[new feature] add Circle component (#608)

packages/circle/index.vue

@@ -0,0 +1,126 @@
+<template>
+  <div class="van-circle" :style="style">
+    <svg viewBox="0 0 1060 1060">
+      <path class="van-circle__hover" :style="hoverStyle" :d="path" />
+      <path class="van-circle__layer" :style="layerStyle" :d="path" />
+    </svg>
+    <slot>
+      <div class="van-circle__text">{{ text }}</div>
+    </slot>
+  </div>
+</template>
+
+<script>
+import { create } from '../utils';
+import { raf, cancel } from '../utils/raf';
+
+export default create({
+  name: 'van-circle',
+
+  props: {
+    text: String,
+    value: Number,
+    speed: Number,
+    size: {
+      type: String,
+      default: '100px'
+    },
+    fill: {
+      type: String,
+      default: 'none'
+    },
+    rate: {
+      type: Number,
+      default: 100
+    },
+    layerColor: {
+      type: String,
+      default: '#fff'
+    },
+    color: {
+      type: String,
+      default: '#38f'
+    },
+    strokeWidth: {
+      type: Number,
+      default: 40
+    },
+    clockwise: {
+      type: Boolean,
+      default: true
+    }
+  },
+
+  beforeCreate() {
+    this.perimeter = Math.PI * 1000;
+    this.path = 'M 530 530 m -500, 0 a 500, 500 0 1, 1 1000, 0 a 500, 500 0 1, 1 -1000, 0';
+  },
+
+  computed: {
+    style() {
+      return {
+        width: this.size,
+        height: this.size
+      };
+    },
+
+    layerStyle() {
+      let offset = this.perimeter * (100 - this.value) / 100;
+      offset = this.clockwise ? offset : this.perimeter * 2 - offset;
+      return {
+        stroke: `${this.color}`,
+        strokeDashoffset: `${offset}px`,
+        strokeWidth: `${this.strokeWidth + 1}px`
+      };
+    },
+
+    hoverStyle() {
+      return {
+        fill: `${this.fill}`,
+        stroke: `${this.layerColor}`,
+        strokeWidth: `${this.strokeWidth}px`
+      };
+    }
+  },
+
+  mounted() {
+    this.render();
+  },
+
+  watch: {
+    rate() {
+      this.render();
+    }
+  },
+
+  methods: {
+    render() {
+      this.startTime = Date.now();
+      this.startRate = this.value;
+      this.endRate = this.format(this.rate);
+      this.increase = this.endRate > this.startRate;
+      this.duration = Math.abs((this.startRate - this.endRate) * 1000 / this.speed);
+      if (this.speed) {
+        cancel(this.rafId);
+        this.rafId = raf(this.animate);
+      } else {
+        this.$emit('input', this.endRate);
+      }
+    },
+
+    animate() {
+      const now = Date.now();
+      const progress = Math.min((now - this.startTime) / this.duration, 1);
+      const rate = progress * (this.endRate - this.startRate) + this.startRate;
+      this.$emit('input', this.format(parseFloat(rate.toFixed(1))));
+      if (this.increase ? rate < this.endRate : rate > this.endRate) {
+        this.rafId = raf(this.animate);
+      }
+    },
+
+    format(rate) {
+      return Math.min(Math.max(rate, 0), 100);
+    }
+  }
+});
+</script>