/// <summary>
/// Test whether the given location is a valid hit.
/// </summary>
/// <remarks>
/// The hit is considered as valid if the location lies inside a node's top insets.
/// </remarks>
/// <param name="context">The current input mode context.</param>
/// <param name="location">The location to test.</param>
/// <returns></returns>
public bool IsHit(IInputModeContext context, PointD location)
{
// Get the current hit tester from the input mode context
IHitTester <IModelItem> enumerator = inputMode.InputModeContext.Lookup(typeof(IHitTester <IModelItem>)) as IHitTester <IModelItem>;
if (enumerator != null)
{
// get an enumerator over all elements at the given location
var hits = enumerator.EnumerateHits(inputMode.InputModeContext, location);
foreach (var item in hits)
{
// if the element is a node and its lookup returns an INodeInsetsProvider
var node = item as INode;
if (node != null)
{
var insetsProvider = node.Lookup <INodeInsetsProvider>();
if (insetsProvider != null)
{
// determine whether the given location lies inside the top insets
InsetsD insets = insetsProvider.GetInsets(node);
if (new RectD(node.Layout.X, node.Layout.Y, node.Layout.Width, insets.Top).Contains(location))
{
// if so: return true
return(true);
}
// else: continue iteration
}
}
}
}
// no hits found: return false
return(false);
}
/// <summary>
/// Determines the group node on that the mouse is currently hovering. If there is no
/// group node <code>null</code> is returned.
/// </summary>
private INode GetHitGroupNode(IInputModeContext context)
{
return(nodeHitTester.EnumerateHits(context, context.CanvasControl.LastEventLocation)
.FirstOrDefault(n => Graph.IsGroupNode(n)));
}