+/**
+ * @license
+ * Copyright 2012 Dan Vanderkam (danvdk@gmail.com)
+ * MIT-licensed (http://opensource.org/licenses/MIT)
+ */
+
+Dygraph.Plugins.Grid = (function() {
+
+/*
+
+Current bits of jankiness:
+
+*/
+
+"use strict";
+
+
+/**
+ * Draws the gridlines, i.e. the gray horizontal & vertical lines running the
+ * length of the chart.
+ *
+ * @constructor
+ */
+var grid = function() {
+};
+
+grid.prototype.toString = function() {
+ return "Gridline Plugin";
+};
+
+grid.prototype.activate = function(g) {
+ return {
+ drawChart: this.drawChart
+ };
+};
+
+grid.prototype.drawChart = function(e) {
+ // Draw the new X/Y grid. Lines appear crisper when pixels are rounded to
+ // half-integers. This prevents them from drawing in two rows/cols.
+ var g = e.dygraph;
+ var ctx = e.drawingContext;
+ var layout = g.layout_;
+ var area = e.dygraph.plotter_.area;
+
+ function halfUp(x) { return Math.round(x) + 0.5; }
+ function halfDown(y){ return Math.round(y) - 0.5; }
+
+ var x, y, i, ticks;
+ if (g.getOption('drawYGrid')) {
+ ticks = layout.yticks;
+ ctx.save();
+ ctx.strokeStyle = g.getOption('gridLineColor');
+ ctx.lineWidth = g.getOption('gridLineWidth');
+ for (i = 0; i < ticks.length; i++) {
+ // TODO(danvk): allow secondary axes to draw a grid, too.
+ if (ticks[i][0] !== 0) continue;
+ x = halfUp(area.x);
+ y = halfDown(area.y + ticks[i][1] * area.h);
+ ctx.beginPath();
+ ctx.moveTo(x, y);
+ ctx.lineTo(x + area.w, y);
+ ctx.closePath();
+ ctx.stroke();
+ }
+ ctx.restore();
+ }
+
+ if (g.getOption('drawXGrid')) {
+ ticks = layout.xticks;
+ ctx.save();
+ ctx.strokeStyle = g.getOption('gridLineColor');
+ ctx.lineWidth = g.getOption('gridLineWidth');
+ for (i = 0; i < ticks.length; i++) {
+ x = halfUp(area.x + ticks[i][0] * area.w);
+ y = halfDown(area.y + area.h);
+ ctx.beginPath();
+ ctx.moveTo(x, y);
+ ctx.lineTo(x, area.y);
+ ctx.closePath();
+ ctx.stroke();
+ }
+ ctx.restore();
+ }
+}
+
+grid.prototype.destroy = function() {
+};
+
+return grid;
+
+})();