public class JApplet extends Applet implements Accessible, RootPaneContainer
An extended version of java.applet.Applet that adds support for the JFC/Swing component architecture. You can find task-oriented documentation about using JApplet in The Java Tutorial, in the section How to Make Applets.
The JApplet class is slightly incompatible with java.applet.Applet. JApplet contains a JRootPane as its only child. The contentPane should be the parent of any children of the JApplet. As a convenience, the add, remove, and setLayout methods of this class are overridden, so that they delegate calls to the corresponding methods of the ContentPane. For example, you can add a child component to an applet as follows:
applet.add(child);And the child will be added to the
contentPane. 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. Refer to RootPaneContainer for details on adding, removing and setting the LayoutManager of a JApplet. Please see the JRootPane documentation for a complete description of the contentPane, glassPane, and layeredPane properties.
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.
RootPaneContainer| Modifier and Type | Class and Description |
|---|---|
protected class |
JApplet.AccessibleJApplet This class implements accessibility support for the |
Applet.AccessibleApplet Panel.AccessibleAWTPanel Container.AccessibleAWTContainer Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy protected JRootPane rootPane
getRootPane(), setRootPane(javax.swing.JRootPane)
protected boolean rootPaneCheckingEnabled
If true then calls to add and setLayout will be forwarded to the contentPane. This is initially false, but is set to true when the JApplet is constructed.
protected AccessibleContext accessibleContext
public JApplet()
throws HeadlessException Creates a swing applet instance.
This constructor sets the component's locale property to the value returned by JComponent.getDefaultLocale.
HeadlessException - if GraphicsEnvironment.isHeadless() returns true.GraphicsEnvironment.isHeadless(), JComponent.getDefaultLocale()
protected JRootPane createRootPane()
Called by the constructor methods to create the default rootPane.
public void setTransferHandler(TransferHandler newHandler)
Sets the transferHandler property, which is a mechanism to support transfer of data into this component. Use null if the component does not support data transfer operations.
If the system property suppressSwingDropSupport is false (the default) and the current drop target on this component is either null or not a user-set drop target, this method will change the drop target as follows: If newHandler is null it will clear the drop target. If not null it will install a new DropTarget.
Note: When used with JApplet, TransferHandler only provides data import capability, as the data export related methods are currently typed to JComponent.
Please see How to Use Drag and Drop and Data Transfer, a section in The Java Tutorial, for more information.
newHandler - the new TransferHandler
TransferHandler, getTransferHandler(), Component.setDropTarget(java.awt.dnd.DropTarget)
public TransferHandler getTransferHandler()
Gets the transferHandler property.
transferHandler propertyTransferHandler, setTransferHandler(javax.swing.TransferHandler)
public void update(Graphics g)
Just calls paint(g). This method was overridden to prevent an unnecessary call to clear the background.
update in class Container
g - the specified Graphics windowComponent.update(Graphics)public void setJMenuBar(JMenuBar menuBar)
Sets the menubar for this applet.
menuBar - the menubar being placed in the appletgetJMenuBar()public JMenuBar getJMenuBar()
Returns the menubar set on this applet.
setJMenuBar(javax.swing.JMenuBar)protected boolean isRootPaneCheckingEnabled()
Returns whether calls to add and setLayout are forwarded to the contentPane.
add and setLayout are forwarded; false otherwiseaddImpl(java.awt.Component, java.lang.Object, int), setLayout(java.awt.LayoutManager), setRootPaneCheckingEnabled(boolean), RootPaneContainer
protected void setRootPaneCheckingEnabled(boolean enabled)
Sets whether calls to add and setLayout are forwarded to the contentPane.
enabled - true if add and setLayout are forwarded, false if they should operate directly on the JApplet.addImpl(java.awt.Component, java.lang.Object, int), setLayout(java.awt.LayoutManager), isRootPaneCheckingEnabled(), RootPaneContainer
protected void addImpl(Component comp,
Object constraints,
int index) Adds the specified child Component. This method is overridden to conditionally forward calls to the contentPane. By default, children are added to the contentPane instead of the frame, refer to RootPaneContainer for details.
addImpl in class Container
comp - the component to be enhancedconstraints - the constraints to be respectedindex - the indexIllegalArgumentException - if index is invalidIllegalArgumentException - if adding the container's parent to itselfIllegalArgumentException - if adding a window to a containersetRootPaneCheckingEnabled(boolean), RootPaneContainer
public void remove(Component comp)
Removes the specified component from the container. If comp is not the rootPane, this will forward the call to the contentPane. This will do nothing if comp is not a child of the JFrame or contentPane.
remove in class Container
comp - the component to be removedNullPointerException - if comp is nullContainer.add(java.awt.Component), RootPaneContainer
public void setLayout(LayoutManager manager)
Sets the LayoutManager. Overridden to conditionally forward the call to the contentPane. Refer to RootPaneContainer for more information.
setLayout in class Container
manager - the LayoutManager
setRootPaneCheckingEnabled(boolean), RootPaneContainer
public JRootPane getRootPane()
Returns the rootPane object for this applet.
getRootPane in interface RootPaneContainer
setRootPane(javax.swing.JRootPane), RootPaneContainer.getRootPane()
protected void setRootPane(JRootPane root)
Sets the rootPane property. This method is called by the constructor.
root - the rootPane object for this appletgetRootPane()public Container getContentPane()
Returns the contentPane object for this applet.
getContentPane in interface RootPaneContainer
setContentPane(java.awt.Container), RootPaneContainer.getContentPane()
public void setContentPane(Container contentPane)
Sets the contentPane property. This method is called by the constructor.
setContentPane in interface RootPaneContainer
contentPane - the contentPane object for this appletIllegalComponentStateException - (a runtime exception) if the content pane parameter is nullgetContentPane(), RootPaneContainer.setContentPane(java.awt.Container)
public JLayeredPane getLayeredPane()
Returns the layeredPane object for this applet.
getLayeredPane in interface RootPaneContainer
IllegalComponentStateException - (a runtime exception) if the layered pane parameter is nullsetLayeredPane(javax.swing.JLayeredPane), RootPaneContainer.getLayeredPane()
public void setLayeredPane(JLayeredPane layeredPane)
Sets the layeredPane property. This method is called by the constructor.
setLayeredPane in interface RootPaneContainer
layeredPane - the layeredPane object for this appletgetLayeredPane(), RootPaneContainer.setLayeredPane(javax.swing.JLayeredPane)
public Component getGlassPane()
Returns the glassPane object for this applet.
getGlassPane in interface RootPaneContainer
setGlassPane(java.awt.Component), RootPaneContainer.getGlassPane()
public void setGlassPane(Component glassPane)
Sets the glassPane property. This method is called by the constructor.
setGlassPane in interface RootPaneContainer
glassPane - the glassPane object for this appletgetGlassPane(), RootPaneContainer.setGlassPane(java.awt.Component)
public Graphics getGraphics()
Creates a graphics context for this component. This method will return null if this component is currently not displayable.
getGraphics in class Component
null if it has noneComponent.paint(java.awt.Graphics)public void repaint(long time,
int x,
int y,
int width,
int height) Repaints the specified rectangle of this component within time milliseconds. Refer to RepaintManager for details on how the repaint is handled.
repaint in class Component
time - maximum time in milliseconds before updatex - the x coordinatey - the y coordinatewidth - the widthheight - the heightRepaintManagerprotected String paramString()
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 null.
paramString in class Container
public AccessibleContext getAccessibleContext()
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.
getAccessibleContext in interface Accessible
getAccessibleContext in class Applet
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