objectdraw
Class ActiveObject

java.lang.Object
  java.lang.Thread
      objectdraw.ActiveObject

All Implemented Interfaces:

java.lang.Runnable

public class ActiveObject

extends java.lang.Thread

The class ActiveObject is used to define objects controlled by sequences of instructions that are executed independently of and simultaneously with other instructions in a program. The code that is to be executed independently should be placed in the body of a parameterless run method defined within a class definition that extends ActiveObject. When the start() method of an ActiveObject is invoked, the system will being to execute whatever code was placed in this run method.

ActiveObject is a simple extension of Java's native Thread class. ActiveObjects are automatically managed so that they are suspended and restarted when an applet is stopped and started. In addition, the sleep method provided in the Thread class is replaced with a similar pause method that does not require exception handling.

Version:

1.1.2 released July 2006

Field Summary

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

ActiveObject()
Construct an ActiveObject.

ActiveObject(java.lang.String name)
Constructs an ActiveObject with a given name.

ActiveObject(java.lang.ThreadGroup group, java.lang.Runnable target, java.lang.String name)
Construct a new ActiveObject with the specified name using the Runnable and ThreadGroup parameters to determine its behavior.

Method Summary

static void	defer() Deprecated. use ActiveObject.yield() instead
static double	getTime() Deprecated. use System.currentTimeMillis()
static void	pause(double millis) Suspend the execution of this ActiveObject for at least the time period specified.
static void	pause(long millis) Suspend the execution of this ActiveObject for at least the time period specified.
static void	pause(long millis, int nano) Suspend the execution of this ActiveObject for at least the time period specified.
static void	yield() Briefly suspend the execution of this ActiveObject code to see if any other ActiveObject or Thread is waiting to execute.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getContextClassLoader, getName, getPriority, getThreadGroup, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, run, setContextClassLoader, setDaemon, setName, setPriority, sleep, sleep, start, stop, stop, suspend, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ActiveObject

public ActiveObject()

Construct an ActiveObject.

ActiveObject

public ActiveObject(java.lang.String name)

Constructs an ActiveObject with a given name.

Parameters:

name - the name of the new ActiveObject.

ActiveObject

public ActiveObject(java.lang.ThreadGroup group,
                    java.lang.Runnable target,
                    java.lang.String name)

Construct a new ActiveObject with the specified name using the Runnable and ThreadGroup parameters to determine its behavior. If the target argument is not null, the run method of the target is executed when this thread is started. If the target argument is null, this thread's run method is executed when this thread is started. If group is null and there is a security manager, the group is determined by the security manager's getThreadGroup method. If group is null and there is not a security manager, or the security manager's getThreadGroup method returns null, the group is set to be the same ThreadGroup as the thread that is creating the new thread. If there is a security manager, its checkAccess method is called with the ThreadGroup as its argument. This may result in a SecurityException.

Parameters:

group - the thread group.

target - the object whose run method is called.

name - the name of the new ActiveObject.

Method Detail

defer

public static void defer()

Deprecated. use ActiveObject.yield() instead

Briefly suspend the execution of this ActiveObjects code to see if any other ActiveObject or Thread is waiting to execute. In addition, this method checks to see if the Controller has requested that this ActiveObject suspend or terminate its execution.

yield

public static void yield()

Briefly suspend the execution of this ActiveObject code to see if any other ActiveObject or Thread is waiting to execute. In addition, this method checks to see if the Controller has requested that this ActiveObject suspend or terminate its execution.

pause

public static void pause(long millis)

Suspend the execution of this ActiveObject for at least the time period specified.

Parameters:

millis - number of milliseconds to pause.

pause

public static void pause(double millis)

Suspend the execution of this ActiveObject for at least the time period specified.

Parameters:

millis - number of milliseconds to pause.

pause

public static void pause(long millis,
                         int nano)

Suspend the execution of this ActiveObject for at least the time period specified.

Parameters:

millis - number of milliseconds to pause.

nano - additional number of nanoseconds to pause.

getTime

public static double getTime()

Deprecated. use System.currentTimeMillis()

In earlier versions of objectdraw, this method was provided to determine the current time in milliseconds. It is now deprecated and throws an exception if invoked.

Returns:

nothing