import * as _angular_core from '@angular/core';
import { TrackByFunction, TemplateRef } from '@angular/core';
import { CdkVirtualScrollViewport } from '@angular/cdk/scrolling';

/**
 * Fixed-size virtual scroll viewport.
 *
 * Thin wrapper around CDK's `cdk-virtual-scroll-viewport` with ngwr
 * theming and sensible buffer defaults. Project a single template — it's
 * called per item with `let-item let-index="index"`.
 *
 * @example
 * ```html
 * <wr-virtual-scroll [items]="rows" [itemSize]="32" [height]="320">
 *   <ng-template let-row let-i="index">
 *     <div class="row">{{ i }}. {{ row.name }}</div>
 *   </ng-template>
 * </wr-virtual-scroll>
 * ```
 *
 * @see https://ngwr.dev/components/virtual-scroll
 */
declare class WrVirtualScroll<T = unknown> {
    /** Items to render. */
    readonly items: _angular_core.InputSignal<readonly T[]>;
    /** Per-item pixel height. All rows must be the same height. @default 32 */
    readonly itemSize: _angular_core.InputSignalWithTransform<number, unknown>;
    /**
     * Viewport height. Pass a number (`px`) or any CSS length string
     * (`'80vh'`, `'40rem'`). @default 256
     */
    readonly height: _angular_core.InputSignal<string | number>;
    /**
     * Pixels of rendered content kept above + below the viewport. CDK
     * keeps adding rows until at least this many pixels are buffered.
     * @default itemSize * 4
     */
    readonly minBufferPx: _angular_core.InputSignal<number | undefined>;
    /**
     * Maximum pixels of buffered content before CDK starts recycling rows.
     * Must be ≥ `minBufferPx`. @default itemSize * 8
     */
    readonly maxBufferPx: _angular_core.InputSignal<number | undefined>;
    /**
     * `trackBy` function for the inner `*cdkVirtualFor`. Defaults to
     * identity (recreates rows when the item reference changes).
     */
    readonly trackBy: _angular_core.InputSignal<TrackByFunction<T>>;
    protected readonly rowTemplate: _angular_core.Signal<TemplateRef<any>>;
    protected readonly viewport: _angular_core.Signal<CdkVirtualScrollViewport>;
    protected readonly resolvedHeight: _angular_core.Signal<string>;
    protected readonly resolvedMinBuffer: _angular_core.Signal<number>;
    protected readonly resolvedMaxBuffer: _angular_core.Signal<number>;
    /** Scroll a specific index into view. Mirrors the CDK API. */
    scrollToIndex(index: number, behavior?: ScrollBehavior): void;
    /** Scroll to a pixel offset. */
    scrollToOffset(offset: number, behavior?: ScrollBehavior): void;
    /** Manually trigger size recheck (e.g. after host resize outside ResizeObserver). */
    checkViewportSize(): void;
    static ɵfac: _angular_core.ɵɵFactoryDeclaration<WrVirtualScroll<any>, never>;
    static ɵcmp: _angular_core.ɵɵComponentDeclaration<WrVirtualScroll<any>, "wr-virtual-scroll", never, { "items": { "alias": "items"; "required": true; "isSignal": true; }; "itemSize": { "alias": "itemSize"; "required": false; "isSignal": true; }; "height": { "alias": "height"; "required": false; "isSignal": true; }; "minBufferPx": { "alias": "minBufferPx"; "required": false; "isSignal": true; }; "maxBufferPx": { "alias": "maxBufferPx"; "required": false; "isSignal": true; }; "trackBy": { "alias": "trackBy"; "required": false; "isSignal": true; }; }, {}, ["rowTemplate"], never, true, never>;
}

export { WrVirtualScroll };