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package java.awt;

import javax.accessibility.*;

Panel is the simplest container class. A panel provides space in which an application can attach any other component, including other panels. 
 The default layout manager for a panel is the FlowLayout layout manager. 
Author:
     Sami Shaio
See Also:
FlowLayout
Since:
  1.0/**
 * {@code Panel} is the simplest container class. A panel
 * provides space in which an application can attach any other
 * component, including other panels.
 * <p>
 * The default layout manager for a panel is the
 * {@code FlowLayout} layout manager.
 *
 * @author      Sami Shaio
 * @see     java.awt.FlowLayout
 * @since   1.0
 */
public class Panel extends Container implements Accessible {
    private static final String base = "panel";
    private static int nameCounter = 0;

    /*
     * JDK 1.1 serialVersionUID
     */
     private static final long serialVersionUID = -2728009084054400034L;

    
Creates a new panel using the default layout manager. The default layout manager for all panels is the FlowLayout class. /**
     * Creates a new panel using the default layout manager.
     * The default layout manager for all panels is the
     * {@code FlowLayout} class.
     */
    public Panel() {
        this(new FlowLayout());
    }

    
Creates a new panel with the specified layout manager.
Params:
layout – the layout manager for this panel.
Since:
1.1/**
     * Creates a new panel with the specified layout manager.
     * @param layout the layout manager for this panel.
     * @since 1.1
     */
    public Panel(LayoutManager layout) {
        setLayout(layout);
    }

    
Construct a name for this component.  Called by getName() when the
name is null.
/**
     * Construct a name for this component.  Called by getName() when the
     * name is null.
     */
    String constructComponentName() {
        synchronized (Panel.class) {
            return base + nameCounter++;
        }
    }

    
Creates the Panel's peer.  The peer allows you to modify the
appearance of the panel without changing its functionality.
/**
     * Creates the Panel's peer.  The peer allows you to modify the
     * appearance of the panel without changing its functionality.
     */

    public void addNotify() {
        synchronized (getTreeLock()) {
            if (peer == null)
                peer = getComponentFactory().createPanel(this);
            super.addNotify();
        }
    }

/////////////////
// Accessibility support
////////////////

    
Gets the AccessibleContext associated with this Panel.
For panels, the AccessibleContext takes the form of an
AccessibleAWTPanel.
A new AccessibleAWTPanel instance is created if necessary.
Returns:
an AccessibleAWTPanel that serves as the
        AccessibleContext of this Panel
Since:
1.3/**
     * Gets the AccessibleContext associated with this Panel.
     * For panels, the AccessibleContext takes the form of an
     * AccessibleAWTPanel.
     * A new AccessibleAWTPanel instance is created if necessary.
     *
     * @return an AccessibleAWTPanel that serves as the
     *         AccessibleContext of this Panel
     * @since 1.3
     */
    public AccessibleContext getAccessibleContext() {
        if (accessibleContext == null) {
            accessibleContext = new AccessibleAWTPanel();
        }
        return accessibleContext;
    }

    
This class implements accessibility support for the Panel class. It provides an implementation of the Java Accessibility API appropriate to panel user-interface elements. 
Since:
1.3/**
     * This class implements accessibility support for the
     * {@code Panel} class.  It provides an implementation of the
     * Java Accessibility API appropriate to panel user-interface elements.
     * @since 1.3
     */
    protected class AccessibleAWTPanel extends AccessibleAWTContainer {

        private static final long serialVersionUID = -6409552226660031050L;

        
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.PANEL;
        }
    }

}