From f562867062deded097cd97d1b0166eb3a3677683 Mon Sep 17 00:00:00 2001
From: jiaming <743192023@qq.com>
Date: Sun, 9 Dec 2018 16:50:02 +0800
Subject: [PATCH] add concentric arc chart

---
 src/components/concentricArcChart/index.vue | 179 ++++++++++++++++++++
 src/components/index.js                     |   2 +
 2 files changed, 181 insertions(+)
 create mode 100644 src/components/concentricArcChart/index.vue

diff --git a/src/components/concentricArcChart/index.vue b/src/components/concentricArcChart/index.vue
new file mode 100644
index 0000000..66483a8
--- /dev/null
+++ b/src/components/concentricArcChart/index.vue
@@ -0,0 +1,179 @@
+<template>
+  <div class="concentric-arc-chart">
+    <loading v-if="!data" />
+
+    <canvas :ref="ref" />
+  </div>
+</template>
+
+<script>
+export default {
+  name: 'ConcentricArcChart',
+  props: ['data'],
+  data () {
+    return {
+      ref: `concentric-arc-chart-${(new Date()).getTime()}`,
+      canvasDom: '',
+      canvasWH: [0, 0],
+      ctx: '',
+
+      arcOriginPos: [],
+
+      defaultArcRadiusArea: [0.2, 0.8],
+      defaultArcGap: 3,
+
+      arcRadius: [],
+      arcRadian: [],
+      arcLineWidth: 0,
+      arcColor: ''
+    }
+  },
+  watch: {
+    data (d) {
+      const { draw } = this
+
+      d && draw()
+    }
+  },
+  methods: {
+    init () {
+      const { $nextTick, initCanvas, calcArcConfig, data, draw } = this
+
+      $nextTick(e => {
+        initCanvas()
+
+        calcArcConfig()
+
+        data && draw()
+      })
+    },
+    initCanvas () {
+      const { $refs, ref, labelRef, canvasWH } = this
+
+      const canvas = this.canvasDom = $refs[ref]
+
+      this.labelDom = $refs[labelRef]
+
+      canvasWH[0] = canvas.clientWidth
+      canvasWH[1] = canvas.clientHeight
+
+      canvas.setAttribute('width', canvasWH[0])
+      canvas.setAttribute('height', canvasWH[1])
+
+      this.ctx = canvas.getContext('2d')
+    },
+    calcArcConfig () {
+      const { canvasWH, arcOriginPos } = this
+
+      arcOriginPos[0] = canvasWH[0] / 2
+      arcOriginPos[1] = canvasWH[1] / 2
+    },
+    draw () {
+      const { ctx, canvasWH, calcArcRadius, calcArcRadian, calcArcColor, drawArc, drawTitle } = this
+
+      ctx.clearRect(0, 0, ...canvasWH)
+
+      calcArcRadius()
+
+      calcArcRadian()
+
+      calcArcColor()
+
+      drawArc()
+
+      drawTitle()
+    },
+    calcArcRadius () {
+      const { data: { data, arcArea, arcGap }, arcOriginPos, defaultArcRadiusArea, defaultArcGap } = this
+
+      const arcNum = data.length
+
+      const fullRadius = (arcOriginPos[0] > arcOriginPos[1] ? arcOriginPos[1] : arcOriginPos[0])
+
+      const currentArcArea = arcArea || defaultArcRadiusArea
+
+      const maxRadius = fullRadius * Math.max(...currentArcArea)
+      const minRadius = fullRadius * Math.min(...currentArcArea)
+
+      const currentArcGap = arcGap || defaultArcGap
+
+      const arcLineWidth = this.arcLineWidth = (maxRadius - minRadius - currentArcGap * (arcNum - 1)) / arcNum
+
+      const fullArcLineWidth = arcLineWidth + currentArcGap
+      const halfArcLineWidth = arcLineWidth / 2
+
+      this.arcRadius = new Array(arcNum).fill(0).map((t, i) => maxRadius - halfArcLineWidth - fullArcLineWidth * i)
+    },
+    calcArcRadian () {
+      const { data: { data } } = this
+
+      const fullRadian = Math.PI / 2 * 3
+
+      const offsetRadian = Math.PI * 0.5
+
+      this.arcRadian = new Array(data.length).fill(0).map((t, i) => data[i].value * fullRadian - offsetRadian)
+    },
+    calcArcColor () {
+      const { ctx, data: { color }, arcRadius: [ radius ], arcLineWidth, arcOriginPos: [x, y] } = this
+
+      const linearGradientColor = ctx.createLinearGradient(x, y - radius - arcLineWidth, x, y + radius + arcLineWidth)
+
+      const colorGap = 1 / (color.length - 1)
+
+      color.forEach((c, i) => linearGradientColor.addColorStop(colorGap * i, c))
+
+      this.arcColor = linearGradientColor
+
+      this.ctx.strokeStyle = linearGradientColor
+    },
+    drawArc () {
+      const { ctx, arcRadius, arcRadian, arcOriginPos, arcLineWidth, arcColor } = this
+
+      const offsetRadian = Math.PI / -2
+
+      ctx.lineWidth = arcLineWidth
+      ctx.strokeStyle = arcColor
+
+      arcRadius.forEach((radius, i) => {
+        ctx.beginPath()
+
+        ctx.arc(...arcOriginPos, radius, offsetRadian, arcRadian[i])
+
+        ctx.stroke()
+      })
+    },
+    drawTitle () {
+      const { ctx, data: { data, fontSize }, arcRadius, arcOriginPos: [ x, y ], arcLineWidth } = this
+
+      const textEndX = x - 10
+
+      ctx.font = `${fontSize || arcLineWidth}px Arial`
+      ctx.textAlign = 'right'
+      ctx.textBaseline = 'middle'
+      ctx.fillStyle = '#fff'
+
+      ctx.beginPath()
+
+      data.forEach(({ title }, i) => {
+        ctx.fillText(title, textEndX, y - arcRadius[i])
+      })
+    }
+  },
+  mounted () {
+    const { init } = this
+
+    init()
+  }
+}
+</script>
+
+<style lang="less">
+.concentric-arc-chart {
+  position: relative;
+
+  canvas {
+    width: 100%;
+    height: 100%;
+  }
+}
+</style>
diff --git a/src/components/index.js b/src/components/index.js
index d55056e..d24dc90 100644
--- a/src/components/index.js
+++ b/src/components/index.js
@@ -13,6 +13,7 @@ import decoration4 from './decoration4/index'
 import capsuleChart from './capsuleChart/index.vue'
 import ringChart from './ringChart/index.vue'
 import polylineChart from './polylineChart/index.vue'
+import concentricArcChart from './concentricArcChart/index.vue'
 
 import numberShow from './numberShow/index.vue'
 
@@ -34,6 +35,7 @@ export default function (Vue) {
   Vue.component('capsuleChart', capsuleChart)
   Vue.component('polylineChart', polylineChart)
   Vue.component('ringChart', ringChart)
+  Vue.component('concentricArcChart', concentricArcChart)
   Vue.component('numberShow', numberShow)
   Vue.component('scrollBoard', scrollBoard)
   Vue.component('loading', loading)