youxi-app/uni_modules/cool-ui/components/cl-list-view/cl-list-view.uvue

<template>
	<view class="cl-list-view" :class="[pt.className]">
		<cl-index-bar
			v-if="hasIndex"
			v-model="activeIndex"
			:list="indexList"
			:pt="{
				className: parseClass([pt.indexBar?.className])
			}"
			@change="onIndexChange"
		>
		</cl-index-bar>

		<scroll-view
			class="cl-list-view__scroller"
			:class="[pt.scroller?.className]"
			:scroll-top="targetScrollTop"
			:scroll-into-view="scrollIntoView"
			:scroll-with-animation="scrollWithAnimation"
			:show-scrollbar="showScrollbar"
			:refresher-triggered="refreshTriggered"
			:refresher-enabled="refresherEnabled"
			:refresher-threshold="refresherThreshold"
			:refresher-background="refresherBackground"
			refresher-default-style="none"
			direction="vertical"
			@scrolltoupper="onScrollToUpper"
			@scrolltolower="onScrollToLower"
			@scroll="onScroll"
			@scrollend="onScrollEnd"
			@refresherpulling="onRefresherPulling"
			@refresherrefresh="onRefresherRefresh"
			@refresherrestore="onRefresherRestore"
			@refresherabort="onRefresherAbort"
		>
			<view
				slot="refresher"
				class="cl-list-view__refresher"
				:class="[
					{
						'is-pulling': refresherStatus === 'pulling',
						'is-refreshing': refresherStatus === 'refreshing'
					},
					pt.refresher?.className
				]"
				:style="{
					height: refresherThreshold + 'px'
				}"
			>
				<slot name="refresher" :status="refresherStatus" :text="refresherText">
					<cl-loading
						v-if="refresherStatus === 'refreshing'"
						:size="28"
						:pt="{
							className: 'mr-2'
						}"
					></cl-loading>
					<cl-text> {{ refresherText }} </cl-text>
				</slot>
			</view>

			<view
				class="cl-list-view__virtual-list"
				:class="[pt.list?.className]"
				:style="listStyle"
			>
				<view class="cl-list-view__spacer-top" :style="spacerTopStyle">
					<slot name="top"></slot>
				</view>

				<view
					v-for="(item, index) in visibleItems"
					:key="item.key"
					class="cl-list-view__virtual-item"
				>
					<view
						class="cl-list-view__header"
						:class="[
							{
								'is-dark': isDark
							}
						]"
						:style="{
							height: headerHeight + 'px'
						}"
						v-if="item.type == 'header'"
					>
						<slot name="header" :index="item.data.index!">
							<cl-text> {{ item.data.label }} </cl-text>
						</slot>
					</view>

					<view
						v-else
						class="cl-list-view__item"
						:class="[
							{
								'is-dark': isDark
							},
							pt.item?.className
						]"
						:style="{
							height: virtual ? itemHeight + 'px' : 'auto'
						}"
						@tap="onItemTap(item)"
					>
						<slot
							name="item"
							:item="item"
							:data="item.data"
							:value="item.data.value"
							:index="index"
						>
							<view class="cl-list-view__item-inner">
								<cl-text> {{ item.data.label }} </cl-text>
							</view>
						</slot>
					</view>
				</view>

				<view class="cl-list-view__spacer-bottom" :style="spacerBottomStyle">
					<slot name="bottom"></slot>
				</view>
			</view>

			<cl-empty v-if="noData" :fixed="false"></cl-empty>
			<cl-back-top :top="scrollTop" v-if="showBackTop" @tap="scrollToTop"></cl-back-top>
		</scroll-view>

		<view
			class="cl-list-view__index"
			:class="[
				{
					'is-dark': isDark
				}
			]"
			:style="{ height: headerHeight + 'px' }"
			v-if="hasIndex"
		>
			<slot name="index" :index="indexList[activeIndex]">
				<cl-text> {{ indexList[activeIndex] }} </cl-text>
			</slot>
		</view>
	</view>
</template>

<script setup lang="ts">
import { computed, getCurrentInstance, nextTick, onMounted, ref, watch, type PropType } from "vue";
import type {
	ClListViewItem,
	ClListViewGroup,
	ClListViewVirtualItem,
	PassThroughProps,
	ClListViewRefresherStatus
} from "../../types";
import { isApp, isDark, isEmpty, parseClass, parsePt } from "@/cool";
import { t } from "@/locale";

defineOptions({
	name: "cl-list-view"
});

defineSlots<{
	// 顶部插槽
	top(): any;
	// 分组头部插槽
	header(props: { index: string }): any;
	// 列表项插槽
	item(props: {
		data: ClListViewItem;
		item: ClListViewVirtualItem;
		value: any | null;
		index: number;
	}): any;
	// 底部插槽
	bottom(): any;
	// 索引插槽
	index(props: { index: string }): any;
	// 下拉刷新插槽
	refresher(props: { status: ClListViewRefresherStatus; text: string }): any;
}>();

const props = defineProps({
	// 透传样式配置
	pt: {
		type: Object,
		default: () => ({})
	},
	// 列表数据源
	data: {
		type: Array as PropType<ClListViewItem[]>,
		default: () => []
	},
	// 列表项高度
	itemHeight: {
		type: Number,
		default: 50
	},
	// 分组头部高度
	headerHeight: {
		type: Number,
		default: 32
	},
	// 列表顶部预留空间高度
	topHeight: {
		type: Number,
		default: 0
	},
	// 列表底部预留空间高度
	bottomHeight: {
		type: Number,
		default: 0
	},
	// 缓冲区大小,即可视区域外预渲染的项目数量
	bufferSize: {
		type: Number,
		default: isApp() ? 5 : 15
	},
	// 是否启用虚拟列表渲染,当数据量大时建议开启以提升性能
	virtual: {
		type: Boolean,
		default: true
	},
	// 滚动到指定位置
	scrollIntoView: {
		type: String,
		default: ""
	},
	// 是否启用滚动动画
	scrollWithAnimation: {
		type: Boolean,
		default: false
	},
	// 是否显示滚动条
	showScrollbar: {
		type: Boolean,
		default: false
	},
	// 是否启用下拉刷新
	refresherEnabled: {
		type: Boolean,
		default: false
	},
	// 下拉刷新触发距离，相当于下拉内容高度
	refresherThreshold: {
		type: Number,
		default: 50
	},
	// 下拉刷新区域背景色
	refresherBackground: {
		type: String,
		default: "transparent"
	},
	// 下拉刷新默认文案
	refresherDefaultText: {
		type: String,
		default: () => t("下拉刷新")
	},
	// 释放刷新文案
	refresherPullingText: {
		type: String,
		default: () => t("释放立即刷新")
	},
	// 正在刷新文案
	refresherRefreshingText: {
		type: String,
		default: () => t("加载中")
	},
	// 是否显示回到顶部按钮
	showBackTop: {
		type: Boolean,
		default: true
	}
});

const emit = defineEmits([
	"item-tap",
	"refresher-pulling",
	"refresher-refresh",
	"refresher-restore",
	"refresher-abort",
	"scrolltoupper",
	"scrolltolower",
	"scroll",
	"scrollend",
	"pull",
	"top",
	"bottom"
]);

// 获取当前组件实例,用于后续DOM操作
const { proxy } = getCurrentInstance()!;

// 透传样式配置类型
type PassThrough = {
	className?: string;
	item?: PassThroughProps;
	list?: PassThroughProps;
	indexBar?: PassThroughProps;
	scroller?: PassThroughProps;
	refresher?: PassThroughProps;
};

// 解析透传样式配置
const pt = computed(() => parsePt<PassThrough>(props.pt));

// 当前激活的索引位置,用于控制索引栏的高亮状态
const activeIndex = ref(0);

// 是否没有数据
const noData = computed(() => {
	return isEmpty(props.data);
});

// 是否包含索引
const hasIndex = computed(() => {
	return props.data.every((e) => e.index != null) && !noData.value;
});

// 计算属性:将原始数据按索引分组
const data = computed<ClListViewGroup[]>(() => {
	// 初始化分组数组
	const group: ClListViewGroup[] = [];

	// 遍历原始数据,按index字段进行分组
	props.data.forEach((item) => {
		// 查找是否已存在相同index的分组
		const index = group.findIndex((group) => group.index == item.index);

		if (index != -1) {
			// 如果分组已存在,将当前项添加到该分组的列表中
			group[index].children.push(item);
		} else {
			// 如果分组不存在,创建新的分组
			group.push({
				index: item.index ?? "",
				children: [item]
			} as ClListViewGroup);
		}
	});

	return group;
});

// 计算属性:提取所有分组的索引列表,用于索引栏显示
const indexList = computed<string[]>(() => {
	return data.value.map((item) => item.index);
});

// 计算属性:将分组数据扁平化为虚拟列表项数组
const virtualItems = computed<ClListViewVirtualItem[]>(() => {
	// 初始化虚拟列表数组
	const items: ClListViewVirtualItem[] = [];

	// 初始化顶部位置,考虑预留空间
	let top = props.topHeight;
	// 初始化索引计数器
	let index = 0;

	// 遍历每个分组,生成虚拟列表项
	data.value.forEach((group, groupIndex) => {
		if (group.index != "") {
			// 添加分组头部项
			items.push({
				key: `header-${groupIndex}`,
				type: "header",
				index: index++,
				top,
				height: props.headerHeight,
				data: {
					label: group.index!,
					index: group.index
				}
			});
			// 更新top位置
			top += props.headerHeight;
		}

		// 添加分组内的所有列表项
		group.children.forEach((item, itemIndex) => {
			items.push({
				key: `item-${groupIndex}-${itemIndex}`,
				type: "item",
				index: index++,
				top,
				height: props.itemHeight,
				data: item
			});
			// 更新top位置
			top += props.itemHeight;
		});
	});

	return items;
});

// 计算属性:计算整个列表的总高度
const listHeight = computed<number>(() => {
	return (
		// 所有项目高度之和
		virtualItems.value.reduce((total, item) => total + item.height, 0) +
		// 加上顶部预留空间高度
		props.topHeight +
		// 加上底部预留空间高度
		props.bottomHeight
	);
});

// 当前滚动位置
const scrollTop = ref(0);

// 目标滚动位置,用于控制滚动到指定位置
const targetScrollTop = ref(0);

// 滚动容器的高度
const scrollerHeight = ref(0);

// 计算属性:获取当前可见区域的列表项
const visibleItems = computed<ClListViewVirtualItem[]>(() => {
	// 如果虚拟列表为空,返回空数组
	if (isEmpty(virtualItems.value)) {
		return [];
	}

	// 如果未启用虚拟列表,直接返回所有项目
	if (!props.virtual) {
		return virtualItems.value;
	}

	// 计算缓冲区高度
	const bufferHeight = props.bufferSize * props.itemHeight;
	// 计算可视区域的顶部位置(包含缓冲区)
	const viewportTop = scrollTop.value - bufferHeight;
	// 计算可视区域的底部位置(包含缓冲区)
	const viewportBottom = scrollTop.value + scrollerHeight.value + bufferHeight;

	// 初始化可见项目数组
	const visible: ClListViewVirtualItem[] = [];

	// 使用二分查找优化查找起始位置
	let startIndex = 0;
	let endIndex = virtualItems.value.length - 1;

	// 二分查找第一个可见项目的索引
	while (startIndex < endIndex) {
		const mid = Math.floor((startIndex + endIndex) / 2);
		const item = virtualItems.value[mid];

		if (item.top + item.height <= viewportTop) {
			startIndex = mid + 1;
		} else {
			endIndex = mid;
		}
	}

	// 从找到的起始位置开始,收集所有可见项目
	for (let i = startIndex; i < virtualItems.value.length; i++) {
		const item = virtualItems.value[i];

		// 如果项目完全超出视口下方,停止收集
		if (item.top >= viewportBottom) {
			break;
		}

		// 如果项目与视口有交集,添加到可见列表
		if (item.top + item.height > viewportTop) {
			visible.push(item);
		}
	}

	return visible;
});

// 计算属性:计算上方占位容器的高度
const spacerTopHeight = computed<number>(() => {
	// 如果没有可见项目,返回0
	if (isEmpty(visibleItems.value)) {
		return 0;
	}
	// 返回第一个可见项目的顶部位置
	return visibleItems.value[0].top;
});

// 计算属性:计算下方占位容器的高度
const spacerBottomHeight = computed<number>(() => {
	// 如果没有可见项目,返回0
	if (isEmpty(visibleItems.value)) {
		return 0;
	}
	// 获取最后一个可见项目
	const lastItem = visibleItems.value[visibleItems.value.length - 1];
	// 计算下方占位高度
	return listHeight.value - (lastItem.top + lastItem.height);
});

// 列表样式
const listStyle = computed(() => {
	return {
		height: props.virtual ? `${listHeight.value}px` : "auto"
	};
});

// 上方占位容器样式
const spacerTopStyle = computed(() => {
	return {
		height: props.virtual ? `${spacerTopHeight.value}px` : "auto"
	};
});

// 下方占位容器样式
const spacerBottomStyle = computed(() => {
	return {
		height: props.virtual ? `${spacerBottomHeight.value}px` : "auto"
	};
});

// 存储每个分组头部距离顶部的位置数组
const tops = ref<number[]>([]);

// 计算并更新所有分组头部的位置
function getTops() {
	// 初始化一个空数组
	const arr = [] as number[];

	// 初始化顶部位置
	let top = 0;

	// 计算每个分组的顶部位置
	data.value.forEach((group) => {
		// 将当前分组头部的位置添加到数组中
		arr.push(top);

		// 累加当前分组的总高度(头部高度+所有项目高度)
		top += props.headerHeight + group.children.length * props.itemHeight;
	});

	tops.value = arr;
}

// 下拉刷新触发标志
const refreshTriggered = ref(false);

// 下拉刷新相关状态
const refresherStatus = ref<"default" | "pulling" | "refreshing">("default");

// 下拉刷新文案
const refresherText = computed(() => {
	switch (refresherStatus.value) {
		case "pulling":
			return props.refresherPullingText;
		case "refreshing":
			return props.refresherRefreshingText;
		default:
			return props.refresherDefaultText;
	}
});

// 停止下拉刷新
function stopRefresh() {
	refreshTriggered.value = false;
	refresherStatus.value = "default";
}

// 滚动到顶部事件处理函数
function onScrollToUpper(e: UniScrollToUpperEvent) {
	emit("scrolltoupper", e);
	emit("top");
}

// 滚动到底部事件处理函数
function onScrollToLower(e: UniScrollToLowerEvent) {
	emit("scrolltolower", e);
	emit("bottom");
}

// 滚动锁定标志,用于防止滚动时触发不必要的计算
let scrollLock = false;

// 滚动事件处理函数
function onScroll(e: UniScrollEvent) {
	// 更新当前滚动位置
	scrollTop.value = Math.floor(e.detail.scrollTop);

	// 如果滚动被锁定,直接返回
	if (scrollLock) return;

	// 根据滚动位置自动更新激活的索引
	tops.value.forEach((top, index) => {
		if (scrollTop.value >= top) {
			activeIndex.value = index;
		}
	});

	emit("scroll", e);
}

// 滚动结束事件处理函数
function onScrollEnd(e: UniScrollEvent) {
	emit("scrollend", e);
}

// 行点击事件处理函数
function onItemTap(item: ClListViewVirtualItem) {
	emit("item-tap", item.data);
}

// 索引栏点击事件处理函数
function onIndexChange(index: number) {
	// 锁定滚动,防止触发不必要的计算
	scrollLock = true;

	// 设置目标滚动位置为对应分组头部的位置
	targetScrollTop.value = tops.value[index];

	// 300ms后解除滚动锁定
	setTimeout(() => {
		scrollLock = false;
	}, 300);
}

// 下拉刷新事件处理函数
function onRefresherPulling(e: UniRefresherEvent) {
	if (e.detail.dy > props.refresherThreshold) {
		refresherStatus.value = "pulling";
	}
	emit("refresher-pulling", e);
}

// 下拉刷新事件处理函数
function onRefresherRefresh(e: UniRefresherEvent) {
	refresherStatus.value = "refreshing";
	refreshTriggered.value = true;
	emit("refresher-refresh", e);
	emit("pull", e);
}

// 恢复下拉刷新
function onRefresherRestore(e: UniRefresherEvent) {
	refresherStatus.value = "default";
	emit("refresher-restore", e);
}

// 停止下拉刷新
function onRefresherAbort(e: UniRefresherEvent) {
	refresherStatus.value = "default";
	emit("refresher-abort", e);
}

// 滚动到顶部
function scrollToTop() {
	targetScrollTop.value = 0.01;

	nextTick(() => {
		targetScrollTop.value = 0;
	});
}

// 获取滚动容器的高度
function getScrollerHeight() {
	setTimeout(() => {
		uni.createSelectorQuery()
			.in(proxy)
			.select(".cl-list-view__scroller")
			.boundingClientRect()
			.exec((res) => {
				if (isEmpty(res)) {
					return;
				}

				// 设置容器高度
				scrollerHeight.value = (res[0] as NodeInfo).height ?? 0;
			});
	}, 100);
}

// 组件挂载后的初始化逻辑
onMounted(() => {
	// 获取容器高度
	getScrollerHeight();

	// 监听数据变化,重新计算位置信息
	watch(
		computed(() => props.data),
		() => {
			getTops();
		},
		{
			// 立即执行一次
			immediate: true
		}
	);
});

defineExpose({
	data,
	stopRefresh
});
</script>

<style lang="scss" scoped>
.cl-list-view {
	@apply h-full w-full relative;

	&__scroller {
		@apply h-full w-full;
	}

	&__virtual-list {
		@apply relative w-full;
	}

	&__spacer-top,
	&__spacer-bottom {
		@apply w-full;
	}

	&__index {
		@apply flex flex-row items-center bg-white;
		@apply absolute top-0 left-0 w-full px-[20rpx] z-20;

		&.is-dark {
			@apply bg-surface-600 border-none;
		}
	}

	&__virtual-item {
		@apply w-full;
	}

	&__header {
		@apply flex flex-row items-center relative px-[20rpx] z-10;
	}

	&__item {
		&-inner {
			@apply flex flex-row items-center px-[20rpx] h-full;
		}
	}

	&__refresher {
		@apply flex flex-row items-center justify-center w-full h-full;
	}
}
</style>