jas.engine
Class SimEngine

java.lang.Object
  jas.engine.SimEngine

All Implemented Interfaces:

ISimEventListener

public class SimEngine
extends java.lang.Object
implements ISimEventListener

The simulation engine. The engine keeps a reference to an EventList object to manage temporal sequence of events. Every object of the running simulation can schedule events at a specified time point and the engine will notify to it at the right time. The SimEngine stores a list of windows created by models. Using the addSimWindow() method each simulation windows is managed by the engine. It is able to show windows detroyed by user. When the windows is shown the engine put the windows in the location where it was when the project document was saved to disk. The window size is stored, too.

Title: JAS

Description: Java Agent-based Simulation library

Copyright (C) 2002 Michele Sonnessa

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.

Author:

Michele Sonnessa

Constructor Summary

SimEngine()
Build a new SimEngine with the TIME-TICKS time unit.

SimEngine(int timeUnit)
Build a new SimEngine with the given time unit.

Method Summary

void	addEngineListener(ISimEngineListener engineListener) Install a listener for events generated by the simulation engine.
void	addModel(ISimModel model) Notify the engine to manage a SimModel.
void	addSimWindow(ISimModel owner, java.awt.Container window) Add a frame window to a local windowBag.
void	buildModels() Call the buildModel() method of each active SimModel.
void	disableRealTime() Disable the real time mode.
java.lang.Class[]	disposeModels() Dispose from memory all running models.
void	enableRealTime() Enable the real time mode.
void	end() Stops the simulation and call the simulationEnd method of each running model.
java.util.ArrayList	getEngineListeners()
EventList	getEventList() Return a reference to the current EventList.
boolean	getModelBuildStatus() Return true if buildModels() method has been called.
java.lang.Object[]	getModels() Return an array representing the running SimModels.
ISimModel	getModelWithID(java.lang.String id) Return a model with the given id string.
long	getRandomSeed() Return the current random seed.
RandomGenerator	getRnd() Return a reference to the current Random generator.
boolean	getRunningStatus() Return the current running status.
SimTime	getTime() Return a reference to the current SimTime.
IWindowManager	getWindowManager() Return the current window manager.
boolean	isRealTimeMode() Test the time mode.
void	performAction(int actionType) React to system events.
void	quit() Stop the simulation, dispose everything and the quit the JVM.
void	rebuildModels() Dispose and rebuild each running model.
void	removeEngineListener(ISimEngineListener engineListener)
void	setRandomSeed(long newSeed) Set the current random seed.
void	setRunning(boolean status) Set the current running status.
void	setWindowManager(IWindowManager manager)
void	start() Start simulation.
void	step() Make one simulation step.
void	step(int forSteps) Make forSteps simulation steps.
void	stepTime() Make simulation steps until next time unit.
void	stop() Stop simulation.

Methods inherited from class java.lang.Object

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

Constructor Detail

SimEngine

public SimEngine()

Build a new SimEngine with the TIME-TICKS time unit.

SimEngine

public SimEngine(int timeUnit)

Build a new SimEngine with the given time unit.

Parameters:

timeUnit - The time uint id. See the public constants in the SimTime class.

Method Detail

addEngineListener

public void addEngineListener(ISimEngineListener engineListener)

Install a listener for events generated by the simulation engine.

Parameters:

engineListener - An object implementing the ISimEngineListener interface.

addModel

public void addModel(ISimModel model)

Notify the engine to manage a SimModel. This method is mandatory to let a model work. The current event list is joined to the given model.

Parameters:

model - The model to be added.

addSimWindow

public void addSimWindow(ISimModel owner,
                         java.awt.Container window)

Add a frame window to a local windowBag. After this operation the engine is able to store window size and postion. It is able to show and dispose windows automatically, too.

Parameters:

owner - The owner model.

window - The frame to be added.

buildModels

public void buildModels()

Call the buildModel() method of each active SimModel.

disableRealTime

public void disableRealTime()

Disable the real time mode. The engine does work in simulated time mode.

disposeModels

public java.lang.Class[] disposeModels()

Dispose from memory all running models. Return an array representing the Class of each disposed models. It is used by rebuildModels().

Returns:

The list of disposed models.

enableRealTime

public void enableRealTime()

Enable the real time mode. The events will be fired according to the current system time.

end

public void end()

Stops the simulation and call the simulationEnd method of each running model.

getEngineListeners

public java.util.ArrayList getEngineListeners()

getEventList

public EventList getEventList()

Return a reference to the current EventList.

Returns:

The event list.

getModelBuildStatus

public boolean getModelBuildStatus()

Return true if buildModels() method has been called. False otherwise.

Returns:

True is models have been built, false otherwise.

getModels

public java.lang.Object[] getModels()

Return an array representing the running SimModels.

Returns:

A list of running models.

getModelWithID

public ISimModel getModelWithID(java.lang.String id)

Return a model with the given id string. If model is not present return null. See SimModel help for details.

Parameters:

id - The string representing model. It must equals to the return of the getID() method of the SimModel class.

Returns:

The asked model. Null if not found.

getRandomSeed

public long getRandomSeed()

Return the current random seed.

Returns:

The current random seed.

getRnd

public RandomGenerator getRnd()

Return a reference to the current Random generator.

Returns:

The current random generator.

getRunningStatus

public boolean getRunningStatus()

Return the current running status.

Returns:

Ture if simulation is running, false otherwise.

getTime

public SimTime getTime()

Return a reference to the current SimTime.

Returns:

The current time object.

getWindowManager

public IWindowManager getWindowManager()

Return the current window manager.

Returns:

The current window manager

isRealTimeMode

public boolean isRealTimeMode()

Test the time mode.

Returns:

True if the engine is in real time, false otherwise.

performAction

public void performAction(int actionType)

React to system events.

Specified by:

performAction in interface ISimEventListener

Parameters:

actionType - Reacts in case of EVENT_SIMULATION_END, EVENT_SIMULATION_RESTART, EVENT_SHUTDOWN events.

quit

public void quit()

Stop the simulation, dispose everything and the quit the JVM.

rebuildModels

public void rebuildModels()

Dispose and rebuild each running model. It is used to restart simulation.

removeEngineListener

public void removeEngineListener(ISimEngineListener engineListener)

setRandomSeed

public void setRandomSeed(long newSeed)

Set the current random seed.

Parameters:

newSeed - The new random seed.

setRunning

public void setRunning(boolean status)

Set the current running status.

Parameters:

status - If true the simulation starts, if false it stops.

setWindowManager

public void setWindowManager(IWindowManager manager)

Parameters:

manager -

start

public void start()

Start simulation. A new thread starts and calls step() method until something stops it.

step

public void step()

Make one simulation step. The first event in the event list is fired.

step

public void step(int forSteps)

Make forSteps simulation steps.

Parameters:

forSteps - The number of steps to be done.

stepTime

public void stepTime()

Make simulation steps until next time unit.

stop

public void stop()

Stop simulation. The running thread is freezed until next step is called.