at-rn-android-kit/components/layout.js

为 React Native 开发 提供的一些Android原生模块/组件 (react native, CoordinatorLayout, AppBarLayout, TabLayout, NestedScrollView, PopupWindow)

import React from 'react';
import {UIManager, findNodeHandle} from 'react-native';
import {ViewGroupProperties} from './types';

export default class Layout {
    static setChildrenLayoutParams(
        component: React.Component<ViewGroupProperties, any>,
        manager: any,
        defaultParams?: any): void {

        if (!component || !manager) {
            return;
        }

        let currentChildrelLayoutParams = (component).__currentChildLayoutParams;

        let nextChildrelLayoutParams: any[] = [];
        const hasDefaultParams = !!defaultParams;

        React.Children.map(component.props.children || [], (child: any, index: number) => {
            if (!child.props.layoutParams && !hasDefaultParams) {
                return;
            }

            nextChildrelLayoutParams.push(Object.assign(
                {},
                defaultParams,
                child.props.layoutParams,
                {childIndex: index}
            ));
        });

        if (!nextChildrelLayoutParams.length) {
            return;
        }

        if (layoutParamsIsEqualTo(currentChildrelLayoutParams, nextChildrelLayoutParams)) {
            return;
        }

        (component).__currentChildLayoutParams = nextChildrelLayoutParams;

        UIManager.dispatchViewManagerCommand(
            findNodeHandle(component),
            manager.Commands.setChildrenLayoutParams,
            [nextChildrelLayoutParams]);
    }
}

function layoutParamsIsEqualTo<T>(params1: T[], params2: T[]) {
    if (!params1 || !params2) {
        return false;
    }

    if (params1.length !== params2.length) {
        return false;
    }

    for (let i = 0, l = params1.length; i < l; i++) {
        if (!paramIsEqualTo(params1[i], params2[i])) {
            return false;
        }
    }

    return true;
}

function paramIsEqualTo(param1: any, param2: any) {
    for (let key of Object.keys(param1)) {
        if (param1[key] !== param2[key]) {
            return false;
        }
    }

    return true;
}