/**
* Adds or updates an item in the series and sends a {@link SeriesChangeEvent} to all registered
* listeners.
*
* @param item the data item (<code>null</code> not permitted).
* @return A copy of the overwritten data item, or <code>null</code> if no item was overwritten.
* @since 1.0.14
*/
public XYDataItem addOrUpdate(XYDataItem item) {
ParamChecks.nullNotPermitted(item, "item");
if (this.allowDuplicateXValues) {
add(item);
return null;
}
// if we get to here, we know that duplicate X values are not permitted
XYDataItem overwritten = null;
int index = indexOf(item.getX());
if (index >= 0) {
XYDataItem existing = (XYDataItem) this.data.get(index);
overwritten = (XYDataItem) existing.clone();
// figure out if we need to iterate through all the y-values
boolean iterate = false;
double oldY = existing.getYValue();
if (!Double.isNaN(oldY)) {
iterate = oldY <= this.minY || oldY >= this.maxY;
}
existing.setY(item.getY());
if (iterate) {
findBoundsByIteration();
} else if (item.getY() != null) {
double yy = item.getY().doubleValue();
this.minY = minIgnoreNaN(this.minY, yy);
this.maxY = maxIgnoreNaN(this.maxY, yy);
}
} else {
// if the series is sorted, the negative index is a result from
// Collections.binarySearch() and tells us where to insert the
// new item...otherwise it will be just -1 and we should just
// append the value to the list...
item = (XYDataItem) item.clone();
if (this.autoSort) {
this.data.add(-index - 1, item);
} else {
this.data.add(item);
}
updateBoundsForAddedItem(item);
// check if this addition will exceed the maximum item count...
if (getItemCount() > this.maximumItemCount) {
XYDataItem removed = (XYDataItem) this.data.remove(0);
updateBoundsForRemovedItem(removed);
}
}
fireSeriesChanged();
return overwritten;
}
/**
* Updates the cached values for the minimum and maximum data values on the basis that the
* specified item has just been removed.
*
* @param item the item added (<code>null</code> not permitted).
* @since 1.0.13
*/
private void updateBoundsForRemovedItem(XYDataItem item) {
boolean itemContributesToXBounds = false;
boolean itemContributesToYBounds = false;
double x = item.getXValue();
if (!Double.isNaN(x)) {
if (x <= this.minX || x >= this.maxX) {
itemContributesToXBounds = true;
}
}
if (item.getY() != null) {
double y = item.getYValue();
if (!Double.isNaN(y)) {
if (y <= this.minY || y >= this.maxY) {
itemContributesToYBounds = true;
}
}
}
if (itemContributesToYBounds) {
findBoundsByIteration();
} else if (itemContributesToXBounds) {
if (getAutoSort()) {
this.minX = getX(0).doubleValue();
this.maxX = getX(getItemCount() - 1).doubleValue();
} else {
findBoundsByIteration();
}
}
}
/**
* Updates the cached values for the minimum and maximum data values.
*
* @param item the item added (<code>null</code> not permitted).
* @since 1.0.13
*/
private void updateBoundsForAddedItem(XYDataItem item) {
double x = item.getXValue();
this.minX = minIgnoreNaN(this.minX, x);
this.maxX = maxIgnoreNaN(this.maxX, x);
if (item.getY() != null) {
double y = item.getYValue();
this.minY = minIgnoreNaN(this.minY, y);
this.maxY = maxIgnoreNaN(this.maxY, y);
}
}
/**
* Returns the y-value for the specified series and item.
*
* @param series the series (zero-based index).
* @param index the index of the item of interest (zero-based).
* @return The value (possibly <code>null</code>).
*/
public Number getY(int series, int index) {
XYSeries ts = (XYSeries) this.data.get(series);
XYDataItem xyItem = ts.getDataItem(index);
return xyItem.getY();
}