import { ShapeState } from "../common/ShapeState.js";
import { IShapeStyle } from "../styles/interfaces/IShapeStyle.js";
import { Point } from "../types/Point.js";
/**
 * Interface representing a shape that can be rendered on a canvas.
 *
 * This interface defines methods for rendering the shape on a canvas and managing observers.
 */
export interface IShape {
    /**
     * Renders the shape to a given canvas context.
     *
     * @param context - The 2D rendering context of the canvas where the shape will be drawn.
     */
    render(context: CanvasRenderingContext2D): void;
    /**
     * Adds an observer function that will be called when the shape undergoes changes.
     *
     * @param observer - A callback function to be invoked when the shape's state changes.
     */
    addObserver(observer: () => void): void;
    /**
     * Removes an observer function that was previously added.
     *
     * @param observer - The observer callback function to be removed.
     */
    removeObserver(observer: () => void): void;
    /**
     * Makes the shape visible, allowing it to be rendered on the canvas.
     * If the shape was previously hidden, calling this method will make it appear
     * during the next rendering cycle.
     */
    show(): void;
    /**
     * Hides the shape, preventing it from being rendered on the canvas.
     * The shape will still exist and retain its properties, but it will not
     * appear during rendering until `show()` is called.
     */
    hide(): void;
    /**
     * Checks whether the shape is currently visible.
     *
     * @returns Returns true if the shape is visible and will be rendered on the canvas.
     *          Returns false if the shape is hidden and will not be rendered.
     */
    isVisible(): boolean;
    /**
     * Checks whether the shape is draggable or not.
     *
     * @returns Returns true if the shape is draggable.
     *          Returns false if the shape is not draggable.
     */
    isDraggable(): boolean;
    /**
     * Determines if the mouse is currently over the shape.
     *
     * @param mousePosition - The current mouse position.
     * @returns True if the mouse is over the shape, false otherwise.
     */
    isMouseOver(mousePosition: Point): boolean;
    /**
     * Handles the drag operation by applying the given delta to the current position.
     *
     * @param delta - The change in position represented as a `Point`.
     */
    onDrag(delta: Point): void;
    /**
     * Gets the current state of the shape.
     *
     * @returns The current state of the shape.
     */
    get state(): ShapeState;
    /**
     * Sets a new state for the shape.
     *
     * @param state - The new state to assign to the shape.
     */
    set state(state: ShapeState);
    /**
     * Retrieves the effective style of the shape based on its current state.
     *
     * @returns The computed style object for the current shape state, with state-specific overrides merged in as necessary.
     */
    get stateStyle(): IShapeStyle;
}