/// <summary>
/// The workhorse to expand a threaded listview item
/// </summary>
/// <param name="lvItem"></param>
/// <param name="activate">true, if lvItem should be activated</param>
internal void ExpandListViewItem(ThreadedListViewItem lvItem, bool activate)
{
int selIdxsCount = SelectedIndices.Count;
var selIdxs = new int[selIdxsCount];
SelectedIndices.CopyTo(selIdxs, 0);
ThreadedListViewItem[] newItems;
if (lvItem != null && lvItem.Collapsed)
{
if (RaiseBeforeExpandEventCancel(lvItem))
{
lvItem.StateImageIndex = 0; // switch to non-state image (no +/-)
return;
}
int paramItemIndex = lvItem.Index;
int currentIndent = lvItem.IndentLevel;
// if (base.SelectedItems.Count > 0 && activate)
// selectedItemIndex = paramItemIndex;
newItems = RaiseExpandEvent(lvItem);
if (newItems == null)
{
ThreadedListViewItem item = _noChildsPlaceHolder;
if (item == null)
{
item = new ThreadedListViewItemPlaceHolder(SR.FeedListNoChildsMessage)
{
Font = new Font(Font.FontFamily, Font.Size, FontStyle.Regular)
};
}
newItems = new[] { item };
}
if (newItems.Length > 1 && ListViewItemSorter != null)
{
// sort new child entries according to listview sortorder
Array.Sort(newItems, ListViewItemSorter);
}
if (_showInGroups)
{
APIEnableGrouping(false);
}
BeginUpdate();
try
{
lvItem.SetThreadState(true);
lock (Items)
{
foreach (var newListItem in newItems)
{
// check, if we have all subitems for correct grouping
while (newListItem.SubItems.Count < Columns.Count)
{
newListItem.SubItems.Add(String.Empty);
}
newListItem.Parent = lvItem;
Items.Insert(paramItemIndex + 1, newListItem);
newListItem.IndentLevel = currentIndent + 1;
paramItemIndex++;
}
}
}
finally
{
EndUpdate();
}
RedrawItems();
if (_showInGroups)
{
APIEnableGrouping(true);
}
// Make the last inserted subfolder visible, then the parent folder visible,
// per default treeview behavior.
try
{
EnsureVisible(paramItemIndex - 1);
EnsureVisible(lvItem.Index);
}
catch (Exception ex)
{
_log.Error("EnsureVisible() failed", ex);
}
if (activate)
{
SelectedItems.Clear();
lvItem.Selected = true;
lvItem.Focused = true;
}
else if (selIdxsCount > 0)
{
// foreach (int i in selIdxs) {
// this.Items[i].Selected = true;
// }
}
RaiseAfterExpandEvent(lvItem, newItems);
}
}
/// <summary>
/// The workhorse to collapse a threaded listview item
/// </summary>
/// <param name="lvItem"></param>
internal void CollapseListViewItem(ThreadedListViewItem lvItem)
{
if (lvItem != null && lvItem.Expanded)
{
if (RaiseBeforeCollapseEventCancel(lvItem))
{
lvItem.StateImageIndex = 0;
return;
}
int focusedItemIndex;
if (FocusedItem == null)
{
focusedItemIndex = lvItem.Index;
}
else
{
focusedItemIndex = FocusedItem.Index;
}
BeginUpdate();
try
{
lvItem.SetThreadState(false);
int paramItemIndex = lvItem.Index;
int currentIndent = lvItem.IndentLevel;
int nextIndex = paramItemIndex + 1;
lock (Items)
{
while (nextIndex < base.Items.Count &&
((ThreadedListViewItem)base.Items[nextIndex]).IndentLevel > currentIndent)
{
Items[nextIndex].Parent = null;
Items.RemoveAt(nextIndex);
if (nextIndex < focusedItemIndex)
{
focusedItemIndex = focusedItemIndex - 1;
}
else if (nextIndex == focusedItemIndex)
{
focusedItemIndex = paramItemIndex;
}
}
}
RaiseCollapseEvent(lvItem);
}
finally
{
EndUpdate();
}
if (focusedItemIndex >= 0)
{
ListViewItem lvi = base.Items[focusedItemIndex];
lvi.Focused = true;
lvi.Selected = true;
}
}
}
