import type { ViewBox } from '../core/types/viewer';
export type FrameBounds = {
    width: number;
    height: number;
};
/**
 * The rectangle of `aspect` that a resize gesture from `before` to `after`
 * should produce.
 *
 * The edges that did not move between the two are the anchor:
 *
 * - a corner drag keeps the opposite corner and sizes the box by the pointer's
 *   projection onto the aspect's diagonal, so both axes of the drag count and
 *   the corner stays under the pointer as nearly as the lock allows — pulling
 *   mostly sideways still shrinks or grows the frame, rather than the frame
 *   holding its height and ignoring the hand;
 * - an edge drag keeps the opposite edge, derives the other dimension from the
 *   aspect, and keeps the box centred on the axis the handle did not touch;
 * - no edge moved — a plain move — and the box is returned as it came.
 *
 * With `bounds`, the result is also kept inside the canvas without breaking
 * the lock: it is shifted back in where it merely hangs over an edge, and
 * shrunk towards its anchor where it is too large to fit.
 */
export declare const lockRectAspect: (before: ViewBox, after: ViewBox, aspect: number, bounds?: FrameBounds | null) => ViewBox;
/**
 * Moves a box inside the canvas, and clamps each side to the canvas where the
 * box is larger than it. Used for plain moves, where the shape is already
 * right and only the position can be wrong.
 */
export declare const clampFrameToBounds: (box: ViewBox, bounds: FrameBounds) => ViewBox;
/**
 * Applies one typed value to a frame without breaking the lock.
 *
 * Typing a width or a height is read as "this big, from the same top-left
 * corner", and the other dimension follows; typing x or y moves the frame.
 * Nothing is re-normalised afterwards, so the number typed is the number kept.
 */
export declare const applyFrameField: (box: ViewBox, field: "x" | "y" | "w" | "h", value: number, aspect: number) => ViewBox;
/**
 * A frame to start a new keyframe from: the reference box shrunk about its
 * centre, so it reads as a distinct nested frame the author can take hold of
 * rather than a second outline on top of the first.
 */
export declare const nestedFrame: (reference: ViewBox, ratio?: number) => ViewBox;