vue实现collapse折叠板动画，可设置动画时间，动画延迟等

之前封装手风琴的时候借鉴列element做了个collapse折叠板动画。

网上有个大神也做了个collapse折叠板动画。传送门这里赞最多的就是element的那个动画。

我的那个element动画也是这个，vue 自定义指令封装一个手风琴嵌套组件这里的组件过度动画

但是这个动画并不支持设置时间，进一步封装还是可以的。

重写了一个collapse 的动画。

效果如下

collapse.gif

设置延时和动画时间.gif

新建collapseMixins.js，内容如下

export default {
  inheritAttrs: false,
  props: {
    duration: {
      type: [Number, Object],
      default: 300
    },
    delay: {
      type: [Number, Object],
      default: 0
    },
    group: Boolean,
    tag: {
      type: String,
      default: "span"
    },
    origin: {
      type: String,
      default: ""
    },
    styles: {
      type: Object,
      default: () => {
        return {
          animationFillMode: "both",
          animationTimingFunction: "ease-out"
        };
      }
    }
  },
  computed: {
    componentType() {
      return this.group ? "transition-group" : "transition";
    },
    hooks() {
      return {
        ...this.$listeners,
        beforeEnter: this.beforeEnter,
        afterEnter: el => {
          this.cleanUpStyles(el);
          this.$emit("after-enter", el);
        },
        beforeLeave: this.beforeLeave,
        leave: this.leave,
        afterLeave: el => {
          this.cleanUpStyles(el);
          this.$emit("after-leave", el);
        }
      };
    }
  },
  methods: {
    beforeEnter(el) {
      let enterDuration = this.duration.enter
        ? this.duration.enter
        : this.duration;
      el.style.animationDuration = `${enterDuration}ms`;

      let enterDelay = this.delay.enter ? this.delay.enter : this.delay;
      el.style.animationDelay = `${enterDelay}ms`;

      this.setStyles(el);
      this.$emit("before-enter", el);
    },
    cleanUpStyles(el) {
      Object.keys(this.styles).forEach(key => {
        const styleValue = this.styles[key];
        if (styleValue) {
          el.style[key] = "";
        }
      });
      el.style.animationDuration = "";
      el.style.animationDelay = "";
    },
    beforeLeave(el) {
      let leaveDuration = this.duration.leave
        ? this.duration.leave
        : this.duration;
      el.style.animationDuration = `${leaveDuration}ms`;

      let leaveDelay = this.delay.leave ? this.delay.leave : this.delay;
      el.style.animationDelay = `${leaveDelay}ms`;

      this.setStyles(el);
      this.$emit("before-leave", el);
    },
    leave(el, done) {
      this.setAbsolutePosition(el);
      this.$emit("leave", el, done);
    },
    setStyles(el) {
      this.setTransformOrigin(el);
      Object.keys(this.styles).forEach(key => {
        const styleValue = this.styles[key];
        if (styleValue) {
          el.style[key] = styleValue;
        }
      });
    },
    setAbsolutePosition(el) {
      if (this.group) {
        el.style.position = "absolute";
      }
      return this;
    },
    setTransformOrigin(el) {
      if (this.origin) {
        el.style.transformOrigin = this.origin;
      }
      return this;
    }
  }
};

建立一个collapseTransition.js，内容如下

import Vue from "../utils/vue";
import collapseMixins from "./collapseMixins";

const name = "NlyCollapseTransition";

export const NlyCollapseTransition = Vue.extend({
  name: name,
  mixins: [collapseMixins],
  methods: {
    transitionStyle(duration = 300) {
      let durationInSeconds = duration / 1000;
      let style = `${durationInSeconds}s height ease-in-out, ${durationInSeconds}s padding-top ease-in-out, ${durationInSeconds}s padding-bottom ease-in-out`;
      return style;
    },
    beforeEnter(el) {
      let enterDuration = this.duration.enter
        ? this.duration.enter
        : this.duration;
      el.style.transition = this.transitionStyle(enterDuration);
      if (!el.dataset) el.dataset = {};

      el.dataset.oldPaddingTop = el.style.paddingTop;
      el.dataset.oldPaddingBottom = el.style.paddingBottom;

      el.style.height = "0";
      el.style.paddingTop = 0;
      el.style.paddingBottom = 0;
      this.setStyles(el);
    },

    enter(el) {
      el.dataset.oldOverflow = el.style.overflow;
      if (el.scrollHeight !== 0) {
        el.style.height = el.scrollHeight + "px";
        el.style.paddingTop = el.dataset.oldPaddingTop;
        el.style.paddingBottom = el.dataset.oldPaddingBottom;
      } else {
        el.style.height = "";
        el.style.paddingTop = el.dataset.oldPaddingTop;
        el.style.paddingBottom = el.dataset.oldPaddingBottom;
      }

      el.style.overflow = "hidden";
    },

    afterEnter(el) {
      el.style.transition = "";
      el.style.height = "";
      el.style.overflow = el.dataset.oldOverflow;
    },

    beforeLeave(el) {
      if (!el.dataset) el.dataset = {};
      el.dataset.oldPaddingTop = el.style.paddingTop;
      el.dataset.oldPaddingBottom = el.style.paddingBottom;
      el.dataset.oldOverflow = el.style.overflow;

      el.style.height = el.scrollHeight + "px";
      el.style.overflow = "hidden";
      this.setStyles(el);
    },

    leave(el) {
      let leaveDuration = this.duration.leave
        ? this.duration.leave
        : this.duration;
      if (el.scrollHeight !== 0) {
        // for safari: add class after set height, or it will jump to zero height suddenly, weired
        el.style.transition = this.transitionStyle(leaveDuration);
        el.style.height = 0;
        el.style.paddingTop = 0;
        el.style.paddingBottom = 0;
      }
      // necessary for transition-group
      this.setAbsolutePosition(el);
    },

    afterLeave(el) {
      el.style.transition = "";
      el.style.height = "";
      el.style.overflow = el.dataset.oldOverflow;
      el.style.paddingTop = el.dataset.oldPaddingTop;
      el.style.paddingBottom = el.dataset.oldPaddingBottom;
    }
  },
  render(h) {
    return h(
      "transition",
      {
        props: {
          is: this.componentType,
          tag: this.tag
        },
        on: {
          "before-enter": this.beforeEnter,
          "after-enter": this.afterEnter,
          enter: this.enter,
          "before-leave": this.beforeLeave,
          leave: this.leave,
          "after-leave": this.afterLeave
        }
      },
      this.$slots.default
    );
  }
});

collapseMixins.js是一个混合类，因为我封装了其他不同类型的动画，所以做了一个mixins。

使用的时候引入collapseTransition组件就行。

  

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