import type { Dimension, DesignSlot, LegacyHeaderFooterSlot, ResolvedDesignBoxElement, ResolvedDesignRuleElement, ResolvedDesignSlot, ResolvedDesignTextElement, TextOverflow } from '../types.js';
export type HeaderFooterSlotKind = 'header' | 'footer';
/** Where a design slot is painted (#628): a running head or folio
 *  (`'header'`, `'footer'`, a heading style's own included), a heading
 *  design (`'heading'`: `advancedDesign.slot`, an opener or an in-column
 *  title), a part page and its verso (`'part'`), a part row of the
 *  contents (`'tocRow'`) or a box style's design (`'box'`, #1014). It sets
 *  the default `overflow` of the slot's text elements
 *  ({@link defaultTextOverflow}). */
export type DesignSlotKind = HeaderFooterSlotKind | 'heading' | 'part' | 'tocRow' | 'box';
/** The `overflow` of a text element of a `kind` slot that sets none: a
 *  heading or part title and a box design's text wrap onto more lines, a
 *  running head, a folio and a contents part row (whose height is fixed)
 *  end in `…`. */
export declare function defaultTextOverflow(kind: DesignSlotKind): TextOverflow;
export declare const DEFAULT_HEADER_FOOTER_SLOT: ResolvedDesignSlot;
/** Reference defaults for a freshly-created text element. Its `overflow`
 *  is a running head's: an element that sets none takes its slot's
 *  ({@link defaultTextOverflow}). */
export declare const DEFAULT_TEXT_ELEMENT: ResolvedDesignTextElement;
export declare const DEFAULT_RULE_ELEMENT: ResolvedDesignRuleElement;
export declare const DEFAULT_BOX_ELEMENT: ResolvedDesignBoxElement;
/** Built-in default header: book title (right, odd) + chapter title (left,
 *  even) + full-width rule. Applied when `config.header` is `undefined`. */
export declare const DEFAULT_HEADER_SLOT: ResolvedDesignSlot;
/** Built-in default footer: centered page number on every page. */
export declare const DEFAULT_FOOTER_SLOT: ResolvedDesignSlot;
/** Returns true when the slot uses the legacy `align`/`marginFromBody` shape. */
export declare function isLegacyHeaderFooterSlot(slot: unknown): slot is LegacyHeaderFooterSlot;
/** Convert a legacy-shaped header/footer slot to a `DesignSlot`. Safe to
 *  call on already-migrated slots (returns them unchanged). */
export declare function migrateLegacyHeaderFooterConfig(slot: unknown, kind: HeaderFooterSlotKind): DesignSlot | undefined;
/** A design text's leading as written (`DesignTextElement.lineHeight`: a
 *  multiplier, or a {@link Dimension}) as the resolved element carries it:
 *  a multiplier, plus the absolute length when one was given. A numeric
 *  string counts as the number it spells; anything unusable — not a
 *  positive finite number, a dimension of an unknown unit — is the default
 *  multiplier. Never NaN. */
export declare function resolveDesignLineHeight(value: unknown, fontSize: Dimension | undefined): {
    lineHeight: number;
    lineHeightLength?: Dimension;
};
/** An element's page-fence condition (#1087) as it is read: `when` and
 *  `unless` kept when they name an attribute (a non-empty string, trimmed),
 *  left out otherwise (the validation reports a value that is not one). */
export declare function fenceConditionOf(el: {
    when?: unknown;
    unless?: unknown;
}): {
    when?: string;
    unless?: string;
};
/** Resolve a design slot painted as `kind` (see {@link DesignSlotKind}),
 *  which sets the default `overflow` of its text elements. `undefined`
 *  returns the built-in default for `kind` (empty but for a running head
 *  and a folio). Legacy slots are migrated on the fly. */
export declare function resolveDesignSlot(slot: DesignSlot | undefined, kind?: DesignSlotKind): ResolvedDesignSlot;
export declare const resolveHeaderFooterConfig: typeof resolveDesignSlot;
/** `slot` as it is stored: one in the pre-placement shape migrated, any
 *  other as given. Nothing is dropped, so it serves where a slot has no
 *  default of its own (a heading style's, which stands for the
 *  document's when unset, #694). */
export declare function migrateDesignSlot(slot: DesignSlot | undefined, kind?: DesignSlotKind): DesignSlot | undefined;
export declare function stripDesignSlotDefaults(slot: DesignSlot | undefined, kind?: DesignSlotKind): DesignSlot | undefined;
export declare const stripHeaderFooterDefaults: typeof stripDesignSlotDefaults;
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