File	Doc	Category	Size	Date	Package
JSlider.java	API Doc	Java SE 5 API	38091	Fri Aug 26 14:57:56 BST 2005	javax.swing

JSlider

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

Fields Summary
private static final String	uiClassID
private boolean	paintTicks
private boolean	paintTrack
private boolean	paintLabels
private boolean	isInverted
protected BoundedRangeModel	sliderModel The data model that handles the numeric maximum value, minimum value, and current-position value for the slider.
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 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.
boolean	snapToValue If true, the knob (and the data value it represents) resolve to the closest slider value next to where the user positioned the knob.
protected int	orientation
private Dictionary	labelTable
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.
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.

Constructors Summary
public JSlider() Creates a horizontal slider with the range 0 to 100 and an initial value of 50. this(HORIZONTAL, 0, 100, 50);
public JSlider(int orientation) Creates a slider using the specified orientation with the range 0 to 100 and an initial value of 50. this(orientation, 0, 100, 50);
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. this(HORIZONTAL, min, max, (min + max) / 2);
public JSlider(int min, int max, int value) Creates a horizontal slider using the specified min, max and value. this(HORIZONTAL, min, max, value);
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. exception IllegalArgumentException if orientation is not one of VERTICAL, HORIZONTAL see #setOrientation see #setMinimum see #setMaximum see #setValue checkOrientation(orientation); this.orientation = orientation; sliderModel = new DefaultBoundedRangeModel(value, 0, min, max); sliderModel.addChangeListener(changeListener); updateUI();
public JSlider(BoundedRangeModel brm) Creates a horizontal slider using the specified BoundedRangeModel. this.orientation = JSlider.HORIZONTAL; setModel(brm); sliderModel.addChangeListener(changeListener); updateUI();

Methods Summary
public void	addChangeListener(javax.swing.event.ChangeListener l) Adds a ChangeListener to the slider. param l the ChangeListener to add see #fireStateChanged see #removeChangeListener listenerList.add(ChangeListener.class, l);
private void	checkOrientation(int orientation) switch (orientation) { case VERTICAL: case HORIZONTAL: break; default: throw new IllegalArgumentException("orientation must be one of: VERTICAL, HORIZONTAL"); }
protected javax.swing.event.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 #fireStateChanged return new ModelListener();
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 #setLabelTable return createStandardLabels( increment, getMinimum() );
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. see #setLabelTable exception IllegalArgumentException if slider label start point out of range or if label increment is less than or equal to zero if ( start > getMaximum() || start < getMinimum() ) { throw new IllegalArgumentException( "Slider label start point out of range." ); } if ( increment <= 0 ) { throw new IllegalArgumentException( "Label incremement must be > 0" ); } class SmartHashtable extends Hashtable implements PropertyChangeListener { int increment = 0; int start = 0; boolean startAtMin = false; class LabelUIResource extends JLabel implements UIResource { public LabelUIResource( String text, int alignment ) { super( text, alignment ); setName("Slider.label"); } } public SmartHashtable( int increment, int start ) { super(); this.increment = increment; this.start = start; startAtMin = start == getMinimum(); createLabels(); } public void propertyChange( PropertyChangeEvent e ) { if ( e.getPropertyName().equals( "minimum" ) && startAtMin ) { start = getMinimum(); } if ( e.getPropertyName().equals( "minimum" ) || e.getPropertyName().equals( "maximum" ) ) { Enumeration keys = getLabelTable().keys(); Object key = null; Hashtable hashtable = new Hashtable(); // Save the labels that were added by the developer while ( keys.hasMoreElements() ) { key = keys.nextElement(); Object value = getLabelTable().get( key ); if ( !(value instanceof LabelUIResource) ) { hashtable.put( key, value ); } } clear(); createLabels(); // Add the saved labels keys = hashtable.keys(); while ( keys.hasMoreElements() ) { key = keys.nextElement(); put( key, hashtable.get( key ) ); } ((JSlider)e.getSource()).setLabelTable( this ); } } void createLabels() { for ( int labelIndex = start; labelIndex <= getMaximum(); labelIndex += increment ) { put( new Integer( labelIndex ), new LabelUIResource( ""+labelIndex, JLabel.CENTER ) ); } } } SmartHashtable table = new SmartHashtable( increment, start ); if ( getLabelTable() != null && (getLabelTable() instanceof PropertyChangeListener) ) { removePropertyChangeListener( (PropertyChangeListener)getLabelTable() ); } addPropertyChangeListener( table ); return table;
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 #addChangeListener see EventListenerList Object[] listeners = listenerList.getListenerList(); for (int i = listeners.length - 2; i >= 0; i -= 2) { if (listeners[i]==ChangeListener.class) { if (changeEvent == null) { changeEvent = new ChangeEvent(this); } ((ChangeListener)listeners[i+1]).stateChanged(changeEvent); } }
public javax.accessibility.AccessibleContext	getAccessibleContext() Gets the AccessibleContext associated with this JSlider. For sliders, the AccessibleContext takes the form of an AccessibleJSlider. A new AccessibleJSlider instance is created if necessary. return an AccessibleJSlider that serves as the AccessibleContext of this JSlider if (accessibleContext == null) { accessibleContext = new AccessibleJSlider(); } return accessibleContext;
public javax.swing.event.ChangeListener[]	getChangeListeners() Returns an array of all the ChangeListeners added to this JSlider with addChangeListener(). return all of the ChangeListeners added or an empty array if no listeners have been added since 1.4 return (ChangeListener[])listenerList.getListeners( ChangeListener.class);
public int	getExtent() Returns the "extent" -- the range of values "covered" by the knob. return an int representing the extent see #setExtent see BoundedRangeModel#getExtent return getModel().getExtent();
public boolean	getInverted() Returns true if the value-range shown for the slider is reversed, return true if the slider values are reversed from their normal order see #setInverted return isInverted;
public java.util.Dictionary	getLabelTable() Returns the dictionary of what labels to draw at which values. return the Dictionary containing labels and where to draw them /* if ( labelTable == null && getMajorTickSpacing() > 0 ) { setLabelTable( createStandardLabels( getMajorTickSpacing() ) ); } */ return labelTable;
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. return the number of values between major ticks see #setMajorTickSpacing return majorTickSpacing;
public int	getMaximum() Returns the maximum value supported by the slider. return the value of the models maximum property see #setMaximum return getModel().getMaximum();
public int	getMinimum() Returns the minimum value supported by the slider. return the value of the models minimum property see #setMinimum return getModel().getMinimum();
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. return the number of values between minor ticks see #getMinorTickSpacing return minorTickSpacing;
public javax.swing.BoundedRangeModel	getModel() Returns data model that handles the sliders three fundamental properties: minimum, maximum, value. see #setModel return sliderModel;
public int	getOrientation() Return this slider's vertical or horizontal orientation. return VERTICAL or HORIZONTAL see #setOrientation return orientation;
public boolean	getPaintLabels() Tells if labels are to be painted. return true if labels are painted, else false see #setPaintLabels return paintLabels;
public boolean	getPaintTicks() Tells if tick marks are to be painted. return true if tick marks are painted, else false see #setPaintTicks return paintTicks;
public boolean	getPaintTrack() Tells if the track (area the slider slides in) is to be painted. return true if track is painted, else false see #setPaintTrack return paintTrack;
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. return true if the value snaps to the nearest tick mark, else false see #setSnapToTicks return snapToTicks;
boolean	getSnapToValue() Returns true if the knob (and the data value it represents) resolve to the closest slider value next to where the user positioned the knob. return true if the value snaps to the nearest slider value, else false return snapToValue;
public javax.swing.plaf.SliderUI	getUI() Gets the UI object which implements the L&F for this component. return the SliderUI object that implements the Slider L&F return(SliderUI)ui;
public java.lang.String	getUIClassID() Returns the name of the L&F class that renders this component. return "SliderUI" see JComponent#getUIClassID see UIDefaults#getUI return uiClassID;
public int	getValue() Returns the sliders value. return the models value property see #setValue return getModel().getValue();
public boolean	getValueIsAdjusting() True if the slider knob is being dragged. return the value of the models valueIsAdjusting property see #setValueIsAdjusting return getModel().getValueIsAdjusting();
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. return a string representation of this JSlider. String paintTicksString = (paintTicks ? "true" : "false"); String paintTrackString = (paintTrack ? "true" : "false"); String paintLabelsString = (paintLabels ? "true" : "false"); String isInvertedString = (isInverted ? "true" : "false"); String snapToTicksString = (snapToTicks ? "true" : "false"); String snapToValueString = (snapToValue ? "true" : "false"); String orientationString = (orientation == HORIZONTAL ? "HORIZONTAL" : "VERTICAL"); return super.paramString() + ",isInverted=" + isInvertedString + ",majorTickSpacing=" + majorTickSpacing + ",minorTickSpacing=" + minorTickSpacing + ",orientation=" + orientationString + ",paintLabels=" + paintLabelsString + ",paintTicks=" + paintTicksString + ",paintTrack=" + paintTrackString + ",snapToTicks=" + snapToTicksString + ",snapToValue=" + snapToValueString;
public void	removeChangeListener(javax.swing.event.ChangeListener l) Removes a ChangeListener from the slider. param l the ChangeListener to remove see #fireStateChanged see #addChangeListener listenerList.remove(ChangeListener.class, l);
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 #getExtent see BoundedRangeModel#setExtent beaninfo expert: true description: Size of the range covered by the knob. getModel().setExtent(extent);
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. The order depends on the slider's ComponentOrientation property. Normal (non-inverted) horizontal sliders with a ComponentOrientation value of LEFT_TO_RIGHT have their maximum on the right. Normal horizontal sliders with a ComponentOrientation value of RIGHT_TO_LEFT have their maximum on the left. Normal vertical sliders have their maximum on the top. These labels are reversed when the slider is inverted. param b true to reverse the slider values from their normal order beaninfo bound: true attribute: visualUpdate true description: If true reverses the slider values from their normal order boolean oldValue = isInverted; isInverted = b; firePropertyChange("inverted", oldValue, isInverted); if (b != oldValue) { repaint(); }
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 #createStandardLabels see #getLabelTable beaninfo hidden: true bound: true attribute: visualUpdate true description: Specifies what labels will be drawn for any given value. Dictionary oldTable = labelTable; labelTable = labels; updateLabelUIs(); firePropertyChange("labelTable", oldTable, labelTable ); if (labels != oldTable) { revalidate(); repaint(); }
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 #getMajorTickSpacing beaninfo bound: true attribute: visualUpdate true description: Sets the number of values between major tick marks. int oldValue = majorTickSpacing; majorTickSpacing = n; if ( labelTable == null && getMajorTickSpacing() > 0 && getPaintLabels() ) { setLabelTable( createStandardLabels( getMajorTickSpacing() ) ); } firePropertyChange("majorTickSpacing", oldValue, majorTickSpacing); if (majorTickSpacing != oldValue && getPaintTicks()) { repaint(); }
public void	setMaximum(int maximum) Sets the models maximum property. see #getMaximum see BoundedRangeModel#setMaximum beaninfo bound: true preferred: true description: The sliders maximum value. int oldMax = getModel().getMaximum(); getModel().setMaximum(maximum); firePropertyChange( "maximum", new Integer( oldMax ), new Integer( maximum ) );
public void	setMinimum(int minimum) Sets the models minimum property. see #getMinimum see BoundedRangeModel#setMinimum beaninfo bound: true preferred: true description: The sliders minimum value. int oldMin = getModel().getMinimum(); getModel().setMinimum(minimum); firePropertyChange( "minimum", new Integer( oldMin ), new Integer( minimum ) );
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 #getMinorTickSpacing beaninfo bound: true attribute: visualUpdate true description: Sets the number of values between minor tick marks. int oldValue = minorTickSpacing; minorTickSpacing = n; firePropertyChange("minorTickSpacing", oldValue, minorTickSpacing); if (minorTickSpacing != oldValue && getPaintTicks()) { repaint(); }
public void	setModel(javax.swing.BoundedRangeModel newModel) Sets the model that handles the sliders three fundamental properties: minimum, maximum, value. see #getModel beaninfo bound: true description: The sliders BoundedRangeModel. BoundedRangeModel oldModel = getModel(); if (oldModel != null) { oldModel.removeChangeListener(changeListener); } sliderModel = newModel; if (newModel != null) { newModel.addChangeListener(changeListener); if (accessibleContext != null) { accessibleContext.firePropertyChange( AccessibleContext.ACCESSIBLE_VALUE_PROPERTY, (oldModel == null ? null : new Integer(oldModel.getValue())), (newModel == null ? null : new Integer(newModel.getValue()))); } } firePropertyChange("model", oldModel, sliderModel);
public void	setOrientation(int orientation) Set the scrollbars orientation to either VERTICAL or HORIZONTAL. exception IllegalArgumentException if orientation is not one of VERTICAL, HORIZONTAL see #getOrientation beaninfo preferred: true bound: true attribute: visualUpdate true description: Set the scrollbars orientation to either VERTICAL or HORIZONTAL. enum: VERTICAL JSlider.VERTICAL HORIZONTAL JSlider.HORIZONTAL checkOrientation(orientation); int oldValue = this.orientation; this.orientation = orientation; firePropertyChange("orientation", oldValue, orientation); if ((oldValue != orientation) && (accessibleContext != null)) { accessibleContext.firePropertyChange( AccessibleContext.ACCESSIBLE_STATE_PROPERTY, ((oldValue == VERTICAL) ? AccessibleState.VERTICAL : AccessibleState.HORIZONTAL), ((orientation == VERTICAL) ? AccessibleState.VERTICAL : AccessibleState.HORIZONTAL)); } if (orientation != oldValue) { revalidate(); }
public void	setPaintLabels(boolean b) Determines whether labels are painted on the slider. see #getPaintLabels beaninfo bound: true attribute: visualUpdate true description: If true labels are painted on the slider. boolean oldValue = paintLabels; paintLabels = b; if ( labelTable == null && getMajorTickSpacing() > 0 ) { setLabelTable( createStandardLabels( getMajorTickSpacing() ) ); } firePropertyChange("paintLabels", oldValue, paintLabels); if (paintLabels != oldValue) { revalidate(); repaint(); }
public void	setPaintTicks(boolean b) Determines whether tick marks are painted on the slider. see #getPaintTicks beaninfo bound: true attribute: visualUpdate true description: If true tick marks are painted on the slider. boolean oldValue = paintTicks; paintTicks = b; firePropertyChange("paintTicks", oldValue, paintTicks); if (paintTicks != oldValue) { revalidate(); repaint(); }
public void	setPaintTrack(boolean b) Determines whether the track is painted on the slider. see #getPaintTrack beaninfo bound: true attribute: visualUpdate true description: If true, the track is painted on the slider. boolean oldValue = paintTrack; paintTrack = b; firePropertyChange("paintTrack", oldValue, paintTrack); if (paintTrack != oldValue) { repaint(); }
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. param b true to snap the knob to the nearest tick mark see #getSnapToTicks beaninfo bound: true description: If true snap the knob to the nearest tick mark. boolean oldValue = snapToTicks; snapToTicks = b; firePropertyChange("snapToTicks", oldValue, snapToTicks);
void	setSnapToValue(boolean b) Specifying true makes the knob (and the data value it represents) resolve to the closest slider value next to where the user positioned the knob. If the snapToTicks property has been set to true, the snap-to-ticks behavior will prevail. param b true to snap the knob to the nearest slider value see #getSnapToValue see #setSnapToTicks beaninfo bound: true description: If true snap the knob to the nearest slider value. boolean oldValue = snapToValue; snapToValue = b; firePropertyChange("snapToValue", oldValue, snapToValue);
public void	setUI(javax.swing.plaf.SliderUI ui) Sets the UI object which implements the L&F for this component. param ui the SliderUI L&F object see UIDefaults#getUI beaninfo bound: true hidden: true attribute: visualUpdate true description: The UI object that implements the slider's LookAndFeel. super.setUI(ui);
public void	setValue(int n) Sets the sliders current value. This method just forwards the value to the model. see #getValue beaninfo preferred: true description: The sliders current value. BoundedRangeModel m = getModel(); int oldValue = m.getValue(); if (oldValue == n) { return; } m.setValue(n); if (accessibleContext != null) { accessibleContext.firePropertyChange( AccessibleContext.ACCESSIBLE_VALUE_PROPERTY, new Integer(oldValue), new Integer(m.getValue())); }
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 #getValueIsAdjusting see BoundedRangeModel#setValueIsAdjusting beaninfo expert: true description: True if the slider knob is being dragged. BoundedRangeModel m = getModel(); boolean oldValue = m.getValueIsAdjusting(); m.setValueIsAdjusting(b); if ((oldValue != b) && (accessibleContext != null)) { accessibleContext.firePropertyChange( AccessibleContext.ACCESSIBLE_STATE_PROPERTY, ((oldValue) ? AccessibleState.BUSY : null), ((b) ? AccessibleState.BUSY : null)); }
protected void	updateLabelUIs() Resets the UI property to a value from the current look and feel. see JComponent#updateUI if ( getLabelTable() == null ) { return; } Enumeration labels = getLabelTable().keys(); while ( labels.hasMoreElements() ) { Object value = getLabelTable().get( labels.nextElement() ); if ( value instanceof JComponent ) { JComponent component = (JComponent)value; component.updateUI(); component.setSize( component.getPreferredSize() ); } }
public void	updateUI() Resets the UI property to a value from the current look and feel. see JComponent#updateUI updateLabelUIs(); setUI((SliderUI)UIManager.getUI(this));
private void	writeObject(java.io.ObjectOutputStream s) See readObject() and writeObject() in JComponent for more information about serialization in Swing. s.defaultWriteObject(); if (getUIClassID().equals(uiClassID)) { byte count = JComponent.getWriteObjCounter(this); JComponent.setWriteObjCounter(this, --count); if (count == 0 && ui != null) { ui.installUI(this); } }