import { InlineTool, SanitizerConfig } from '@editorjs/editorjs';
import { StyleObject } from '../editorjs-tool.component';
import { InlineStyleTool } from './tool-type/inline-style-tool.component';
/**
 * Underline formatting tool for EditorJS
 * Allows applying underline formatting to selected text or entire blocks
 */
export declare class UnderlineTool extends InlineStyleTool implements InlineTool {
    static title: string;
    private readonly commandName;
    tag: string;
    hasSeparatorBefore: boolean;
    private readonly CSS;
    style: StyleObject;
    modifies: {
        tag: boolean;
        style: boolean;
        class: boolean;
        attribute: boolean;
    };
    private nodes;
    private selectedBlocksService;
    api: any;
    private _state;
    static get isInline(): boolean;
    static get sanitize(): SanitizerConfig;
    get state(): boolean;
    set state(state: boolean);
    get shortcut(): string;
    constructor({ api }: {
        api: any;
    });
    /**
     * Creates and configures the tool button
     */
    render(): HTMLElement;
    /**
     * Applies underline formatting to selected text or selected blocks
     */
    surround(range: Range): Promise<void>;
    /**
     * Applies underline formatting to all selected blocks
     */
    private applyUnderlineToSelectedBlocks;
    /**
     * Applies underline formatting to a specific block
     */
    private applyUnderlineToBlock;
    /**
     * Applies underline formatting to a text element
     */
    private applyUnderlineToTextElement;
    /**
     * Removes existing underline elements
     */
    private removeExistingUnderlineElements;
    /**
     * Creates and applies a new underline element
     */
    private createAndApplyUnderlineElement;
    /**
     * Applies underline to block elements by wrapping only the text
     */
    private applyUnderlineToBlockElements;
    /**
     * Applies underline to the content of a block element
     */
    private applyUnderlineToBlockContent;
    /**
     * Gets a block by its ID
     */
    private getBlockById;
    /**
     * Gets the editable text element of a block
     */
    private getTextElement;
    /**
     * Checks the tool state based on selection
     */
    checkState(selection: Selection | null): boolean;
}