shop4.3.57/components/basic-component/u-tabs-swiper/u-tabs-swiper.vue

<template>
    <view
            class="u-tabs"
            :style="{
			zIndex: zIndex,
			background: bgColor
		}"
    >
        <scroll-view scroll-x class="u-scroll-view" :scroll-left="scrollLeft" scroll-with-animation :style="{ zIndex: zIndex + 1 }">
            <view class="u-tabs-scroll-box" :class="{'u-tabs-scorll-flex': !isScroll}">
                <view
                        class="u-tabs-item"
                        :style="{
						height: height + 'rpx',
						lineHeight: height + 'rpx',
						padding: `0 ${gutter / 2}rpx`,
						color: tabsInfo.length > 0 ? (tabsInfo[index] ? tabsInfo[index].color : activeColor) : inactiveColor,
						fontSize: fontSize + 'rpx',
						zIndex: zIndex + 2,
						fontWeight: (index == getCurrent && bold) ? 'bold' : 'normal'
					}"
                        v-for="(item, index) in getTabs"
                        :key="index"
                        :class="[preId + index]"
                        @tap="emit(index)"
                >
                    {{ item[name] || item['name']}}
                </view>
                <view
                        class="u-scroll-bar"
                        :style="{
						width: barWidthPx + 'px',
						height: barHeight + 'rpx',
						borderRadius: '100px',
						backgroundColor: activeColor,
						left: scrollBarLeft + 'px'
					}"
                ></view>
            </view>
        </scroll-view>
    </view>
</template>

<script>
    import colorGradient from '../../../core/libs/function/colorGradient';
    let color = colorGradient;
    const { windowWidth } = uni.getSystemInfoSync();
    const preId = 'UEl_';

    export default {
        props: {
            // 导航菜单是否需要滚动，如只有2或者3个的时候，就不需要滚动了，此时使用flex平分tab的宽度
            isScroll: {
                type: Boolean,
                default: true
            },
            //需循环的标签列表
            list: {
                type: Array,
                default() {
                    return [];
                }
            },
            // 当前活动tab的索引
            current: {
                type: [Number, String],
                default: 0
            },
            // 导航栏的高度和行高，单位rpx
            height: {
                type: [Number, String],
                default: 80
            },
            // 字体大小，单位rpx
            fontSize: {
                type: [Number, String],
                default: 30
            },
            // 过渡动画时长, 单位s
            // duration: {
            // 	type: [Number, String],
            // 	default: 0.5
            // },
            swiperWidth: {
                //line3生效, 外部swiper的宽度, 单位rpx
                type: [String, Number],
                default: 750
            },
            // 选中项的主题颜色
            activeColor: {
                type: String,
                default: '#2979ff'
            },
            // 未选中项的颜色
            inactiveColor: {
                type: String,
                default: '#303133'
            },
            // 菜单底部移动的bar的宽度，单位rpx
            barWidth: {
                type: [Number, String],
                default: 40
            },
            // 移动bar的高度
            barHeight: {
                type: [Number, String],
                default: 6
            },
            // 单个tab的左或右内边距（各占一半），单位rpx
            gutter: {
                type: [Number, String],
                default: 40
            },
            // 如果是绝对定位，添加z-index值
            zIndex: {
                type: [Number, String],
                default: 1
            },
            // 导航栏的背景颜色
            bgColor: {
                type: String,
                default: '#ffffff'
            },
            //滚动至中心目标类型
            autoCenterMode: {
                type: String,
                default: 'window'
            },
            // 读取传入的数组对象的属性
            name: {
                type: String,
                default: 'name'
            },
            // 活动tab字体是否加粗
            bold: {
                type: Boolean,
                default: true
            }
        },
        data() {
            return {
                scrollLeft: 0, // 滚动scroll-view的左边滚动距离
                tabQueryInfo: [], // 存放对tab菜单查询后的节点信息
                windowWidth: 0, // 屏幕宽度，单位为px
                //scrollBarLeft: 0, // 移动bar需要通过translateX()移动的距离
                animationFinishCurrent: this.current,
                componentsWidth: 0,
                line3AddDx: 0,
                line3Dx: 0,
                preId,
                sW: 0,
                tabsInfo: [],
                colorGradientArr: [],
                colorStep: 100 // 两个颜色之间的渐变等分
            };
        },
        computed: {
            // 获取当前活跃的current值
            getCurrent() {
                const current = Number(this.current);
                // 判断是否超出边界
                if (current > this.getTabs.length - 1) {
                    return this.getTabs.length - 1;
                }
                if (current < 0) return 0;
                return current;
            },
            getTabs() {
                return this.list;
            },
            // 滑块需要移动的距离
            scrollBarLeft() {
                return Number(this.line3Dx) + Number(this.line3AddDx);
            },
            // 滑块的宽度转为px单位
            barWidthPx() {
                return uni.upx2px(this.barWidth);
            }
        },
        watch: {
            current(n, o) {
                this.change(n);
                this.setFinishCurrent(n);
            },
            list() {
                this.$nextTick(() => {
                    this.init();
                })
            }
        },
        mounted() {
            this.init();
        },
        methods: {

            async init() {
                this.countPx();
                await this.getTabsInfo();
                this.countLine3Dx();
                this.getQuery(() => {
                    this.setScrollViewToCenter();
                });
                // 颜色渐变过程数组
                this.colorGradientArr = color.colorGradient(this.inactiveColor, this.activeColor, this.colorStep);
            },
            // 获取各个tab的节点信息
            getTabsInfo() {
                return new Promise((resolve, reject) => {
                    let view = uni.createSelectorQuery().in(this);
                    for (let i = 0; i < this.list.length; i++) {
                        view.select('.' + preId + i).boundingClientRect();
                    }
                    view.exec(res => {
                        const arr = [];
                        for (let i = 0; i < res.length; i++) {
                            // 给每个tab添加其文字颜色属性
                            res[i].color = this.inactiveColor;
                            // 当前tab直接赋予activeColor
                            if (i == this.getCurrent) res[i].color = this.activeColor;
                            arr.push(res[i]);
                        }
                        this.tabsInfo = arr;
                        resolve();
                    });
                })
            },
            // 当swiper滑动结束，计算滑块最终要停留的位置
            countLine3Dx() {
                const tab = this.tabsInfo[this.animationFinishCurrent];
                // 让滑块中心点和当前tab中心重合
                if (tab) this.line3Dx = tab.left + tab.width / 2 - this.barWidthPx / 2;
            },
            countPx() {
                // swiper宽度由rpx转为px单位，因为dx等，都是px单位
                this.sW = uni.upx2px(Number(this.swiperWidth));
            },
            emit(index) {
                this.$emit('change', index);
            },
            change() {
                this.setScrollViewToCenter();
            },
            getQuery(cb) {
                try {
                    let view = uni.createSelectorQuery().in(this).select('.u-tabs');
                    view.fields(
                        {
                            size: true
                        },
                        data => {
                            if (data) {
                                this.componentsWidth = data.width;
                                if (cb && typeof cb === 'function') cb(data);
                            } else {
                                this.getQuery(cb);
                            }
                        }
                    ).exec();
                } catch (e) {
                    this.componentsWidth = windowWidth;
                }
            },
            // 把活动tab移动到屏幕中心点
            setScrollViewToCenter() {
                let tab;
                tab = this.tabsInfo[this.animationFinishCurrent];
                if (tab) {
                    let tabCenter = tab.left + tab.width / 2;
                    let fatherWidth;
                    // 活动tab移动到中心时，以屏幕还是tab组件为宽度为基准
                    if (this.autoCenterMode === 'window') {
                        fatherWidth = windowWidth;
                    } else {
                        fatherWidth = this.componentsWidth;
                    }
                    this.scrollLeft = tabCenter - fatherWidth / 2;
                }
            },
            setDx(dx) {
                let nextTabIndex = dx > 0 ? this.animationFinishCurrent + 1 : this.animationFinishCurrent - 1;
                // 判断索引是否超出边界
                nextTabIndex = nextTabIndex <= 0 ? 0 : nextTabIndex;
                nextTabIndex = nextTabIndex >= this.list.length ? this.list.length - 1 : nextTabIndex;
                const tab = this.tabsInfo[nextTabIndex];
                // 当前tab中心点x轴坐标
                let nowTab = this.tabsInfo[this.animationFinishCurrent];
                let nowTabX = nowTab.left + nowTab.width / 2;
                // 下一个tab
                let nextTab = this.tabsInfo[nextTabIndex];
                let nextTabX = nextTab.left + nextTab.width / 2;
                // 两个tab之间的距离，因为下一个tab可能在当前tab的左边或者右边，取绝对值即可
                let distanceX = Math.abs(nextTabX - nowTabX);
                this.line3AddDx = (dx / this.sW) * distanceX;
                this.setTabColor(this.animationFinishCurrent, nextTabIndex, dx);
            },
            // 设置tab的颜色
            setTabColor(nowTabIndex, nextTabIndex, dx) {
                let colorIndex = Math.abs(Math.ceil((dx / this.sW) * 100));
                let colorLength = this.colorGradientArr.length;
                // 处理超出索引边界的情况
                colorIndex = colorIndex >= colorLength ? colorLength - 1 : colorIndex <= 0 ? 0 : colorIndex;
                // 设置下一个tab的颜色
                this.tabsInfo[nextTabIndex].color = this.colorGradientArr[colorIndex];
                // 设置当前tab的颜色
                this.tabsInfo[nowTabIndex].color = this.colorGradientArr[colorLength - 1 - colorIndex];
            },
            // swiper结束滑动
            setFinishCurrent(current) {
                // 如果滑动的索引不一致，修改tab颜色变化，因为可能会有直接点击tab的情况
                if (current != this.animationFinishCurrent) {
                    this.tabsInfo.map((val, index) => {
                        if (current == index) val.color = this.activeColor;
                        else val.color = this.inactiveColor;
                        return val;
                    });
                }
                this.line3AddDx = 0;
                this.animationFinishCurrent = current;
                this.countLine3Dx();
            }
        }
    };
</script>

<style scoped lang="scss">
    view,
    scroll-view {
        box-sizing: border-box;
    }

    .u-tabs {
        width: 100%;
        transition-property: background-color, color;
    }

    ::-webkit-scrollbar,
    ::-webkit-scrollbar,
    ::-webkit-scrollbar {
        display: none;
        width: 0 !important;
        height: 0 !important;
        -webkit-appearance: none;
        background: transparent;
    }

    /* #ifdef H5 */
    // 通过样式穿透，隐藏H5下，scroll-view下的滚动条
    scroll-view /deep/ ::-webkit-scrollbar {
        display: none;
        width: 0 !important;
        height: 0 !important;
        -webkit-appearance: none;
        background: transparent;
    }
    /* #endif */

    .u-scroll-view {
        width: 100%;
        white-space: nowrap;
        position: relative;
    }

    .u-tabs-scroll-box {
        position: relative;
    }

    .u-tabs-scorll-flex {
        display: flex;
        justify-content: space-between;
    }

    .u-tabs-scorll-flex .u-tabs-item {
        flex: 1;
    }

    .u-tabs-item {
        position: relative;
        display: inline-block;
        text-align: center;
        transition-property: background-color, color, font-weight;
    }

    .content {
        overflow: hidden;
        white-space: nowrap;
        text-overflow: ellipsis;
    }

    .boxStyle {
        pointer-events: none;
        position: absolute;
        transition-property: all;
    }

    .boxStyle2 {
        pointer-events: none;
        position: absolute;
        bottom: 0;
        transition-property: all;
        transform: translateY(-100%);
    }

    .itemBackgroundBox {
        pointer-events: none;
        position: absolute;
        top: 0;
        transition-property: left, background-color;
        display: flex;
        flex-direction: row;
        justify-content: center;
        align-items: center;
    }

    .itemBackground {
        height: 100%;
        width: 100%;
        transition-property: all;
    }

    .u-scroll-bar {
        position: absolute;
        bottom: 4rpx;
    }
</style>