init

src/components/Sticky/index.vue

@@ -0,0 +1,91 @@
+<template>
+  <div :style="{height:height+'px',zIndex:zIndex}">
+    <div
+      :class="className"
+      :style="{top:(isSticky ? stickyTop +'px' : ''),zIndex:zIndex,position:position,width:width,height:height+'px'}"
+    >
+      <slot>
+        <div>sticky</div>
+      </slot>
+    </div>
+  </div>
+</template>
+
+<script>
+export default {
+  name: 'Sticky',
+  props: {
+    stickyTop: {
+      type: Number,
+      default: 0
+    },
+    zIndex: {
+      type: Number,
+      default: 1
+    },
+    className: {
+      type: String,
+      default: ''
+    }
+  },
+  data() {
+    return {
+      active: false,
+      position: '',
+      width: undefined,
+      height: undefined,
+      isSticky: false
+    }
+  },
+  mounted() {
+    this.height = this.$el.getBoundingClientRect().height
+    window.addEventListener('scroll', this.handleScroll)
+    window.addEventListener('resize', this.handleResize)
+  },
+  activated() {
+    this.handleScroll()
+  },
+  destroyed() {
+    window.removeEventListener('scroll', this.handleScroll)
+    window.removeEventListener('resize', this.handleResize)
+  },
+  methods: {
+    sticky() {
+      if (this.active) {
+        return
+      }
+      this.position = 'fixed'
+      this.active = true
+      this.width = this.width + 'px'
+      this.isSticky = true
+    },
+    handleReset() {
+      if (!this.active) {
+        return
+      }
+      this.reset()
+    },
+    reset() {
+      this.position = ''
+      this.width = 'auto'
+      this.active = false
+      this.isSticky = false
+    },
+    handleScroll() {
+      const width = this.$el.getBoundingClientRect().width
+      this.width = width || 'auto'
+      const offsetTop = this.$el.getBoundingClientRect().top
+      if (offsetTop < this.stickyTop) {
+        this.sticky()
+        return
+      }
+      this.handleReset()
+    },
+    handleResize() {
+      if (this.isSticky) {
+        this.width = this.$el.getBoundingClientRect().width + 'px'
+      }
+    }
+  }
+}
+</script>