/// <summary>
/// Initializes a new instance of the <see cref="TreeItemContainerGenerator{T}"/> class.
/// </summary>
/// <param name="owner">The owner control.</param>
/// <param name="contentProperty">The container's Content property.</param>
/// <param name="itemsProperty">The container's Items property.</param>
/// <param name="isExpandedProperty">The container's IsExpanded property.</param>
/// <param name="rootGenerator">
/// The item container for the root of the tree, or null if this generator is itself the
/// root of the tree.
/// </param>
public TreeItemContainerGenerator(
IControl owner,
PerspexProperty contentProperty,
PerspexProperty itemsProperty,
PerspexProperty isExpandedProperty,
ITreeItemContainerGenerator rootGenerator)
: base(owner, contentProperty)
{
ItemsProperty = itemsProperty;
IsExpandedProperty = isExpandedProperty;
RootGenerator = rootGenerator;
if (rootGenerator == null)
{
_itemToContainer = new Dictionary <object, T>();
_containerToItem = new Dictionary <IControl, object>();
}
}
public void Update(TreeView treeView, ITreeItemContainerGenerator itemContainerGenerator, IDropInfo dropInfo)
{
int indexOfDrop = dropInfo.InsertIndex;
var container = itemContainerGenerator.ContainerFromIndex(indexOfDrop);
if (container == null)
{
if (indexOfDrop == 0)
{
drawRect = new Rect(0, 0, treeView.Width, 1);
}
else
{
container = itemContainerGenerator.ContainerFromIndex(indexOfDrop - 1);
if (container != null)
{
drawRect = new Rect(container.Bounds.X, container.Bounds.Bottom, container.Bounds.Width, 1);
}
else
{
drawRect = new Rect(0, 0, 0, 1);
}
}
}
else
{
double y = 0;
IVisual parent = container.VisualParent;
while (parent != null && parent != treeView)
{
y += parent.Bounds.Y;
parent = parent.VisualParent;
}
var header = container.GetVisualChildren().FirstOrDefault().GetVisualChildren().FirstOrDefault();
var height = header?.Bounds.Height ?? container.Bounds.Height;
double top = container.TranslatePoint(new Point(0, 0), treeView)?.Y ?? 0;
double bottom = container.TranslatePoint(new Point(0, height), treeView)?.Y ?? 0;
if (dropInfo.InsertPosition.HasFlag(RelativeInsertPosition.TargetItemCenter) &&
dropInfo.DropTargetAdorner == DropTargetAdorners.Highlight)
{
drawRect = new Rect(container.Bounds.X + 1, top, container.Bounds.Width - 2, container.Bounds.Height);
}
else if (dropInfo.InsertPosition.HasFlag(RelativeInsertPosition.BeforeTargetItem))
{
drawRect = new Rect(container.Bounds.X, top, container.Bounds.Width, 1);
}
else
{
drawRect = new Rect(container.Bounds.X, bottom, container.Bounds.Width, 1);
}
}
/*var scroll = treeView.FindDescendantOfType<ScrollViewer>();
* if (scroll != null)
* drawRect = new Rect(drawRect.X, drawRect.Y - scroll.Offset.Y, drawRect.Width, drawRect.Height);
*/
InvalidateVisual();
}