| <template> | |
| 	<view class="u-tabbar"> | |
| 		<view | |
| 		    class="u-tabbar__content" | |
| 		    ref="u-tabbar__content" | |
| 		    @touchmove.stop.prevent="noop" | |
| 		    :class="[border && 'u-border-top', fixed && 'u-tabbar--fixed']" | |
| 		    :style="[tabbarStyle]" | |
| 		> | |
| 			<view class="u-tabbar__content__item-wrapper"> | |
| 				<slot /> | |
| 			</view> | |
| 			<u-safe-bottom v-if="safeAreaInsetBottom"></u-safe-bottom> | |
| 		</view> | |
| 		<view | |
| 		    class="u-tabbar__placeholder" | |
| 			v-if="placeholder" | |
| 		    :style="{ | |
| 				height: placeholderHeight + 'px', | |
| 			}" | |
| 		></view> | |
| 	</view> | |
| </template> | |
|  | |
| <script> | |
| 	import props from './props.js'; | |
| 	// #ifdef APP-NVUE | |
| 	const dom = uni.requireNativePlugin('dom') | |
| 	// #endif | |
| 	/** | |
| 	 * Tabbar 底部导航栏 | |
| 	 * @description 此组件提供了自定义tabbar的能力。 | |
| 	 * @tutorial https://www.uviewui.com/components/tabbar.html | |
| 	 * @property {String | Number}	value				当前匹配项的name | |
| 	 * @property {Boolean}			safeAreaInsetBottom	是否为iPhoneX留出底部安全距离(默认 true ) | |
| 	 * @property {Boolean}			border				是否显示上方边框(默认 true ) | |
| 	 * @property {String | Number}	zIndex				元素层级z-index(默认 1 ) | |
| 	 * @property {String}			activeColor			选中标签的颜色(默认 '#1989fa' ) | |
| 	 * @property {String}			inactiveColor		未选中标签的颜色(默认 '#7d7e80' ) | |
| 	 * @property {Boolean}			fixed				是否固定在底部(默认 true ) | |
| 	 * @property {Boolean}			placeholder			fixed定位固定在底部时,是否生成一个等高元素防止塌陷(默认 true ) | |
| 	 * @property {Object}			customStyle			定义需要用到的外部样式 | |
| 	 *  | |
| 	 * @example <u-tabbar :value="value2" :placeholder="false" @change="name => value2 = name" :fixed="false" :safeAreaInsetBottom="false"><u-tabbar-item text="首页" icon="home" dot ></u-tabbar-item></u-tabbar> | |
| 	 */ | |
| 	export default { | |
| 		name: 'u-tabbar', | |
| 		mixins: [uni.$u.mpMixin, uni.$u.mixin,props], | |
| 		data() { | |
| 			return { | |
| 				placeholderHeight: 0 | |
| 			} | |
| 		}, | |
| 		computed: { | |
| 			tabbarStyle() { | |
| 				const style = { | |
| 					zIndex: this.zIndex | |
| 				} | |
| 				// 合并来自父组件的customStyle样式 | |
| 				return uni.$u.deepMerge(style, uni.$u.addStyle(this.customStyle)) | |
| 			}, | |
| 			// 监听多个参数的变化,通过在computed执行对应的操作 | |
| 			updateChild() { | |
| 				return [this.value, this.activeColor, this.inactiveColor] | |
| 			}, | |
| 			updatePlaceholder() { | |
| 				return [this.fixed, this.placeholder] | |
| 			} | |
| 		}, | |
| 		watch: { | |
| 			updateChild() { | |
| 				// 如果updateChildren中的元素发生了变化,则执行子元素初始化操作 | |
| 				this.updateChildren() | |
| 			}, | |
| 			updatePlaceholder() { | |
| 				// 如果fixed,placeholder等参数发生变化,重新计算占位元素的高度 | |
| 				this.setPlaceholderHeight() | |
| 			} | |
| 		}, | |
| 		created() { | |
| 			this.children = [] | |
| 		}, | |
| 		mounted() { | |
| 			this.setPlaceholderHeight() | |
| 		}, | |
| 		methods: { | |
| 			updateChildren() { | |
| 				// 如果存在子元素,则执行子元素的updateFromParent进行更新数据 | |
| 				this.children.length && this.children.map(child => child.updateFromParent()) | |
| 			}, | |
| 			// 设置用于防止塌陷元素的高度 | |
| 			async setPlaceholderHeight() { | |
| 				if (!this.fixed || !this.placeholder) return | |
| 				// 延时一定时间 | |
| 				await uni.$u.sleep(20) | |
| 				// #ifndef APP-NVUE | |
| 				this.$uGetRect('.u-tabbar__content').then(({height = 50}) => { | |
| 					// 修复IOS safearea bottom 未填充高度 | |
| 					this.placeholderHeight = height | |
| 				}) | |
| 				// #endif | |
|  | |
| 				// #ifdef APP-NVUE | |
| 				dom.getComponentRect(this.$refs['u-tabbar__content'], (res) => { | |
| 					const { | |
| 						size | |
| 					} = res | |
| 					this.placeholderHeight = size.height | |
| 				}) | |
| 				// #endif | |
| 			} | |
| 		} | |
| 	} | |
| </script> | |
| 
 | |
| <style lang="scss" scoped> | |
| 	@import "../../libs/css/components.scss"; | |
| 
 | |
| 	.u-tabbar { | |
| 		@include flex(column); | |
| 		flex: 1; | |
| 		justify-content: center; | |
| 		 | |
| 		&__content { | |
| 			@include flex(column); | |
| 			background-color: #fff; | |
| 			 | |
| 			&__item-wrapper { | |
| 				height: 50px; | |
| 				@include flex(row); | |
| 			} | |
| 		} | |
| 
 | |
| 		&--fixed { | |
| 			position: fixed; | |
| 			bottom: 0; | |
| 			left: 0; | |
| 			right: 0; | |
| 		} | |
| 	} | |
| </style>
 |