desmoj.core.statistic

Class ValueSupplier

java.lang.Object

java.util.Observable

desmoj.core.statistic.ValueSupplier

public abstract class ValueSupplier
extends java.util.Observable

Supplies observers with values of their interest. It resembles the "observable" part of the observer pattern as described in [Gamm95]. Thus it extends the standard "Observable" class provided by the Java.util package. Usually, statistical data collectors are interested in the new value whenever a certain status variable of a simulation object changes. Also there are statistical evaluation systems, such as AKAROA, which extract information from several running simulations on different remote computers to gain better statistical data and finally, extracting values during runtime enables better visualizatioin of the simulation progress if these values are displayed using a graphical interface. There are two possible ways to have other objects register changes of another object's status:

1. Call the "update(double value)" method of an observer to pass the changed value directly to one other object interested. Using the direct call allows easy passing of a value to a single observer. No instance of this ValueSupplier class is needed using direct passing of values.
2. Using the ValueSupplier to publish the information to interested observers requires you to derive a class and implement the call of the observer's update(Observable, Object) method with the required values. This way of passing values involves more code to be written, but offer the potential to have multiple observers and change the number of observers during runtime. These options are not available when using the simpler version above.

Version:

DESMO-J, Ver. 2.5.1c copyright (c) 2015

Author:

Tim Lechler, modifications as the method: notifyStatistics(Object arg) by Soenke Claassen Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Constructor Summary

Constructors

Constructor and Description
ValueSupplier(java.lang.String name) Constructs a simple valuesupplier by giving it a name.

Method Summary

Modifier and Type	Method and Description
java.lang.String	getName() Returns the name of the named object.
java.lang.String	getQuotedName() Returns the quoted name of the named object.
void	notifyStatistics(java.lang.Object arg) Indicates that this ValueSupplier (as an Observable) has changed and notifies all its observers of this change providing the modified value as parameter.
void	rename(java.lang.String newName) Changes the name of the named object.
java.lang.String	toString() Overrides the java.lang.Object's toString method to return the named object's name when given as parameter to a method that expects a string to be passed.
abstract double	value() When using the Pull-Model or the automatic update function this method must be overridden by the user in a way that it provides the value (as a double) desired.

Methods inherited from class java.util.Observable

addObserver, countObservers, deleteObserver, deleteObservers, hasChanged, notifyObservers, notifyObservers

Methods inherited from class java.lang.Object

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

Constructor Detail

ValueSupplier

public ValueSupplier(java.lang.String name)

Constructs a simple valuesupplier by giving it a name.

Method Detail

getName

public java.lang.String getName()

Returns the name of the named object. This is the same name displayed in reports and trace files when this named object is shown in those reports or trace files.

Returns:

java.lang.String : The name of the named object

getQuotedName

public java.lang.String getQuotedName()

Returns the quoted name of the named object. This is the name displayed in reports and trace files when this named object is shown.

Returns:

java.lang.String : The quoted name of the named object

notifyStatistics

public void notifyStatistics(java.lang.Object arg)

Indicates that this ValueSupplier (as an Observable) has changed and notifies all its observers of this change providing the modified value as parameter. This is the "Push-model", thus pushing the value (in the parameter arg) to the Observer (thus the StatisticObject).

Parameters:

arg - Object : The Object wrapping the value with which the observers will be updated

rename

public void rename(java.lang.String newName)

Changes the name of the named object. This might be necessary for automatically created named object of a user defined model, but should not be used for elements of the framework or basic objects of the user model. Changing names of objects while runtime will confuse any trace output and generally make traces more difficult if not impossible to follow.

Parameters:

newName - java.lang.String : The new name for the named object

toString

public java.lang.String toString()

Overrides the java.lang.Object's toString method to return the named object's name when given as parameter to a method that expects a string to be passed.

Overrides:

toString in class java.lang.Object

Returns:

java.lang.String : The named object's name

value

public abstract double value()

When using the Pull-Model or the automatic update function this method must be overridden by the user in a way that it provides the value (as a double) desired.

Returns:

double : The value calculated within this method.