public override HistoryMemento OnExecute(IHistoryWorkspace historyWorkspace)
{
if (historyWorkspace.Selection.IsEmpty)
{
return(null);
}
else
{
SelectionHistoryMemento sha = new SelectionHistoryMemento(
StaticName,
StaticImage,
historyWorkspace);
//PdnGraphicsPath selectedPath = historyWorkspace.Selection.GetPathReadOnly();
PdnGraphicsPath selectedPath = historyWorkspace.Selection.CreatePath();
PdnGraphicsPath boundsOutline = new PdnGraphicsPath();
boundsOutline.AddRectangle(historyWorkspace.Document.Bounds);
PdnGraphicsPath clippedPath = PdnGraphicsPath.Combine(selectedPath, CombineMode.Intersect, boundsOutline);
PdnGraphicsPath invertedPath = PdnGraphicsPath.Combine(clippedPath, CombineMode.Xor, boundsOutline);
selectedPath.Dispose();
selectedPath = null;
clippedPath.Dispose();
clippedPath = null;
EnterCriticalRegion();
historyWorkspace.Selection.PerformChanging();
historyWorkspace.Selection.Reset();
historyWorkspace.Selection.SetContinuation(invertedPath, CombineMode.Replace, true);
historyWorkspace.Selection.CommitContinuation();
historyWorkspace.Selection.PerformChanged();
boundsOutline.Dispose();
boundsOutline = null;
return(sha);
}
}