public override IList <OLVGroup> GetGroups(GroupingParameters parms)
{
// This strategy can only be used on FastObjectListViews
FastObjectListView folv = (FastObjectListView)parms.ListView;
// Separate the list view items into groups, using the group key as the descrimanent
int objectCount = 0;
NullableDictionary <object, List <object> > map = new NullableDictionary <object, List <object> >();
foreach (object model in folv.Objects)
{
object key = parms.GroupByColumn.GetGroupKey(model);
if (!map.ContainsKey(key))
{
map[key] = new List <object>();
}
map[key].Add(model);
objectCount++;
}
// Sort the items within each group
OLVColumn primarySortColumn = parms.SortItemsByPrimaryColumn ? parms.ListView.GetColumn(0) : parms.PrimarySort;
ModelObjectComparer sorter = new ModelObjectComparer(primarySortColumn, parms.PrimarySortOrder,
parms.SecondarySort, parms.SecondarySortOrder);
foreach (object key in map.Keys)
{
map[key].Sort(sorter);
}
// Make a list of the required groups
List <OLVGroup> groups = new List <OLVGroup>();
foreach (object key in map.Keys)
{
string title = parms.GroupByColumn.ConvertGroupKeyToTitle(key);
if (!String.IsNullOrEmpty(parms.TitleFormat))
{
int count = map[key].Count;
title = String.Format((count == 1 ? parms.TitleSingularFormat : parms.TitleFormat), title, count);
}
OLVGroup lvg = new OLVGroup(title);
lvg.Key = key;
lvg.SortValue = key as IComparable;
lvg.Contents = map[key].ConvertAll <int>(delegate(object x) { return(folv.IndexOf(x)); });
lvg.VirtualItemCount = map[key].Count;
if (parms.GroupByColumn.GroupFormatter != null)
{
parms.GroupByColumn.GroupFormatter(lvg, parms);
}
groups.Add(lvg);
}
// Sort the groups
groups.Sort(new OLVGroupComparer(parms.PrimarySortOrder));
// Build an array that remembers which group each item belongs to.
this.indexToGroupMap = new List <int>(objectCount);
this.indexToGroupMap.AddRange(new int[objectCount]);
for (int i = 0; i < groups.Count; i++)
{
OLVGroup group = groups[i];
List <int> members = (List <int>)group.Contents;
foreach (int j in members)
{
this.indexToGroupMap[j] = i;
}
}
return(groups);
}
public FastObjectListDataSource(FastObjectListView listView)
: base(listView)
{
}