OpenTween.TweenMain.MenuItemOperate_DropDownOpening C# (CSharp) Method

        private void MenuItemOperate_DropDownOpening(object sender, EventArgs e)
        {
            if (ListTab.SelectedTab == null) return;
            if (_statuses == null || _statuses.Tabs == null || !_statuses.Tabs.ContainsKey(ListTab.SelectedTab.Text)) return;
            if (!this.ExistCurrentPost)
            {
                this.ReplyOpMenuItem.Enabled = false;
                this.ReplyAllOpMenuItem.Enabled = false;
                this.DmOpMenuItem.Enabled = false;
                this.ShowProfMenuItem.Enabled = false;
                this.ShowUserTimelineToolStripMenuItem.Enabled = false;
                this.ListManageMenuItem.Enabled = false;
                this.OpenFavOpMenuItem.Enabled = false;
                this.CreateTabRuleOpMenuItem.Enabled = false;
                this.CreateIdRuleOpMenuItem.Enabled = false;
                this.CreateSourceRuleOpMenuItem.Enabled = false;
                this.ReadOpMenuItem.Enabled = false;
                this.UnreadOpMenuItem.Enabled = false;
            }
            else
            {
                this.ReplyOpMenuItem.Enabled = true;
                this.ReplyAllOpMenuItem.Enabled = true;
                this.DmOpMenuItem.Enabled = true;
                this.ShowProfMenuItem.Enabled = true;
                this.ShowUserTimelineToolStripMenuItem.Enabled = true;
                this.ListManageMenuItem.Enabled = true;
                this.OpenFavOpMenuItem.Enabled = true;
                this.CreateTabRuleOpMenuItem.Enabled = true;
                this.CreateIdRuleOpMenuItem.Enabled = true;
                this.CreateSourceRuleOpMenuItem.Enabled = true;
                this.ReadOpMenuItem.Enabled = true;
                this.UnreadOpMenuItem.Enabled = true;
            }

            if (_statuses.Tabs[ListTab.SelectedTab.Text].TabType == MyCommon.TabUsageType.DirectMessage || !this.ExistCurrentPost || _curPost.IsDm)
            {
                this.FavOpMenuItem.Enabled = false;
                this.UnFavOpMenuItem.Enabled = false;
                this.OpenStatusOpMenuItem.Enabled = false;
                this.OpenFavotterOpMenuItem.Enabled = false;
                this.ShowRelatedStatusesMenuItem2.Enabled = false;
                this.RtOpMenuItem.Enabled = false;
                this.RtUnOpMenuItem.Enabled = false;
                this.QtOpMenuItem.Enabled = false;
                this.FavoriteRetweetMenuItem.Enabled = false;
                this.FavoriteRetweetUnofficialMenuItem.Enabled = false;
            }
            else
            {
                this.FavOpMenuItem.Enabled = true;
                this.UnFavOpMenuItem.Enabled = true;
                this.OpenStatusOpMenuItem.Enabled = true;
                this.OpenFavotterOpMenuItem.Enabled = true;
                this.ShowRelatedStatusesMenuItem2.Enabled = true;  //PublicSearchの時問題出るかも

                if (!_curPost.CanRetweetBy(this.twitterApi.CurrentUserId))
                {
                    this.RtOpMenuItem.Enabled = false;
                    this.RtUnOpMenuItem.Enabled = false;
                    this.QtOpMenuItem.Enabled = false;
                    this.FavoriteRetweetMenuItem.Enabled = false;
                    this.FavoriteRetweetUnofficialMenuItem.Enabled = false;
                }
                else
                {
                    this.RtOpMenuItem.Enabled = true;
                    this.RtUnOpMenuItem.Enabled = true;
                    this.QtOpMenuItem.Enabled = true;
                    this.FavoriteRetweetMenuItem.Enabled = true;
                    this.FavoriteRetweetUnofficialMenuItem.Enabled = true;
                }
            }

            if (_statuses.Tabs[ListTab.SelectedTab.Text].TabType != MyCommon.TabUsageType.Favorites)
            {
                this.RefreshPrevOpMenuItem.Enabled = true;
            }
            else
            {
                this.RefreshPrevOpMenuItem.Enabled = false;
            }
            if (!this.ExistCurrentPost
                || _curPost.InReplyToStatusId == null)
            {
                OpenRepSourceOpMenuItem.Enabled = false;
            }
            else
            {
                OpenRepSourceOpMenuItem.Enabled = true;
            }
            if (!this.ExistCurrentPost || string.IsNullOrEmpty(_curPost.RetweetedBy))
            {
                OpenRterHomeMenuItem.Enabled = false;
            }
            else
            {
                OpenRterHomeMenuItem.Enabled = true;
            }

            if (this.ExistCurrentPost)
            {
                this.DelOpMenuItem.Enabled = this._curPost.CanDeleteBy(this.tw.UserId);
            }
        }