/// <summary>
/// Tests the item for membership in all child groups and adds it if appropriate.
/// </summary>
/// <returns>True if the item was added to at least one child group.</returns>
protected virtual bool AddItemToChildren(T item)
{
if (!_specification.Test(item).Success)
{
return(false);
}
bool addedToChild = false;
foreach (FilteredGroup <T> childGroup in _childGroups)
{
if (childGroup.AddItem(item))
{
addedToChild = true;
}
}
if (!addedToChild)
{
FilteredGroup <T> newGroup = CreateNewGroup(item);
if (newGroup != null)
{
ChildGroups.Add(newGroup);
addedToChild = AddItemToChild(item, newGroup);
Platform.CheckTrue(addedToChild, "Item should be guaranteed to have been inserted.");
}
}
return(addedToChild);
}
private void OnChildGroupEmpty(FilteredGroup <T> childGroup)
{
bool remove;
OnChildGroupEmpty(childGroup, out remove);
if (remove)
{
ChildGroups.Remove(childGroup);
}
}
/// <summary>
/// Tests the item for membership in <paramref name="child"/> and adds it if appropriate.
/// </summary>
/// <param name="item">The item to add.</param>
/// <param name="child">The child group.</param>
/// <returns>True if the item was added, otherwise false.</returns>
protected virtual bool AddItemToChild(T item, FilteredGroup <T> child)
{
Platform.CheckTrue(ChildGroups.Contains(child), "Group is not a child of this group.");
if (!_specification.Test(item).Success)
{
return(false);
}
return(child.AddItem(item));
}
/// <summary>
/// Called when a child group becomes empty.
/// </summary>
/// <param name="childGroup">The child group that has just become empty.</param>
/// <param name="remove">Out parameter indicates whether or not the child group should be removed. By default,
/// this value depends on whether there is an <see cref="IFilteredGroupFactory{T}"/> in this node that is capable
/// of automatically recreating an appropriate child group; if there is such a factory, then the value is true,
/// otherwise it is false.</param>
protected virtual void OnChildGroupEmpty(FilteredGroup <T> childGroup, out bool remove)
{
//TODO (CR May09): make it so if there is a factory, you can't add your own groups.
//NOTE: in the interest of time, deferring actually doing this since it involves no API changes.
remove = _childGroupFactory != null;
}