import { Point } from '../math';
import { HitTestResult } from './hit-test';
import { PaintingContext } from './painting-context';
import { RenderBox } from './render-box';
import { RenderContainer } from './render-container';
import { RenderObject, Visitor } from './render-object';
import type { RenderPipeline } from './render-pipeline';
/**
 * 有且仅有一个子节点的 RenderObject
 */
export declare class RenderSingleChild<ChildType extends RenderObject> extends RenderBox implements RenderContainer<ChildType> {
    get child(): ChildType | undefined;
    set child(value: ChildType | undefined);
    protected _child?: ChildType;
    visitChildren(visitor: Visitor<ChildType>): void;
    protected redepthChildren(): void;
    performLayout(): void;
    attach(owner: RenderPipeline): void;
    detach(): void;
    paint(context: PaintingContext, offset: Point): void;
    _paint(context: PaintingContext, offset: Point): void;
    hitTestChildren(result: HitTestResult, position: Point): boolean;
    hitTestSelf(): boolean;
    get childCount(): number;
    protected _childCount: number;
    get firstChild(): ChildType | undefined;
    get lastChild(): ChildType | undefined;
    childBefore(child: ChildType): undefined;
    childAfter(child: ChildType): undefined;
    insertAfter(child: ChildType, _after?: ChildType): void;
    insertBefore(child: ChildType, _before?: ChildType): void;
    appendChild(child: ChildType): void;
    removeChild(child: ChildType): void;
    removeAllChildren(): void;
    get debugChildren(): ChildType[];
    protected allocChildrenYogaNode(): void;
    protected deallocYogaNodeChildren(): void;
}