/// <summary>
/// Notifies this tree view model that the selection state of an item which is part of it's logical descendants has changed.
/// </summary>
/// <param name="item"></param>
public void NotifyItemSelectionChanged(ITreeViewModelItem item)
{
if (!HasBoundSelection)
{
SetDefaultSelectionBinding();
}
SelectionBinding.OnItemSelectionStatusChanged(item);
}
/// <summary>
/// Handles the item selection changed event for all the current items.
/// Initializes a default selection binding in accordance with the current selection mode if there is none and forwards the selected item to it.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void ItemSelectionChanged(object sender, PropertyChangedEventArgs e)
{
if (!HasBoundSelection)
{
SetDefaultSelectionBinding();
}
SelectionBinding.OnItemSelectionStatusChanged((IListViewModelItem)sender);
}
/// <summary>
/// Breaks the current selection binding. <para/>
/// NOTE : If there is no active selection binding, an exception will be thrown.
/// </summary>
protected void BreakSelectionBinding()
{
if (!HasBoundSelection)
{
throw new Exception("Error : Attempting to break a selection binding on a list view model that is not bound to any selection.");
}
SelectionBinding.TearDown();
SelectionBinding = null;
}
/// <summary>
/// Invalidates the children of this list view model internally, without updating the UI.
/// </summary>
private void InvalidateChildrenInternal()
{
if (!HasBoundSelection)
{
SetDefaultSelectionBinding();
}
foreach (var item in Items)
{
PropertyChangedEventManager.RemoveHandler(item, ItemSelectionChanged, nameof(item.IsSelected));
item.TearDown();
SelectionBinding.OnItemDisposed(item);
}
items.Clear();
foreach (var item in CreateContentItems())
{
item.Initialize(this);
PropertyChangedEventManager.AddHandler(item, ItemSelectionChanged, nameof(item.IsSelected));
SelectionBinding.OnItemCreated(item);
items.Add(item);
}
}
/// <summary>
/// Notifies this tree view model that an item has been removed from it's logical descendants.
/// </summary>
/// <param name="item"></param>
public void NotifyItemDisposed(ITreeViewModelItem item)
{
SelectionBinding.OnItemDisposed(item);
items.Remove(item);
}
/*******************************************************
***************** Item Notifications ******************
*******************************************************/
/// <summary>
/// Notifies this tree view model that a new item has been created as part of it's logical descendants.
/// </summary>
/// <param name="item"></param>
public void NotifyItemCreated(ITreeViewModelItem item)
{
SelectionBinding.OnItemCreated(item);
items.Add(item);
}
