import * as _angular_core from '@angular/core';
import { AfterViewInit, OnChanges, TemplateRef, SimpleChanges } from '@angular/core';
import * as i2 from '@angular/common';

interface VirtualItem<T = unknown> {
    index: number;
    data: T;
}
declare class VirtualScrollComponent<T = unknown> implements AfterViewInit, OnChanges {
    private readonly viewport;
    private readonly templateContainer;
    /** 列表数据 */
    ncItems: _angular_core.InputSignal<T[]>;
    /** 列表项模板 */
    ncItemTemplate: _angular_core.InputSignal<TemplateRef<{
        $implicit: T;
        index: number;
    }> | null>;
    /** 缓冲item数量，前后各2项 */
    ncBufferCount: _angular_core.InputSignalWithTransform<number, unknown>;
    readonly initialized: _angular_core.WritableSignal<boolean>;
    readonly visibleItems: _angular_core.WritableSignal<VirtualItem<T>[]>;
    readonly totalPadding: _angular_core.WritableSignal<number>;
    readonly topPadding: _angular_core.WritableSignal<number>;
    readonly scrollTop: _angular_core.WritableSignal<number>;
    itemHeight: number;
    viewportHeight: number;
    private readonly cdr;
    private readonly destroyRef;
    private readonly ngZone;
    private readonly renderer;
    private viewInitialized;
    private resizeObserver;
    private measureTimer;
    /**
     * 场景	触发行	原因
     * 初始就有值（同步）	第 49 行measureAndUpdate	ngOnChanges 先执行但 viewInitialized=false 跳过，由 ngAfterViewInit 补调
     * 初始无值，后续赋值（异步）	第 75 行measureAndUpdate	ngAfterViewInit 时无数据跳过，数据到达时 ngOnChanges 直接调用
     */
    constructor();
    ngAfterViewInit(): void;
    ngOnChanges(changes: SimpleChanges): void;
    onScroll(): void;
    updateVisibleItems(): void;
    updateTotalPadding(): void;
    private clearItemsState;
    trackByIndex(item: VirtualItem<T>): number;
    /** 测量 itemHeight 并更新列表（需在 ngAfterViewInit 之后调用） */
    private measureAndUpdate;
    private cleanup;
    private clearMeasureTimer;
    static ɵfac: _angular_core.ɵɵFactoryDeclaration<VirtualScrollComponent<any>, never>;
    static ɵcmp: _angular_core.ɵɵComponentDeclaration<VirtualScrollComponent<any>, "nc-virtual-scroll", never, { "ncItems": { "alias": "ncItems"; "required": false; "isSignal": true; }; "ncItemTemplate": { "alias": "ncItemTemplate"; "required": false; "isSignal": true; }; "ncBufferCount": { "alias": "ncBufferCount"; "required": false; "isSignal": true; }; }, {}, never, never, true, never>;
}

declare class NcVirtualScrollModule {
    static ɵfac: _angular_core.ɵɵFactoryDeclaration<NcVirtualScrollModule, never>;
    static ɵmod: _angular_core.ɵɵNgModuleDeclaration<NcVirtualScrollModule, never, [typeof VirtualScrollComponent, typeof i2.CommonModule], [typeof VirtualScrollComponent]>;
    static ɵinj: _angular_core.ɵɵInjectorDeclaration<NcVirtualScrollModule>;
}

export { NcVirtualScrollModule, VirtualScrollComponent };