https://openjdk.java.net/ 
/*
 * Copyright (c) 1997, 2015, Oracle and/or its affiliates. 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package javax.swing;

import javax.swing.plaf.*;
import javax.accessibility.*;

import java.beans.JavaBean;
import java.beans.BeanProperty;
import java.io.ObjectOutputStream;
import java.io.IOException;


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 JavaBeans™
has been added to the java.beans package. Please see XMLEncoder. 
Author:Georges Saab, Jeff Shapiro
Since:1.2
/**
 * <code>JSeparator</code> 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 <code>JSeparator</code> directly,
 * you can use the <code>JMenu</code> or <code>JPopupMenu</code>
 * <code>addSeparator</code> method to create and add a separator.
 * <code>JSeparator</code>s may also be used elsewhere in a GUI
 * wherever a visual divider is useful.
 *
 * <p>
 *
 * For more information and examples see
 * <a
 href="http://docs.oracle.com/javase/tutorial/uiswing/components/menu.html">How to Use Menus</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&trade;
 * has been added to the <code>java.beans</code> package.
 * Please see {@link java.beans.XMLEncoder}.
 *
 * @author Georges Saab
 * @author Jeff Shapiro
 * @since 1.2
 */
@JavaBean(defaultProperty = "UI", description = "A divider between menu items.")
@SwingContainer(false)
@SuppressWarnings("serial")
public class JSeparator extends JComponent implements SwingConstants, Accessible
{
    
See Also:
/**
     * @see #getUIClassID
     * @see #readObject
     */
    private static final String uiClassID = "SeparatorUI";

    private int orientation = HORIZONTAL;

    
Creates a new horizontal separator. 
/** Creates a new horizontal separator. */
    public JSeparator()
    {
        this( HORIZONTAL );
    }

    
Creates a new separator with the specified horizontal or
vertical orientation.

Params:
  • orientation – an integer specifying
         SwingConstants.HORIZONTAL or
         SwingConstants.VERTICAL
Throws:
/**
     * Creates a new separator with the specified horizontal or
     * vertical orientation.
     *
     * @param orientation an integer specifying
     *          <code>SwingConstants.HORIZONTAL</code> or
     *          <code>SwingConstants.VERTICAL</code>
     * @exception IllegalArgumentException if <code>orientation</code>
     *          is neither <code>SwingConstants.HORIZONTAL</code> nor
     *          <code>SwingConstants.VERTICAL</code>
     */
    public JSeparator( int orientation )
    {
        checkOrientation( orientation );
        this.orientation = orientation;
        setFocusable(false);
        updateUI();
    }

    
Returns the L&F object that renders this component.

Returns:the SeparatorUI object that renders this component
/**
     * Returns the L&amp;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.

Params:
  • ui –  the SeparatorUI L&F object
See Also:
/**
     * Sets the L&amp;F object that renders this component.
     *
     * @param ui  the SeparatorUI L&amp;F object
     * @see UIDefaults#getUI
     */
    @BeanProperty(hidden = true, 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 Also:
  • updateUI.updateUI
/**
     * 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.

See Also:
Returns:the string "SeparatorUI"
/**
     * Returns the name of the L&amp;F class that renders this component.
     *
     * @return the string "SeparatorUI"
     * @see JComponent#getUIClassID
     * @see UIDefaults#getUI
     */
    @BeanProperty(bound = false)
    public String getUIClassID() {
        return uiClassID;
    }


    
See readObject and writeObject in
JComponent for more
information about serialization in Swing.

/**
     * See <code>readObject</code> and <code>writeObject</code> in
     * <code>JComponent</code> 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.

See Also:
Returns:  The value of the orientation property, one of the
          following constants defined in SwingConstants:
          VERTICAL, or
          HORIZONTAL.
/**
     * Returns the orientation of this separator.
     *
     * @return   The value of the orientation property, one of the
     *           following constants defined in <code>SwingConstants</code>:
     *           <code>VERTICAL</code>, or
     *           <code>HORIZONTAL</code>.
     *
     * @see SwingConstants
     * @see #setOrientation
     */
    public int getOrientation() {
        return this.orientation;
    }

    
Sets the orientation of the separator.
The default value of this property is HORIZONTAL.

Params:
  • orientation –  either SwingConstants.HORIZONTAL
                 or SwingConstants.VERTICAL
Throws:
See Also:
/**
     * Sets the orientation of the separator.
     * The default value of this property is HORIZONTAL.
     * @param orientation  either <code>SwingConstants.HORIZONTAL</code>
     *                  or <code>SwingConstants.VERTICAL</code>
     * @exception IllegalArgumentException  if <code>orientation</code>
     *          is neither <code>SwingConstants.HORIZONTAL</code>
     *          nor <code>SwingConstants.VERTICAL</code>
     *
     * @see SwingConstants
     * @see #getOrientation
     */
    @BeanProperty(preferred = true, visualUpdate = true, enumerationValues = {
            "SwingConstants.HORIZONTAL",
            "SwingConstants.VERTICAL"}, 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.

Returns: a string representation of this JSeparator
/**
     * Returns a string representation of this <code>JSeparator</code>.
     * 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 <code>JSeparator</code>
     */
    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.

Returns:an AccessibleJSeparator that serves as the
        AccessibleContext of this JSeparator
/**
     * 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
     */
    @BeanProperty(bound = false)
    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 JavaBeans™
has been added to the java.beans package. Please see XMLEncoder. 
/**
     * This class implements accessibility support for the
     * <code>JSeparator</code> class.  It provides an implementation of the
     * Java Accessibility API appropriate to separator 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&trade;
     * has been added to the <code>java.beans</code> package.
     * Please see {@link java.beans.XMLEncoder}.
     */
    @SuppressWarnings("serial")
    protected class AccessibleJSeparator extends AccessibleJComponent {

        
Get the role of this object.

Returns:an instance of AccessibleRole describing the role of the
object
/**
         * Get the role of this object.
         *
         * @return an instance of AccessibleRole describing the role of the
         * object
         */
        public AccessibleRole getAccessibleRole() {
            return AccessibleRole.SEPARATOR;
        }
    }
}