internal void Replace(string idToUpdate, Rock rock)
{
if (rock == null)
{
throw new ArgumentNullException("rock");
}
int index = IndexOf(idToUpdate);
if (index == -1)
{
throw new ArgumentException("Supplied ID not found in collection.");
}
//Remove the rock from the collection.
Rocks.RemoveAt(index);
//Verify the (possibly changed) ID not in collection already
if (IndexOf(rock.UniqueId) != -1)
{
throw new ArgumentException("A rock with the specified ID already exists in the collection.");
}
//Insert the new rock at the same place.
Rocks.Insert(index, rock);
}
/// <summary>
/// Deletes the rock with the selected ID and returns the previous element in the collection (or null if there are no more elements in the collection to edit).
/// </summary>
/// <param name="selectedID">The Unique ID of the rock to delete.</param>
/// <returns>The next rock to be deleted (or 0 is no more rocks).</returns>
internal Rock Delete(string selectedID)
{
if (selectedID == null)
{
throw new ArgumentNullException("selectedID");
}
int index = this.IndexOf(selectedID);
if (index < 0)
{
throw new ArgumentException("specified item not found in collection.");
}
Rocks.RemoveAt(index);
int nextID = Math.Min(Rocks.Count - 1, index);
//if the count is 0, this will be -1, we want to return that there is no "Next" rock.
return(nextID < 0 ? null : Rocks[nextID]);
}
