| 提交 | 用户 | age | ||
| 36b711 | 1 | <template> |
| L | 2 | <transition :name="transitionName"> |
| 3 | <div v-show="visible" :style="customStyle" class="back-to-ceiling" @click="backToTop"> | |
| 4 | <svg width="16" height="16" viewBox="0 0 17 17" xmlns="http://www.w3.org/2000/svg" class="Icon Icon--backToTopArrow" aria-hidden="true" style="height:16px;width:16px"><path d="M12.036 15.59a1 1 0 0 1-.997.995H5.032a.996.996 0 0 1-.997-.996V8.584H1.03c-1.1 0-1.36-.633-.578-1.416L7.33.29a1.003 1.003 0 0 1 1.412 0l6.878 6.88c.782.78.523 1.415-.58 1.415h-3.004v7.004z" /></svg> | |
| 5 | </div> | |
| 6 | </transition> | |
| 7 | </template> | |
| 8 | ||
| 9 | <script> | |
| 10 | export default { | |
| 11 | name: 'BackToTop', | |
| 12 | props: { | |
| 13 | visibilityHeight: { | |
| 14 | type: Number, | |
| 15 | default: 400 | |
| 16 | }, | |
| 17 | backPosition: { | |
| 18 | type: Number, | |
| 19 | default: 0 | |
| 20 | }, | |
| 21 | customStyle: { | |
| 22 | type: Object, | |
| 23 | default: function() { | |
| 24 | return { | |
| 25 | right: '50px', | |
| 26 | bottom: '50px', | |
| 27 | width: '40px', | |
| 28 | height: '40px', | |
| 29 | 'border-radius': '4px', | |
| 30 | 'line-height': '45px', | |
| 31 | background: '#e7eaf1' | |
| 32 | } | |
| 33 | } | |
| 34 | }, | |
| 35 | transitionName: { | |
| 36 | type: String, | |
| 37 | default: 'fade' | |
| 38 | } | |
| 39 | }, | |
| 40 | data() { | |
| 41 | return { | |
| 42 | visible: false, | |
| 43 | interval: null, | |
| 44 | isMoving: false | |
| 45 | } | |
| 46 | }, | |
| 47 | mounted() { | |
| 48 | window.addEventListener('scroll', this.handleScroll) | |
| 49 | }, | |
| 50 | beforeDestroy() { | |
| 51 | window.removeEventListener('scroll', this.handleScroll) | |
| 52 | if (this.interval) { | |
| 53 | clearInterval(this.interval) | |
| 54 | } | |
| 55 | }, | |
| 56 | methods: { | |
| 57 | handleScroll() { | |
| 58 | this.visible = window.pageYOffset > this.visibilityHeight | |
| 59 | }, | |
| 60 | backToTop() { | |
| 61 | if (this.isMoving) return | |
| 62 | const start = window.pageYOffset | |
| 63 | let i = 0 | |
| 64 | this.isMoving = true | |
| 65 | this.interval = setInterval(() => { | |
| 66 | const next = Math.floor(this.easeInOutQuad(10 * i, start, -start, 500)) | |
| 67 | if (next <= this.backPosition) { | |
| 68 | window.scrollTo(0, this.backPosition) | |
| 69 | clearInterval(this.interval) | |
| 70 | this.isMoving = false | |
| 71 | } else { | |
| 72 | window.scrollTo(0, next) | |
| 73 | } | |
| 74 | i++ | |
| 75 | }, 16.7) | |
| 76 | }, | |
| 77 | easeInOutQuad(t, b, c, d) { | |
| 78 | if ((t /= d / 2) < 1) return c / 2 * t * t + b | |
| 79 | return -c / 2 * (--t * (t - 2) - 1) + b | |
| 80 | } | |
| 81 | } | |
| 82 | } | |
| 83 | </script> | |
| 84 | ||
| 85 | <style scoped> | |
| 86 | .back-to-ceiling { | |
| 87 | position: fixed; | |
| 88 | display: inline-block; | |
| 89 | text-align: center; | |
| 90 | cursor: pointer; | |
| 91 | } | |
| 92 | ||
| 93 | .back-to-ceiling:hover { | |
| 94 | background: #d5dbe7; | |
| 95 | } | |
| 96 | ||
| 97 | .fade-enter-active, | |
| 98 | .fade-leave-active { | |
| 99 | transition: opacity .5s; | |
| 100 | } | |
| 101 | ||
| 102 | .fade-enter, | |
| 103 | .fade-leave-to { | |
| 104 | opacity: 0 | |
| 105 | } | |
| 106 | ||
| 107 | .back-to-ceiling .Icon { | |
| 108 | fill: #9aaabf; | |
| 109 | background: none; | |
| 110 | } | |
| 111 | </style> | |
