Bloom.CollectionTab.LibraryListView.DownLoadedBooksChanged C# (CSharp) Method

        private void DownLoadedBooksChanged(object sender, ProjectChangedEventArgs eventArgs)
        {
            SafeInvoke.InvokeIfPossible("LibraryListView update downloaded books",this,true,(Action) (() =>
            {
                // We may notice a change to the downloaded books directory before the other Bloom instance has finished
                // copying the new book there. Finishing should not take long, because the download is done...at worst
                // we have to copy the book on our own filesystem. Typically we only have to move the directory.
                // As a safeguard, wait half a second before we update things.
                if (_newDownloadTimer != null)
                {
                    // Things changed again before we started the update! Forget the old update and wait until things
                    // are stable for the required interval.
                    _newDownloadTimer.Stop();
                    _newDownloadTimer.Dispose();
                }
                _newDownloadTimer = new Timer();
                _newDownloadTimer.Tick += (o, args) =>
                {
                    _newDownloadTimer.Stop();
                    _newDownloadTimer.Dispose();
                    _newDownloadTimer = null;

                    UpdateDownloadedBooks(eventArgs.Path);
                };
                _newDownloadTimer.Interval = 500;
                _newDownloadTimer.Start();
            }));
        }