export interface FontSpec {
    font_family: string;
    font_size: number;
    font_style: string;
    font_variant: string;
    font_weight: string;
    font_stretch: string;
    line_height: number;
}
export interface TextLineMetrics {
    readonly text: string;
    readonly width: number;
    readonly ascent: number;
    readonly descent: number;
    readonly height: number;
    readonly source: `canvas` | `fallback`;
}
type TextWidthMeasure = (text: string, font: Readonly<FontSpec>) => {
    readonly width: number;
};
interface FontReadiness {
    readonly ready: PromiseLike<unknown>;
}
export declare const DEFAULT_FONT_SPEC: Readonly<FontSpec>;
export declare function resolve_font_size_css(value: string | undefined, parent_font_size?: number): number;
export declare function resolve_font_spec(element: HTMLElement | SVGElement | null | undefined, fallback?: Readonly<FontSpec>): FontSpec;
export declare function font_spec_to_css(font: Readonly<FontSpec>): string;
export declare function measure_text_line(text: string, font?: Readonly<FontSpec>): TextLineMetrics;
export declare function wrap_text_paragraph(paragraph: string, available_width: number, font: Readonly<FontSpec>, measure?: TextWidthMeasure, preserve_empty_line?: boolean): string[];
export declare function clear_text_metrics_cache(): number;
export declare const get_text_metrics_revision: () => number;
export declare function invalidate_text_metrics_after_fonts_ready(font_readiness?: FontReadiness | undefined): Promise<number>;
export {};