/**
* Implementation of the virtual <code>update(Observable, Object)</code> method of the <code>
* Observer</code> interface. This method will be called automatically from an <code>Observable
* </code> object within its <code>notifyObservers()</code> method. <br>
* If no Object (a<code>null</code> value) is passed as arg, the actual value of the ValueSupplier
* will be fetched with the <code>value()</code> method of the ValueSupplier. Otherwise it is
* expected that the actual value is passed in the Object arg.
*
* @param o java.util.Observable : The Observable calling this method within its own <code>
* notifyObservers()</code> method.
* @param arg Object : The Object with which this <code>Tally</code> is updated. Normally a double
* number which is added to the statistics or <code>null</code>.
*/
public void update(Observable o, Object arg) {
if (o == null) // null was passed instead of an Observable
{
sendWarning(
"Attempt to update a Histogram with no reference to an "
+ "Observable. The actual value of '"
+ getValueSupplier().getName()
+ "' will be fetched and processed anyway.",
"Histogram: " + this.getName() + " Method: update (Observable " + "o, Object arg)",
"The passed Observable: o in this method is only a null pointer.",
"The update()-method was not called via notifyObservers() from an "
+ "Observable. Who was calling it? Why don't you let the Observable do"
+ " the work?");
}
super.update(o, arg); // update Accumulate
if (this.nextToLastValue != null) {
int n = this.findCellIndex(this.nextToLastValue);
TimeSpan delta = TimeOperations.diff(this.presentTime(), this.nextToLastTime);
_table[n] = TimeOperations.add(_table[n], delta);
}
this.nextToLastTime = this.presentTime();
this.nextToLastValue = this.getLastValue();
}
/**
* Resets this Histogram object by resetting the counters for each cell to zero. That means the
* array of the cell counters will be reset, but the interval and the number of sections this
* interval is divided into will remain the same. The parameters of the interval can be changed
* with the <code>changeParameters</code> method after the reset.
*/
public void reset() {
super.reset(); // reset the Tally, too.
// reset the array of cells #### only if the table already exists! Ruth 24/01/2008
if (_table != null) {
initTable();
}
}
/**
* Updates this <code>Histogram</code> object with the double value given as parameter. In some
* cases it might be more convenient to pass the value this <code>Histogram</code> will be updated
* with directly within the <code>update(double val)</code> method instead of going via the <code>
* ValueSupplier</code>.
*
* @param val double : The value with which this <code>Histogram</code> will be updated.
*/
public void update(double value) {
super.update(value); // update Accumulate
if (this.nextToLastValue != null) {
int n = this.findCellIndex(this.nextToLastValue);
TimeSpan delta = TimeOperations.diff(this.presentTime(), this.nextToLastTime);
_table[n] = TimeOperations.add(_table[n], delta);
}
this.nextToLastTime = this.presentTime();
this.nextToLastValue = value;
}
