初始化（包含登录模块）

components/mpvue-echarts/src/wx-canvas.js

@@ -0,0 +1,73 @@
+export default class WxCanvas {
+  constructor(ctx, canvasId) {
+    this.ctx = ctx;
+    this.canvasId = canvasId;
+    this.chart = null;
+
+    WxCanvas.initStyle(ctx);
+    this.initEvent();
+  }
+
+  getContext(contextType) {
+    return contextType === '2d' ? this.ctx : null;
+  }
+
+  setChart(chart) {
+    this.chart = chart;
+  }
+
+  attachEvent() {
+    // noop
+  }
+
+  detachEvent() {
+    // noop
+  }
+
+  static initStyle(ctx) {
+    const styles = ['fillStyle', 'strokeStyle', 'globalAlpha',
+      'textAlign', 'textBaseAlign', 'shadow', 'lineWidth',
+      'lineCap', 'lineJoin', 'lineDash', 'miterLimit', 'fontSize'];
+
+    styles.forEach((style) => {
+      Object.defineProperty(ctx, style, {
+        set: (value) => {
+          if ((style !== 'fillStyle' && style !== 'strokeStyle')
+            || (value !== 'none' && value !== null)
+          ) {
+            ctx[`set${style.charAt(0).toUpperCase()}${style.slice(1)}`](value);
+          }
+        },
+      });
+    });
+
+    ctx.createRadialGradient = () => ctx.createCircularGradient(arguments);
+  }
+
+  initEvent() {
+    this.event = {};
+    const eventNames = [{
+      wxName: 'touchStart',
+      ecName: 'mousedown',
+    }, {
+      wxName: 'touchMove',
+      ecName: 'mousemove',
+    }, {
+      wxName: 'touchEnd',
+      ecName: 'mouseup',
+    }, {
+      wxName: 'touchEnd',
+      ecName: 'click',
+    }];
+
+    eventNames.forEach((name) => {
+      this.event[name.wxName] = (e) => {
+        const touch = e.mp.touches[0];
+        this.chart._zr.handler.dispatch(name.ecName, {
+          zrX: name.wxName === 'tap' ? touch.clientX : touch.x,
+          zrY: name.wxName === 'tap' ? touch.clientY : touch.y,
+        });
+      };
+    });
+  }
+}