// Generate sub-group based on property equality
void GroupBy(INTERNAL_PropertyGroupDescription operation)
{
List <Collection <object> > childGroups = new List <Collection <object> >();
foreach (object item in Items)
{
bool find = false;
foreach (Collection <object> child in childGroups)
{
if (Object.Equals(GetValue(child[0], operation), GetValue(item, operation)))
{
child.Add(item);
find = true;
break;
}
}
if (!find)
{
childGroups.Add(new Collection <object>());
childGroups[childGroups.Count - 1].Add(item);
}
}
foreach (Collection <object> child in childGroups)
{
INTERNAL_CollectionViewGroupInternal newView = new INTERNAL_CollectionViewGroupInternal(child, this, _operations, _level + 1);
_operations.Requester.AddView(newView); // create child branch (level matter in grouping views)
}
}
//Returns a value that indicates if a specified item has passed the filter
public bool PassesFilter(object item)
{
INTERNAL_CollectionViewGroupInternal filterView = GetFilterView();
if (filterView != null)
{
return(filterView.Items.Contains(item));
}
return(true); // if no filter, we consider the filter as passed
}
// Take the result of the parent and generate the result for the next operation
internal INTERNAL_CollectionViewGroupInternal(ICollection <object> source, INTERNAL_CollectionViewGroupInternal parent, INTERNAL_Operations operations, int level = 0)
{
Items = source;
_level = level;
_parentView = parent;
_operations = operations;
object operationToDo = _operations.HandleNextOperation(_level);
ExecuteOperation(operationToDo);
}
// Sort the data source with a default comparer
void Sort(PropertySortDescription operation)
{
if (VerifyComparable(operation))// if we can't compare data, we don't try to sort
{
ListSortDirection directionBackup = operation.Direction;
operation.Direction = _operations.GetFixedDirection(operation);
Collection <object> childItems = new Collection <object>();
//todo: replace with a sort algorithm that is O(NLogN), for example by creating a List<T> and calling List<T>.Sort(comparer).
foreach (object item in Items)
{
int index;
// we get the value of the sorting property on this item to allow comparison (if we are here, we know that data is comparable)
// then we get the position where we need to insert this item
#if OPENSILVER
if (true)
#elif BRIDGE
if (CSHTML5.Interop.IsRunningInTheSimulator)
#endif
{
IComparable value = (IComparable)GetValue(item, operation);
index = GetPosIndex_SimulatorOnly(operation, value, 0, childItems.Count, childItems);
}
else
{
dynamic value = GetValue(item, operation);
index = GetPosIndex_JSOnly(operation, value, 0, childItems.Count, childItems);
}
childItems.Insert(index, item);
}
operation.Direction = directionBackup;
// Pass the result of the sort to a child CollectionViewGroup in order to apply other operations (such as sort) if any:
INTERNAL_CollectionViewGroupInternal newView = new INTERNAL_CollectionViewGroupInternal(childItems, this, _operations);
_operations.Requester.AddView(newView); // create child branch after sorting operation
}
else
{
INTERNAL_CollectionViewGroupInternal newView = new INTERNAL_CollectionViewGroupInternal(Items, this, _operations);
_operations.Requester.AddView(newView); // create child branch without sorting
}
}
// Filter the data source with a predicate
void Filter(Predicate <Object> predicate)
{
// Create a new collection with the result of the filtering:
Collection <object> childItems = new Collection <object>();
foreach (object obj in Items)
{
if (predicate(obj))
{
childItems.Add(obj);
}
}
// Pass the result of the filtering to a child CollectionViewGroup in order to apply other operations (such as sort) if any:
INTERNAL_CollectionViewGroupInternal newView = new INTERNAL_CollectionViewGroupInternal(childItems, this, _operations);
_operations.Requester.AddView(newView); // create child branch
}
// create all the operation tree with a new source
void CreateTree()
{
_views.Clear();
_operations = new INTERNAL_Operations(this); // we reset the operations to do
ICollection <object> newCollection = new Collection <object>();
foreach (object obj in _originalDataSource)
{
newCollection.Add(obj);
}
INTERNAL_CollectionViewGroupInternal treeRoot = new INTERNAL_CollectionViewGroupInternal(newCollection.ToList <object>(), null, _operations);
_views.Add(treeRoot); // we make sure that the treeRoot is the last element to be added to the _views collection because the call to the CollectionViewGroupInternal contructor creates a tree via recursion, which by itself adds the branches in _views.
ConstrainIndexToRemainInsideAllowedRange(); // because some leaves can disappear if it's not the first generation (ie. if it has already been refreshed once)
}
// Filter the data source using an event (the user sets e.Accepted to true or false in the event handler):
void Filter(FilterEventHandler logicMethod)
{
// Create a new collection with the result of the filtering:
Collection <object> childItems = new Collection <object>();
foreach (object obj in Items)
{
FilterEventArgs args = new FilterEventArgs(obj);
logicMethod(this, args);
if (args.Accepted)
{
childItems.Add(obj);
}
}
// Pass the result of the filtering to a child CollectionViewGroup in order to apply other operations (such as sort) if any:
INTERNAL_CollectionViewGroupInternal newView = new INTERNAL_CollectionViewGroupInternal(childItems, this, _operations);
_operations.Requester.AddView(newView); // create child branch
}
// add a new child view in the paged collection (not necessarily a leaf)
internal void AddView(INTERNAL_CollectionViewGroupInternal view)
{
_views.Add(view);
}