javax.swing
Class JSlider

java.lang.Object
  java.awt.Component
      java.awt.Container
          javax.swing.JComponent
              javax.swing.JSlider

All Implemented Interfaces:

java.awt.image.ImageObserver, java.io.Serializable, SwingConstants

public class JSlider

extends JComponent

implements SwingConstants

A component that lets the user graphically select a value by sliding a knob within a bounded interval. The slider can show both major tick marks and minor tick marks between them. The number of values between the tick marks is controlled with setMajorTickSpacing and setMinorTickSpacing.

For further information and examples see How to Use Sliders, a section in The Java Tutorial.

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

Field Summary

protected ChangeEvent	changeEvent Only one ChangeEvent is needed per slider instance since the event's only (read-only) state is the source property.
protected ChangeListener	changeListener The changeListener (no suffix) is the listener we add to the Sliders model.
protected int	majorTickSpacing The number of values between the major tick marks -- the larger marks that break up the minor tick marks.
protected int	minorTickSpacing The number of values between the minor tick marks -- the smaller marks that occur between the major tick marks.
protected int	orientation
protected BoundedRangeModel	sliderModel The data model that handles the numeric maximum value, minimum value, and current-position value for the slider.
protected boolean	snapToTicks If true, the knob (and the data value it represents) resolve to the closest tick mark next to where the user positioned the knob.

Fields inherited from class javax.swing.JComponent

listenerList, TOOL_TIP_TEXT_KEY, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW

Fields inherited from class java.awt.Component

BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Fields inherited from 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

Fields inherited from interface java.awt.image.ImageObserver

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

Constructor Summary

JSlider()
Creates a horizontal slider with the range 0 to 100 and an initial value of 50.

JSlider(BoundedRangeModel brm)
Creates a horizontal slider using the specified BoundedRangeModel.

JSlider(int orientation)
Creates a slider using the specified orientation with the range 0 to 100 and an initial value of 50.

JSlider(int min, int max)
Creates a horizontal slider using the specified min and max with an initial value equal to the average of the min plus max.

JSlider(int min, int max, int value)
Creates a horizontal slider using the specified min, max and value.

JSlider(int orientation, int min, int max, int value)
Creates a slider with the specified orientation and the specified minimum, maximum, and initial values.

Method Summary

void	addChangeListener(ChangeListener l) Adds a ChangeListener to the slider.
protected ChangeListener	createChangeListener() Subclasses that want to handle model ChangeEvents differently can override this method to return their own ChangeListener implementation.
java.util.Hashtable	createStandardLabels(int increment) Creates a hashtable that will draw text labels starting at the slider minimum using the increment specified.
java.util.Hashtable	createStandardLabels(int increment, int start) Creates a hashtable that will draw text labels starting at the start point specified using the increment specified.
protected void	fireStateChanged() Send a ChangeEvent, whose source is this Slider, to each listener.
ChangeListener[]	getChangeListeners() Returns an array of all the ChangeListeners added to this JSlider with addChangeListener().
int	getExtent() Returns the "extent" -- the range of values "covered" by the knob.
boolean	getInverted() Returns true if the value-range shown for the slider is reversed,
java.util.Dictionary	getLabelTable() Returns the dictionary of what labels to draw at which values.
int	getMajorTickSpacing() This method returns the major tick spacing.
int	getMaximum() Returns the maximum value supported by the slider.
int	getMinimum() Returns the minimum value supported by the slider.
int	getMinorTickSpacing() This method returns the minor tick spacing.
BoundedRangeModel	getModel() Returns data model that handles the sliders three fundamental properties: minimum, maximum, value.
int	getOrientation() Return this slider's vertical or horizontal orientation.
boolean	getPaintLabels() Tells if labels are to be painted.
boolean	getPaintTicks() Tells if tick marks are to be painted.
boolean	getPaintTrack() Tells if the track (area the slider slides in) is to be painted.
boolean	getSnapToTicks() Returns true if the knob (and the data value it represents) resolve to the closest tick mark next to where the user positioned the knob.
int	getValue() Returns the sliders value.
boolean	getValueIsAdjusting() True if the slider knob is being dragged.
void	paint(java.awt.Graphics g) Invoked by Swing to draw components.
protected void	paintBorder(java.awt.Graphics g) Paints the component's border.
protected void	paintComponent(java.awt.Graphics g) Calls the UI delegate's paint method, if the UI delegate is non-null.
void	paintComponents(java.awt.Graphics g)
protected java.lang.String	paramString() Returns a string representation of this JSlider.
protected void	printBorder(java.awt.Graphics g) Prints the component's border.
protected void	printComponent(java.awt.Graphics g) This is invoked during a printing operation.
void	printComponents(java.awt.Graphics g)
void	removeChangeListener(ChangeListener l) Removes a ChangeListener from the slider.
void	setExtent(int extent) Sets the size of the range "covered" by the knob.
void	setInverted(boolean b) Specify true to reverse the value-range shown for the slider and false to put the value range in the normal order.
void	setLabelTable(java.util.Dictionary labels) Used to specify what label will be drawn at any given value.
void	setMajorTickSpacing(int n) This method sets the major tick spacing.
void	setMaximum(int maximum) Sets the models maximum property.
void	setMinimum(int minimum) Sets the models minimum property.
void	setMinorTickSpacing(int n) This method sets the minor tick spacing.
void	setModel(BoundedRangeModel newModel) Sets the model that handles the sliders three fundamental properties: minimum, maximum, value.
void	setOrientation(int orientation) Set the scrollbars orientation to either VERTICAL or HORIZONTAL.
void	setPaintLabels(boolean b) Determines whether labels are painted on the slider.
void	setPaintTicks(boolean b) Determines whether tick marks are painted on the slider.
void	setPaintTrack(boolean b) Determines whether the track is painted on the slider.
void	setSnapToTicks(boolean b) Specifying true makes the knob (and the data value it represents) resolve to the closest tick mark next to where the user positioned the knob.
void	setValue(int n) Sets the sliders current value.
void	setValueIsAdjusting(boolean b) Sets the models valueIsAdjusting property.

Methods inherited from class javax.swing.JComponent

addAncestorListener, addNotify, addPropertyChangeListener, addPropertyChangeListener, addVetoableChangeListener, computeVisibleRect, contains, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getAlignmentX, getAlignmentY, getAncestorListeners, getAutoscrolls, getBorder, getBounds, getClientProperty, getComponentGraphics, getConditionForKeyStroke, getDefaultLocale, getGraphics, getHeight, getInputMap, getInputMap, getInputVerifier, getInsets, getInsets, getListeners, getLocation, getMaximumSize, getMinimumSize, getPreferredSize, getPropertyChangeListeners, getPropertyChangeListeners, getRegisteredKeyStrokes, getSize, getToolTipText, getVerifyInputWhenFocusTarget, getVetoableChangeListeners, getVisibleRect, getWidth, getX, getY, isDoubleBuffered, isMaximumSizeSet, isMinimumSizeSet, isOpaque, isOptimizedDrawingEnabled, isPaintingTile, isPreferredSizeSet, isRequestFocusEnabled, isValidateRoot, paintChildren, paintImmediately, paintImmediately, print, printAll, printChildren, processComponentKeyEvent, processKeyBinding, processKeyEvent, processMouseMotionEvent, putClientProperty, registerKeyboardAction, registerKeyboardAction, removeAncestorListener, removeNotify, removePropertyChangeListener, removePropertyChangeListener, removeVetoableChangeListener, repaint, repaint, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, resetKeyboardActions, reshape, revalidate, scrollRectToVisible, setActionMap, setAlignmentX, setAlignmentY, setAutoscrolls, setBackground, setBorder, setDefaultLocale, setDoubleBuffered, setEnabled, setFont, setForeground, setInputMap, setInputVerifier, setMaximumSize, setMinimumSize, setOpaque, setPreferredSize, setRequestFocusEnabled, setToolTipText, setVerifyInputWhenFocusTarget, setVisible, unregisterKeyboardAction, update

Methods inherited from class java.awt.Container

add, add, add, add, add, addContainerListener, addImpl, areFocusTraversalKeysSet, doLayout, findComponentAt, findComponentAt, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getContainerListeners, getFocusTraversalKeys, getFocusTraversalPolicy, getLayout, invalidate, isAncestorOf, isFocusCycleRoot, isFocusCycleRoot, isFocusTraversalPolicySet, list, list, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, setFocusCycleRoot, setFocusTraversalKeys, setFocusTraversalPolicy, setLayout, transferFocusBackward, transferFocusDownCycle, validate, validateTree

Methods inherited from class java.awt.Component

addComponentListener, addFocusListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, checkImage, checkImage, coalesceEvents, contains, createImage, createImage, createVolatileImage, createVolatileImage, disableEvents, dispatchEvent, enableEvents, enableInputMethods, getBackground, getBounds, getColorModel, getComponentListeners, getCursor, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphicsConfiguration, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocale, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMouseWheelListeners, getName, getParent, getSize, getToolkit, getTreeLock, hasFocus, imageUpdate, isBackgroundSet, isCursorSet, isDisplayable, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isShowing, isValid, isVisible, list, list, list, paintAll, prepareImage, prepareImage, processComponentEvent, processFocusEvent, processInputMethodEvent, processMouseEvent, processMouseWheelEvent, removeComponentListener, removeFocusListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, repaint, repaint, repaint, setBounds, setBounds, setCursor, setFocusable, setFocusTraversalKeysEnabled, setIgnoreRepaint, setLocale, setLocation, setLocation, setName, setSize, setSize, toString, transferFocus, transferFocusUpCycle

Methods inherited from class java.lang.Object

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

Field Detail

sliderModel

protected BoundedRangeModel sliderModel

The data model that handles the numeric maximum value, minimum value, and current-position value for the slider.

majorTickSpacing

protected int majorTickSpacing

The number of values between the major tick marks -- the larger marks that break up the minor tick marks.

minorTickSpacing

protected int minorTickSpacing

The number of values between the minor tick marks -- the smaller marks that occur between the major tick marks.

See Also:

setMinorTickSpacing(int)

snapToTicks

protected boolean snapToTicks

If true, the knob (and the data value it represents) resolve to the closest tick mark next to where the user positioned the knob. The default is false.

See Also:

setSnapToTicks(boolean)

orientation

protected int orientation

See Also:

setOrientation(int)

changeListener

protected ChangeListener changeListener

The changeListener (no suffix) is the listener we add to the Sliders model. By default this listener just forwards events to ChangeListeners (if any) added directly to the slider.

See Also:

addChangeListener(javax.swing.event.ChangeListener), createChangeListener()

changeEvent

protected transient ChangeEvent changeEvent

Only one ChangeEvent is needed per slider instance since the event's only (read-only) state is the source property. The source of events generated here is always "this". The event is lazily created the first time that an event notification is fired.

See Also:

fireStateChanged()

Constructor Detail

JSlider

public JSlider()

Creates a horizontal slider with the range 0 to 100 and an initial value of 50.

JSlider

public JSlider(int orientation)

Creates a slider using the specified orientation with the range 0 to 100 and an initial value of 50.

JSlider

public JSlider(int min,
               int max)

Creates a horizontal slider using the specified min and max with an initial value equal to the average of the min plus max.

JSlider

public JSlider(int min,
               int max,
               int value)

Creates a horizontal slider using the specified min, max and value.

JSlider

public JSlider(int orientation,
               int min,
               int max,
               int value)

Creates a slider with the specified orientation and the specified minimum, maximum, and initial values.

Throws:

java.lang.IllegalArgumentException - if orientation is not one of VERTICAL, HORIZONTAL

See Also:

setOrientation(int), setMinimum(int), setMaximum(int), setValue(int)

JSlider

public JSlider(BoundedRangeModel brm)

Creates a horizontal slider using the specified BoundedRangeModel.

Method Detail

paint

public final void paint(java.awt.Graphics g)

Description copied from class: JComponent

Invoked by Swing to draw components. Applications should not invoke paint directly, but should instead use the repaint method to schedule the component for redrawing.

This method actually delegates the work of painting to three protected methods: paintComponent, paintBorder, and paintChildren. They're called in the order listed to ensure that children appear on top of component itself. Generally speaking, the component and its children should not paint in the insets area allocated to the border. Subclasses can just override this method, as always.

Overrides:

paint in class JComponent

Parameters:

g - the Graphics context in which to paint

See Also:

JComponent.paintBorder(java.awt.Graphics), JComponent.paintChildren(java.awt.Graphics), JComponent.getComponentGraphics(java.awt.Graphics), JComponent.repaint(long, int, int, int, int)

createChangeListener

protected ChangeListener createChangeListener()

Subclasses that want to handle model ChangeEvents differently can override this method to return their own ChangeListener implementation. The default ChangeListener just forwards ChangeEvents to the ChangeListeners added directly to the slider.

See Also:

fireStateChanged()

addChangeListener

public void addChangeListener(ChangeListener l)

Adds a ChangeListener to the slider.

Parameters:

l - the ChangeListener to add

See Also:

fireStateChanged(), removeChangeListener(javax.swing.event.ChangeListener)

removeChangeListener

public void removeChangeListener(ChangeListener l)

Removes a ChangeListener from the slider.

Parameters:

l - the ChangeListener to remove

See Also:

fireStateChanged(), addChangeListener(javax.swing.event.ChangeListener)

getChangeListeners

public ChangeListener[] getChangeListeners()

Returns an array of all the ChangeListeners added to this JSlider with addChangeListener().

Returns:

all of the ChangeListeners added or an empty array if no listeners have been added

Since:

1.4

fireStateChanged

protected void fireStateChanged()

Send a ChangeEvent, whose source is this Slider, to each listener. This method method is called each time a ChangeEvent is received from the model.

See Also:

addChangeListener(javax.swing.event.ChangeListener), EventListenerList

getModel

public BoundedRangeModel getModel()

Returns data model that handles the sliders three fundamental properties: minimum, maximum, value.

See Also:

setModel(javax.swing.BoundedRangeModel)

setModel

public void setModel(BoundedRangeModel newModel)

Sets the model that handles the sliders three fundamental properties: minimum, maximum, value.

See Also:

getModel()

getValue

public int getValue()

Returns the sliders value.

Returns:

the models value property

See Also:

setValue(int)

setValue

public void setValue(int n)

Sets the sliders current value. This method just forwards the value to the model.

See Also:

getValue()

getMinimum

public int getMinimum()

Returns the minimum value supported by the slider.

Returns:

the value of the models minimum property

See Also:

setMinimum(int)

setMinimum

public void setMinimum(int minimum)

Sets the models minimum property.

See Also:

getMinimum(), BoundedRangeModel.setMinimum(int)

getMaximum

public int getMaximum()

Returns the maximum value supported by the slider.

Returns:

the value of the models maximum property

See Also:

setMaximum(int)

setMaximum

public void setMaximum(int maximum)

Sets the models maximum property.

See Also:

getMaximum(), BoundedRangeModel.setMaximum(int)

getValueIsAdjusting

public boolean getValueIsAdjusting()

True if the slider knob is being dragged.

Returns:

the value of the models valueIsAdjusting property

See Also:

setValueIsAdjusting(boolean)

setValueIsAdjusting

public void setValueIsAdjusting(boolean b)

Sets the models valueIsAdjusting property. Slider look and feel implementations should set this property to true when a knob drag begins, and to false when the drag ends. The slider model will not generate ChangeEvents while valueIsAdjusting is true.

See Also:

getValueIsAdjusting(), BoundedRangeModel.setValueIsAdjusting(boolean)

getExtent

public int getExtent()

Returns the "extent" -- the range of values "covered" by the knob.

Returns:

an int representing the extent

See Also:

setExtent(int), BoundedRangeModel.getExtent()

setExtent

public void setExtent(int extent)

Sets the size of the range "covered" by the knob. Most look and feel implementations will change the value by this amount if the user clicks on either side of the knob.

See Also:

getExtent(), BoundedRangeModel.setExtent(int)

getOrientation

public int getOrientation()

Return this slider's vertical or horizontal orientation.

Returns:

VERTICAL or HORIZONTAL

See Also:

setOrientation(int)

setOrientation

public void setOrientation(int orientation)

Set the scrollbars orientation to either VERTICAL or HORIZONTAL.

Throws:

java.lang.IllegalArgumentException - if orientation is not one of VERTICAL, HORIZONTAL

See Also:

getOrientation()

getLabelTable

public java.util.Dictionary getLabelTable()

Returns the dictionary of what labels to draw at which values.

Returns:

the Dictionary containing labels and where to draw them

setLabelTable

public void setLabelTable(java.util.Dictionary labels)

Used to specify what label will be drawn at any given value. The key-value pairs are of this format: { Integer value, java.swing.JComponent label }.

See Also:

createStandardLabels(int), getLabelTable()

createStandardLabels

public java.util.Hashtable createStandardLabels(int increment)

Creates a hashtable that will draw text labels starting at the slider minimum using the increment specified. If you call createStandardLabels( 10 ) and the slider minimum is zero, then it will make labels for the values 0, 10, 20, 30, and so on.

See Also:

setLabelTable(java.util.Dictionary)

createStandardLabels

public java.util.Hashtable createStandardLabels(int increment,
                                                int start)

Creates a hashtable that will draw text labels starting at the start point specified using the increment specified. If you call createStandardLabels( 10, 2 ), then it will make labels for the values 2, 12, 22, 32, and so on.

Throws:

java.lang.IllegalArgumentException - if slider label start point out of range or if label increment is less than or equal to zero

See Also:

setLabelTable(java.util.Dictionary)

getInverted

public boolean getInverted()

Returns true if the value-range shown for the slider is reversed,

Returns:

true if the slider values are reversed from their normal order

See Also:

setInverted(boolean)

setInverted

public void setInverted(boolean b)

Specify true to reverse the value-range shown for the slider and false to put the value range in the normal order. Normal vertical sliders have their maximum on the top. These labels are reversed when the slider is inverted.

Parameters:

b - true to reverse the slider values from their normal order

getMajorTickSpacing

public int getMajorTickSpacing()

This method returns the major tick spacing. The number that is returned represents the distance, measured in values, between each major tick mark. If you have a slider with a range from 0 to 50 and the major tick spacing is set to 10, you will get major ticks next to the following values: 0, 10, 20, 30, 40, 50.

Returns:

the number of values between major ticks

See Also:

setMajorTickSpacing(int)

setMajorTickSpacing

public void setMajorTickSpacing(int n)

This method sets the major tick spacing. The number that is passed-in represents the distance, measured in values, between each major tick mark. If you have a slider with a range from 0 to 50 and the major tick spacing is set to 10, you will get major ticks next to the following values: 0, 10, 20, 30, 40, 50.

See Also:

getMajorTickSpacing()

getMinorTickSpacing

public int getMinorTickSpacing()

This method returns the minor tick spacing. The number that is returned represents the distance, measured in values, between each minor tick mark. If you have a slider with a range from 0 to 50 and the minor tick spacing is set to 10, you will get minor ticks next to the following values: 0, 10, 20, 30, 40, 50.

Returns:

the number of values between minor ticks

See Also:

getMinorTickSpacing()

setMinorTickSpacing

public void setMinorTickSpacing(int n)

This method sets the minor tick spacing. The number that is passed-in represents the distance, measured in values, between each minor tick mark. If you have a slider with a range from 0 to 50 and the minor tick spacing is set to 10, you will get minor ticks next to the following values: 0, 10, 20, 30, 40, 50.

See Also:

getMinorTickSpacing()

getSnapToTicks

public boolean getSnapToTicks()

Returns true if the knob (and the data value it represents) resolve to the closest tick mark next to where the user positioned the knob.

Returns:

true if the value snaps to the nearest tick mark, else false

See Also:

setSnapToTicks(boolean)

setSnapToTicks

public void setSnapToTicks(boolean b)

Specifying true makes the knob (and the data value it represents) resolve to the closest tick mark next to where the user positioned the knob.

Parameters:

b - true to snap the knob to the nearest tick mark

See Also:

getSnapToTicks()

getPaintTicks

public boolean getPaintTicks()

Tells if tick marks are to be painted.

Returns:

true if tick marks are painted, else false

See Also:

setPaintTicks(boolean)

setPaintTicks

public void setPaintTicks(boolean b)

Determines whether tick marks are painted on the slider.

See Also:

getPaintTicks()

getPaintTrack

public boolean getPaintTrack()

Tells if the track (area the slider slides in) is to be painted.

Returns:

true if track is painted, else false

See Also:

setPaintTrack(boolean)

setPaintTrack

public void setPaintTrack(boolean b)

Determines whether the track is painted on the slider.

See Also:

getPaintTrack()

getPaintLabels

public boolean getPaintLabels()

Tells if labels are to be painted.

Returns:

true if labels are painted, else false

See Also:

setPaintLabels(boolean)

setPaintLabels

public void setPaintLabels(boolean b)

Determines whether labels are painted on the slider.

See Also:

getPaintLabels()

paramString

protected java.lang.String paramString()

Returns a string representation of this JSlider. 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 JSlider.

paintComponent

protected final void paintComponent(java.awt.Graphics g)

Description copied from class: JComponent

Calls the UI delegate's paint method, if the UI delegate is non-null. We pass the delegate a copy of the Graphics object to protect the rest of the paint code from irrevocable changes (for example, Graphics.translate).

Overrides:

paintComponent in class JComponent

Parameters:

g - the Graphics object to protect

See Also:

JComponent.paint(java.awt.Graphics), ComponentUI

paintBorder

protected final void paintBorder(java.awt.Graphics g)

Description copied from class: JComponent

Paints the component's border.

Overrides:

paintBorder in class JComponent

Parameters:

g - the Graphics context in which to paint

See Also:

JComponent.paint(java.awt.Graphics), JComponent.setBorder(javax.swing.border.Border)

paintComponents

public final void paintComponents(java.awt.Graphics g)

printComponent

protected final void printComponent(java.awt.Graphics g)

Description copied from class: JComponent

This is invoked during a printing operation. This is implemented to invoke paintComponent on the component.

Overrides:

printComponent in class JComponent

Parameters:

g - the Graphics context in which to paint

See Also:

JComponent.print(java.awt.Graphics)

printBorder

protected final void printBorder(java.awt.Graphics g)

Description copied from class: JComponent

Prints the component's border. This is implemented to invoke paintBorder on the component.

Overrides:

printBorder in class JComponent

Parameters:

g - the Graphics context in which to paint

See Also:

JComponent.print(java.awt.Graphics)

printComponents

public final void printComponents(java.awt.Graphics g)