/**
 * Rich text in a cell — different fonts on different parts of the same value.
 *
 * Typical flow: set the cell text, create a font with {@link Workbook.createFont},
 * then apply it to a character span with
 * `cell.richText.characters(start, end).font = font`.
 *
 * Character indices are inclusive and 0-based. There is no public `setFont`;
 * assign through the `characters(...).font` property.
 *
 * Citations:
 * - `docs/api/RICH-TEXT-PROPOSAL.md`
 * - `docs/specs/rich-text.md`
 * - ECMA-376-1 §18.4; transitional `sml.xsd` `CT_RElt` / `CT_RPrElt`
 */
import { RichTextRun } from '../shared-strings/rich-text-xml';
import { Color as ColorValue, Font as FontInput, FontSchemeValue, UnderlineValue } from '../styles/styles-xml';
/**
 * Font settings for a span of rich text in a cell (typeface, size, bold, color, and so on).
 *
 * Create with {@link Workbook.createFont}, set the properties you need, then assign
 * the font to a character range. The assignment copies the current values; changing
 * this object later does not update text that already received the font.
 *
 * This is independent of the workbook styles table — it does not create a shared style font.
 */
export declare class Font {
    /** Font family name, such as `"Calibri"` or `"Arial"`. */
    name: string | undefined;
    /** Font size in points. */
    size: number | undefined;
    /** Whether the text is bold. */
    bold: boolean | undefined;
    /** Whether the text is italic. */
    italic: boolean | undefined;
    /** Underline style, or `true`/`false` for a simple underline on/off. */
    underline: UnderlineValue | boolean | undefined;
    /** Whether the text is struck through. */
    strike: boolean | undefined;
    /** Text color. */
    color: ColorValue | undefined;
    /** Font family class used by Excel (optional advanced setting). */
    family: number | undefined;
    /** Character set used by Excel (optional advanced setting). */
    charset: number | undefined;
    /** Theme font scheme, when the run follows a theme font. */
    scheme: FontSchemeValue | undefined;
    /** Superscript, subscript, or baseline vertical alignment. */
    vertAlign: string | undefined;
    /** Whether outline (hollow) text is drawn. */
    outline: boolean | undefined;
    /** Whether a shadow effect is applied. */
    shadow: boolean | undefined;
    /** Whether condensed spacing is applied. */
    condense: boolean | undefined;
    /** Whether extended spacing is applied. */
    extend: boolean | undefined;
    /**
     * Snapshot current fields as a plain {@link FontInput}.
     *
     * @private
     */
    toFontInput(): FontInput;
    /**
     * Populate fields from a {@link FontInput} snapshot.
     *
     * @private
     */
    copyFromInput(input: FontInput | undefined): void;
}
/**
 * Host callbacks from {@link Cell} into worksheet SST / model.
 *
 * @private
 */
export interface RichTextCellHost {
    getPlainText(): string;
    getRuns(): RichTextRun[];
    commitRuns(runs: ReadonlyArray<RichTextRun>): void;
    hasRichFormatting(): boolean;
}
/**
 * Rich text for one cell: the full string plus character ranges you can format.
 *
 * Obtained from {@link Cell.richText}. Use {@link text} for the whole value and
 * {@link characters} to bold, color, or otherwise style part of it.
 */
export declare class RichTextString {
    private readonly host;
    /**
     * @private
     */
    constructor(host: RichTextCellHost);
    /**
     * The full cell text as plain characters (formatting ignored when reading).
     *
     * Setting replaces the entire value with one unformatted run, or clears it when empty.
     */
    text: string;
    /**
     * Select a stretch of characters so you can read or set their font.
     *
     * Indices are 0-based and inclusive on both ends (for example, `characters(0, 2)`
     * covers the first three characters).
     *
     * @param start - First character index (inclusive).
     * @param end - Last character index (inclusive).
     * @returns A handle whose {@link RichTextCharacters.font} property gets or sets formatting.
     * @throws {@link InvalidArgumentError} when indices are invalid, `start` is greater than
     *   `end`, the range is outside the text, or the cell text is empty.
     */
    characters(start: number, end: number): RichTextCharacters;
    /**
     * Structured runs (snapshot). Prefer {@link characters} for mutation.
     *
     * @private
     */
    getRuns(): RichTextRun[];
}
/**
 * A selected range of characters inside a cell's rich text.
 *
 * Returned by {@link RichTextString.characters}. Assign {@link font} to format the span.
 */
export declare class RichTextCharacters {
    private readonly host;
    private readonly start;
    private readonly end;
    /**
     * @private
     */
    constructor(host: RichTextCellHost, start: number, end: number);
    /**
     * Font applied to this character range.
     *
     * **Get:** returns a new {@link Font} for the first character in the range. If the
     * range mixes several fonts, only the first character's formatting is shown.
     * **Set:** copies the assigned {@link Font} (or plain font fields) onto every
     * character in the range and commits coalesced runs to the cell.
     */
    font: Font | FontInput | undefined;
}
/**
 * True when runs carry any explicit character formatting.
 *
 * @private
 */
export declare function richRunsIndicateRichText(runs: ReadonlyArray<RichTextRun>): boolean;
/**
 * Coalesce helper re-export for cell host.
 *
 * @private
 */
export declare function normalizeRichRuns(runs: ReadonlyArray<RichTextRun>): RichTextRun[];