CardMaker.Forms.MDIProject.addGoogleSpreadsheetReferenceToolStripMenuItem_Click C# (CSharp) Метод

        private void addGoogleSpreadsheetReferenceToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (String.IsNullOrEmpty(CardMakerInstance.GoogleAccessToken))
            {
                if(DialogResult.Cancel == MessageBox.Show(this,
                    "You do not appear to have any Google credentials configured. Press OK to configure.",
                    "Google Credentials Missing",
                    MessageBoxButtons.OKCancel,
                    MessageBoxIcon.Information))
                {
                    return;
                }
                GoogleAuthManager.Instance.FireGoogleAuthUpdateRequestedEvent();
                return;
            }

            var zDialog = new GoogleSpreadsheetBrowser(GoogleReferenceReader.APP_NAME, GoogleReferenceReader.CLIENT_ID,
                CardMakerInstance.GoogleAccessToken, true);
            if (DialogResult.OK == zDialog.ShowDialog(this))
            {
                var bNewDefault = 0 == treeView.SelectedNode.Nodes.Count;
                var zLayout = (ProjectLayout)treeView.SelectedNode.Tag;
                var tnReference = AddReferenceNode(
                    treeView.SelectedNode,
                    CardMakerConstants.GOOGLE_REFERENCE + CardMakerConstants.GOOGLE_REFERENCE_SPLIT_CHAR +
                    zDialog.SelectedSpreadsheet.Title.Text + CardMakerConstants.GOOGLE_REFERENCE_SPLIT_CHAR +
                    zDialog.SelectedSheet.Title.Text,
                    bNewDefault,
                    zLayout);
                if (null == tnReference)
                {
                    MessageBox.Show(this, "The specified reference is already associated with this layout.", "Reference Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    return;
                }
                if (bNewDefault)
                {
                    tnReference.Parent.Expand();
                    LayoutManager.Instance.FireLayoutUpdatedEvent(true);
                }
                ProjectManager.Instance.FireProjectUpdated(true);
            }
        }