ScrollListener scrollListener
```
    Scroll listener
  - propertyChangeListener
```
protected PropertyChangeListener propertyChangeListener
```
    Property change listener
  - scrollTimer
```
protected Timer scrollTimer
```
    Scroll timer
  - scrollBarWidth
```
protected int scrollBarWidth
```
    Hint as to what width (when vertical) or height (when horizontal) should be.
    
    Since:
    
    1.7
  - incrGap
```
protected int incrGap
```
    Distance between the increment button and the track. This may be a negative number. If negative, then an overlap between the button and track will occur, which is useful for shaped buttons.
    
    Since:
    
    1.7
  - decrGap
```
protected int decrGap
```
    Distance between the decrement button and the track. This may be a negative number. If negative, then an overlap between the button and track will occur, which is useful for shaped buttons.
    
    Since:
    
    1.7
- Constructor Detail
  - BasicScrollBarUI
```
public BasicScrollBarUI()
```
- Method Detail
  - createUI
```
public static ComponentUI createUI(JComponent c)
```
    Creates the UI.
    
    Parameters:
    
    c - the component
    
    Returns:
    
    the UI
  - configureScrollBarColors
```
protected void configureScrollBarColors()
```
    Configures the scroll bar colors.
  - installUI
```
public void installUI(JComponent c)
```
    Installs the UI.
    
    Overrides:
    
    installUI in class ComponentUI
    
    Parameters:
    
    c - the component
    
    See Also:
    
    ComponentUI.uninstallUI(javax.swing.JComponent), JComponent.setUI(javax.swing.plaf.ComponentUI), JComponent.updateUI()
  - uninstallUI
```
public void uninstallUI(JComponent c)
```
    Uninstalls the UI.
    
    Overrides:
    
    uninstallUI in class ComponentUI
    
    Parameters:
    
    c - the component
    
    See Also:
    
    ComponentUI.installUI(javax.swing.JComponent), JComponent.updateUI()
  - installDefaults
```
protected void installDefaults()
```
    Installs the defaults.
  - installComponents
```
protected void installComponents()
```
    Installs the components.
  - uninstallComponents
```
protected void uninstallComponents()
```
    Uninstalls the components.
  - installListeners
```
protected void installListeners()
```
    Installs the listeners.
  - installKeyboardActions
```
protected void installKeyboardActions()
```
    Installs the keyboard actions.
  - uninstallKeyboardActions
```
protected void uninstallKeyboardActions()
```
    Uninstalls the keyboard actions.
  - uninstallListeners
```
protected void uninstallListeners()
```
    Uninstall the listeners.
  - uninstallDefaults
```
protected void uninstallDefaults()
```
    Uninstalls the defaults.
  - createTrackListener
```
protected BasicScrollBarUI.TrackListener createTrackListener()
```
    Creates a track listener.
    
    Returns:
    
    a track listener
  - createArrowButtonListener
```
protected BasicScrollBarUI.ArrowButtonListener createArrowButtonListener()
```
    Creates an arrow button listener.
    
    Returns:
    
    an arrow button listener
  - createModelListener
```
protected BasicScrollBarUI.ModelListener createModelListener()
```
    Creates a model listener.
    
    Returns:
    
    a model listener
  - createScrollListener
```
protected BasicScrollBarUI.ScrollListener createScrollListener()
```
    Creates a scroll listener.
    
    Returns:
    
    a scroll listener
  - createPropertyChangeListener
```
protected PropertyChangeListener createPropertyChangeListener()
```
    Creates a property change listener.
    
    Returns:
    
    a property change listener
  - setThumbRollover
```
protected void setThumbRollover(boolean active)
```
    Sets whether or not the mouse is currently over the thumb.
    
    Parameters:
    
    active - True indicates the thumb is currently active.
    
    Since:
    
    1.5
  - isThumbRollover
```
public boolean isThumbRollover()
```
    Returns true if the mouse is currently over the thumb.
    
    Returns:
    
    true if the thumb is currently active
    
    Since:
    
    1.5
  - getPreferredSize
```
public Dimension getPreferredSize(JComponent c)
```
    A vertical scrollbar's preferred width is the maximum of preferred widths of the (non null) increment/decrement buttons, and the minimum width of the thumb. The preferred height is the sum of the preferred heights of the same parts. The basis for the preferred size of a horizontal scrollbar is similar.
    The preferredSize is only computed once, subsequent calls to this method just return a cached size.
    
    Overrides:
    
    getPreferredSize in class ComponentUI
    
    Parameters:
    
    c - the JScrollBar that's delegating this method to us
    
    Returns:
    
    the preferred size of a Basic JScrollBar
    
    See Also:
    
    getMaximumSize(javax.swing.JComponent), ComponentUI.getMinimumSize(javax.swing.JComponent)
  - getMaximumSize
```
public Dimension getMaximumSize(JComponent c)
```
    Description copied from class: ComponentUI
    
    Returns the specified component's maximum size appropriate for the look and feel. If null is returned, the maximum size will be calculated by the component's layout manager instead (this is the preferred approach for any component with a specific layout manager installed). The default implementation of this method invokes getPreferredSize and returns that value.
    
    Overrides:
    
    getMaximumSize in class ComponentUI
    
    Parameters:
    
    c - The JScrollBar that's delegating this method to us.
    
    Returns:
    
    new Dimension(Integer.MAX_VALUE, Integer.MAX_VALUE);
    
    See Also:
    
    ComponentUI.getMinimumSize(javax.swing.JComponent), getPreferredSize(javax.swing.JComponent)
  - createDecreaseButton
```
protected JButton createDecreaseButton(int orientation)
```
    Creates a decrease button.
    
    Parameters:
    
    orientation - the orientation
    
    Returns:
    
    a decrease button
  - createIncreaseButton
```
protected JButton createIncreaseButton(int orientation)
```
    Creates an increase button.
    
    Parameters:
    
    orientation - the orientation
    
    Returns:
    
    an increase button
  - paintDecreaseHighlight
```
protected void paintDecreaseHighlight(Graphics g)
```
    Paints the decrease highlight.
    
    Parameters:
    
    g - the graphics
  - paintIncreaseHighlight
```
protected void paintIncreaseHighlight(Graphics g)
```
    Paints the increase highlight.
    
    Parameters:
    
    g - the graphics
  - paintTrack
```
protected void paintTrack(Graphics g,
                          JComponent c,
                          Rectangle trackBounds)
```
    Paints the track.
    
    Parameters:
    
    g - the graphics
    
    c - the component
    
    trackBounds - the track bounds
  - paintThumb
```
protected void paintThumb(Graphics g,
                          JComponent c,
                          Rectangle thumbBounds)
```
    Paints the thumb.
    
    Parameters:
    
    g - the graphics
    
    c - the component
    
    thumbBounds - the thumb bounds
  - getMinimumThumbSize
```
protected Dimension getMinimumThumbSize()
```
    Returns the smallest acceptable size for the thumb. If the scrollbar becomes so small that this size isn't available, the thumb will be hidden.
    Warning : the value returned by this method should not be be modified, it's a shared static constant.
    
    Returns:
    
    The smallest acceptable size for the thumb.
    
    See Also:
    
    getMaximumThumbSize()
  - getMaximumThumbSize
```
protected Dimension getMaximumThumbSize()
```
    Returns the largest acceptable size for the thumb. To create a fixed size thumb one make this method and getMinimumThumbSize return the same value.
    Warning : the value returned by this method should not be be modified, it's a shared static constant.
    
    Returns:
    
    The largest acceptable size for the thumb.
    
    See Also:
    
    getMinimumThumbSize()
  - layoutVScrollbar
```
protected void layoutVScrollbar(JScrollBar sb)
```
    Laysouts a vertical scroll bar.
    
    Parameters:
    
    sb - the scroll bar
  - layoutHScrollbar
```
protected void layoutHScrollbar(JScrollBar sb)
```
    Laysouts a vertical scroll bar.
    
    Parameters:
    
    sb - the scroll bar
  - setThumbBounds
```
protected void setThumbBounds(int x,
                              int y,
                              int width,
                              int height)
```
    Set the bounds of the thumb and force a repaint that includes the old thumbBounds and the new one.
    
    Parameters:
    
    x - set the x location of the thumb
    
    y - set the y location of the thumb
    
    width - set the width of the thumb
    
    height - set the height of the thumb
    
    See Also:
    
    getThumbBounds()
  - getThumbBounds
```
protected Rectangle getThumbBounds()
```
    Return the current size/location of the thumb.
    Warning : the value returned by this method should not be be modified, it's a reference to the actual rectangle, not a copy.
    
    Returns:
    
    The current size/location of the thumb.
    
    See Also:
    
    setThumbBounds(int, int, int, int)
  - getTrackBounds
```
protected Rectangle getTrackBounds()
```
    Returns the current bounds of the track, i.e. the space in between the increment and decrement buttons, less the insets. The value returned by this method is updated each time the scrollbar is laid out (validated).
    Warning : the value returned by this method should not be be modified, it's a reference to the actual rectangle, not a copy.
    
    Returns:
    
    the current bounds of the scrollbar track
    
    See Also:
    
    LayoutManager.layoutContainer(java.awt.Container)
  - scrollByBlock
```
protected void scrollByBlock(int direction)
```
    Scrolls by block.
    
    Parameters:
    
    direction - the direction to scroll
  - scrollByUnit
```
protected void scrollByUnit(int direction)
```
    Scrolls by unit.
    
    Parameters:
    
    direction - the direction to scroll
  - getSupportsAbsolutePositioning
```
public boolean getSupportsAbsolutePositioning()
```
    Indicates whether the user can absolutely position the thumb with a mouse gesture (usually the middle mouse button).
    
    Returns:
    
    true if a mouse gesture can absolutely position the thumb
    
    Since:
    
    1.5

Class BasicScrollBarUI

Nested Class Summary

Field Summary

Fields declared in interface javax.swing.SwingConstants

Constructor Summary

Method Summary

Methods declared in class javax.swing.plaf.ComponentUI

Methods declared in interface java.awt.LayoutManager

Methods declared in class java.lang.Object

Field Detail

minimumThumbSize

maximumThumbSize

thumbHighlightColor

thumbLightShadowColor

thumbDarkShadowColor

thumbColor

trackColor

trackHighlightColor

scrollbar

incrButton

decrButton

isDragging

trackListener

buttonListener

modelListener

thumbRect

trackRect

trackHighlight

NO_HIGHLIGHT

DECREASE_HIGHLIGHT

INCREASE_HIGHLIGHT

scrollListener

propertyChangeListener

scrollTimer

scrollBarWidth

incrGap

decrGap

Constructor Detail

BasicScrollBarUI

Method Detail

createUI

configureScrollBarColors

installUI

uninstallUI

installDefaults

installComponents

uninstallComponents

installListeners

installKeyboardActions

uninstallKeyboardActions

uninstallListeners

uninstallDefaults

createTrackListener

createArrowButtonListener

createModelListener

createScrollListener

createPropertyChangeListener

setThumbRollover

isThumbRollover

getPreferredSize

getMaximumSize

createDecreaseButton

createIncreaseButton

paintDecreaseHighlight

paintIncreaseHighlight

paintTrack

paintThumb

getMinimumThumbSize

getMaximumThumbSize

layoutVScrollbar

layoutHScrollbar

setThumbBounds

getThumbBounds

getTrackBounds

scrollByBlock

scrollByUnit

getSupportsAbsolutePositioning