/// <summary> /// Add an item to the desired subgroup(s) of the given group /// </summary> /// <param name="item">Item to add</param> /// <param name="group">Group to add item to</param> /// <param name="level">The level of grouping</param> /// <param name="loading">Whether we are currently loading</param> /// <param name="insertedBefore">The item to insert this item before, /// or <c>null</c> if the item should be added at the end.</param> private void AddToSubgroups(object item, CollectionViewGroupInternal group, int level, bool loading, object insertedBefore) { object name = this.GetGroupName(item, group.GroupBy, level); ICollection nameList; if (name == UseAsItemDirectly) { // the item belongs to the group itself (not to any subgroups) if (loading) { group.Add(item); } else { int localIndex = -1; // If we were given an item to insert before, find its index // within the target group. If it's not in the group, we'll // get -1 back, which we'll translate into putting the item // at the end of the list. if (insertedBefore != null) { localIndex = group.LeafIndexOf(insertedBefore); } if (localIndex == -1) { localIndex = group.ItemCount; } group.Insert(item, localIndex); int index = group.LeafIndexFromItem(item, localIndex); this.OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, item, index)); } } else if ((nameList = name as ICollection) == null) { // the item belongs to one subgroup this.AddToSubgroup(item, group, level, name, loading, insertedBefore); } else { // the item belongs to multiple subgroups foreach (object o in nameList) { this.AddToSubgroup(item, group, level, o, loading, insertedBefore); } } }
/// <summary> /// Initialize the given group /// </summary> /// <param name="group">Group to initialize</param> /// <param name="level">The level of grouping</param> /// <param name="seedItem">The seed item to compare with to see where to insert</param> private void InitializeGroup(CollectionViewGroupInternal group, int level, object seedItem) { // set the group description for dividing the group into subgroups GroupDescription groupDescription = this.GetGroupDescription(group, level); group.GroupBy = groupDescription; // create subgroups for each of the explicit names ObservableCollection <object> explicitNames = (groupDescription != null) ? groupDescription.GroupNames : null; if (explicitNames != null) { for (int k = 0, n = explicitNames.Count; k < n; ++k) { CollectionViewGroupInternal subgroup = new CollectionViewGroupInternal(explicitNames[k], group); this.InitializeGroup(subgroup, level + 1, seedItem); group.Add(subgroup); } } group.LastIndex = 0; }
//------------------------------------------------------ // // Private Methods // //------------------------------------------------------ /// <summary> /// Add an item to the subgroup with the given name /// </summary> /// <param name="item">Item to add</param> /// <param name="group">Group to add item to</param> /// <param name="level">The level of grouping.</param> /// <param name="name">Name of subgroup to add to</param> /// <param name="loading">Whether we are currently loading</param> /// <param name="insertedBefore">The item to insert this item before, /// or <c>null</c> if the item should be added at the end.</param> private void AddToSubgroup(object item, CollectionViewGroupInternal group, int level, object name, bool loading, object insertedBefore) { CollectionViewGroupInternal subgroup; int index = (this._isDataInGroupOrder) ? group.LastIndex : 0; // find the desired subgroup for (int n = group.Items.Count; index < n; ++index) { subgroup = group.Items[index] as CollectionViewGroupInternal; if (subgroup == null) { continue; // skip children that are not groups } if (group.GroupBy.NamesMatch(subgroup.Name, name)) { group.LastIndex = index; this.AddToSubgroups(item, subgroup, level + 1, loading, insertedBefore); return; } } // the item didn't match any subgroups. Create a new subgroup and add the item. subgroup = new CollectionViewGroupInternal(name, group); this.InitializeGroup(subgroup, level + 1, item); if (loading) { group.Add(subgroup); group.LastIndex = index; } else { if (insertedBefore != null && group.ItemCount > 0) { index = 0; // If we were given an item to insert before, find its index // within the target group. If it's not in the group, we'll // get -1 back, which we'll translate into putting the item // at the end of the list. int itemIndex = group.LeafIndexOf(insertedBefore); if (itemIndex == -1) { index = group.ItemCount; } else { // But if the item to be inserted before is within this // group, then we need to find the correct group position // for the insert. Iterate through the groups, finding // the correct insert position. CollectionViewGroupInternal nextGroup = ((CollectionViewGroupInternal)group.Items[index]); while (itemIndex >= nextGroup.ItemCount) { itemIndex -= nextGroup.ItemCount; // Increment the index and set the next group nextGroup = ((CollectionViewGroupInternal)group.Items[++index]); } } } group.Insert(subgroup, index); } this.AddToSubgroups(item, subgroup, level + 1, loading, insertedBefore); }