/*
* Copyright (c) 1995, 2007, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
*
*
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*
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*
*
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*
*/
package java.awt;
import javax.accessibility.*;
/**
* <code>Panel</code> 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</code> layout manager.
*
* @author Sami Shaio
* @see java.awt.FlowLayout
* @since JDK1.0
*/
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
* <code>FlowLayout</code> class.
*/
public
Panel() {
this(new
FlowLayout());
}
/**
* Creates a new panel with the specified layout manager.
* @param layout the layout manager for this panel.
* @since JDK1.1
*/
public
Panel(
LayoutManager layout) {
setLayout(
layout);
}
/**
* 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.
*/
public void
addNotify() {
synchronized (
getTreeLock()) {
if (
peer == null)
peer =
getToolkit().
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.
*
* @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
* <code>Panel</code> 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.
*
* @return an instance of AccessibleRole describing the role of the
* object
*/
public
AccessibleRole getAccessibleRole() {
return
AccessibleRole.
PANEL;
}
}
}