[Improvement] Tab animation fluency && position (#379)

README.md

@@ -20,12 +20,12 @@
 
 - 45+ Reusable components
 - 90%+ Unit test coverage
-- Extensive documentation and demos.
+- Extensive documentation and demos
 - Support [babel-plugin-import](https://github.com/ant-design/babel-plugin-import)
 - Support TypeScript
 
 <p align="center">
-  <img alt="feature demo" src="https://img.yzcdn.cn/public_files/2017/12/05/6a69f80c7ba6754795a7cc6d0766950f.png">
+  <img alt="components preview" src="https://img.yzcdn.cn/public_files/2017/12/05/95f5ee7524b7845abb2f51803a01d65e.png">
 </p >
 
 ## Install

README.zh-CN.md

@@ -22,7 +22,7 @@
 - 支持 TypeScript
 
 <p align="center">
-  <img alt="feature demo" src="https://img.yzcdn.cn/public_files/2017/12/05/6a69f80c7ba6754795a7cc6d0766950f.png">
+  <img alt="components preview" src="https://img.yzcdn.cn/public_files/2017/12/05/95f5ee7524b7845abb2f51803a01d65e.png">
 </p >
  
 ## 安装

docs/demos/views/tab.vue

@@ -2,7 +2,7 @@
   <demo-section>
     <demo-block :title="$t('basicUsage')">
       <van-tabs :active="active">
-        <van-tab :title="$t('tab') + index" v-for="index in 4" :key="index">
+        <van-tab :title="$t('tab') + index" v-for="index in tabs" :key="index">
           {{ $t('content') }} {{ index }}
         </van-tab>
       </van-tabs>
@@ -64,7 +64,8 @@ export default {
 
   data() {
     return {
-      active: 2
+      active: 2,
+      tabs: [1, 2, 3, 4]
     };
   },
 

docs/markdown/en-US/tab.md

@@ -106,7 +106,7 @@ export default {
 |-----------|-----------|-----------|-------------|-------------|
 | type | There are two style tabs, set this attribute to change tab style | `String` | `line` | `card` |
 | active | Index of active tab | `String` `Number` | `0` | - |
-| duration | Toggle tab's animation time | `Number` | `0.3` | - | - |
+| duration | Toggle tab's animation time | `Number` | `0.2` | - | - |
 | swipeThreshold | Set swipe tabs threshold | `Number` | `4` | - | - |
 
 ### Tab API

docs/markdown/zh-CN/tab.md

@@ -106,7 +106,7 @@ export default {
 |-----------|-----------|-----------|-------------|-------------|
 | type | Tab 样式类型 | `String` | `line` | `card` |
 | active | 默认激活的 tab | `String` `Number` | `0` | - |
-| duration | 切换 tab 的动画时间 | `Number` | `0.3` | - | - |
+| duration | 切换 tab 的动画时间 | `Number` | `0.2` | - | - |
 | swipeThreshold | 滚动阀值，设置 Tab 超过多少个可滚动 | `Number` | `4` | - | - |
 
 ### Tab API

packages/sku/containers/SkuContainer.vue

@@ -72,7 +72,6 @@
 
 <script>
 import Vue from 'vue';
-import { isServer } from '../../utils';
 import Popup from '../../popup';
 import Toast from '../../toast';
 import SkuHeader from '../components/SkuHeader';
@@ -177,7 +176,7 @@ export default {
 
   computed: {
     bodyStyle() {
-      if (isServer) {
+      if (this.$isServer) {
         return;
       }
 

packages/tab/index.vue

@@ -1,5 +1,5 @@
 <template>
-  <div class="van-tab__pane" :class="{ 'van-tab__pane--select': key === $parent.curActive }">
+  <div class="van-tab__pane" :class="{ 'van-tab__pane--select': index === parentGroup.curActive }">
     <slot></slot>
   </div>
 </template>
@@ -20,46 +20,19 @@ export default {
     disabled: Boolean
   },
 
-  data() {
+  computed: {
+    index() {
+      return this.parentGroup.tabs.indexOf(this);
+    }
+  },
+
+  created() {
     this.findParentByName('van-tabs');
-    const nextIndex = this.parentGroup.tabs.length;
-    this.updateParentData(nextIndex);
-    return {
-      key: nextIndex
-    };
-  },
-
-  watch: {
-    title() {
-      this.updateParentData();
-    },
-    disabled() {
-      this.updateParentData();
-    }
-  },
-
-  methods: {
-    updateParentData(nextIndex) {
-      const index = arguments.length ? nextIndex : this.key;
-      this.parentGroup.tabs.splice(index, 1, {
-        title: this.title,
-        disabled: this.disabled,
-        index
-      });
-    }
+    this.parentGroup.tabs.push(this);
   },
 
   destroyed() {
-    const key = this.key;
-    const tabs = this.parentGroup.tabs;
-
-    for (let i = 0; i < tabs.length; i++) {
-      /* istanbul ignore else */
-      if (tabs[i].index === key) {
-        this.parentGroup.tabs.splice(i, 1);
-        return;
-      }
-    }
+    this.parentGroup.tabs.splice(this.index, 1);
   }
 };
 </script>

packages/tabs/index.vue

@@ -1,39 +1,23 @@
 <template>
   <div class="van-tabs" :class="`van-tabs--${type}`">
-    <div class="van-tabs__nav-wrap" v-if="type === 'line' && tabs.length > swipeThreshold">
-      <div class="van-tabs__swipe" ref="swipe">
-        <div class="van-tabs__nav van-tabs__nav--line">
-          <div class="van-tabs__nav-bar" :style="navBarStyle"></div>
+    <div :class="{ 'van-tabs__swipe': scrollable, 'van-hairline--top-bottom': type === 'line' }">
+      <div class="van-tabs__nav" :class="`van-tabs__nav--${type}`" ref="nav">
+        <div v-if="type === 'line'" class="van-tabs__nav-bar" :style="navBarStyle" />
         <div
           v-for="(tab, index) in tabs"
           :key="index"
-            class="van-tab van-hairline"
-            :class="{ 'van-tab--active': index === curActive }"
-            ref="tabkey"
-            @click="handleTabClick(index)"
+          ref="tabs"
+          class="van-tab"
+          :class="{
+            'van-tab--active': index === curActive,
+            'van-tab--disabled': tab.disabled
+          }"
+          @click="onClick(index)"
         >
           <span>{{ tab.title }}</span>
         </div>
       </div>
     </div>
-    </div>
-    <div
-      v-else
-      class="van-tabs__nav"
-      :class="`van-tabs__nav--${type}`"
-    >
-      <div class="van-tabs__nav-bar" :style="navBarStyle" v-if="type === 'line'"></div>
-      <div
-        v-for="(tab, index) in tabs"
-        :key="index"
-        class="van-tab van-hairline"
-        :class="{ 'van-tab--active': index === curActive }"
-        ref="tabkey"
-        @click="handleTabClick(index)"
-      >
-        <span>{{ tab.title }}</span>
-      </div>
-    </div>
     <div class="van-tabs__content">
       <slot></slot>
     </div>
@@ -41,27 +25,23 @@
 </template>
 
 <script>
-  import swipe from './swipe';
-  import translateUtil from '../utils/transition';
+import { raf } from '../utils/raf';
 
-  export default {
+export default {
   name: 'van-tabs',
 
   props: {
-      // 外部传入的激活的tab标签
     active: {
       type: [Number, String],
       default: 0
     },
-      // 是默认的line还是card
     type: {
       type: String,
       default: 'line'
     },
-      // 切换tab的动画时间
     duration: {
       type: Number,
-        default: 0.3
+      default: 0.2
     },
     swipeThreshold: {
       type: Number,
@@ -70,163 +50,101 @@
   },
 
   data() {
+    this.winWidth = this.$isServer ? 0 : window.innerWidth;
+
     return {
       tabs: [],
-        curActive: +this.active,
-        isSwiping: false,
-        isInitEvents: false,
+      curActive: 0,
       navBarStyle: {}
     };
   },
 
   watch: {
     active(val) {
-        this.curActive = +val;
+      this.correctActive(val);
+    },
+
+    tabs(tabs) {
+      this.correctActive(this.curActive);
+      this.setNavBar();
     },
 
     curActive() {
-        this.setNavBarStyle();
-        /* istanbul ignore else */
-        if (this.tabs.length > this.swipeThreshold) {
-          this.doOnValueChange();
-        }
-      },
-      
-      tabs(val) {
-        this.$nextTick(() => {
-          this.setNavBarStyle();
-          if (val.length > this.swipeThreshold) {
-            this.initEvents();
-            this.doOnValueChange();
-          } else {
-            this.isInitEvents = false;
-          }
-
-          const activeExist = val.some(tab => tab.index === this.curActive);
-          if (!activeExist) {
-            this.curActive = val[0].index || 0;
-          }
-        });
-      }
-    },
-
-    computed: {
-      swipeWidth() {
-        return this.$refs.swipe && this.$refs.swipe.getBoundingClientRect().width;
-      },
-      maxTranslate() {
-        /* istanbul ignore if */
-        if (!this.$refs.tabkey) return;
-
-        const lastTab = this.$refs.tabkey[this.tabs.length - 1];
-        const lastTabWidth = lastTab.offsetWidth;
-        const lastTabOffsetLeft = lastTab.offsetLeft;
-
-        return (lastTabOffsetLeft + lastTabWidth) - this.swipeWidth;
+      this.scrollIntoView();
+      this.setNavBar();
     }
   },
 
   mounted() {
-      // 页面载入完成
-      this.$nextTick(() => {
-        this.setNavBarStyle();
+    this.correctActive(this.active);
+    this.setNavBar();
+  },
 
-        if (this.tabs.length > this.swipeThreshold) {
-          this.initEvents();
-          this.doOnValueChange();
+  computed: {
+    scrollable() {
+      return this.tabs.length > this.swipeThreshold;
     }
-      });
   },
 
   methods: {
-      /**
-       * `type`为`line`时，tab下方的横线的样式
-       */
-      setNavBarStyle() {
-        if (this.type !== 'line' || !this.$refs.tabkey) return {};
-
-        const tabKey = this.curActive;
-        const elem = this.$refs.tabkey[tabKey];
-        const offsetWidth = `${elem.offsetWidth || 0}px`;
-        const offsetLeft = `${elem.offsetLeft || 0}px`;
-
+    setNavBar() {
+      this.$nextTick(() => {
+        const tab = this.$refs.tabs[this.curActive];
         this.navBarStyle = {
-          width: offsetWidth,
-          transform: `translate3d(${offsetLeft}, 0, 0)`,
+          width: `${tab.offsetWidth || 0}px`,
+          transform: `translate3d(${tab.offsetLeft || 0}px, 0, 0)`,
           transitionDuration: `${this.duration}s`
-        };
-      },
-
-      handleTabClick(index) {
-        if (this.tabs[index].disabled) {
-          this.$emit('disabled', index);
-          return;
-        }
-
-        this.$emit('click', index);
-        this.curActive = index;
-      },
-
-      /**
-       * 将当前value值转换为需要translate的值
-       */
-      value2Translate(value) {
-        /* istanbul ignore if */
-        if (!this.$refs.tabkey) return 0;
-
-        const tab = this.$refs.tabkey[value];
-        const maxTranslate = this.maxTranslate;
-        const tabWidth = tab.offsetWidth;
-        const tabOffsetLeft = tab.offsetLeft;
-        let translate = tabOffsetLeft + (tabWidth * 2.7) - this.swipeWidth;
-        if (translate < 0) {
-          translate = 0;
-        }
-
-        return -1 * (translate > maxTranslate ? maxTranslate : translate);
-      },
-
-      initEvents() {
-        const el = this.$refs.swipe;
-        if (!el || this.isInitEvents) return;
-
-        this.isInitEvents = true;
-        let swipeState = {};
-
-        swipe(el, {
-          start: event => {
-            swipeState = {
-              start: new Date(),
-              startLeft: event.pageX,
-              startTranslateLeft: translateUtil.getElementTranslate(el).left
-            };
-          },
-
-          drag: event => {
-            this.isSwiping = true;
-
-            swipeState.left = event.pageX;
-            const deltaX = swipeState.left - swipeState.startLeft;
-            const translate = swipeState.startTranslateLeft + deltaX;
-
-            /* istanbul ignore else */
-            if (translate > 0 || (translate * -1) > this.maxTranslate) return;
-
-            translateUtil.translateElement(el, translate, null);
-          },
-
-          end: () => {
-            this.isSwiping = false;
         }
       });
     },
 
-      doOnValueChange() {
-        const value = +this.curActive;
-        const swipe = this.$refs.swipe;
+    correctActive(active) {
+      active = +active;
+      const exist = this.tabs.some(tab => tab.index === active);
+      this.curActive = exist ? active : (this.tabs[0].index || 0);
+    },
 
-        translateUtil.translateElement(swipe, this.value2Translate(value), null);
+    onClick(index) {
+      if (this.tabs[index].disabled) {
+        this.$emit('disabled', index);
+      } else {
+        this.$emit('click', index);
+        this.curActive = index;
+      }
+    },
+
+    scrollIntoView() {
+      if (!this.scrollable) {
+        return;
+      }
+
+      const tab = this.$refs.tabs[this.curActive];
+      const { nav } = this.$refs;
+      const { winWidth } = this;
+      const { scrollLeft } = nav;
+      const { offsetLeft, offsetWidth: tabWidth } = tab;
+
+      // out of right side
+      if ((winWidth + scrollLeft - offsetLeft - tabWidth * 1.8) < 0) {
+        this.scrollTo(nav, scrollLeft, offsetLeft + tabWidth * 1.8 - winWidth);
+      }
+      // out of left side
+      else if (offsetLeft < (scrollLeft + tabWidth * 0.8)) {
+        this.scrollTo(nav, scrollLeft, offsetLeft - tabWidth * 0.8);
+      }
+    },
+
+    scrollTo(el, from, to) {
+      let count = 0;
+      const frames = Math.round(this.duration * 1000 / 16);
+      const animate = () => {
+        el.scrollLeft += (to - from) / frames;
+        if (++count < frames) {
+          raf(animate);
         }
       }
-  };
+      animate();
+    }
+  }
+};
 </script>

packages/tabs/swipe.js

@@ -1,46 +0,0 @@
-import Vue from 'vue';
-
-let isSwiping = false;
-
-const supportTouch = !Vue.prototype.$isServer && 'ontouchstart' in window;
-
-export default function(element, options) {
-  const moveFn = function(event) {
-    if (options.drag) {
-      options.drag(supportTouch ? event.changedTouches[0] || event.touches[0] : event);
-    }
-  };
-
-  const endFn = function(event) {
-    if (!supportTouch) {
-      document.removeEventListener('mousemove', moveFn);
-      document.removeEventListener('mouseup', endFn);
-    }
-
-    isSwiping = false;
-
-    if (options.end) {
-      options.end(supportTouch ? event.changedTouches[0] || event.touches[0] : event);
-    }
-  };
-
-  element.addEventListener(supportTouch ? 'touchstart' : 'mousedown', function(event) {
-    if (isSwiping) return;
-
-    if (!supportTouch) {
-      document.addEventListener('mousemove', moveFn);
-      document.addEventListener('mouseup', endFn);
-    }
-    isSwiping = true;
-
-    if (options.start) {
-      options.start(supportTouch ? event.changedTouches[0] || event.touches[0] : event);
-    }
-  });
-
-  if (supportTouch) {
-    element.addEventListener('touchmove', moveFn);
-    element.addEventListener('touchend', endFn);
-    element.addEventListener('touchcancel', endFn);
-  }
-};

packages/utils/raf.js

@@ -0,0 +1,32 @@
+/**
+ * requestAnimationFrame polyfill
+ */
+
+import { isServer } from './index';
+
+let prev = Date.now();
+function fallback(fn) {
+  const curr = Date.now();
+  const ms = Math.max(0, 16 - (curr - prev));
+  const id = setTimeout(fn, ms);
+  prev = curr + ms;
+  return id;
+}
+
+const global = isServer ? global : window;
+const iRaf =
+  global.requestAnimationFrame ||
+  global.webkitRequestAnimationFrame ||
+  fallback;
+const iCancel =
+  global.cancelAnimationFrame ||
+  global.webkitCancelAnimationFrame ||
+  global.clearTimeout;
+
+export function raf(fn) {
+  return iRaf.call(global, fn);
+}
+
+export function cancel(id) {
+  iCancel.call(global, id);
+}

packages/utils/transition.js

@@ -1,73 +0,0 @@
-import Vue from 'vue';
-
-var exportObj = {};
-
-if (!Vue.prototype.$isServer) {
-  var cssPrefix = '-webkit-';
-  var vendorPrefix = 'Webkit';
-  var transformProperty = vendorPrefix + 'Transform';
-  var transformStyleName = cssPrefix + 'transform';
-  var transitionProperty = vendorPrefix + 'Transition';
-  var transitionStyleName = cssPrefix + 'transition';
-  var transitionEndProperty = vendorPrefix.toLowerCase() + 'TransitionEnd';
-
-  var getTranslate = function(element) {
-    var result = { left: 0, top: 0 };
-    if (element === null || element.style === null) return result;
-
-    var transform = element.style[transformProperty];
-    var matches = /translate\(\s*(-?\d+(\.?\d+?)?)px,\s*(-?\d+(\.\d+)?)px\)\s*translateZ\(0px\)/ig.exec(transform);
-    if (matches) {
-      result.left = +matches[1];
-      result.top = +matches[3];
-    }
-
-    return result;
-  };
-
-  var translateElement = function(element, x, y) {
-    if (x === null && y === null) return;
-
-    if (element === null || element === undefined || element.style === null) return;
-
-    if (!element.style[transformProperty] && x === 0 && y === 0) return;
-
-    if (x === null || y === null) {
-      var translate = getTranslate(element);
-      if (x === null) {
-        x = translate.left;
-      }
-      if (y === null) {
-        y = translate.top;
-      }
-    }
-
-    cancelTranslateElement(element);
-    element.style[transformProperty] += ' translate(' + (x ? (x + 'px') : '0px') + ',' + (y ? (y + 'px') : '0px') + ') translateZ(0px)';
-  };
-
-  var cancelTranslateElement = function(element) {
-    if (element === null || element.style === null) return;
-
-    var transformValue = element.style[transformProperty];
-
-    if (transformValue) {
-      transformValue = transformValue.replace(/translate\(\s*(-?\d+(\.?\d+?)?)px,\s*(-?\d+(\.\d+)?)px\)\s*translateZ\(0px\)/g, '');
-      element.style[transformProperty] = transformValue;
-    }
-  };
-
-  exportObj = {
-    transformProperty: transformProperty,
-    transformStyleName: transformStyleName,
-    transitionProperty: transitionProperty,
-    transitionStyleName: transitionStyleName,
-    transitionEndProperty: transitionEndProperty,
-    getElementTranslate: getTranslate,
-    translateElement: translateElement,
-    cancelTranslateElement: cancelTranslateElement
-  };
-};
-
-export default exportObj;
-

packages/vant-css/src/tab.css

@@ -4,46 +4,38 @@
 .van-tabs {
   position: relative;
 
-  &__nav-wrap {
-    overflow: hidden;
-  }
-
   &__swipe {
     user-select: none;
-    transition: transform linear .2s;
 
     .van-tab {
       flex: 0 0 22%;
     }
 
     .van-tabs__nav {
-      overflow: visible;
+      overflow-y: auto;
+      -webkit-overflow-scrolling: touch;
+
+      &::-webkit-scrollbar {
+        display: none;
+        background-color: transparent;
+      }
     }
   }
 
   &__nav {
-    overflow: hidden;
-    transition: transform .5s cubic-bezier(.645, .045, .355, 1);
-    position: relative;
     display: flex;
+    position: relative;
+    background-color: $white;
 
     &--line {
       height: 44px;
-
-      .van-tab {
-        &::after {
-          border-width: 1px 0;
-        }
-      }
     }
 
     &--card {
       height: 28px;
       margin: 0 15px;
-      background-color: $white;
       border-radius: 2px;
       border: 1px solid $gray-darker;
-      overflow: hidden;
 
       .van-tab {
         color: $gray-darker;
@@ -55,8 +47,8 @@
         }
 
         &.van-tab--active {
-          background-color: $gray-darker;
           color: $white;
+          background-color: $gray-darker;
         }
       }
     }
@@ -64,27 +56,25 @@
 
   &__nav-bar {
     z-index: 1;
-    position: absolute;
     left: 0;
     bottom: 0;
     height: 2px;
-    background-color: #f13e3a;
-    transition: transform .3s cubic-bezier(.645, .045, .355, 1);
-    transform-origin: 0 0;
+    position: absolute;
+    background-color: $red;
   }
 }
 
 .van-tab {
+  flex: 1;
+  cursor: pointer;
+  padding: 0 5px;
+  font-size: 14px;
   position: relative;
   color: $text-color;
-  background-color: $white;
-  font-size: 14px;
   line-height: 44px;
-  box-sizing: border-box;
-  cursor: pointer;
   text-align: center;
-  flex: 1;
-  padding: 0 5px;
+  box-sizing: border-box;
+  background-color: $white;
   min-width: 0; /* hack for flex ellipsis */
 
   span {
@@ -92,10 +82,22 @@
     @mixin ellipsis;
   }
 
+  &:active {
+    background-color: $active-color;
+  }
+
   &--active {
     color: $red;
   }
 
+  &--disabled {
+    color: $gray;
+
+    &:active {
+      background-color: $white;
+    }
+  }
+
   &__pane {
     display: none;