Class java.applet.Applet
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Class java.applet.Applet
Object
|
+----Component
|
+----Container
|
+----Panel
|
+----java.applet.Applet
- public class Applet
- extends Panel
An applet is a small program that is intended not to be run on
its own, but rather to be embedded inside another application.
The Applet
class must be the superclass of any
applet that is to be embedded in a Web page or viewed by the Java
Applet Viewer. The Applet
class provides a standard
interface between applets and their environment.
- Version:
- 1.43, 07/01/98
- Author:
- Arthur van Hoff, Chris Warth
- Since:
- JDK1.0
-
java.applet.Applet()
-
-
destroy()
- Called by the browser or applet viewer to inform
this applet that it is being reclaimed and that it should destroy
any resources that it has allocated.
-
getAppletContext()
- Determines this applet's context, which allows the applet to
query and affect the environment in which it runs.
-
getAppletInfo()
- Returns information about this applet.
-
getAudioClip(URL)
- Returns the
AudioClip
object specified by the
URL
argument.
-
getAudioClip(URL, String)
- Returns the
AudioClip
object specified by the
URL
and name
arguments.
-
getCodeBase()
- Gets the base URL.
-
getDocumentBase()
- Gets the document URL.
-
getImage(URL)
- Returns an
Image
object that can then be painted on
the screen.
-
getImage(URL, String)
- Returns an
Image
object that can then be painted on
the screen.
-
getLocale()
-
Gets the Locale for the applet, if it has been set.
-
getParameter(String)
- Returns the value of the named parameter in the HTML tag.
-
getParameterInfo()
- Returns information about the parameters than are understood by
this applet.
-
init()
- Called by the browser or applet viewer to inform
this applet that it has been loaded into the system.
-
isActive()
- Determines if this applet is active.
-
play(URL)
- Plays the audio clip at the specified absolute URL.
-
play(URL, String)
- Plays the audio clip given the URL and a specifier that is
relative to it.
-
resize(int, int)
- Requests that this applet be resized.
-
resize(Dimension)
- Requests that this applet be resized.
-
setStub(AppletStub)
- Sets this applet's stub.
-
showStatus(String)
- Requests that the argument string be displayed in the
"status window".
-
start()
- Called by the browser or applet viewer to inform
this applet that it should start its execution.
-
stop()
- Called by the browser or applet viewer to inform
this applet that it should stop its execution.
Applet
public Applet()
destroy
public void destroy()
- Called by the browser or applet viewer to inform
this applet that it is being reclaimed and that it should destroy
any resources that it has allocated. The
stop
method
will always be called before destroy
.
A subclass of Applet
should override this method if
it has any operation that it wants to perform before it is
destroyed. For example, an applet with threads would use the
init
method to create the threads and the
destroy
method to kill them.
The implementation of this method provided by the
Applet
class does nothing.
- Since:
- JDK1.0
- See Also:
- init(), start(), stop()
getAppletContext
public java.applet.AppletContext getAppletContext()
- Determines this applet's context, which allows the applet to
query and affect the environment in which it runs.
This environment of an applet represents the document that
contains the applet.
- Returns:
- the applet's context.
- Since:
- JDK1.0
getAppletInfo
public java.lang.String getAppletInfo()
- Returns information about this applet. An applet should override
this method to return a
String
containing information
about the author, version, and copyright of the applet.
The implementation of this method provided by the
Applet
class returns null
.
- Returns:
- a string containing information about the author, version, and
copyright of the applet.
- Since:
- JDK1.0
getAudioClip
public java.applet.AudioClip getAudioClip(URL url)
- Returns the
AudioClip
object specified by the
URL
argument.
This method always returns immediately, whether or not the audio
clip exists. When this applet attempts to play the audio clip, the
data will be loaded.
- Parameters:
- url - an absolute URL giving the location of the audio clip.
- Returns:
- the audio clip at the specified URL.
- Since:
- JDK1.0
- See Also:
- AudioClip
getAudioClip
public java.applet.AudioClip getAudioClip(URL url,
String name)
- Returns the
AudioClip
object specified by the
URL
and name
arguments.
This method always returns immediately, whether or not the audio
clip exists. When this applet attempts to play the audio clip, the
data will be loaded.
- Parameters:
- url - an absolute URL giving the base location of the
audio clip.
- name - the location of the audio clip, relative to the
url
argument.
- Returns:
- the audio clip at the specified URL.
- Since:
- JDK1.0
- See Also:
- AudioClip
getCodeBase
public java.net.URL getCodeBase()
- Gets the base URL. This is the URL of the applet itself.
- Returns:
- the
URL
of
this applet.
- Since:
- JDK1.0
- See Also:
- getDocumentBase()
getDocumentBase
public java.net.URL getDocumentBase()
- Gets the document URL. This is the URL of the document in which
the applet is embedded.
- Returns:
- the
URL
of
the document that contains this applet.
- Since:
- JDK1.0
- See Also:
- getCodeBase()
getImage
public java.awt.Image getImage(URL url)
- Returns an
Image
object that can then be painted on
the screen. The url
that is passed as an argument
must specify an absolute URL.
This method always returns immediately, whether or not the image
exists. When this applet attempts to draw the image on the screen,
the data will be loaded. The graphics primitives that draw the
image will incrementally paint on the screen.
- Parameters:
- url - an absolute URL giving the location of the image.
- Returns:
- the image at the specified URL.
- Since:
- JDK1.0
- See Also:
- Image
getImage
public java.awt.Image getImage(URL url,
String name)
- Returns an
Image
object that can then be painted on
the screen. The url
argument must specify an absolute
URL. The name
argument is a specifier that is
relative to the url
argument.
This method always returns immediately, whether or not the image
exists. When this applet attempts to draw the image on the screen,
the data will be loaded. The graphics primitives that draw the
image will incrementally paint on the screen.
- Parameters:
- url - an absolute URL giving the base location of the image.
- name - the location of the image, relative to the
url
argument.
- Returns:
- the image at the specified URL.
- Since:
- JDK1.0
- See Also:
- Image
getLocale
public java.util.Locale getLocale()
- Gets the Locale for the applet, if it has been set.
If no Locale has been set, then the default Locale
is returned.
- Returns:
- [Needs to be documented!]
- Overrides:
- getLocale in class Component
- Since:
- JDK1.1
getParameter
public java.lang.String getParameter(String name)
- Returns the value of the named parameter in the HTML tag. For
example, if this applet is specified as
<applet code="Clock" width=50 height=50>
<param name=Color value="blue">
</applet>
then a call to getParameter("Color")
returns the
value "blue"
.
The name
argument is case insensitive.
- Parameters:
- name - a parameter name.
- Returns:
- the value of the named parameter.
- Since:
- JDK1.0
getParameterInfo
public java.lang.String[][] getParameterInfo()
- Returns information about the parameters than are understood by
this applet. An applet should override this method to return an
array of
Strings
describing these parameters.
Each element of the array should be a set of three
Strings
containing the name, the type, and a
description. For example:
String pinfo[][] = {
{"fps", "1-10", "frames per second"},
{"repeat", "boolean", "repeat image loop"},
{"imgs", "url", "images directory"}
};
The implementation of this method provided by the
Applet
class returns null
.
- Returns:
- an array describing the parameters this applet looks for.
- Since:
- JDK1.0
init
public void init()
- Called by the browser or applet viewer to inform
this applet that it has been loaded into the system. It is always
called before the first time that the
start
method is
called.
A subclass of Applet
should override this method if
it has initialization to perform. For example, an applet with
threads would use the init
method to create the
threads and the destroy
method to kill them.
The implementation of this method provided by the
Applet
class does nothing.
- Since:
- JDK1.0
- See Also:
- destroy(), start(), stop()
isActive
public boolean isActive()
- Determines if this applet is active. An applet is marked active
just before its
start
method is called. It becomes
inactive immediately after its stop
method is called.
- Returns:
-
true
if the applet is active;
false
otherwise.
- Since:
- JDK1.0
- See Also:
- start(), stop()
play
public void play(URL url)
- Plays the audio clip at the specified absolute URL. Nothing
happens if the audio clip cannot be found.
- Parameters:
- url - an absolute URL giving the location of the audio clip.
- Since:
- JDK1.0
play
public void play(URL url,
String name)
- Plays the audio clip given the URL and a specifier that is
relative to it. Nothing happens if the audio clip cannot be found.
- Parameters:
- url - an absolute URL giving the base location of the
audio clip.
- name - the location of the audio clip, relative to the
url
argument.
- Since:
- JDK1.0
resize
public void resize(int width,
int height)
- Requests that this applet be resized.
- Parameters:
- width - the new requested width for the applet.
- height - the new requested height for the applet.
- Overrides:
- resize in class Component
- Since:
- JDK1.0
resize
public void resize(Dimension d)
- Requests that this applet be resized.
- Parameters:
- d - an object giving the new width and height.
- Overrides:
- resize in class Component
- Since:
- JDK1.0
setStub
public final void setStub(AppletStub stub)
- Sets this applet's stub. This is done automatically by the system.
- Parameters:
- stub - the new stub.
- Since:
- JDK1.0
showStatus
public void showStatus(String msg)
- Requests that the argument string be displayed in the
"status window". Many browsers and applet viewers
provide such a window, where the application can inform users of
its current state.
- Parameters:
- msg - a string to display in the status window.
- Since:
- JDK1.0
start
public void start()
- Called by the browser or applet viewer to inform
this applet that it should start its execution. It is called after
the
init
method and each time the applet is revisited
in a Web page.
A subclass of Applet
should override this method if
it has any operation that it wants to perform each time the Web
page containing it is visited. For example, an applet with
animation might want to use the start
method to
resume animation, and the stop
method to suspend the
animation.
The implementation of this method provided by the
Applet
class does nothing.
- Since:
- JDK1.0
- See Also:
- destroy(), init(), stop()
stop
public void stop()
- Called by the browser or applet viewer to inform
this applet that it should stop its execution. It is called when
the Web page that contains this applet has been replaced by
another page, and also just before the applet is to be destroyed.
A subclass of Applet
should override this method if
it has any operation that it wants to perform each time the Web
page containing it is no longer visible. For example, an applet
with animation might want to use the start
method to
resume animation, and the stop
method to suspend the
animation.
The implementation of this method provided by the
Applet
class does nothing.
- Since:
- JDK1.0
- See Also:
- destroy(), init()
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