edu.berkeley.guir.lib.satin.watch
Class WatchableImpl

java.lang.Object
  |
  +--edu.berkeley.guir.lib.satin.watch.WatchableImpl

All Implemented Interfaces:

Cloneable, Serializable, Watchable

Direct Known Subclasses:

CommandSubsystem

public class WatchableImpl

extends Object

implements Watchable

This is a sample implementation of Watchable. It is designed to be used as a delegate class. That is, if you want to implement the Watchable interface but don't want to implement the methods, you can have a WatchableImpl object contained within and just delegate the Watchable methods to this object.

This class is intended to be a delegate, and is not really intended to be subclassed. Calling any of the normal notify methods causes RuntimeExceptions to be thrown, just to let you know you shouldn't be using this class this way.

 Revisions:  - SATIN-v1.0-1.0.0, Mar 08 1999, JH
               Created class
             - SATIN-v2.1-1.0.0, Aug 11 2000, JH
               Touched for SATIN release
 

Since:

JDK 1.2

Version:

SATIN-v2.1-1.0.0, Aug 11 2000

Author:

Jason Hong ( jasonh@cs.berkeley.edu )

See Also:

Serialized Form

Constructor Summary

WatchableImpl()

Method Summary

Watcher	addWatcher(Watcher w) Add a watcher to this object.
void	clearWatchers() Delete all watchers on this object.
Object	clone() Make a clone of this Watchable object.
int	countWatchers() Count the number of watchers watching this object.
void	disableNotify() Turn off ability to notify others.
void	enableNotify() Turn on ability to notify others.
boolean	hasNotifyEnabled() Check current ability to notify others.
void	notifyWatchers() Throws an exception.
void	notifyWatchers(Object arg) Throws an exception.
void	notifyWatchers(Watchable watchable)
void	notifyWatchers(Watchable watchable, Object arg) This is a convenience method if this class is used in a delegation fashion.
void	notifyWatchersDelete() Throws an exception.
void	notifyWatchersDelete(Watchable watchable) This is a convenience method if this class is used in a delegation fashion.
void	notifyWatchersUpdate(Object arg) Throws an exception.
void	notifyWatchersUpdate(String strProperty, Object oldVal, Object newVal) Throws an exception.
void	notifyWatchersUpdate(Watchable watchable) This is a convenience method if this class is used in a delegation fashion.
void	notifyWatchersUpdate(Watchable watchable, Object arg) This is a convenience method if this class is used in a delegation fashion.
void	notifyWatchersUpdate(Watchable watchable, String strProperty, Object oldVal, Object newVal) This is a convenience method if this class is used in a delegation fashion.
Watcher	removeWatcher(Watcher w) Delete a watcher on this object.
String	toString()

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

WatchableImpl

public WatchableImpl()

Method Detail

addWatcher

public Watcher addWatcher(Watcher w)

Description copied from interface: Watchable

Add a watcher to this object.

Specified by:

addWatcher in interface Watchable

Following copied from interface: edu.berkeley.guir.lib.satin.watch.Watchable

Parameters:

w - is the Watcher to add.

Returns:

a reference to the added Watcher.

countWatchers

public int countWatchers()

Description copied from interface: Watchable

Count the number of watchers watching this object.

Specified by:

countWatchers in interface Watchable

removeWatcher

public Watcher removeWatcher(Watcher w)

Description copied from interface: Watchable

Delete a watcher on this object.

Specified by:

removeWatcher in interface Watchable

Following copied from interface: edu.berkeley.guir.lib.satin.watch.Watchable

Returns:

a reference to the removed Watcher.

clearWatchers

public void clearWatchers()

Description copied from interface: Watchable

Delete all watchers on this object.

Specified by:

clearWatchers in interface Watchable

disableNotify

public void disableNotify()

Description copied from interface: Watchable

Turn off ability to notify others. This works like a counting semaphore. Every time you call this method, the enabled value is incremented by 1. The watch is enabled if and only if the value is 0.

Specified by:

disableNotify in interface Watchable

enableNotify

public void enableNotify()

Description copied from interface: Watchable

Turn on ability to notify others.

Specified by:

enableNotify in interface Watchable

Following copied from interface: edu.berkeley.guir.lib.satin.watch.Watchable

See Also:

Watchable.disableNotify()

hasNotifyEnabled

public boolean hasNotifyEnabled()

Description copied from interface: Watchable

Check current ability to notify others.

Specified by:

hasNotifyEnabled in interface Watchable

Following copied from interface: edu.berkeley.guir.lib.satin.watch.Watchable

See Also:

Watchable.disableNotify(), Watchable.enableNotify()

notifyWatchers

public void notifyWatchers()

Throws an exception. This method should not be called. Use one of the other notifyWatchers() methods, specifying the object using this implementation as the Watchable.

Specified by:

notifyWatchers in interface Watchable

notifyWatchers

public void notifyWatchers(Object arg)

Throws an exception. This method should not be called. Use one of the other notifyWatchers() methods, specifying the object using this implementation as the Watchable.

Specified by:

notifyWatchers in interface Watchable

notifyWatchers

public void notifyWatchers(Watchable watchable)

notifyWatchers

public void notifyWatchers(Watchable watchable,
                           Object arg)

This is a convenience method if this class is used in a delegation fashion. This lets you set who the Watchable object really is.

Parameters:

watchable - is the Watchable object that will be passed to the Watcher on the callback.

arg - is the generic argument.

See Also:

Watchable.notifyWatchers()

notifyWatchersUpdate

public void notifyWatchersUpdate(Object arg)

Throws an exception. This method should not be called. Use one of the other notifyWatchers() methods, specifying the object using this implementation as the Watchable.

Specified by:

notifyWatchersUpdate in interface Watchable

Following copied from interface: edu.berkeley.guir.lib.satin.watch.Watchable

Parameters:

arg - is the argument to send to all Watchers.

notifyWatchersUpdate

public void notifyWatchersUpdate(String strProperty,
                                 Object oldVal,
                                 Object newVal)

Throws an exception. This method should not be called. Use one of the other notifyWatchers() methods, specifying the object using this implementation as the Watchable.

Specified by:

notifyWatchersUpdate in interface Watchable

Following copied from interface: edu.berkeley.guir.lib.satin.watch.Watchable

Parameters:

strProperty - is some agreed upon name for the property.

oldVal - is the old value.

newVal - is the new value. It should be a clone, not a reference to the actual value, unless it is prohibitively expensive to clone. Whether this is a copy or a reference should be defined in the SatinConstants file.

See Also:

SatinConstants

notifyWatchersUpdate

public void notifyWatchersUpdate(Watchable watchable)

This is a convenience method if this class is used in a delegation fashion. This lets you set who the Watchable object really is. Sends a null argument.

Parameters:

watchable - is the Watchable object that will be passed to the Watcher on the callback.

See Also:

Watchable.notifyWatchersUpdate(Object)

notifyWatchersUpdate

public void notifyWatchersUpdate(Watchable watchable,
                                 Object arg)

This is a convenience method if this class is used in a delegation fashion. This lets you set who the Watchable object really is.

Parameters:

watchable - is the Watchable object that will be passed to the Watcher on the callback.

arg - is the argument to send.

notifyWatchersUpdate

public void notifyWatchersUpdate(Watchable watchable,
                                 String strProperty,
                                 Object oldVal,
                                 Object newVal)

This is a convenience method if this class is used in a delegation fashion. This lets you set who the Watchable object really is.

Parameters:

watchable - is the Watchable object that will be passed to the Watcher on the callback.

strProperty - is the agreed-upon name of the property.

oldVal - is the old value of the property.

newVal - is the new value of the property.

See Also:

Watchable.notifyWatchersUpdate(String, Object, Object)

notifyWatchersDelete

public void notifyWatchersDelete()

Throws an exception. This method should not be called. Use one of the other notifyWatchers() methods, specifying the object using this implementation as the Watchable.

Specified by:

notifyWatchersDelete in interface Watchable

notifyWatchersDelete

public void notifyWatchersDelete(Watchable watchable)

This is a convenience method if this class is used in a delegation fashion. This lets you set who the Watchable object really is.

Parameters:

watchable - is the Watchable object that will be passed to the Watcher on the callback.

See Also:

Watchable.notifyWatchersDelete()

toString

public String toString()

Overrides:

toString in class Object

clone

public Object clone()

Description copied from interface: Watchable

Make a clone of this Watchable object.

Specified by:

clone in interface Watchable

Overrides:

clone in class Object