/// <summary>
/// Return the list of groups that should be shown according to the given parameters
/// </summary>
/// <param name="parameters"></param>
/// <returns></returns>
public virtual IList <OLVGroup> GetGroups(GroupingParameters parameters)
{
return(new List <OLVGroup>());
}
/// <summary>
/// Create groups for FastListView
/// </summary>
/// <param name="parmameters"></param>
/// <returns></returns>
public override IList <OLVGroup> GetGroups(GroupingParameters parmameters)
{
// There is a lot of overlap between this method and ObjectListView.MakeGroups()
// Any changes made here may need to be reflected there
// This strategy can only be used on FastObjectListViews
FastObjectListView folv = (FastObjectListView)parmameters.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.FilteredObjects)
{
object key = parmameters.GroupByColumn.GetGroupKey(model);
if (!map.ContainsKey(key))
{
map[key] = new List <object>();
}
map[key].Add(model);
objectCount++;
}
// Sort the items within each group
// TODO: Give parameters a ModelComparer property
OLVColumn primarySortColumn = parmameters.SortItemsByPrimaryColumn ? parmameters.ListView.GetColumn(0) : parmameters.PrimarySort;
ModelObjectComparer sorter = new ModelObjectComparer(primarySortColumn, parmameters.PrimarySortOrder,
parmameters.SecondarySort, parmameters.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 = parmameters.GroupByColumn.ConvertGroupKeyToTitle(key);
if (!String.IsNullOrEmpty(parmameters.TitleFormat))
{
int count = map[key].Count;
string format = (count == 1 ? parmameters.TitleSingularFormat : parmameters.TitleFormat);
try {
title = String.Format(format, title, count);
} catch (FormatException) {
title = "Invalid group format: " + format;
}
}
OLVGroup lvg = new OLVGroup(title);
lvg.Collapsible = folv.HasCollapsibleGroups;
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 (parmameters.GroupByColumn.GroupFormatter != null)
{
parmameters.GroupByColumn.GroupFormatter(lvg, parmameters);
}
groups.Add(lvg);
}
// Sort the groups
if (parmameters.GroupByOrder != SortOrder.None)
{
groups.Sort(parmameters.GroupComparer ?? new OLVGroupComparer(parmameters.GroupByOrder));
}
// 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);
}