import type { Rect } from '../core/layout';
import type { FontSpec } from '../core/text-metrics';
import type { TreemapArc } from './treemap';
import type { ClassValue } from 'svelte/elements';
export type TreemapLabelFit = `hide` | `shrink` | `clip`;
export interface TreemapLabelLine {
    text: string;
    class?: ClassValue;
    font_scale?: number;
    font_weight?: string | number;
    opacity?: number;
    fill?: string;
}
type TreemapLabelContent = string | TreemapLabelLine | null | undefined;
export type TreemapLabelFormatter<Metadata extends Record<string, unknown> = Record<string, unknown>> = (arc: TreemapArc<Metadata>) => TreemapLabelContent | readonly TreemapLabelContent[];
export interface TreemapLabelBlock {
    lines: readonly TreemapLabelLine[];
    font_size: number;
    width: number;
    height: number;
}
export interface TreemapLabelPlacement {
    x: number;
    lines: (TreemapLabelLine & {
        y: number;
    })[];
    font_size: number;
    header: boolean;
    dominant_baseline: `central`;
    transform?: string;
}
export declare const safe_font_size: (font_size: number, fallback: number) => number;
export declare function normalize_treemap_label_lines(content: ReturnType<TreemapLabelFormatter>): TreemapLabelLine[];
export declare function measure_treemap_label_block(lines: readonly TreemapLabelLine[], font_size: number, font: Readonly<FontSpec>): TreemapLabelBlock;
export declare function place_treemap_label({ rect, block, header, fit, min_font_size, padding_top, margin, }: {
    rect: Rect;
    block: TreemapLabelBlock;
    header: boolean;
    fit: TreemapLabelFit;
    min_font_size: number;
    padding_top: number;
    margin: number;
}): TreemapLabelPlacement | null;
export {};