/**
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * SPDX-License-Identifier: Apache-2.0
 */

import * as $ from 'jquery';
import APLRenderer from '../APLRenderer';
import { Component, FactoryFunction, IComponentProperties } from './Component';
import { Scrollable } from './Scrollable';

/**
 * @ignore
 */
export class ScrollView extends Scrollable<IComponentProperties> {

    constructor(renderer: APLRenderer, component: APL.Component, factory: FactoryFunction, parent?: Component) {
        super(renderer, component, factory, parent);
        this.container.classList.add('scrollView');
    }

    public init() {
        super.init();
    }

    /**
     * @param component child component
     * @returns [offset,size on direction]
     * @memberof ScrollViewComponent
     */
    public getChildTopOffset(component: Component): number {
        if (this.children.length === 0) {
            // no children
            return 0;
        }
        const topContainer = this.container;
        let element = component.container as HTMLElement;
        let top = 0;
        // use this instead of getClientBoundingRect to account for
        // scaling of the APLRenderer
        do {
            top += element.offsetTop  || 0;
            element = element.offsetParent as HTMLElement;
        } while (element && element !== topContainer);

        return top;
    }

    public destroy() {
        $(this.container).off('scroll');
        super.destroy();
    }
}