/**
 * Label sizing for shapes Mango draws itself.
 *
 * Shared deliberately by the story overlay and the annotation editor. The
 * canvas package clamps a label's size but cannot wrap it, and a sentence on a
 * region has to wrap somewhere — so both surfaces fit their labels here, which
 * is what stops the same annotation being laid out one way while playing and
 * another way while being edited.
 *
 * Two rules, and both exist because the previous version had neither. Sizes are
 * bounded: the search used to run up to 42% of the rectangle's height with no
 * ceiling, so a region covering a manuscript page produced a headline. And
 * sizes respond to the reader's text settings: an absolute pixel size in a
 * transformed SVG ignores browser text zoom entirely, which for anyone relying
 * on larger text means the one piece of text they cannot enlarge is the label.
 */
export type RectangleLabelLayout = {
    /** Screen pixels, clamped into the band. */
    fontSize: number;
    lineHeight: number;
    lines: string[];
    /** True when the label does not fit even at the smallest permitted size. */
    overflow: boolean;
    /**
     * How many lines actually fit the region at this size.
     *
     * Equal to `lines.length` unless the label overflows, where it is what the
     * caller may show before clipping. A caller that clamps to a fixed number
     * either wastes room in a tall region or cuts a short label that would have
     * fitted.
     */
    visibleLines: number;
};
/** Lower and upper bound for a label, in screen pixels at default text size. */
export type LabelSizing = {
    min: number;
    max: number;
};
/**
 * The story band is slightly larger than the editor band because story labels
 * are read from further back, in a presentation rather than an editing context.
 */
export declare const EDITOR_LABEL_SIZING: LabelSizing;
export declare const STORY_LABEL_SIZING: LabelSizing;
/** No label exceeds this, whatever the band asks for. */
export declare const LABEL_CEILING = 24;
/** The root font size the bands above are expressed against. */
export declare const BASE_ROOT_FONT_SIZE = 16;
/** Scales a band by the reader's text size, keeping the absolute ceiling. */
export declare const scaleSizing: (sizing: LabelSizing, root?: number) => LabelSizing;
export type FitOptions = {
    sizing?: LabelSizing;
    /** Root font size to size against. Read from the document when omitted. */
    root?: number;
};
/**
 * Largest banded size at which the label fits the rectangle.
 *
 * `width` and `height` are screen pixels. Passing image coordinates would size
 * the label against the region rather than against the reader's screen, which
 * is the mistake this replaced.
 */
export declare const fitRectangleLabelLayout: (width: number, height: number, label: string, options?: FitOptions) => RectangleLabelLayout;
export declare const fitRectangleLabelFontSize: (width: number, height: number, label: string, options?: FitOptions) => number;
export declare const rectangleLabelOutlineWidth: (fontSize: number) => number;