JSeparator provides a general purpose component for
* implementing divider lines - most commonly used as a divider
* between menu items that breaks them up into logical groupings.
* Instead of using JSeparator directly,
* you can use the JMenu or JPopupMenu
* addSeparator method to create and add a separator.
* JSeparators may also be used elsewhere in a GUI
* wherever a visual divider is useful.
*
* * * For more information and examples see * How to Use Menus, * a section in The Java Tutorial. *
* Warning: Swing is not thread safe. For more * information see Swing's Threading * Policy. *
* Warning:
* Serialized objects of this class will not be compatible with
* future Swing releases. The current serialization support is
* appropriate for short term storage or RMI between applications running
* the same version of Swing. As of 1.4, support for long term storage
* of all JavaBeansTM
* has been added to the java.beans package.
* Please see {@link java.beans.XMLEncoder}.
*
* @beaninfo
* attribute: isContainer false
* description: A divider between menu items.
*
* @author Georges Saab
* @author Jeff Shapiro
*/
public class JSeparator extends JComponent implements SwingConstants, Accessible
{
/**
* @see #getUIClassID
* @see #readObject
*/
private static final String uiClassID = "SeparatorUI";
private int orientation = HORIZONTAL;
/** Creates a new horizontal separator. */
public JSeparator()
{
this( HORIZONTAL );
}
/**
* Creates a new separator with the specified horizontal or
* vertical orientation.
*
* @param orientation an integer specifying
* SwingConstants.HORIZONTAL or
* SwingConstants.VERTICAL
* @exception IllegalArgumentException if orientation
* is neither SwingConstants.HORIZONTAL nor
* SwingConstants.VERTICAL
*/
public JSeparator( int orientation )
{
checkOrientation( orientation );
this.orientation = orientation;
setFocusable(false);
updateUI();
}
/**
* Returns the L&F object that renders this component.
*
* @return the SeparatorUI object that renders this component
*/
public SeparatorUI getUI() {
return (SeparatorUI)ui;
}
/**
* Sets the L&F object that renders this component.
*
* @param ui the SeparatorUI L&F object
* @see UIDefaults#getUI
* @beaninfo
* bound: true
* hidden: true
* attribute: visualUpdate true
* description: The UI object that implements the Component's LookAndFeel.
*/
public void setUI(SeparatorUI ui) {
super.setUI(ui);
}
/**
* Resets the UI property to a value from the current look and feel.
*
* @see JComponent#updateUI
*/
public void updateUI() {
setUI((SeparatorUI)UIManager.getUI(this));
}
/**
* Returns the name of the L&F class that renders this component.
*
* @return the string "SeparatorUI"
* @see JComponent#getUIClassID
* @see UIDefaults#getUI
*/
public String getUIClassID() {
return uiClassID;
}
/**
* 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 the orientation of this separator.
*
* @return The value of the orientation property, one of the
* following constants defined in SwingConstants:
* VERTICAL, or
* HORIZONTAL.
*
* @see SwingConstants
* @see #setOrientation
*/
public int getOrientation() {
return this.orientation;
}
/**
* Sets the orientation of the separator.
* The default value of this property is HORIZONTAL.
* @param orientation either SwingConstants.HORIZONTAL
* or SwingConstants.VERTICAL
* @exception IllegalArgumentException if orientation
* is neither SwingConstants.HORIZONTAL
* nor SwingConstants.VERTICAL
*
* @see SwingConstants
* @see #getOrientation
* @beaninfo
* bound: true
* preferred: true
* enum: HORIZONTAL SwingConstants.HORIZONTAL
* VERTICAL SwingConstants.VERTICAL
* attribute: visualUpdate true
* description: The orientation of the separator.
*/
public void setOrientation( int orientation ) {
if (this.orientation == orientation) {
return;
}
int oldValue = this.orientation;
checkOrientation( orientation );
this.orientation = orientation;
firePropertyChange("orientation", oldValue, orientation);
revalidate();
repaint();
}
private void checkOrientation( int orientation )
{
switch ( orientation )
{
case VERTICAL:
case HORIZONTAL:
break;
default:
throw new IllegalArgumentException( "orientation must be one of: VERTICAL, HORIZONTAL" );
}
}
/**
* Returns a string representation of this JSeparator.
* 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 JSeparator
*/
protected String paramString() {
String orientationString = (orientation == HORIZONTAL ?
"HORIZONTAL" : "VERTICAL");
return super.paramString() +
",orientation=" + orientationString;
}
/////////////////
// Accessibility support
////////////////
/**
* Gets the AccessibleContext associated with this JSeparator.
* For separators, the AccessibleContext takes the form of an
* AccessibleJSeparator.
* A new AccessibleJSeparator instance is created if necessary.
*
* @return an AccessibleJSeparator that serves as the
* AccessibleContext of this JSeparator
*/
public AccessibleContext getAccessibleContext() {
if (accessibleContext == null) {
accessibleContext = new AccessibleJSeparator();
}
return accessibleContext;
}
/**
* This class implements accessibility support for the
* JSeparator class. It provides an implementation of the
* Java Accessibility API appropriate to separator user-interface elements.
*
* 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 JavaBeansTM
* has been added to the java.beans package.
* Please see {@link java.beans.XMLEncoder}.
*/
protected class AccessibleJSeparator extends AccessibleJComponent {
/**
* Get the role of this object.
*
* @return an instance of AccessibleRole describing the role of the
* object
*/
public AccessibleRole getAccessibleRole() {
return AccessibleRole.SEPARATOR;
}
}
}