调整分包，完成隐私协议（样式待优化）

childPackage/miniprogram_npm/towxml/echarts/wx-canvas.js

@@ -0,0 +1,97 @@
+export default class WxCanvas {
+  constructor(ctx, canvasId) {
+    this.ctx = ctx;
+    this.canvasId = canvasId;
+    this.chart = null;
+
+    // this._initCanvas(zrender, ctx);
+    this._initStyle(ctx);
+    this._initEvent();
+  }
+
+  getContext(contextType) {
+    if (contextType === '2d') {
+      return this.ctx;
+    }
+  }
+
+  // canvasToTempFilePath(opt) {
+  //   if (!opt.canvasId) {
+  //     opt.canvasId = this.canvasId;
+  //   }
+
+  //   return wx.canvasToTempFilePath(opt, this);
+  // }
+
+  setChart(chart) {
+    this.chart = chart;
+  }
+
+  attachEvent () {
+    // noop
+  }
+
+  detachEvent() {
+    // noop
+  }
+
+  _initCanvas(zrender, ctx) {
+    zrender.util.getContext = function () {
+      return ctx;
+    };
+
+    zrender.util.$override('measureText', function (text, font) {
+      ctx.font = font || '12px sans-serif';
+      return ctx.measureText(text);
+    });
+  }
+
+  _initStyle(ctx) {
+    var 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 = () => {
+      return 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.touches[0];
+        this.chart.getZr().handler.dispatch(name.ecName, {
+          zrX: name.wxName === 'tap' ? touch.clientX : touch.x,
+          zrY: name.wxName === 'tap' ? touch.clientY : touch.y
+        });
+      };
+    });
+  }
+}