/// <summary>
/// Toggle expand/collapse for the an item at the given index
/// </summary>
private bool ExpandCollapse(int itemIndex, ForceExpansion forceExpansion)
{
var selectedItem = GetItem(itemIndex);
if (selectedItem == null)
{
return(false);
}
// handles a node expansion
var currentItem = selectedItem as FilteredTypeTreeListItem;
if (currentItem != null && currentItem.CanExpand)
{
string currentItemPathDescriptor = currentItem.PathDescriptor;
// switch state
if (forceExpansion != ForceExpansion.Idle)
{
currentItem.IsExpanded = (forceExpansion == ForceExpansion.ForceExpand);
}
else
{
currentItem.IsExpanded = !currentItem.IsExpanded;
}
// saves expansion state
if (_savedState.ContainsKey(currentItemPathDescriptor))
{
_savedState[currentItemPathDescriptor] = currentItem.IsExpanded;
}
else
{
_savedState.Add(currentItemPathDescriptor, currentItem.IsExpanded);
}
ApplyExpansionState();
return(true);
}
return(false);
}
/// <summary>
/// Returns the full list of items to be displayed, taking into account expanded items
/// </summary>
private List <ListItem> GetExpandedItemsList(List <FilteredTypeTreeListItem> list, ForceExpansion forceExpansion)
{
if (list == null)
{
return(new List <ListItem>());
}
var outList = new List <ListItem>();
foreach (var item in list)
{
outList.Add(item);
var descriptor = item.PathDescriptor;
if (item.CanExpand)
{
// force expand/collapse?
if (forceExpansion != ForceExpansion.Idle)
{
if (_savedState.ContainsKey(descriptor))
{
_savedState[descriptor] = forceExpansion == ForceExpansion.ForceExpand;
}
else
{
_savedState.Add(descriptor, forceExpansion == ForceExpansion.ForceExpand);
}
}
// restore the expand state of the item if needed
if (_savedState.ContainsKey(descriptor))
{
item.IsExpanded = _savedState[descriptor];
}
if (item.IsExpanded)
{
var children = GetExpandedItemsList(item.GetItemChildren(), forceExpansion);
if (children != null)
{
outList.AddRange(children);
}
}
else if (forceExpansion != ForceExpansion.Idle)
{
// to also force the savedState of the children node
GetExpandedItemsList(item.GetItemChildren(), forceExpansion);
}
}
}
return(outList);
}