public bool OpenDocument(string file)
{
Timeline timeline = FileSerializer.LoadFromFile(file);
if (timeline == null)
{
OpenNewDocument();
return(false);
}
FilePath = file;
CurrentDocument = MakeSequencerViewModel(timeline);
IsDirty = false;
CurrentDocument.ActionManager.CollectionChanged += (_, __) => IsDirty = true;
return(true);
}