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JavaTM 2 Platform Standard Edition |
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SUMMARY: INNER | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Object | +--java.awt.Component | +--java.awt.Container | +--java.awt.Panel | +--java.applet.Applet | +--javax.swing.JApplet
An extended version of java.applet.Applet that adds support for interposing input and painting behavior in front of the applets children (see glassPane), support for special children that are managed by a LayeredPane (see rootPane) and for Swing MenuBars.
The JApplet class is slightly incompatible with java.applet.Applet. JApplet contains a JRootPane as it's only child. The contentPane should be the parent of any children of the JApplet. This is different than java.applet.Applet, e.g. to add a child to an an java.applet.Applet you'd write:
applet.add(child);However using JApplet you need to add the child to the JApplet's contentPane instead:
applet.getContentPane().add(child);The same is true for setting LayoutManagers, removing components, listing children, etc. All these methods should normally be sent to the contentPane() instead of the JApplet itself. The contentPane() will always be non-null. Attempting to set it to null will cause the JApplet to throw an exception. The default contentPane() will have a BorderLayout manager set on it.
Please see the JRootPane documentation for a complete description of the contentPane, glassPane, and layeredPane properties.
For the keyboard keys used by this component in the standard Look and Feel (L&F) renditions, see the JApplet key assignments.
Both Netscape Communicator and Internet Explorer 4.0 unconditionally print an error message to the Java console when an applet attempts to access the AWT system event queue. Swing applets do this once, to check if access is permitted. To prevent the warning message in a production applet one can set a client property called "defeatSystemEventQueueCheck" on the JApplets RootPane to any non null value, e.g:
JRootPane rp = myJApplet.getRootPane(); rp.putClientProperty("defeatSystemEventQueueCheck", Boolean.TRUE);We hope that future versions of the browsers will not have this limitation and we'll be able to retire this hack.
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. A future release of Swing will provide support for long term persistence.
Inner Class Summary | |
protected class |
JApplet.AccessibleJApplet
|
Field Summary | |
protected AccessibleContext |
accessibleContext
|
protected JRootPane |
rootPane
|
protected boolean |
rootPaneCheckingEnabled
|
Fields inherited from class java.awt.Component |
BOTTOM_ALIGNMENT,
CENTER_ALIGNMENT,
LEFT_ALIGNMENT,
RIGHT_ALIGNMENT,
TOP_ALIGNMENT |
Constructor Summary | |
JApplet()
Creates a swing applet instance. |
Method Summary | |
protected void |
addImpl(Component comp,
Object constraints,
int index)
By default, children may not be added directly to a this component, they must be added to its contentPane instead. |
protected JRootPane |
createRootPane()
Called by the constructor methods to create the default rootPane. |
AccessibleContext |
getAccessibleContext()
Get the AccessibleContext associated with this JApplet |
Container |
getContentPane()
Returns the contentPane object for this applet. |
Component |
getGlassPane()
Returns the glassPane object for this applet. |
JMenuBar |
getJMenuBar()
Returns the menubar set on this applet. |
JLayeredPane |
getLayeredPane()
Returns the layeredPane object for this applet. |
JRootPane |
getRootPane()
Returns the rootPane object for this applet. |
protected boolean |
isRootPaneCheckingEnabled()
|
protected String |
paramString()
Returns a string representation of this JApplet. |
protected void |
processKeyEvent(KeyEvent e)
Processes key events occurring on this component by dispatching them to any registered KeyListener objects. |
void |
remove(Component comp)
Removes the specified component from this container. |
void |
setContentPane(Container contentPane)
Sets the contentPane property. |
void |
setGlassPane(Component glassPane)
Sets the glassPane property. |
void |
setJMenuBar(JMenuBar menuBar)
Sets the menubar for this applet. |
void |
setLayeredPane(JLayeredPane layeredPane)
Sets the layeredPane property. |
void |
setLayout(LayoutManager manager)
By default the layout of this component may not be set, the layout of its contentPane should be set instead. |
protected void |
setRootPane(JRootPane root)
Sets the rootPane property. |
protected void |
setRootPaneCheckingEnabled(boolean enabled)
If true then calls to add() and setLayout() will cause an exception to be thrown. |
void |
update(Graphics g)
Just calls paint(g) . |
Methods inherited from class java.applet.Applet |
destroy,
getAppletContext,
getAppletInfo,
getAudioClip,
getAudioClip,
getCodeBase,
getDocumentBase,
getImage,
getImage,
getLocale,
getParameter,
getParameterInfo,
init,
isActive,
newAudioClip,
play,
play,
resize,
resize,
setStub,
showStatus,
start,
stop |
Methods inherited from class java.awt.Panel |
addNotify |
Methods inherited from class java.awt.Container |
add,
add,
add,
add,
add,
addContainerListener,
countComponents,
deliverEvent,
doLayout,
findComponentAt,
findComponentAt,
getAlignmentX,
getAlignmentY,
getComponent,
getComponentAt,
getComponentAt,
getComponentCount,
getComponents,
getInsets,
getLayout,
getMaximumSize,
getMinimumSize,
getPreferredSize,
insets,
invalidate,
isAncestorOf,
layout,
list,
list,
locate,
minimumSize,
paint,
paintComponents,
preferredSize,
print,
printComponents,
processContainerEvent,
processEvent,
remove,
removeAll,
removeContainerListener,
removeNotify,
setCursor,
setFont,
validate,
validateTree |
Methods inherited from class java.lang.Object |
clone,
equals,
finalize,
getClass,
hashCode,
notify,
notifyAll,
wait,
wait,
wait |
Field Detail |
protected JRootPane rootPane
getRootPane()
,
setRootPane(javax.swing.JRootPane)
protected boolean rootPaneCheckingEnabled
isRootPaneCheckingEnabled()
,
setRootPaneCheckingEnabled(boolean)
protected AccessibleContext accessibleContext
Constructor Detail |
public JApplet()
Method Detail |
protected JRootPane createRootPane()
protected void processKeyEvent(KeyEvent e)
KeyListener
objects.
This method is not called unless key events are enabled for this component. Key events are enabled when one of the following occurs:
KeyListener
object is registered
via addKeyListener
.
enableEvents
.
e
- the key event.KeyEvent
,
KeyListener
,
Component.addKeyListener(java.awt.event.KeyListener)
,
Component.enableEvents(long)
public void update(Graphics g)
paint(g)
. This method was overridden to
prevent an unneccessary call to clear the background.g
- the specified Graphics windowComponent.update(java.awt.Graphics)
public void setJMenuBar(JMenuBar menuBar)
menubar
- the menubar being placed in the appletgetJMenuBar()
public JMenuBar getJMenuBar()
setJMenuBar(javax.swing.JMenuBar)
protected boolean isRootPaneCheckingEnabled()
addImpl(java.awt.Component, java.lang.Object, int)
,
setLayout(java.awt.LayoutManager)
,
setRootPaneCheckingEnabled(boolean)
protected void setRootPaneCheckingEnabled(boolean enabled)
addImpl(java.awt.Component, java.lang.Object, int)
,
setLayout(java.awt.LayoutManager)
,
isRootPaneCheckingEnabled()
protected void addImpl(Component comp, Object constraints, int index)
thiComponent.getContentPane().add(child)An attempt to add to directly to this component will cause an runtime exception to be thrown. Subclasses can disable this behavior.
setRootPaneCheckingEnabled(boolean)
public void remove(Component comp)
comp
- the component to be removedContainer.add(java.awt.Component)
public void setLayout(LayoutManager manager)
thiComponent.getContentPane().setLayout(new BorderLayout())An attempt to set the layout of this component will cause an runtime exception to be thrown. Subclasses can disable this behavior.
setRootPaneCheckingEnabled(boolean)
public JRootPane getRootPane()
setRootPane(javax.swing.JRootPane)
,
RootPaneContainer.getRootPane()
protected void setRootPane(JRootPane root)
root
- the rootPane object for this appletgetRootPane()
public Container getContentPane()
setContentPane(java.awt.Container)
,
RootPaneContainer.getContentPane()
public void setContentPane(Container contentPane)
contentPane
- the contentPane object for this appletgetContentPane()
,
RootPaneContainer.setContentPane(java.awt.Container)
public JLayeredPane getLayeredPane()
setLayeredPane(javax.swing.JLayeredPane)
,
RootPaneContainer.getLayeredPane()
public void setLayeredPane(JLayeredPane layeredPane)
layeredPane
- the layeredPane object for this appletgetLayeredPane()
,
RootPaneContainer.setLayeredPane(javax.swing.JLayeredPane)
public Component getGlassPane()
setGlassPane(java.awt.Component)
,
RootPaneContainer.getGlassPane()
public void setGlassPane(Component glassPane)
glassPane
- the glassPane object for this appletgetGlassPane()
,
RootPaneContainer.setGlassPane(java.awt.Component)
protected String paramString()
null
.public AccessibleContext getAccessibleContext()
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JavaTM 2 Platform Standard Edition |
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