OpenTween.FilterDialog.ButtonAddTab_Click C# (CSharp) Method

        private async void ButtonAddTab_Click(object sender, EventArgs e)
        {
            string tabName = null;
            MyCommon.TabUsageType tabType;
            using (InputTabName inputName = new InputTabName())
            {
                inputName.TabName = _sts.MakeTabName("MyTab");
                inputName.IsShowUsage = true;
                inputName.ShowDialog();
                if (inputName.DialogResult == DialogResult.Cancel) return;
                tabName = inputName.TabName;
                tabType = inputName.Usage;
            }
            if (!string.IsNullOrEmpty(tabName))
            {
                //List対応
                ListElement list = null;
                if (tabType == MyCommon.TabUsageType.Lists)
                {
                    try
                    {
                        using (var dialog = new WaitingDialog(Properties.Resources.ListsGetting))
                        {
                            var cancellationToken = dialog.EnableCancellation();

                            var task = ((TweenMain)this.Owner).TwitterInstance.GetListsApi();
                            await dialog.WaitForAsync(this, task);

                            cancellationToken.ThrowIfCancellationRequested();
                        }
                    }
                    catch (OperationCanceledException) { return; }
                    catch (WebApiException ex)
                    {
                        MessageBox.Show("Failed to get lists. (" + ex.Message + ")");
                    }
                    using (ListAvailable listAvail = new ListAvailable())
                    {
                        if (listAvail.ShowDialog(this) == DialogResult.Cancel) return;
                        if (listAvail.SelectedList == null) return;
                        list = listAvail.SelectedList;
                    }
                }

                TabModel tab;
                switch (tabType)
                {
                    case MyCommon.TabUsageType.UserDefined:
                        tab = new FilterTabModel(tabName);
                        break;
                    case MyCommon.TabUsageType.PublicSearch:
                        tab = new PublicSearchTabModel(tabName);
                        break;
                    case MyCommon.TabUsageType.Lists:
                        tab = new ListTimelineTabModel(tabName, list);
                        break;
                    default:
                        return;
                }

                if (!_sts.AddTab(tab) || !((TweenMain)this.Owner).AddNewTab(tab, startup: false))
                {
                    string tmp = string.Format(Properties.Resources.AddTabMenuItem_ClickText1, tabName);
                    MessageBox.Show(tmp, Properties.Resources.AddTabMenuItem_ClickText2, MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
                    return;
                }
                else
                {
                    // タブ作成成功

                    // 末尾のタブを取得する
                    var lastIdx = this.ListTabs.Items.Count - 1;
                    var lastTab = lastIdx != -1
                        ? this._sts.Tabs[(string)this.ListTabs.Items[lastIdx]]
                        : null;

                    // 末尾がミュートタブであればその手前に追加する
                    if (lastTab != null && lastTab.TabType == MyCommon.TabUsageType.Mute)
                        this.ListTabs.Items.Insert(lastIdx, tabName);
                    else
                        this.ListTabs.Items.Add(tabName);
                }
            }
        }