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* Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
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*/
package javax.swing;
import java.awt.*;
import java.awt.event.*;
import java.applet.
Applet;
import java.beans.
PropertyChangeListener;
import java.util.
Locale;
import java.util.
Vector;
import java.io.
Serializable;
import javax.accessibility.*;
/**
* An extended version of <code>java.applet.Applet</code> that adds support for
* the JFC/Swing component architecture.
* You can find task-oriented documentation about using <code>JApplet</code>
* in <em>The Java Tutorial</em>,
* in the section
* <a
href="https://docs.oracle.com/javase/tutorial/uiswing/components/applet.html">How to Make Applets</a>.
* <p>
* The <code>JApplet</code> class is slightly incompatible with
* <code>java.applet.Applet</code>. <code>JApplet</code> contains a
* <code>JRootPane</code> as its only child. The <code>contentPane</code>
* should be the parent of any children of the <code>JApplet</code>.
* As a convenience, the {@code add}, {@code remove}, and {@code setLayout}
* methods of this class are overridden, so that they delegate calls
* to the corresponding methods of the {@code ContentPane}.
* For example, you can add a child component to an applet as follows:
* <pre>
* applet.add(child);
* </pre>
*
* And the child will be added to the <code>contentPane</code>.
* The <code>contentPane</code> will always be non-<code>null</code>.
* Attempting to set it to <code>null</code> will cause the
* <code>JApplet</code> to throw an exception. The default
* <code>contentPane</code> will have a <code>BorderLayout</code>
* manager set on it.
* Refer to {@link javax.swing.RootPaneContainer}
* for details on adding, removing and setting the <code>LayoutManager</code>
* of a <code>JApplet</code>.
* <p>
* Please see the <code>JRootPane</code> documentation for a
* complete description of the <code>contentPane</code>, <code>glassPane</code>,
* and <code>layeredPane</code> properties.
* <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™
* has been added to the <code>java.beans</code> package.
* Please see {@link java.beans.XMLEncoder}.
*
* @see javax.swing.RootPaneContainer
* @beaninfo
* attribute: isContainer true
* attribute: containerDelegate getContentPane
* description: Swing's Applet subclass.
*
* @author Arnaud Weber
*/
public class
JApplet extends
Applet implements
Accessible,
RootPaneContainer,
TransferHandler.
HasGetTransferHandler
{
/**
* @see #getRootPane
* @see #setRootPane
*/
protected
JRootPane rootPane;
/**
* If true then calls to <code>add</code> and <code>setLayout</code>
* will be forwarded to the <code>contentPane</code>. This is initially
* false, but is set to true when the <code>JApplet</code> is constructed.
*
* @see #isRootPaneCheckingEnabled
* @see #setRootPaneCheckingEnabled
* @see javax.swing.RootPaneContainer
*/
protected boolean
rootPaneCheckingEnabled = false;
/**
* The <code>TransferHandler</code> for this applet.
*/
private
TransferHandler transferHandler;
/**
* Creates a swing applet instance.
* <p>
* This constructor sets the component's locale property to the value
* returned by <code>JComponent.getDefaultLocale</code>.
*
* @exception HeadlessException if GraphicsEnvironment.isHeadless()
* returns true.
* @see java.awt.GraphicsEnvironment#isHeadless
* @see JComponent#getDefaultLocale
*/
public
JApplet() throws
HeadlessException {
super();
// Check the timerQ and restart if necessary.
TimerQueue q =
TimerQueue.
sharedInstance();
if(
q != null) {
q.
startIfNeeded();
}
/* Workaround for bug 4155072. The shared double buffer image
* may hang on to a reference to this applet; unfortunately
* Image.getGraphics() will continue to call JApplet.getForeground()
* and getBackground() even after this applet has been destroyed.
* So we ensure that these properties are non-null here.
*/
setForeground(
Color.
black);
setBackground(
Color.
white);
setLocale(
JComponent.
getDefaultLocale() );
setLayout(new
BorderLayout());
setRootPane(
createRootPane());
setRootPaneCheckingEnabled(true);
setFocusTraversalPolicyProvider(true);
sun.awt.
SunToolkit.
checkAndSetPolicy(this);
enableEvents(
AWTEvent.
KEY_EVENT_MASK);
}
/** Called by the constructor methods to create the default rootPane. */
protected
JRootPane createRootPane() {
JRootPane rp = new
JRootPane();
// NOTE: this uses setOpaque vs LookAndFeel.installProperty as there
// is NO reason for the RootPane not to be opaque. For painting to
// work the contentPane must be opaque, therefor the RootPane can
// also be opaque.
rp.
setOpaque(true);
return
rp;
}
/**
* Sets the {@code transferHandler} property, which is a mechanism to
* support transfer of data into this component. Use {@code null}
* if the component does not support data transfer operations.
* <p>
* If the system property {@code suppressSwingDropSupport} is {@code false}
* (the default) and the current drop target on this component is either
* {@code null} or not a user-set drop target, this method will change the
* drop target as follows: If {@code newHandler} is {@code null} it will
* clear the drop target. If not {@code null} it will install a new
* {@code DropTarget}.
* <p>
* Note: When used with {@code JApplet}, {@code TransferHandler} only
* provides data import capability, as the data export related methods
* are currently typed to {@code JComponent}.
* <p>
* Please see
* <a href="https://docs.oracle.com/javase/tutorial/uiswing/dnd/index.html">
* How to Use Drag and Drop and Data Transfer</a>, a section in
* <em>The Java Tutorial</em>, for more information.
*
* @param newHandler the new {@code TransferHandler}
*
* @see TransferHandler
* @see #getTransferHandler
* @see java.awt.Component#setDropTarget
* @since 1.6
*
* @beaninfo
* bound: true
* hidden: true
* description: Mechanism for transfer of data into the component
*/
public void
setTransferHandler(
TransferHandler newHandler) {
TransferHandler oldHandler =
transferHandler;
transferHandler =
newHandler;
SwingUtilities.
installSwingDropTargetAsNecessary(this,
transferHandler);
firePropertyChange("transferHandler",
oldHandler,
newHandler);
}
/**
* Gets the <code>transferHandler</code> property.
*
* @return the value of the <code>transferHandler</code> property
*
* @see TransferHandler
* @see #setTransferHandler
* @since 1.6
*/
public
TransferHandler getTransferHandler() {
return
transferHandler;
}
/**
* Just calls <code>paint(g)</code>. This method was overridden to
* prevent an unnecessary call to clear the background.
*/
public void
update(
Graphics g) {
paint(
g);
}
/**
* Sets the menubar for this applet.
* @param menuBar the menubar being placed in the applet
*
* @see #getJMenuBar
*
* @beaninfo
* hidden: true
* description: The menubar for accessing pulldown menus from this applet.
*/
public void
setJMenuBar(
JMenuBar menuBar) {
getRootPane().
setMenuBar(
menuBar);
}
/**
* Returns the menubar set on this applet.
*
* @see #setJMenuBar
*/
public
JMenuBar getJMenuBar() {
return
getRootPane().
getMenuBar();
}
/**
* Returns whether calls to <code>add</code> and
* <code>setLayout</code> are forwarded to the <code>contentPane</code>.
*
* @return true if <code>add</code> and <code>setLayout</code>
* are forwarded; false otherwise
*
* @see #addImpl
* @see #setLayout
* @see #setRootPaneCheckingEnabled
* @see javax.swing.RootPaneContainer
*/
protected boolean
isRootPaneCheckingEnabled() {
return
rootPaneCheckingEnabled;
}
/**
* Sets whether calls to <code>add</code> and
* <code>setLayout</code> are forwarded to the <code>contentPane</code>.
*
* @param enabled true if <code>add</code> and <code>setLayout</code>
* are forwarded, false if they should operate directly on the
* <code>JApplet</code>.
*
* @see #addImpl
* @see #setLayout
* @see #isRootPaneCheckingEnabled
* @see javax.swing.RootPaneContainer
* @beaninfo
* hidden: true
* description: Whether the add and setLayout methods are forwarded
*/
protected void
setRootPaneCheckingEnabled(boolean
enabled) {
rootPaneCheckingEnabled =
enabled;
}
/**
* Adds the specified child <code>Component</code>.
* This method is overridden to conditionally forward calls to the
* <code>contentPane</code>.
* By default, children are added to the <code>contentPane</code> instead
* of the frame, refer to {@link javax.swing.RootPaneContainer} for
* details.
*
* @param comp the component to be enhanced
* @param constraints the constraints to be respected
* @param index the index
* @exception IllegalArgumentException if <code>index</code> is invalid
* @exception IllegalArgumentException if adding the container's parent
* to itself
* @exception IllegalArgumentException if adding a window to a container
*
* @see #setRootPaneCheckingEnabled
* @see javax.swing.RootPaneContainer
*/
protected void
addImpl(
Component comp,
Object constraints, int
index)
{
if(
isRootPaneCheckingEnabled()) {
getContentPane().
add(
comp,
constraints,
index);
}
else {
super.addImpl(
comp,
constraints,
index);
}
}
/**
* Removes the specified component from the container. If
* <code>comp</code> is not the <code>rootPane</code>, this will forward
* the call to the <code>contentPane</code>. This will do nothing if
* <code>comp</code> is not a child of the <code>JFrame</code> or
* <code>contentPane</code>.
*
* @param comp the component to be removed
* @throws NullPointerException if <code>comp</code> is null
* @see #add
* @see javax.swing.RootPaneContainer
*/
public void
remove(
Component comp) {
if (
comp ==
rootPane) {
super.remove(
comp);
} else {
getContentPane().
remove(
comp);
}
}
/**
* Sets the <code>LayoutManager</code>.
* Overridden to conditionally forward the call to the
* <code>contentPane</code>.
* Refer to {@link javax.swing.RootPaneContainer} for
* more information.
*
* @param manager the <code>LayoutManager</code>
* @see #setRootPaneCheckingEnabled
* @see javax.swing.RootPaneContainer
*/
public void
setLayout(
LayoutManager manager) {
if(
isRootPaneCheckingEnabled()) {
getContentPane().
setLayout(
manager);
}
else {
super.setLayout(
manager);
}
}
/**
* Returns the rootPane object for this applet.
*
* @see #setRootPane
* @see RootPaneContainer#getRootPane
*/
public
JRootPane getRootPane() {
return
rootPane;
}
/**
* Sets the rootPane property. This method is called by the constructor.
* @param root the rootPane object for this applet
*
* @see #getRootPane
*
* @beaninfo
* hidden: true
* description: the RootPane object for this applet.
*/
protected void
setRootPane(
JRootPane root) {
if(
rootPane != null) {
remove(
rootPane);
}
rootPane =
root;
if(
rootPane != null) {
boolean
checkingEnabled =
isRootPaneCheckingEnabled();
try {
setRootPaneCheckingEnabled(false);
add(
rootPane,
BorderLayout.
CENTER);
}
finally {
setRootPaneCheckingEnabled(
checkingEnabled);
}
}
}
/**
* Returns the contentPane object for this applet.
*
* @see #setContentPane
* @see RootPaneContainer#getContentPane
*/
public
Container getContentPane() {
return
getRootPane().
getContentPane();
}
/**
* Sets the contentPane property. This method is called by the constructor.
* @param contentPane the contentPane object for this applet
*
* @exception java.awt.IllegalComponentStateException (a runtime
* exception) if the content pane parameter is null
* @see #getContentPane
* @see RootPaneContainer#setContentPane
*
* @beaninfo
* hidden: true
* description: The client area of the applet where child
* components are normally inserted.
*/
public void
setContentPane(
Container contentPane) {
getRootPane().
setContentPane(
contentPane);
}
/**
* Returns the layeredPane object for this applet.
*
* @exception java.awt.IllegalComponentStateException (a runtime
* exception) if the layered pane parameter is null
* @see #setLayeredPane
* @see RootPaneContainer#getLayeredPane
*/
public
JLayeredPane getLayeredPane() {
return
getRootPane().
getLayeredPane();
}
/**
* Sets the layeredPane property. This method is called by the constructor.
* @param layeredPane the layeredPane object for this applet
*
* @see #getLayeredPane
* @see RootPaneContainer#setLayeredPane
*
* @beaninfo
* hidden: true
* description: The pane which holds the various applet layers.
*/
public void
setLayeredPane(
JLayeredPane layeredPane) {
getRootPane().
setLayeredPane(
layeredPane);
}
/**
* Returns the glassPane object for this applet.
*
* @see #setGlassPane
* @see RootPaneContainer#getGlassPane
*/
public
Component getGlassPane() {
return
getRootPane().
getGlassPane();
}
/**
* Sets the glassPane property.
* This method is called by the constructor.
* @param glassPane the glassPane object for this applet
*
* @see #getGlassPane
* @see RootPaneContainer#setGlassPane
*
* @beaninfo
* hidden: true
* description: A transparent pane used for menu rendering.
*/
public void
setGlassPane(
Component glassPane) {
getRootPane().
setGlassPane(
glassPane);
}
/**
* {@inheritDoc}
*
* @since 1.6
*/
public
Graphics getGraphics() {
JComponent.
getGraphicsInvoked(this);
return super.getGraphics();
}
/**
* Repaints the specified rectangle of this component within
* <code>time</code> milliseconds. Refer to <code>RepaintManager</code>
* for details on how the repaint is handled.
*
* @param time maximum time in milliseconds before update
* @param x the <i>x</i> coordinate
* @param y the <i>y</i> coordinate
* @param width the width
* @param height the height
* @see RepaintManager
* @since 1.6
*/
public void
repaint(long
time, int
x, int
y, int
width, int
height) {
if (
RepaintManager.
HANDLE_TOP_LEVEL_PAINT) {
RepaintManager.
currentManager(this).
addDirtyRegion(
this,
x,
y,
width,
height);
}
else {
super.repaint(
time,
x,
y,
width,
height);
}
}
/**
* Returns a string representation of this JApplet. 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 JApplet.
*/
protected
String paramString() {
String rootPaneString = (
rootPane != null ?
rootPane.
toString() : "");
String rootPaneCheckingEnabledString = (
rootPaneCheckingEnabled ?
"true" : "false");
return super.paramString() +
",rootPane=" +
rootPaneString +
",rootPaneCheckingEnabled=" +
rootPaneCheckingEnabledString;
}
/////////////////
// Accessibility support
////////////////
protected
AccessibleContext accessibleContext = null;
/**
* Gets the AccessibleContext associated with this JApplet.
* For JApplets, the AccessibleContext takes the form of an
* AccessibleJApplet.
* A new AccessibleJApplet instance is created if necessary.
*
* @return an AccessibleJApplet that serves as the
* AccessibleContext of this JApplet
*/
public
AccessibleContext getAccessibleContext() {
if (
accessibleContext == null) {
accessibleContext = new
AccessibleJApplet();
}
return
accessibleContext;
}
/**
* This class implements accessibility support for the
* <code>JApplet</code> class.
*/
protected class
AccessibleJApplet extends
AccessibleApplet {
// everything moved to new parent, AccessibleApplet
}
}