/// <summary>
/// The subtree is upon to be dragged.
/// </summary>
public void InitializeDrag(IInputModeContext context)
{
subtree = new Subtree(context.GetGraph(), node);
layoutHelper = new RelocateSubtreeLayoutHelper((GraphControl)context.CanvasControl, subtree);
layoutHelper.InitializeLayout();
compositeHandler = CreateCompositeHandler(subtree);
compositeHandler.InitializeDrag(context);
}
/// <summary>
/// Creates a mapping to specify the components which should not be modified by <see cref="ClearAreaLayout"/>.
/// </summary>
private void UpdateComponents()
{
components.Clear();
if (subtree.NewParent != null)
{
foreach (var edge in Graph.OutEdgesAt(subtree.NewParent))
{
var siblingSubtree = new Subtree(Graph, edge.GetTargetNode());
foreach (var node in siblingSubtree.Nodes)
{
components[node] = siblingSubtree;
}
}
}
}
/// <summary>
/// Creates an <see cref="IPositionHandler"/> that moves the whole subtree.
/// </summary>
/// <param name="subtree">The nodes and edges of the subtree.</param>
/// <returns></returns>
private static IPositionHandler CreateCompositeHandler(Subtree subtree)
{
var positionHandlers = new List <IPositionHandler>();
foreach (var node in subtree.Nodes)
{
var positionHandler = node.Lookup <IPositionHandler>();
if (positionHandler != null)
{
var subtreeHandler = positionHandler as SubtreePositionHandler;
positionHandlers.Add(subtreeHandler != null ? subtreeHandler.nodePositionHandler : positionHandler);
}
}
foreach (var edge in subtree.Edges)
{
var positionHandler = edge.Lookup <IPositionHandler>();
if (positionHandler != null)
{
positionHandlers.Add(positionHandler);
}
}
return(PositionHandlers.Combine(positionHandlers));
}
/// <summary>
/// Initializes the helper.
/// </summary>
/// <param name="graphControl">The control that displays the graph.</param>
/// <param name="subtree">The subgraph the is dragged.</param>
public RelocateSubtreeLayoutHelper(GraphControl graphControl, Subtree subtree)
{
this.graphControl = graphControl;
this.subtree = subtree;
}