初始化

components/echarts-uniapp/wx-canvas.js

@@ -0,0 +1,105 @@
+export default class WxCanvas {
+  constructor(ctx, canvasId, isNew, canvasNode) {
+    this.ctx = ctx;
+    this.canvasId = canvasId;
+    this.chart = null;
+    this.isNew = isNew
+    if (isNew) {
+      this.canvasNode = canvasNode;
+    }
+    else {
+      this._initStyle(ctx);
+    }
+
+    // this._initCanvas(zrender, 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) {
+    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
+        });
+      };
+    });
+  }
+
+  set width(w) {
+    if (this.canvasNode) this.canvasNode.width = w
+  }
+  set height(h) {
+    if (this.canvasNode) this.canvasNode.height = h
+  }
+
+  get width() {
+    if (this.canvasNode)
+      return this.canvasNode.width
+    return 0
+  }
+  get height() {
+    if (this.canvasNode)
+      return this.canvasNode.height
+    return 0
+  }
+}