/// <summary>
/// Add a category to the list of known categories.
/// </summary>
/// <param name="id">The category ID</param>
/// <param name="parentId">The parent ID. Zero is none (even though 0 is a valid category).</param>
/// <param name="name">The category display name.</param>
/// <param name="active">The default active state.</param>
public void AddCategory(ushort id, ushort parentId, string name, bool active)
{
Category cat = new Category();
cat.ID = id;
cat.ParentID = parentId;
cat.Name = name;
cat.Active = active;
_categories[cat.ID] = cat;
bool parentActive = parentId == 0 || CategoriesState.IsActive(parentId);
CategoriesState.SetActive(cat.ID, cat.Active && parentActive);
NotifyNewCategory(cat);
}
/// <summary>
/// Set the active state of all descendants of the category identified by <paramref name="id"/>.
/// </summary>
/// <param name="id">The parent category ID.</param>
/// <param name="active">The new active state.</param>
private void PropagateActiveToChildren(ushort id, bool active)
{
// Skip default category.
if (id == 0)
{
return;
}
// Also affect all children.
foreach (Category cat in ChildCategories(id))
{
if (CategoriesState.IsActive(cat.ID) != active)
{
CategoriesState.SetActive(cat.ID, active);
}
PropagateActiveToChildren(cat.ID, active);
}
}
/// <summary>
/// Set the active state of a category.
/// </summary>
/// <param name="id">The category ID.</param>
/// <param name="active">The desired active state.</param>
/// <remarks>
/// This invokes the <see cref="OnActivationChange"/> event when <paramref name="active"/>
/// does not match the category state.
///
/// Unknown <paramref name="id"/> values are ignored.
/// </remarks>
public void SetActive(ushort id, bool active)
{
Category cat;
if (_categories.TryGetValue(id, out cat))
{
if (cat.Active != active)
{
cat.Active = active;
// Update the dictionary.
_categories[cat.ID] = cat;
// Check hierarchy to determin final state.
bool mergedActive = active && CheckHierarchyActive(cat.ParentID);
CategoriesState.SetActive(cat.ID, mergedActive);
PropagateActiveToChildren(id, mergedActive);
if (OnActivationChange != null)
{
OnActivationChange(id, active);
}
}
}
}