/// <summary>
/// Replay an expanded state record to return a sub-tree to its previously expanded/collapsed state.
/// </summary>
/// <param name="item">The tree view item.</param>
/// <param name="expand">The expand record.</param>
private static void ReplayExpandState(TreeViewItem item, ExpandState expand)
{
if (expand.Children == null)
{
item.IsExpanded = false;
}
else
{
item.IsExpanded = true;
if (item.ItemContainerGenerator.Status == GeneratorStatus.ContainersGenerated)
{
TreeViewHelper.ReplayExpandState(item, expand.Children);
}
else
{
EventHandler replay = null;
replay = delegate(object sender, EventArgs eventArgs)
{
if (item.ItemContainerGenerator.Status == GeneratorStatus.ContainersGenerated)
{
item.ItemContainerGenerator.StatusChanged -= replay;
TreeViewHelper.ReplayExpandState(item, expand);
}
};
item.ItemContainerGenerator.StatusChanged += replay;
}
}
}
/// <summary>
/// Create a record of the expanded/collapsed state of a sub-tree.
/// </summary>
/// <param name="item">The tree view item.</param>
/// <returns>The record of the expanded/collapsed state.</returns>
private static ExpandState RecordExpandState(TreeViewItem item)
{
ExpandState expand = new ExpandState()
{
Node = item.DataContext as FolderTreeNode
};
if (item.IsExpanded)
{
expand.Children = new List <ExpandState>();
foreach (FolderTreeNode node in expand.Node)
{
TreeViewItem treeViewItem = item.ItemContainerGenerator.ContainerFromItem(node) as TreeViewItem;
if (treeViewItem != null)
{
expand.Children.Add(TreeViewHelper.RecordExpandState(treeViewItem));
}
// We can't wait for the item to be generated, so we'll to ignore it.
else
{
expand.Children.Add(new ExpandState()
{
Node = node, Children = null
});
}
}
}
return(expand);
}
/// <summary>
/// Create a record of the expanded/collapsed state of the tree.
/// </summary>
/// <param name="view">The tree view.</param>
/// <returns>The record of the expanded/collapsed state.</returns>
public static ExpandState RecordExpandState(this FolderTreeView view)
{
ExpandState expand = new ExpandState()
{
Node = view.ItemsSource as FolderTreeNode, Children = new List <ExpandState>()
};
foreach (FolderTreeNode node in expand.Node)
{
TreeViewItem treeViewItem = view.ItemContainerGenerator.ContainerFromItem(node) as TreeViewItem;
if (treeViewItem != null)
{
expand.Children.Add(TreeViewHelper.RecordExpandState(treeViewItem));
}
// We can't wait for the item to be generated, so we'll to ignore it.
else
{
expand.Children.Add(new ExpandState()
{
Node = node, Children = null
});
}
}
return(expand);
}
/// <summary>
/// Replay an expanded state record to return a tree to its previously expanded/collapsed state.
/// </summary>
/// <param name="view">The tree view.</param>
/// <param name="expand">The expand record.</param>
public static void ReplayExpandState(this FolderTreeView view, ExpandState expand)
{
if (view.ItemContainerGenerator.Status == GeneratorStatus.ContainersGenerated)
{
TreeViewHelper.ReplayExpandState(view, expand.Children);
}
else
{
EventHandler replay = null;
replay = delegate(object sender, EventArgs eventArgs)
{
if (view.ItemContainerGenerator.Status == GeneratorStatus.ContainersGenerated)
{
view.ItemContainerGenerator.StatusChanged -= replay;
TreeViewHelper.ReplayExpandState(view, expand.Children);
}
};
view.ItemContainerGenerator.StatusChanged += replay;
}
}
//
// /// <summary>
// /// Use to add a UIView to a section, it makes the section opaque, to
// /// get a transparent one, you must manually call UIViewElement
// public void Add(UIView view)
// {
// if (view == null)
// return;
// Add(new UIViewElement(null, view, false));
// }
//
// /// <summary>
// /// Adds the UIViews to the section.
// /// </summary>fparent
// /// <param name="views">
// /// An enumarable list that can be produced by something like:
// /// from x in ... select (UIView) new UIFoo ();
// /// </param>
// public void Add(IEnumerable<UIView> views)
// {
// foreach (var v in views)
// Add(v);
// }
public void SetExpandState(ExpandState state)
{
if (_ExpandState != state)
{
_ExpandState = state;
if (Root != null && IsExpandable)
{
if (_HiddenElements == null)
_HiddenElements = Elements.ToList();
Root.TableView.BeginUpdates();
if (_ExpandState == ExpandState.Opened)
{
Elements.Clear();
Insert(0, UITableViewRowAnimation.Bottom, _HiddenElements.ToArray());
}
else
{
_HiddenElements = Elements.ToList();
RemoveRange(0, Elements.Count, UITableViewRowAnimation.Top);
}
Root.TableView.ReloadSections(new NSIndexSet((uint)Index), UITableViewRowAnimation.None);
Root.TableView.EndUpdates();
}
}
}
public void OnClick()
{
// Invert the flags for expansion
_targetState = _isExpanded ? ExpandState.UNEXPANDED : ExpandState.EXPANDED;
_isExpanded = _isExpanded ? false : true;
}
