/// <summary>
/// StartLasso
/// </summary>
/// <param name="points"></param>
private void StartLasso(List <Point> points)
{
Debug.Assert(!_disableLasso && _lassoHelper == null, "StartLasso is called unexpectedly.");
if (InkCanvas.ClearSelectionRaiseSelectionChanging() // If user cancels clearing the selection, we shouldn't initiate Lasso.
// NTRAID:WINDOWS#1534264-2006/02/28-WAYNEZEN
// If the active editng mode is no longer as Select, we shouldn't activate LassoSelectionBehavior.
// Note the order really matters here. This checking has to be done
// after ClearSelectionRaiseSelectionChanging is invoked.
&& EditingCoordinator.ActiveEditingMode == InkCanvasEditingMode.Select)
{
//
// obtain a dynamic hit-tester for selecting with lasso
//
_incrementalLassoHitTester =
this.InkCanvas.Strokes.GetIncrementalLassoHitTester(_percentIntersectForInk);
//
// add event handler
//
_incrementalLassoHitTester.SelectionChanged += new LassoSelectionChangedEventHandler(OnSelectionChanged);
//
// start dynamic rendering
//
_lassoHelper = new LassoHelper();
InkCanvas.BeginDynamicSelection(_lassoHelper.Visual);
Point[] lassoPoints = _lassoHelper.AddPoints(points);
if (0 != lassoPoints.Length)
{
_incrementalLassoHitTester.AddPoints(lassoPoints);
}
}
else
{
// If we fail on clearing the selection or switching to Select mode, we should just disable lasso.
_disableLasso = true;
}
}