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

'use strict';

var DatasetController = require('../core/core.datasetController');
var defaults = require('../core/core.defaults');
var elements = require('../elements/index');
var helpers = require('../helpers/index');

var valueOrDefault = helpers.valueOrDefault;
var resolve = helpers.options.resolve;

defaults._set('bubble', {
	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() {
				// Title doesn't make sense for scatter since we format the data as a point
				return '';
			},
			label: function(item, data) {
				var datasetLabel = data.datasets[item.datasetIndex].label || '';
				var dataPoint = data.datasets[item.datasetIndex].data[item.index] || {r: '?'};
				return datasetLabel + ': (' + item.label + ', ' + item.value + ', ' + dataPoint.r + ')';
			}
		}
	}
});

module.exports = DatasetController.extend({
	/**
	 * @protected
	 */
	dataElementType: elements.Point,

	/**
	 * @private
	 */
	_dataElementOptions: [
		'backgroundColor',
		'borderColor',
		'borderWidth',
		'hoverBackgroundColor',
		'hoverBorderColor',
		'hoverBorderWidth',
		'hoverRadius',
		'hitRadius',
		'pointStyle',
		'rotation'
	],

	/**
	 * Parse array of objects
	 * @private
	 */
	_parseObjectData: function(meta, data, start, count) {
		var xScale = this.getScaleForId(meta.xAxisID);
		var yScale = this.getScaleForId(meta.yAxisID);
		var parsed = [];
		var i, ilen, item, obj;
		for (i = start, ilen = start + count; i < ilen; ++i) {
			obj = data[i];
			item = {};
			item[xScale.id] = xScale._parseObject(obj, 'x', i);
			item[yScale.id] = yScale._parseObject(obj, 'y', i);
			item._custom = obj && obj.r && +obj.r;
			parsed.push(item);
		}
		return parsed;
	},

	/**
	 * @protected
	 */
	update: function(reset) {
		var me = this;
		var meta = me.getMeta();
		var points = meta.data;

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

	/**
	 * @protected
	 */
	updateElement: function(point, index, reset) {
		var me = this;
		var meta = me.getMeta();
		var xScale = me.getScaleForId(meta.xAxisID);
		var yScale = me.getScaleForId(meta.yAxisID);
		var options = me._resolveDataElementOptions(index);
		var parsed = !reset && me._getParsed(index);
		var x = reset ? xScale.getPixelForDecimal(0.5) : xScale.getPixelForValue(parsed[xScale.id]);
		var y = reset ? yScale.getBasePixel() : yScale.getPixelForValue(parsed[yScale.id]);

		point._options = options;
		point._model = {
			backgroundColor: options.backgroundColor,
			borderColor: options.borderColor,
			borderWidth: options.borderWidth,
			hitRadius: options.hitRadius,
			pointStyle: options.pointStyle,
			rotation: options.rotation,
			radius: reset ? 0 : options.radius,
			skip: isNaN(x) || isNaN(y),
			x: x,
			y: y,
		};

		point.pivot(me.chart._animationsDisabled);
	},

	/**
	 * @protected
	 */
	setHoverStyle: function(point) {
		var model = point._model;
		var options = point._options;
		var getHoverColor = helpers.getHoverColor;

		point.$previousStyle = {
			backgroundColor: model.backgroundColor,
			borderColor: model.borderColor,
			borderWidth: model.borderWidth,
			radius: model.radius
		};

		model.backgroundColor = valueOrDefault(options.hoverBackgroundColor, getHoverColor(options.backgroundColor));
		model.borderColor = valueOrDefault(options.hoverBorderColor, getHoverColor(options.borderColor));
		model.borderWidth = valueOrDefault(options.hoverBorderWidth, options.borderWidth);
		model.radius = options.radius + options.hoverRadius;
	},

	/**
	 * @private
	 */
	_resolveDataElementOptions: function(index) {
		var me = this;
		var chart = me.chart;
		var dataset = me.getDataset();
		var parsed = me._getParsed(index);
		var values = DatasetController.prototype._resolveDataElementOptions.apply(me, arguments);

		// Scriptable options
		var context = {
			chart: chart,
			dataIndex: index,
			dataset: dataset,
			datasetIndex: me.index
		};

		// In case values were cached (and thus frozen), we need to clone the values
		if (me._cachedDataOpts === values) {
			values = helpers.extend({}, values);
		}

		// Custom radius resolution
		values.radius = resolve([
			parsed && parsed._custom,
			me._config.radius,
			chart.options.elements.point.radius
		], context, index);

		return values;
	}
});