com.sas.util
Class AppletHost

com.sas.util.AppletHost

All Implemented Interfaces:

java.applet.AppletContext, java.applet.AppletStub, java.awt.event.ActionListener, java.awt.image.ImageObserver, java.awt.MenuContainer, java.io.Serializable, java.util.EventListener, javax.accessibility.Accessible

public class AppletHost
implements java.applet.AppletStub, java.applet.AppletContext, java.awt.event.ActionListener

AppletHost - implements AppletContext and AppletStub to allow any applet to easily run as an application. The only thing it can't do is access URL's. Applet parameters are entered on the command line with name as one word and value as the next.

See Also:

Serialized Form

Field Summary

protected java.util.Vector	applets
protected int	initial_height
protected int	initial_width
protected java.util.Hashtable	params
protected java.awt.Button	startButton
protected java.awt.TextField	status
protected java.awt.Button	stopButton

Constructor Summary

AppletHost(java.applet.Applet applet, int default_width, int default_height, java.lang.String[] args)
Constructor for the main class, given an existing applet object and a default frame (window) width and height.

AppletHost(java.applet.Applet applet, java.lang.String[] args)
Constructor for the main class, given an existing applet object.

AppletHost(java.lang.String[] args)
Constructor for the main class, from the command line arguments.

AppletHost(java.lang.String appletClassName, int default_width, int default_height, java.lang.String[] args)
Constructor for the main class, given a name of an applet object and a default frame (window) width and height.

Method Summary

void	actionPerformed(java.awt.event.ActionEvent evt)
void	appletResize(int width, int height) Called when the applet wants to be resized.
java.applet.Applet	getApplet(java.lang.String name) Gets an applet by name.
java.applet.AppletContext	getAppletContext() Gets a handler to the applet's context.
java.util.Enumeration	getApplets() Enumerates the applets in this context.
java.applet.AudioClip	getAudioClip(java.net.URL url) Gets an audio clip.
java.net.URL	getCodeBase() Gets the codebase URL.
java.net.URL	getDocumentBase() Gets the document URL.
java.awt.Image	getImage(java.net.URL url) Gets an image.
java.lang.String	getParameter(java.lang.String name) Gets a parameter of the applet.
java.io.InputStream	getStream(java.lang.String key) Returns the stream to which specified key is associated within this applet context.
java.util.Iterator	getStreamKeys() Finds all the keys of the streams in this applet context.
boolean	isActive() Returns true if the applet is active.
static void	main(java.lang.String[] args) Entry point into the standalone program.
void	parseArgs(java.lang.String[] args, int startidx) Parse the command line arguments.
void	processWindowEvent(java.awt.event.WindowEvent evt)
void	setStream(java.lang.String key, java.io.InputStream stream) Associates the specified stream with the specified key in this applet context.
void	showDocument(java.net.URL url) Shows a new document.
void	showDocument(java.net.URL url, java.lang.String target) Show a new document in a target window or frame.
void	showStatus(java.lang.String text) Show a status string in the status area (the Text object at the bottom of the window.

Field Detail

status

protected java.awt.TextField status

startButton

protected java.awt.Button startButton

stopButton

protected java.awt.Button stopButton

params

protected java.util.Hashtable params

applets

protected java.util.Vector applets

initial_width

protected int initial_width

initial_height

protected int initial_height

Constructor Detail

AppletHost

public AppletHost(java.applet.Applet applet,
                  java.lang.String[] args)

Constructor for the main class, given an existing applet object.

Parameters:

applet - the applet embedded in this AppletContext

args - the command line arguments. Contains possibly height and width, and any applet parameters

AppletHost

public AppletHost(java.applet.Applet applet,
                  int default_width,
                  int default_height,
                  java.lang.String[] args)

Constructor for the main class, given an existing applet object and a default frame (window) width and height.

Parameters:

applet - the applet embedded in this AppletContext

default_width - the default width of the window

default_height - the default width of the window

args - the command line arguments. Contains possibly height and width, and any applet parameters

AppletHost

public AppletHost(java.lang.String appletClassName,
                  int default_width,
                  int default_height,
                  java.lang.String[] args)

Constructor for the main class, given a name of an applet object and a default frame (window) width and height.

Parameters:

appletClassName - the applet embedded in this AppletContext

default_width - the default width of the window

default_height - the default width of the window

args - the command line arguments. Contains possibly height and width, and any applet parameters

AppletHost

public AppletHost(java.lang.String[] args)

Constructor for the main class, from the command line arguments.

Parameters:

args - the command line arguments. Contains the name of the applet class, possibly height and width, and any applet parameters.

Method Detail

main

public static void main(java.lang.String[] args)

Entry point into the standalone program.

Parameters:

args - the command line arguments

parseArgs

public void parseArgs(java.lang.String[] args,
                      int startidx)

Parse the command line arguments. Get the initial width and height of the window if specified (-width [value] -height [value]), and the applet parameters (name value pairs, or name=value).

Parameters:

args - the command line arguments. Contains possibly height and width, and any applet parameters

startidx - index in the args array at which to start parsing

processWindowEvent

public void processWindowEvent(java.awt.event.WindowEvent evt)

Overrides:

processWindowEvent in class java.awt.Window

actionPerformed

public void actionPerformed(java.awt.event.ActionEvent evt)

Specified by:

actionPerformed in interface java.awt.event.ActionListener

isActive

public boolean isActive()

Returns true if the applet is active.

Specified by:

isActive in interface java.applet.AppletStub

Overrides:

isActive in class java.awt.Window

Returns:

always true

getDocumentBase

public java.net.URL getDocumentBase()

Gets the document URL.

Specified by:

getDocumentBase in interface java.applet.AppletStub

Returns:

a "file:" URL for the current directory

getCodeBase

public final java.net.URL getCodeBase()

Gets the codebase URL.

Specified by:

getCodeBase in interface java.applet.AppletStub

Returns:

in this case, the same value as getDocumentBase()

getParameter

public final java.lang.String getParameter(java.lang.String name)

Gets a parameter of the applet.

Specified by:

getParameter in interface java.applet.AppletStub

Parameters:

name - the name of the parameter

Returns:

the value, or null if not defined

getAppletContext

public final java.applet.AppletContext getAppletContext()

Gets a handler to the applet's context.

Specified by:

getAppletContext in interface java.applet.AppletStub

Returns:

this object

appletResize

public void appletResize(int width,
                         int height)

Called when the applet wants to be resized. This causes the Frame (window) to be resized to accomodate the new Applet size.

Specified by:

appletResize in interface java.applet.AppletStub

Parameters:

width - the new width of the applet

height - the new height of the applet

getAudioClip

public final java.applet.AudioClip getAudioClip(java.net.URL url)

Gets an audio clip. (There doesn't seem to be a "Toolkit" for audio clips in my JDK, so this always returns null. You could implement this differently, returning a dummy AudioClip object for which the class could be defined at the bottom of this file.)

Specified by:

getAudioClip in interface java.applet.AppletContext

Parameters:

url - URL of the AudioClip to load

Returns:

the AudioClip object if it exists (in our case, this is always null

getImage

public final java.awt.Image getImage(java.net.URL url)

Gets an image. This usually involves downloading it over the net. However, the environment may decide to cache images. This method takes an array of URLs, each of which will be tried until the image is found.

Specified by:

getImage in interface java.applet.AppletContext

Parameters:

url - URL of the Image to load

Returns:

the Image object

getApplet

public final java.applet.Applet getApplet(java.lang.String name)

Gets an applet by name.

Specified by:

getApplet in interface java.applet.AppletContext

Parameters:

name - the name of the applet

Returns:

null if the applet does not exist, and it never does since we never name the applet.

getApplets

public final java.util.Enumeration getApplets()

Enumerates the applets in this context. Only applets that are accessible will be returned. This list always includes the applet itself.

Specified by:

getApplets in interface java.applet.AppletContext

Returns:

the Enumeration -- contains ONLY the applet created with this DummyAppletContext

showDocument

public void showDocument(java.net.URL url)

Shows a new document. This may be ignored by the applet context (and in our case, it is, but we'll show the user, in the status area, that the document was requested and WOULD be loaded if in a browser).

Specified by:

showDocument in interface java.applet.AppletContext

Parameters:

url - URL to load

showDocument

public void showDocument(java.net.URL url,
                         java.lang.String target)

Show a new document in a target window or frame. This may be ignored by the applet context. (Again, it is ignored, but we'll show the request information to the user in the status area.) This method accepts the target strings: _self show in current frame _parent show in parent frame _top show in top-most frame _blank show in new unnamed top-level window show in new top-level window named

Specified by:

showDocument in interface java.applet.AppletContext

Parameters:

url - URL to load

target - the target string

showStatus

public void showStatus(java.lang.String text)

Show a status string in the status area (the Text object at the bottom of the window.

Specified by:

showStatus in interface java.applet.AppletContext

Parameters:

text - the text to display

getStream

public java.io.InputStream getStream(java.lang.String key)

Returns the stream to which specified key is associated within this applet context.

Specified by:

getStream in interface java.applet.AppletContext

getStreamKeys

public java.util.Iterator getStreamKeys()

Finds all the keys of the streams in this applet context.

Specified by:

getStreamKeys in interface java.applet.AppletContext

setStream

public void setStream(java.lang.String key,
                      java.io.InputStream stream)

Associates the specified stream with the specified key in this applet context.

Specified by:

setStream in interface java.applet.AppletContext