public TreeView()
{
m_CurrentSelection = null;
m_ExpandedItemIds = new List <int>();
m_ItemWrappers = new List <TreeViewItemWrapper>();
m_ListView = new ListView();
m_ListView.name = s_ListViewName;
m_ListView.itemsSource = m_ItemWrappers;
m_ListView.viewDataKey = s_ListViewName;
m_ListView.AddToClassList(s_ListViewName);
hierarchy.Add(m_ListView);
m_ListView.makeItem = MakeTreeItem;
m_ListView.bindItem = BindTreeItem;
m_ListView.getItemId = GetItemId;
m_ListView.onItemChosen += OnItemChosen;
m_ListView.onSelectionChanged += OnSelectionChanged;
m_ScrollView = m_ListView.Q <ScrollView>();
m_ScrollView.contentContainer.RegisterCallback <KeyDownEvent>(OnKeyDown);
RegisterCallback <MouseUpEvent>(OnTreeViewMouseUp, TrickleDown.TrickleDown);
RegisterCallback <CustomStyleResolvedEvent>(OnCustomStyleResolved);
}
