how change font available filers in FilterPopup

        public RadForm1()
        {
            InitializeComponent();

            this.radGridView1.EnableFiltering = true;
            this.radGridView1.ShowHeaderCellButtons = true;
            this.radGridView1.FilterPopupInitialized+=radGridView1_FilterPopupInitialized;
        }

        Font f = new Font("Arial", 12f, FontStyle.Italic );
        private void radGridView1_FilterPopupInitialized(object sender, FilterPopupInitializedEventArgs e)
        {
            RadListFilterPopup popup = e.FilterPopup as RadListFilterPopup;
            if (popup!=null)
            {
                popup.Font = f;
                foreach (RadItem item in popup.Items)
                {
                    item.Font = f;
                    RadMenuItem menuItem= item as RadMenuItem;
                    if (menuItem!=null && menuItem.Items.Count>0)
                    {
                        foreach (RadItem childItem in menuItem.Items)
                        {
                            childItem.Font = f;
                        }
                    }
                }
                popup.MenuTreeElement.TreeView.NodeFormatting-=TreeView_NodeFormatting;
                popup.MenuTreeElement.TreeView.NodeFormatting+=TreeView_NodeFormatting;

              
            }
        }

        private void TreeView_NodeFormatting(object sender, TreeNodeFormattingEventArgs e)
        {
            e.NodeElement.Font = f;
        }

        private void RadGridView1_CreateCompositeFilterDialog(object sender, GridViewCreateCompositeFilterDialogEventArgs e)
        {
            CompositeDataFilterForm form = e.Dialog as CompositeDataFilterForm;
            if (form!=null)
            {
                form.Font = f;
                ChangeFont(form.Controls);
                
                form.DataFilter.NodeFormatting -= DataFilter_NodeFormatting;
                form.DataFilter.NodeFormatting += DataFilter_NodeFormatting;

                form.DataFilter.EditorInitialized -= DataFilter_EditorInitialized; 
                form.DataFilter.EditorInitialized += DataFilter_EditorInitialized;
            }
        }

        private void ChangeFont(Control.ControlCollection controls)
        {
            foreach (Control c in controls)
            {
                c.Font = f;
                if (c.Controls.Count>0)
                {
                    ChangeFont(c.Controls);
                }
            }
        }

        private void DataFilter_EditorInitialized(object sender, TreeNodeEditorInitializedEventArgs e)
        {
            TreeViewDropDownListEditor dropDownEditor = e.Editor as TreeViewDropDownListEditor;
            if (dropDownEditor!=null)
            {
                BaseDropDownListEditorElement el = dropDownEditor.EditorElement as BaseDropDownListEditorElement;
                el.Font = f;
                el.VisualItemFormatting -= El_VisualItemFormatting; 
                el.VisualItemFormatting += El_VisualItemFormatting;
            }
        }

        private void El_VisualItemFormatting(object sender, VisualItemFormattingEventArgs args)
        {
            args.VisualItem.Font = f;
        }

        private void DataFilter_NodeFormatting(object sender, TreeNodeFormattingEventArgs e)
        {
            DataFilterCriteriaElement dataExpressionFilterElement = e.NodeElement as DataFilterCriteriaElement;
            if (dataExpressionFilterElement!=null)
            {
                dataExpressionFilterElement.FieldElement.Font = f;
                dataExpressionFilterElement.OperatorElement.Font = f;
                dataExpressionFilterElement.ValueElement.Font = f;
            }
            e.NodeElement.Font = f;
        }

        Font f = new Font("Arial", 12f, FontStyle.Italic );

        private void DataFilter_NodeFormatting(object sender, TreeNodeFormattingEventArgs e)
        {
            DataFilterCriteriaElement dataExpressionFilterElement = e.NodeElement as DataFilterCriteriaElement;
            if (dataExpressionFilterElement!=null)
            {
                dataExpressionFilterElement.FieldElement.Font = f;
                dataExpressionFilterElement.OperatorElement.Font = f;
                dataExpressionFilterElement.ValueElement.Font = f;
            }
            DataFilterAddNodeElement addNodeElement = e.NodeElement as DataFilterAddNodeElement;
            if (addNodeElement !=null)
            {
                foreach (RadItem item in addNodeElement.DropDownButton.Items)
                {
                    item.Font = f;
                }
            }
            e.NodeElement.Font = f;
        }

        this.radGridView1.ContextMenuOpening += RadGridView1_ContextMenuOpening;

        private void RadGridView1_ContextMenuOpening(object sender, ContextMenuOpeningEventArgs e)
        {
            if (e.ContextMenuProvider is GridHeaderCellElement)
            {
                foreach (RadItem item in e.ContextMenu.Items)
                {
                    item.Font = f;
                }
            }
        }

        this.radGridView1.ConditionalFormattingFormShown += RadGridView1_ConditionalFormattingFormShown; 

        private void RadGridView1_ConditionalFormattingFormShown(object sender, EventArgs e)
        {
            ConditionalFormattingForm form = sender as ConditionalFormattingForm;
            form.Font = f;
            ChangeFont(form.Controls);

        }
        private void ChangeFont(Control.ControlCollection controls)
        {
            foreach (Control c in controls)
            {
                c.Font = f;
                if (c.Controls.Count > 0)
                {
                    ChangeFont(c.Controls);
                }
            }
        }