"drawXGrid": true,
"gridLineColor": "rgb(128,128,128)",
"fillAlpha": 0.15,
+ "underlayCallback": null
};
Dygraph.update(this.options, options);
DygraphCanvasRenderer.prototype.render = function() {
// Draw the new X/Y grid
var ctx = this.element.getContext("2d");
+
+ if (this.options.underlayCallback) {
+ this.options.underlayCallback(ctx, this.area, this.layout);
+ }
+
if (this.options.drawYGrid) {
var ticks = this.layout.yticks;
ctx.save();