/// <summary>
/// Remove an axis from the collection if it is no longer used.
/// </summary>
/// <param name="sender">The axis that has had its registered
/// listeners collection changed.</param>
/// <param name="e">Information about the event.</param>
private void AxisRegisteredListenersCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
IAxis axis = this.Where(currentAxis => currentAxis.RegisteredListeners == sender).First();
if (e.OldItems != null)
{
if (!PersistentAxes.Contains(axis) && !SeriesHost.IsUsedByASeries(axis))
{
this.Remove(axis);
}
}
}
/// <summary>
/// Removes an item from the axes collection but throws an exception
/// if a series in the series host is listening to it.
/// </summary>
/// <param name="index">The index of the item being removed.</param>
protected override void RemoveItem(int index)
{
IAxis axis = this[index];
if (SeriesHost.IsUsedByASeries(axis))
{
throw new InvalidOperationException(Resources.SeriesHostAxesCollection_RemoveItem_AxisCannotBeRemovedFromASeriesHostWhenOneOrMoreSeriesAreListeningToIt);
}
else if (PersistentAxes.Contains(axis))
{
throw new InvalidOperationException(Resources.SeriesHostAxesCollection_InvalidAttemptToRemovePermanentAxisFromSeriesHost);
}
else
{
base.RemoveItem(index);
}
}
/// <summary>
/// This method synchronizes the collection with the persistent axes
/// collection when it is changed.
/// </summary>
/// <param name="sender">The source of the event.</param>
/// <param name="e">Information about the event.</param>
public void PersistentAxesCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
if (e.NewItems != null)
{
foreach (IAxis axis in e.NewItems)
{
if (!this.Contains(axis))
{
this.Add(axis);
}
}
}
if (e.OldItems != null)
{
foreach (IAxis axis in e.OldItems)
{
if (this.Contains(axis) && !SeriesHost.IsUsedByASeries(axis))
{
this.Remove(axis);
}
}
}
}
