6613529: Avoid duplicate object creation within JDK packages
Summary: avoid using constructors when unique values are not necessary
Reviewed-by: volk, igor, peterz
/*
* Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
package javax.swing;
import javax.swing.border.*;
import javax.swing.event.*;
import javax.swing.plaf.*;
import javax.accessibility.*;
import java.io.Serializable;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;
import java.awt.Color;
import java.awt.Font;
import java.util.*;
import java.beans.*;
/**
* A component that lets the user graphically select a value by sliding
* a knob within a bounded interval.
* <p>
* The slider can show both
* major tick marks, and minor tick marks between the major ones. The number of
* values between the tick marks is controlled with
* <code>setMajorTickSpacing</code> and <code>setMinorTickSpacing</code>.
* Painting of tick marks is controlled by {@code setPaintTicks}.
* <p>
* Sliders can also print text labels at regular intervals (or at
* arbitrary locations) along the slider track. Painting of labels is
* controlled by {@code setLabelTable} and {@code setPaintLabels}.
* <p>
* For further information and examples see
* <a
href="http://java.sun.com/docs/books/tutorial/uiswing/components/slider.html">How to Use Sliders</a>,
* a section in <em>The Java Tutorial.</em>
* <p>
* <strong>Warning:</strong> Swing is not thread safe. For more
* information see <a
* href="package-summary.html#threading">Swing's Threading
* Policy</a>.
* <p>
* <strong>Warning:</strong>
* 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<sup><font size="-2">TM</font></sup>
* has been added to the <code>java.beans</code> package.
* Please see {@link java.beans.XMLEncoder}.
*
* @beaninfo
* attribute: isContainer false
* description: A component that supports selecting a integer value from a range.
*
* @author David Kloba
*/
public class JSlider extends JComponent implements SwingConstants, Accessible {
/**
* @see #getUIClassID
* @see #readObject
*/
private static final String uiClassID = "SliderUI";
private boolean paintTicks = false;
private boolean paintTrack = true;
private boolean paintLabels = false;
private boolean isInverted = false;
/**
* The data model that handles the numeric maximum value,
* minimum value, and current-position value for the slider.
*/
protected BoundedRangeModel sliderModel;
/**
* The number of values between the major tick marks -- the
* larger marks that break up the minor tick marks.
*/
protected int majorTickSpacing;
/**
* The number of values between the minor tick marks -- the
* smaller marks that occur between the major tick marks.
* @see #setMinorTickSpacing
*/
protected int minorTickSpacing;
/**
* 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 #setSnapToTicks
*/
protected boolean snapToTicks = false;
/**
* If true, the knob (and the data value it represents)
* resolve to the closest slider value next to where the user
* positioned the knob.
*/
boolean snapToValue = true;
/**
* Whether the slider is horizontal or vertical
* The default is horizontal.
*
* @see #setOrientation
*/
protected int orientation;
/**
* {@code Dictionary} of what labels to draw at which values
*/
private Dictionary labelTable;
/**
* The changeListener (no suffix) is the listener we add to the
* slider's model. This listener is initialized to the
* {@code ChangeListener} returned from {@code createChangeListener},
* which by default just forwards events
* to {@code ChangeListener}s (if any) added directly to the slider.
*
* @see #addChangeListener
* @see #createChangeListener
*/
protected ChangeListener changeListener = createChangeListener();
/**
* Only one <code>ChangeEvent</code> 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 #fireStateChanged
*/
protected transient ChangeEvent changeEvent = null;
private void checkOrientation(int orientation) {
switch (orientation) {
case VERTICAL:
case HORIZONTAL:
break;
default:
throw new IllegalArgumentException("orientation must be one of: VERTICAL, HORIZONTAL");
}
}
/**
* Creates a horizontal slider with the range 0 to 100 and
* an initial value of 50.
*/
public JSlider() {
this(HORIZONTAL, 0, 100, 50);
}
/**
* Creates a slider using the specified orientation with the
* range {@code 0} to {@code 100} and an initial value of {@code 50}.
* The orientation can be
* either <code>SwingConstants.VERTICAL</code> or
* <code>SwingConstants.HORIZONTAL</code>.
*
* @param orientation the orientation of the slider
* @throws IllegalArgumentException if orientation is not one of {@code VERTICAL}, {@code HORIZONTAL}
* @see #setOrientation
*/
public JSlider(int orientation) {
this(orientation, 0, 100, 50);
}
/**
* Creates a horizontal slider using the specified min and max
* with an initial value equal to the average of the min plus max.
* <p>
* The <code>BoundedRangeModel</code> that holds the slider's data
* handles any issues that may arise from improperly setting the
* minimum and maximum values on the slider. See the
* {@code BoundedRangeModel} documentation for details.
*
* @param min the minimum value of the slider
* @param max the maximum value of the slider
*
* @see BoundedRangeModel
* @see #setMinimum
* @see #setMaximum
*/
public JSlider(int min, int max) {
this(HORIZONTAL, min, max, (min + max) / 2);
}
/**
* Creates a horizontal slider using the specified min, max and value.
* <p>
* The <code>BoundedRangeModel</code> that holds the slider's data
* handles any issues that may arise from improperly setting the
* minimum, initial, and maximum values on the slider. See the
* {@code BoundedRangeModel} documentation for details.
*
* @param min the minimum value of the slider
* @param max the maximum value of the slider
* @param value the initial value of the slider
*
* @see BoundedRangeModel
* @see #setMinimum
* @see #setMaximum
* @see #setValue
*/
public JSlider(int min, int max, int value) {
this(HORIZONTAL, min, max, value);
}
/**
* Creates a slider with the specified orientation and the
* specified minimum, maximum, and initial values.
* The orientation can be
* either <code>SwingConstants.VERTICAL</code> or
* <code>SwingConstants.HORIZONTAL</code>.
* <p>
* The <code>BoundedRangeModel</code> that holds the slider's data
* handles any issues that may arise from improperly setting the
* minimum, initial, and maximum values on the slider. See the
* {@code BoundedRangeModel} documentation for details.
*
* @param orientation the orientation of the slider
* @param min the minimum value of the slider
* @param max the maximum value of the slider
* @param value the initial value of the slider
*
* @throws IllegalArgumentException if orientation is not one of {@code VERTICAL}, {@code HORIZONTAL}
*
* @see BoundedRangeModel
* @see #setOrientation
* @see #setMinimum
* @see #setMaximum
* @see #setValue
*/
public JSlider(int orientation, int min, int max, int value)
{
checkOrientation(orientation);
this.orientation = orientation;
sliderModel = new DefaultBoundedRangeModel(value, 0, min, max);
sliderModel.addChangeListener(changeListener);
updateUI();
}
/**
* Creates a horizontal slider using the specified
* BoundedRangeModel.
*/
public JSlider(BoundedRangeModel brm)
{
this.orientation = JSlider.HORIZONTAL;
setModel(brm);
sliderModel.addChangeListener(changeListener);
updateUI();
}
/**
* Gets the UI object which implements the L&F for this component.
*
* @return the SliderUI object that implements the Slider L&F
*/
public SliderUI getUI() {
return(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.
*/
public void setUI(SliderUI ui) {
super.setUI(ui);
}
/**
* Resets the UI property to a value from the current look and feel.
*
* @see JComponent#updateUI
*/
public void updateUI() {
setUI((SliderUI)UIManager.getUI(this));
// The labels preferred size may be derived from the font
// of the slider, so we must update the UI of the slider first, then
// that of labels. This way when setSize is called the right
// font is used.
updateLabelUIs();
}
/**
* Returns the name of the L&F class that renders this component.
*
* @return "SliderUI"
* @see JComponent#getUIClassID
* @see UIDefaults#getUI
*/
public String getUIClassID() {
return uiClassID;
}
/**
* We pass Change events along to the listeners with the
* the slider (instead of the model itself) as the event source.
*/
private class ModelListener implements ChangeListener, Serializable {
public void stateChanged(ChangeEvent e) {
fireStateChanged();
}
}
/**
* Subclasses that want to handle {@code ChangeEvent}s
* from the model differently
* can override this to return
* an instance of a custom <code>ChangeListener</code> implementation.
* The default {@code ChangeListener} simply calls the
* {@code fireStateChanged} method to forward {@code ChangeEvent}s
* to the {@code ChangeListener}s that have been added directly to the
* slider.
* @see #changeListener
* @see #fireStateChanged
* @see javax.swing.event.ChangeListener
* @see javax.swing.BoundedRangeModel
*/
protected ChangeListener createChangeListener() {
return new ModelListener();
}
/**
* Adds a ChangeListener to the slider.
*
* @param l the ChangeListener to add
* @see #fireStateChanged
* @see #removeChangeListener
*/
public void addChangeListener(ChangeListener l) {
listenerList.add(ChangeListener.class, l);
}
/**
* Removes a ChangeListener from the slider.
*
* @param l the ChangeListener to remove
* @see #fireStateChanged
* @see #addChangeListener
*/
public void removeChangeListener(ChangeListener l) {
listenerList.remove(ChangeListener.class, l);
}
/**
* Returns an array of all the <code>ChangeListener</code>s added
* to this JSlider with addChangeListener().
*
* @return all of the <code>ChangeListener</code>s added or an empty
* array if no listeners have been added
* @since 1.4
*/
public ChangeListener[] getChangeListeners() {
return (ChangeListener[])listenerList.getListeners(
ChangeListener.class);
}
/**
* Send a {@code ChangeEvent}, whose source is this {@code JSlider}, to
* all {@code ChangeListener}s that have registered interest in
* {@code ChangeEvent}s.
* This method is called each time a {@code ChangeEvent} is received from
* the model.
* <p>
* The event instance is created if necessary, and stored in
* {@code changeEvent}.
*
* @see #addChangeListener
* @see EventListenerList
*/
protected void fireStateChanged() {
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);
}
}
}
/**
* Returns the {@code BoundedRangeModel} that handles the slider's three
* fundamental properties: minimum, maximum, value.
*
* @return the data model for this component
* @see #setModel
* @see BoundedRangeModel
*/
public BoundedRangeModel getModel() {
return sliderModel;
}
/**
* Sets the {@code BoundedRangeModel} that handles the slider's three
* fundamental properties: minimum, maximum, value.
*<p>
* Attempts to pass a {@code null} model to this method result in
* undefined behavior, and, most likely, exceptions.
*
* @param newModel the new, {@code non-null} <code>BoundedRangeModel</code> to use
*
* @see #getModel
* @see BoundedRangeModel
* @beaninfo
* bound: true
* description: The sliders BoundedRangeModel.
*/
public void setModel(BoundedRangeModel newModel)
{
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 : Integer.valueOf(oldModel.getValue())),
(newModel == null
? null : Integer.valueOf(newModel.getValue())));
}
}
firePropertyChange("model", oldModel, sliderModel);
}
/**
* Returns the slider's current value
* from the {@code BoundedRangeModel}.
*
* @return the current value of the slider
* @see #setValue
* @see BoundedRangeModel#getValue
*/
public int getValue() {
return getModel().getValue();
}
/**
* Sets the slider's current value to {@code n}. This method
* forwards the new value to the model.
* <p>
* The data model (an instance of {@code BoundedRangeModel})
* handles any mathematical
* issues arising from assigning faulty values. See the
* {@code BoundedRangeModel} documentation for details.
* <p>
* If the new value is different from the previous value,
* all change listeners are notified.
*
* @param n the new value
* @see #getValue
* @see #addChangeListener
* @see BoundedRangeModel#setValue
* @beaninfo
* preferred: true
* description: The sliders current value.
*/
public void setValue(int n) {
BoundedRangeModel m = getModel();
int oldValue = m.getValue();
if (oldValue == n) {
return;
}
m.setValue(n);
if (accessibleContext != null) {
accessibleContext.firePropertyChange(
AccessibleContext.ACCESSIBLE_VALUE_PROPERTY,
Integer.valueOf(oldValue),
Integer.valueOf(m.getValue()));
}
}
/**
* Returns the minimum value supported by the slider
* from the <code>BoundedRangeModel</code>.
*
* @return the value of the model's minimum property
* @see #setMinimum
* @see BoundedRangeModel#getMinimum
*/
public int getMinimum() {
return getModel().getMinimum();
}
/**
* Sets the slider's minimum value to {@code minimum}. This method
* forwards the new minimum value to the model.
* <p>
* The data model (an instance of {@code BoundedRangeModel})
* handles any mathematical
* issues arising from assigning faulty values. See the
* {@code BoundedRangeModel} documentation for details.
* <p>
* If the new minimum value is different from the previous minimum value,
* all change listeners are notified.
*
* @param minimum the new minimum
* @see #getMinimum
* @see #addChangeListener
* @see BoundedRangeModel#setMinimum
* @beaninfo
* bound: true
* preferred: true
* description: The sliders minimum value.
*/
public void setMinimum(int minimum) {
int oldMin = getModel().getMinimum();
getModel().setMinimum(minimum);
firePropertyChange( "minimum", Integer.valueOf( oldMin ), Integer.valueOf( minimum ) );
}
/**
* Returns the maximum value supported by the slider
* from the <code>BoundedRangeModel</code>.
*
* @return the value of the model's maximum property
* @see #setMaximum
* @see BoundedRangeModel#getMaximum
*/
public int getMaximum() {
return getModel().getMaximum();
}
/**
* Sets the slider's maximum value to {@code maximum}. This method
* forwards the new maximum value to the model.
* <p>
* The data model (an instance of {@code BoundedRangeModel})
* handles any mathematical
* issues arising from assigning faulty values. See the
* {@code BoundedRangeModel} documentation for details.
* <p>
* If the new maximum value is different from the previous maximum value,
* all change listeners are notified.
*
* @param maximum the new maximum
* @see #getMaximum
* @see #addChangeListener
* @see BoundedRangeModel#setMaximum
* @beaninfo
* bound: true
* preferred: true
* description: The sliders maximum value.
*/
public void setMaximum(int maximum) {
int oldMax = getModel().getMaximum();
getModel().setMaximum(maximum);
firePropertyChange( "maximum", Integer.valueOf( oldMax ), Integer.valueOf( maximum ) );
}
/**
* Returns the {@code valueIsAdjusting} property from the model. For
* details on how this is used, see the {@code setValueIsAdjusting}
* documentation.
*
* @return the value of the model's {@code valueIsAdjusting} property
* @see #setValueIsAdjusting
*/
public boolean getValueIsAdjusting() {
return getModel().getValueIsAdjusting();
}
/**
* Sets the model's {@code valueIsAdjusting} property. Slider look and
* feel implementations should set this property to {@code true} when
* a knob drag begins, and to {@code false} when the drag ends. The
* slider model will not generate {@code ChangeEvent}s while
* {@code valueIsAdjusting} is {@code true}.
*
* @param b the new value for the {@code valueIsAdjusting} property
* @see #getValueIsAdjusting
* @see BoundedRangeModel#setValueIsAdjusting
* @beaninfo
* expert: true
* description: True if the slider knob is being dragged.
*/
public void setValueIsAdjusting(boolean b) {
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));
}
}
/**
* Returns the "extent" from the <code>BoundedRangeModel</code>.
* This respresents the range of values "covered" by the knob.
*
* @return an int representing the extent
* @see #setExtent
* @see BoundedRangeModel#getExtent
*/
public int getExtent() {
return getModel().getExtent();
}
/**
* 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. This method just
* forwards the new extent value to the model.
* <p>
* The data model (an instance of {@code BoundedRangeModel})
* handles any mathematical
* issues arising from assigning faulty values. See the
* {@code BoundedRangeModel} documentation for details.
* <p>
* If the new extent value is different from the previous extent value,
* all change listeners are notified.
*
* @param extent the new extent
* @see #getExtent
* @see BoundedRangeModel#setExtent
* @beaninfo
* expert: true
* description: Size of the range covered by the knob.
*/
public void setExtent(int extent) {
getModel().setExtent(extent);
}
/**
* Return this slider's vertical or horizontal orientation.
* @return {@code SwingConstants.VERTICAL} or
* {@code SwingConstants.HORIZONTAL}
* @see #setOrientation
*/
public int getOrientation() {
return orientation;
}
/**
* Set the slider's orientation to either {@code SwingConstants.VERTICAL} or
* {@code SwingConstants.HORIZONTAL}.
*
* @param orientation {@code HORIZONTAL} or {@code VERTICAL}
* @throws IllegalArgumentException if orientation is not one of {@code VERTICAL}, {@code 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
*
*/
public void setOrientation(int orientation)
{
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();
}
}
/**
* {@inheritDoc}
*
* @since 1.6
*/
public void setFont(Font font) {
super.setFont(font);
updateLabelSizes();
}
/**
* Returns the dictionary of what labels to draw at which values.
*
* @return the <code>Dictionary</code> containing labels and
* where to draw them
*/
public Dictionary getLabelTable() {
/*
if ( labelTable == null && getMajorTickSpacing() > 0 ) {
setLabelTable( createStandardLabels( getMajorTickSpacing() ) );
}
*/
return labelTable;
}
/**
* Used to specify what label will be drawn at any given value.
* The key-value pairs are of this format:
* <code>{ Integer value, java.swing.JComponent label }</code>.
* <p>
* An easy way to generate a standard table of value labels is by using the
* {@code createStandardLabels} method.
* <p>
* Once the labels have been set, this method calls {@link #updateLabelUIs}.
* Note that the labels are only painted if the {@code paintLabels}
* property is {@code true}.
*
* @param labels new {@code Dictionary} of labels, or {@code null} to
* remove all labels
* @see #createStandardLabels(int)
* @see #getLabelTable
* @see #setPaintLabels
* @beaninfo
* hidden: true
* bound: true
* attribute: visualUpdate true
* description: Specifies what labels will be drawn for any given value.
*/
public void setLabelTable( Dictionary labels ) {
Dictionary oldTable = labelTable;
labelTable = labels;
updateLabelUIs();
firePropertyChange("labelTable", oldTable, labelTable );
if (labels != oldTable) {
revalidate();
repaint();
}
}
/**
* Updates the UIs for the labels in the label table by calling
* {@code updateUI} on each label. The UIs are updated from
* the current look and feel. The labels are also set to their
* preferred size.
*
* @see #setLabelTable
* @see JComponent#updateUI
*/
protected void updateLabelUIs() {
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() );
}
}
}
private void updateLabelSizes() {
Dictionary labelTable = getLabelTable();
if (labelTable != null) {
Enumeration labels = labelTable.elements();
while (labels.hasMoreElements()) {
Object value = labels.nextElement();
if (value instanceof JComponent) {
JComponent component = (JComponent)value;
component.setSize(component.getPreferredSize());
}
}
}
}
/**
* Creates a {@code Hashtable} of numerical text labels, starting at the
* slider minimum, and using the increment specified.
* For example, if you call <code>createStandardLabels( 10 )</code>
* and the slider minimum is zero,
* then labels will be created for the values 0, 10, 20, 30, and so on.
* <p>
* For the labels to be drawn on the slider, the returned {@code Hashtable}
* must be passed into {@code setLabelTable}, and {@code setPaintLabels}
* must be set to {@code true}.
* <p>
* For further details on the makeup of the returned {@code Hashtable}, see
* the {@code setLabelTable} documentation.
*
* @param increment distance between labels in the generated hashtable
* @return a new {@code Hashtable} of labels
* @see #setLabelTable
* @see #setPaintLabels
* @throws IllegalArgumentException if {@code increment} is less than or
* equal to zero
*/
public Hashtable createStandardLabels( int increment ) {
return createStandardLabels( increment, getMinimum() );
}
/**
* Creates a {@code Hashtable} of numerical text labels, starting at the
* starting point specified, and using the increment specified.
* For example, if you call
* <code>createStandardLabels( 10, 2 )</code>,
* then labels will be created for the values 2, 12, 22, 32, and so on.
* <p>
* For the labels to be drawn on the slider, the returned {@code Hashtable}
* must be passed into {@code setLabelTable}, and {@code setPaintLabels}
* must be set to {@code true}.
* <p>
* For further details on the makeup of the returned {@code Hashtable}, see
* the {@code setLabelTable} documentation.
*
* @param increment distance between labels in the generated hashtable
* @param start value at which the labels will begin
* @return a new {@code Hashtable} of labels
* @see #setLabelTable
* @see #setPaintLabels
* @exception IllegalArgumentException if {@code start} is
* out of range, or if {@code increment} is less than or equal
* to zero
*/
public Hashtable createStandardLabels( int increment, int start ) {
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 Font getFont() {
Font font = super.getFont();
if (font != null && !(font instanceof UIResource)) {
return font;
}
return JSlider.this.getFont();
}
public Color getForeground() {
Color fg = super.getForeground();
if (fg != null && !(fg instanceof UIResource)) {
return fg;
}
if (!(JSlider.this.getForeground() instanceof UIResource)) {
return JSlider.this.getForeground();
}
return fg;
}
}
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( Integer.valueOf( 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;
}
/**
* 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
*/
public boolean getInverted() {
return isInverted;
}
/**
* 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 <code>ComponentOrientation</code> property. Normal (non-inverted)
* horizontal sliders with a <code>ComponentOrientation</code> value of
* <code>LEFT_TO_RIGHT</code> have their maximum on the right.
* Normal horizontal sliders with a <code>ComponentOrientation</code> value of
* <code>RIGHT_TO_LEFT</code> have their maximum on the left. Normal vertical
* sliders have their maximum on the top. These labels are reversed when the
* slider is inverted.
* <p>
* By default, the value of this property is {@code false}.
*
* @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
*
*/
public void setInverted( boolean b ) {
boolean oldValue = isInverted;
isInverted = b;
firePropertyChange("inverted", oldValue, isInverted);
if (b != oldValue) {
repaint();
}
}
/**
* 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
*/
public int getMajorTickSpacing() {
return majorTickSpacing;
}
/**
* 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.
* <p>
* In order for major ticks to be painted, {@code setPaintTicks} must be
* set to {@code true}.
* <p>
* This method will also set up a label table for you.
* If there is not already a label table, and the major tick spacing is
* {@code > 0}, and {@code getPaintLabels} returns
* {@code true}, a standard label table will be generated (by calling
* {@code createStandardLabels}) with labels at the major tick marks.
* For the example above, you would get text labels: "0",
* "10", "20", "30", "40", "50".
* The label table is then set on the slider by calling
* {@code setLabelTable}.
*
* @param n new value for the {@code majorTickSpacing} property
* @see #getMajorTickSpacing
* @see #setPaintTicks
* @see #setLabelTable
* @see #createStandardLabels(int)
* @beaninfo
* bound: true
* attribute: visualUpdate true
* description: Sets the number of values between major tick marks.
*
*/
public void setMajorTickSpacing(int n) {
int oldValue = majorTickSpacing;
majorTickSpacing = n;
if ( labelTable == null && getMajorTickSpacing() > 0 && getPaintLabels() ) {
setLabelTable( createStandardLabels( getMajorTickSpacing() ) );
}
firePropertyChange("majorTickSpacing", oldValue, majorTickSpacing);
if (majorTickSpacing != oldValue && getPaintTicks()) {
repaint();
}
}
/**
* 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
*/
public int getMinorTickSpacing() {
return minorTickSpacing;
}
/**
* 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.
* <p>
* In order for minor ticks to be painted, {@code setPaintTicks} must be
* set to {@code true}.
*
* @param n new value for the {@code minorTickSpacing} property
* @see #getMinorTickSpacing
* @see #setPaintTicks
* @beaninfo
* bound: true
* attribute: visualUpdate true
* description: Sets the number of values between minor tick marks.
*/
public void setMinorTickSpacing(int n) {
int oldValue = minorTickSpacing;
minorTickSpacing = n;
firePropertyChange("minorTickSpacing", oldValue, minorTickSpacing);
if (minorTickSpacing != oldValue && getPaintTicks()) {
repaint();
}
}
/**
* 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
*/
public boolean getSnapToTicks() {
return snapToTicks;
}
/**
* 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
* @see #setSnapToValue
*/
boolean getSnapToValue() {
return snapToValue;
}
/**
* 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.
* By default, this property is {@code false}.
*
* @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.
*/
public void setSnapToTicks(boolean b) {
boolean oldValue = snapToTicks;
snapToTicks = b;
firePropertyChange("snapToTicks", oldValue, snapToTicks);
}
/**
* 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 {@code snapToTicks} property has also been
* set to {@code true}, the snap-to-ticks behavior will prevail.
* By default, the snapToValue property is {@code true}.
*
* @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.
*/
void setSnapToValue(boolean b) {
boolean oldValue = snapToValue;
snapToValue = b;
firePropertyChange("snapToValue", oldValue, snapToValue);
}
/**
* Tells if tick marks are to be painted.
* @return true if tick marks are painted, else false
* @see #setPaintTicks
*/
public boolean getPaintTicks() {
return paintTicks;
}
/**
* Determines whether tick marks are painted on the slider.
* By default, this property is {@code false}.
*
* @param b whether or not tick marks should be painted
* @see #getPaintTicks
* @beaninfo
* bound: true
* attribute: visualUpdate true
* description: If true tick marks are painted on the slider.
*/
public void setPaintTicks(boolean b) {
boolean oldValue = paintTicks;
paintTicks = b;
firePropertyChange("paintTicks", oldValue, paintTicks);
if (paintTicks != oldValue) {
revalidate();
repaint();
}
}
/**
* Tells if the track (area the slider slides in) is to be painted.
* @return true if track is painted, else false
* @see #setPaintTrack
*/
public boolean getPaintTrack() {
return paintTrack;
}
/**
* Determines whether the track is painted on the slider.
* By default, this property is {@code true}.
*
* @param b whether or not to paint the slider track
* @see #getPaintTrack
* @beaninfo
* bound: true
* attribute: visualUpdate true
* description: If true, the track is painted on the slider.
*/
public void setPaintTrack(boolean b) {
boolean oldValue = paintTrack;
paintTrack = b;
firePropertyChange("paintTrack", oldValue, paintTrack);
if (paintTrack != oldValue) {
repaint();
}
}
/**
* Tells if labels are to be painted.
* @return true if labels are painted, else false
* @see #setPaintLabels
*/
public boolean getPaintLabels() {
return paintLabels;
}
/**
* Determines whether labels are painted on the slider.
* <p>
* This method will also set up a label table for you.
* If there is not already a label table, and the major tick spacing is
* {@code > 0},
* a standard label table will be generated (by calling
* {@code createStandardLabels}) with labels at the major tick marks.
* The label table is then set on the slider by calling
* {@code setLabelTable}.
* <p>
* By default, this property is {@code false}.
*
* @param b whether or not to paint labels
* @see #getPaintLabels
* @see #getLabelTable
* @see #createStandardLabels(int)
* @beaninfo
* bound: true
* attribute: visualUpdate true
* description: If true labels are painted on the slider.
*/
public void setPaintLabels(boolean b) {
boolean oldValue = paintLabels;
paintLabels = b;
if ( labelTable == null && getMajorTickSpacing() > 0 ) {
setLabelTable( createStandardLabels( getMajorTickSpacing() ) );
}
firePropertyChange("paintLabels", oldValue, paintLabels);
if (paintLabels != oldValue) {
revalidate();
repaint();
}
}
/**
* See readObject() and writeObject() in JComponent for more
* information about serialization in Swing.
*/
private void writeObject(ObjectOutputStream s) throws IOException {
s.defaultWriteObject();
if (getUIClassID().equals(uiClassID)) {
byte count = JComponent.getWriteObjCounter(this);
JComponent.setWriteObjCounter(this, --count);
if (count == 0 && ui != null) {
ui.installUI(this);
}
}
}
/**
* 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 <code>null</code>.
*
* @return a string representation of this JSlider.
*/
protected String paramString() {
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;
}
/////////////////
// Accessibility support
////////////////
/**
* 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
*/
public AccessibleContext getAccessibleContext() {
if (accessibleContext == null) {
accessibleContext = new AccessibleJSlider();
}
return accessibleContext;
}
/**
* This class implements accessibility support for the
* <code>JSlider</code> class. It provides an implementation of the
* Java Accessibility API appropriate to slider user-interface elements.
* <p>
* <strong>Warning:</strong>
* 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<sup><font size="-2">TM</font></sup>
* has been added to the <code>java.beans</code> package.
* Please see {@link java.beans.XMLEncoder}.
*/
protected class AccessibleJSlider extends AccessibleJComponent
implements AccessibleValue {
/**
* Get the state set of this object.
*
* @return an instance of AccessibleState containing the current state
* of the object
* @see AccessibleState
*/
public AccessibleStateSet getAccessibleStateSet() {
AccessibleStateSet states = super.getAccessibleStateSet();
if (getValueIsAdjusting()) {
states.add(AccessibleState.BUSY);
}
if (getOrientation() == VERTICAL) {
states.add(AccessibleState.VERTICAL);
}
else {
states.add(AccessibleState.HORIZONTAL);
}
return states;
}
/**
* Get the role of this object.
*
* @return an instance of AccessibleRole describing the role of the object
*/
public AccessibleRole getAccessibleRole() {
return AccessibleRole.SLIDER;
}
/**
* Get the AccessibleValue associated with this object. In the
* implementation of the Java Accessibility API for this class,
* return this object, which is responsible for implementing the
* AccessibleValue interface on behalf of itself.
*
* @return this object
*/
public AccessibleValue getAccessibleValue() {
return this;
}
/**
* Get the accessible value of this object.
*
* @return The current value of this object.
*/
public Number getCurrentAccessibleValue() {
return Integer.valueOf(getValue());
}
/**
* Set the value of this object as a Number.
*
* @return True if the value was set.
*/
public boolean setCurrentAccessibleValue(Number n) {
// TIGER - 4422535
if (n == null) {
return false;
}
setValue(n.intValue());
return true;
}
/**
* Get the minimum accessible value of this object.
*
* @return The minimum value of this object.
*/
public Number getMinimumAccessibleValue() {
return Integer.valueOf(getMinimum());
}
/**
* Get the maximum accessible value of this object.
*
* @return The maximum value of this object.
*/
public Number getMaximumAccessibleValue() {
// TIGER - 4422362
BoundedRangeModel model = JSlider.this.getModel();
return Integer.valueOf(model.getMaximum() - model.getExtent());
}
} // AccessibleJSlider
}