+DygraphCanvasRenderer.makeNextPointStep_ = function(connect, points, end) {
+ if (connect) {
+ return function(j) {
+ while (++j < end) {
+ if (!(points[j].yval === null)) break;
+ }
+ return j;
+ }
+ } else {
+ return function(j) { return j + 1 };
+ }
+};
+
+DygraphCanvasRenderer.prototype._drawStyledLine = function(
+ ctx, i, setName, color, strokeWidth, strokePattern, drawPoints,
+ drawPointCallback, pointSize) {
+ var isNullOrNaN = function(x) {
+ return (x === null || isNaN(x));
+ };
+
+ var stepPlot = this.attr_("stepPlot");
+ var firstIndexInSet = this.layout.setPointsOffsets[i];
+ var setLength = this.layout.setPointsLengths[i];
+ var afterLastIndexInSet = firstIndexInSet + setLength;
+ var points = this.layout.points;
+ var prevX = null;
+ var prevY = null;
+ var pointsOnLine = []; // Array of [canvasx, canvasy] pairs.
+ if (!Dygraph.isArrayLike(strokePattern)) {
+ strokePattern = null;
+ }
+ var drawGapPoints = this.dygraph_.attr_('drawGapPoints', setName);
+
+ var point;
+ var next = DygraphCanvasRenderer.makeNextPointStep_(
+ this.attr_('connectSeparatedPoints'), points, afterLastIndexInSet);
+ ctx.save();
+ for (var j = firstIndexInSet; j < afterLastIndexInSet; j = next(j)) {
+ point = points[j];
+ if (isNullOrNaN(point.canvasy)) {
+ if (stepPlot && prevX !== null) {
+ // Draw a horizontal line to the start of the missing data
+ ctx.beginPath();
+ ctx.strokeStyle = color;
+ ctx.lineWidth = this.attr_('strokeWidth');
+ this._dashedLine(ctx, prevX, prevY, point.canvasx, prevY, strokePattern);
+ ctx.stroke();
+ }
+ // this will make us move to the next point, not draw a line to it.
+ prevX = prevY = null;
+ } else {
+ // A point is "isolated" if it is non-null but both the previous
+ // and next points are null.
+ var isIsolated = (!prevX && (j == points.length - 1 ||
+ isNullOrNaN(points[j+1].canvasy)));
+ if (drawGapPoints) {
+ // Also consider a point to be is "isolated" if it's adjacent to a
+ // null point, excluding the graph edges.
+ if ((j > 0 && !prevX) ||
+ (j < points.length - 1 && isNullOrNaN(points[j+1].canvasy))) {
+ isIsolated = true;
+ }
+ }
+ if (prevX === null) {
+ prevX = point.canvasx;
+ prevY = point.canvasy;
+ } else {
+ // Skip over points that will be drawn in the same pixel.
+ if (Math.round(prevX) == Math.round(point.canvasx) &&
+ Math.round(prevY) == Math.round(point.canvasy)) {
+ continue;
+ }
+ // TODO(antrob): skip over points that lie on a line that is already
+ // going to be drawn. There is no need to have more than 2
+ // consecutive points that are collinear.
+ if (strokeWidth) {
+ ctx.beginPath();
+ ctx.strokeStyle = color;
+ ctx.lineWidth = strokeWidth;
+ if (stepPlot) {
+ this._dashedLine(ctx, prevX, prevY, point.canvasx, prevY, strokePattern);
+ prevX = point.canvasx;
+ }
+ this._dashedLine(ctx, prevX, prevY, point.canvasx, point.canvasy, strokePattern);
+ prevX = point.canvasx;
+ prevY = point.canvasy;
+ ctx.stroke();
+ }
+ }
+
+ if (drawPoints || isIsolated) {
+ pointsOnLine.push([point.canvasx, point.canvasy]);
+ }
+ }
+ }
+ for (var idx = 0; idx < pointsOnLine.length; idx++) {
+ var cb = pointsOnLine[idx];
+ ctx.save();
+ drawPointCallback(
+ this.dygraph_, setName, ctx, cb[0], cb[1], color, pointSize);
+ ctx.restore();
+ }
+ ctx.restore();
+};
+
+DygraphCanvasRenderer.prototype._drawLine = function(ctx, i) {
+ var setNames = this.layout.setNames;
+ var setName = setNames[i];
+
+ var strokeWidth = this.dygraph_.attr_("strokeWidth", setName);
+ var borderWidth = this.dygraph_.attr_("strokeBorderWidth", setName);
+ var drawPointCallback = this.dygraph_.attr_("drawPointCallback", setName) ||
+ Dygraph.Circles.DEFAULT;
+ if (borderWidth && strokeWidth) {
+ this._drawStyledLine(ctx, i, setName,
+ this.dygraph_.attr_("strokeBorderColor", setName),
+ strokeWidth + 2 * borderWidth,
+ this.dygraph_.attr_("strokePattern", setName),
+ this.dygraph_.attr_("drawPoints", setName),
+ drawPointCallback,
+ this.dygraph_.attr_("pointSize", setName));
+ }
+
+ this._drawStyledLine(ctx, i, setName,
+ this.colors[setName],
+ strokeWidth,
+ this.dygraph_.attr_("strokePattern", setName),
+ this.dygraph_.attr_("drawPoints", setName),
+ drawPointCallback,
+ this.dygraph_.attr_("pointSize", setName));
+};