update: function()

in riff-raff/public/javascripts/rickshaw.js [1759:1847]
46 lines of code
14 McCabe index (conditional complexity)

	update: function(e) {

		e = e || this.lastEvent;
		if (!e) return;
		this.lastEvent = e;

		if (!e.target.nodeName.match(/^(path|svg|rect)$/)) return;

		var graph = this.graph;

		var eventX = e.offsetX || e.layerX;
		var eventY = e.offsetY || e.layerY;

		var j = 0;
		var points = [];
		var nearestPoint;

		this.graph.series.active().forEach( function(series) {

			var data = this.graph.stackedData[j++];

			var domainX = graph.x.invert(eventX);

			var domainIndexScale = d3.scale.linear()
				.domain([data[0].x, data.slice(-1)[0].x])
				.range([0, data.length - 1]);

			var approximateIndex = Math.round(domainIndexScale(domainX));
			var dataIndex = Math.min(approximateIndex || 0, data.length - 1);

			for (var i = approximateIndex; i < data.length - 1;) {

				if (!data[i] || !data[i + 1]) break;

				if (data[i].x <= domainX && data[i + 1].x > domainX) {
					dataIndex = i;
					break;
				}

				if (data[i + 1].x <= domainX) { i++ } else { i-- }
			}

			if (dataIndex < 0) dataIndex = 0;
			var value = data[dataIndex];

			var distance = Math.sqrt(
				Math.pow(Math.abs(graph.x(value.x) - eventX), 2) +
				Math.pow(Math.abs(graph.y(value.y + value.y0) - eventY), 2)
			);

			var xFormatter = series.xFormatter || this.xFormatter;
			var yFormatter = series.yFormatter || this.yFormatter;

			var point = {
				formattedXValue: xFormatter(value.x),
				formattedYValue: yFormatter(value.y),
				series: series,
				value: value,
				distance: distance,
				order: j,
				name: series.name
			};

			if (!nearestPoint || distance < nearestPoint.distance) {
				nearestPoint = point;
			}

			points.push(point);

		}, this );


		nearestPoint.active = true;

		var domainX = nearestPoint.value.x;
		var formattedXValue = nearestPoint.formattedXValue;

		this.element.innerHTML = '';
		this.element.style.left = graph.x(domainX) + 'px';

		this.visible && this.render( {
			points: points,
			detail: points, // for backwards compatibility
			mouseX: eventX,
			mouseY: eventY,
			formattedXValue: formattedXValue,
			domainX: domainX
		} );
	},