import type { ViewportState } from "./types.js";
/**
 * Controls the pan/zoom viewport of the canvas.
 *
 * Uses the Pointer Events API (covering mouse, touch, and pen) with
 * `requestAnimationFrame`-batched rendering so interactions stay smooth at
 * 60 fps with no perceptible input lag.
 *
 * - **Mouse**: left-button drag to pan, scroll wheel to zoom toward cursor.
 * - **Touch**: one-finger drag to pan, two-finger pinch to zoom.
 * - **Keyboard**: handled externally in `keyboard.ts` via `zoomAt` / `set`.
 */
export declare class ViewportController {
    /** The host div — receives the `is-panning` CSS class. */
    private readonly _host;
    /** The SVG element that receives pointer/wheel events. */
    private readonly _svg;
    /** The `<g>` element whose `transform` attribute is updated. */
    private readonly _group;
    /** The dot-grid `<pattern>` element (optional). Kept in sync with the viewport. */
    private readonly _gridPattern;
    /** Called on every rendered frame with the new viewport state. */
    private readonly _onChanged;
    private _tx;
    private _ty;
    private _scale;
    private _raf;
    private _dirty;
    private _dragging;
    private _lastX;
    private _lastY;
    private _dragDist;
    private _locked;
    private _activePointers;
    private _lastPinchDist;
    constructor(
    /** The host div — receives the `is-panning` CSS class. */
    _host: HTMLElement, 
    /** The SVG element that receives pointer/wheel events. */
    _svg: SVGSVGElement, 
    /** The `<g>` element whose `transform` attribute is updated. */
    _group: SVGGElement, 
    /** The dot-grid `<pattern>` element (optional). Kept in sync with the viewport. */
    _gridPattern: SVGPatternElement | null, 
    /** Called on every rendered frame with the new viewport state. */
    _onChanged: (state: ViewportState) => void);
    /** Current viewport state snapshot. */
    get state(): ViewportState;
    /**
     * When locked, pointer-down is ignored (no new pan starts) and pointer-move
     * does not continue any in-progress pan. Scroll-wheel zoom is unaffected.
     */
    lock(locked: boolean): void;
    /**
     * Whether the last pointer interaction was a drag (as opposed to a click).
     * The canvas uses this to suppress `element:click` events after panning.
     */
    get didPan(): boolean;
    /** Programmatically sets viewport state. Any omitted fields are unchanged. */
    set(state: Partial<ViewportState>): void;
    /**
     * Zooms the viewport by `factor`, keeping the point at (`screenX`, `screenY`)
     * fixed in screen space (zoom-toward-cursor behaviour).
     */
    zoomAt(screenX: number, screenY: number, factor: number): void;
    /** Removes all event listeners and cancels any pending animation frame. */
    destroy(): void;
    private _scheduleApply;
    private _apply;
    private readonly _onWheel;
    private readonly _onPointerDown;
    private readonly _onPointerMove;
    private readonly _onPointerUp;
    private _bindEvents;
    private _unbindEvents;
}
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