Chart.js/src/controllers/controller.bubble.js

"use strict";

module.exports = function(Chart) {

	var helpers = Chart.helpers;

	Chart.defaults.bubble = {
		hover: {
			mode: "single"
		},

		scales: {
			xAxes: [{
				type: "linear", // bubble should probably use a linear scale by default
				position: "bottom",
				id: "x-axis-0" // need an ID so datasets can reference the scale
			}],
			yAxes: [{
				type: "linear",
				position: "left",
				id: "y-axis-0"
			}]
		},

		tooltips: {
			callbacks: {
				title: function(tooltipItems, data) {
					// Title doesn't make sense for scatter since we format the data as a point
					return '';
				},
				label: function(tooltipItem, data) {
					var datasetLabel = data.datasets[tooltipItem.datasetIndex].label || '';
					var dataPoint = data.datasets[tooltipItem.datasetIndex].data[tooltipItem.index];
					return datasetLabel + ': (' + dataPoint.x + ', ' + dataPoint.y + ', ' + dataPoint.r + ')';
				}
			}
		}
	};


	Chart.controllers.bubble = Chart.DatasetController.extend({
		addElements: function() {
			var meta = this.getMeta();
			helpers.each(this.getDataset().data, function(value, index) {
				meta.data[index] = meta.data[index] || new Chart.elements.Point({
					_chart: this.chart.chart,
					_datasetIndex: this.index,
					_index: index
				});
			}, this);
		},
		addElementAndReset: function(index) {
			var point = new Chart.elements.Point({
				_chart: this.chart.chart,
				_datasetIndex: this.index,
				_index: index
			});

			// Add to the points array and reset it
			this.getMeta().data.splice(index, 0, point);
			this.updateElement(point, index, true);
		},

		update: function update(reset) {
			var meta = this.getMeta();
			var points = meta.data;
			var yScale = this.getScaleForId(meta.yAxisID);
			var xScale = this.getScaleForId(meta.xAxisID);
			var scaleBase;

			if (yScale.min < 0 && yScale.max < 0) {
				scaleBase = yScale.getPixelForValue(yScale.max);
			} else if (yScale.min > 0 && yScale.max > 0) {
				scaleBase = yScale.getPixelForValue(yScale.min);
			} else {
				scaleBase = yScale.getPixelForValue(0);
			}

			// Update Points
			helpers.each(points, function(point, index) {
				this.updateElement(point, index, reset);
			}, this);

		},

		updateElement: function(point, index, reset) {
			var meta = this.getMeta();
			var yScale = this.getScaleForId(meta.yAxisID);
			var xScale = this.getScaleForId(meta.xAxisID);
			var scaleBase;

			var custom = point.custom || {};
			var dataset = this.getDataset();
			var data = dataset.data[index];
			var pointElementOptions = this.chart.options.elements.point;

			if (yScale.min < 0 && yScale.max < 0) {
				scaleBase = yScale.getPixelForValue(yScale.max);
			} else if (yScale.min > 0 && yScale.max > 0) {
				scaleBase = yScale.getPixelForValue(yScale.min);
			} else {
				scaleBase = yScale.getPixelForValue(0);
			}

			helpers.extend(point, {
				// Utility
				_chart: this.chart.chart,
				_xScale: xScale,
				_yScale: yScale,
				_datasetIndex: this.index,
				_index: index,

				// Desired view properties
				_model: {
					x: reset ? xScale.getPixelForDecimal(0.5) : xScale.getPixelForValue(data, index, this.index, this.chart.isCombo),
					y: reset ? scaleBase : yScale.getPixelForValue(data, index, this.index),
					// Appearance
					radius: reset ? 0 : custom.radius ? custom.radius : this.getRadius(data),
					backgroundColor: custom.backgroundColor ? custom.backgroundColor : helpers.getValueAtIndexOrDefault(dataset.backgroundColor, index, pointElementOptions.backgroundColor),
					borderColor: custom.borderColor ? custom.borderColor : helpers.getValueAtIndexOrDefault(dataset.borderColor, index, pointElementOptions.borderColor),
					borderWidth: custom.borderWidth ? custom.borderWidth : helpers.getValueAtIndexOrDefault(dataset.borderWidth, index, pointElementOptions.borderWidth),

					// Tooltip
					hitRadius: custom.hitRadius ? custom.hitRadius : helpers.getValueAtIndexOrDefault(dataset.hitRadius, index, pointElementOptions.hitRadius)
				}
			});

			var model = point._model;
			model.skip = custom.skip ? custom.skip : (isNaN(model.x) || isNaN(model.y));

			point.pivot();
		},

		getRadius: function(value) {
			return value.r || this.chart.options.elements.point.radius;
		},

		draw: function(ease) {
			var easingDecimal = ease || 1;

			// Transition and Draw the Points
			helpers.each(this.getMeta().data, function(point, index) {
				point.transition(easingDecimal);
				point.draw();
			});

		},

		setHoverStyle: function(point) {
			// Point
			var dataset = this.chart.data.datasets[point._datasetIndex];
			var index = point._index;
			var custom = point.custom || {};
			var model = point._model;

			model.radius = custom.hoverRadius ? custom.hoverRadius : (helpers.getValueAtIndexOrDefault(dataset.hoverRadius, index, this.chart.options.elements.point.hoverRadius)) + this.getRadius(this.getDataset().data[point._index]);
			model.backgroundColor = custom.hoverBackgroundColor ? custom.hoverBackgroundColor : helpers.getValueAtIndexOrDefault(dataset.hoverBackgroundColor, index, helpers.getHoverColor(model.backgroundColor));
			model.borderColor = custom.hoverBorderColor ? custom.hoverBorderColor : helpers.getValueAtIndexOrDefault(dataset.hoverBorderColor, index, helpers.getHoverColor(model.borderColor));
			model.borderWidth = custom.hoverBorderWidth ? custom.hoverBorderWidth : helpers.getValueAtIndexOrDefault(dataset.hoverBorderWidth, index, model.borderWidth);
		},

		removeHoverStyle: function(point) {
			var dataset = this.chart.data.datasets[point._datasetIndex];
			var index = point._index;
			var custom = point.custom || {};
			var model = point._model;
			var pointElementOptions = this.chart.options.elements.point;

			model.radius = custom.radius ? custom.radius : this.getRadius(dataset.data[point._index]);
			model.backgroundColor = custom.backgroundColor ? custom.backgroundColor : helpers.getValueAtIndexOrDefault(dataset.backgroundColor, index, pointElementOptions.backgroundColor);
			model.borderColor = custom.borderColor ? custom.borderColor : helpers.getValueAtIndexOrDefault(dataset.borderColor, index, pointElementOptions.borderColor);
			model.borderWidth = custom.borderWidth ? custom.borderWidth : helpers.getValueAtIndexOrDefault(dataset.borderWidth, index, pointElementOptions.borderWidth);
		}
	});
};