src/controllers/controller.line.js
import DatasetController from '../core/core.datasetController.js';
import {isNullOrUndef} from '../helpers/index.js';
import {isNumber} from '../helpers/helpers.math.js';
import {_getStartAndCountOfVisiblePoints, _scaleRangesChanged} from '../helpers/helpers.extras.js';
export default class LineController extends DatasetController {
static id = 'line';
/**
* @type {any}
*/
static defaults = {
datasetElementType: 'line',
dataElementType: 'point',
showLine: true,
spanGaps: false,
};
/**
* @type {any}
*/
static overrides = {
scales: {
_index_: {
type: 'category',
},
_value_: {
type: 'linear',
},
}
};
initialize() {
this.enableOptionSharing = true;
this.supportsDecimation = true;
super.initialize();
}
update(mode) {
const meta = this._cachedMeta;
const {dataset: line, data: points = [], _dataset} = meta;
// @ts-ignore
const animationsDisabled = this.chart._animationsDisabled;
let {start, count} = _getStartAndCountOfVisiblePoints(meta, points, animationsDisabled);
this._drawStart = start;
this._drawCount = count;
if (_scaleRangesChanged(meta)) {
start = 0;
count = points.length;
}
// Update Line
line._chart = this.chart;
line._datasetIndex = this.index;
line._decimated = !!_dataset._decimated;
line.points = points;
const options = this.resolveDatasetElementOptions(mode);
if (!this.options.showLine) {
options.borderWidth = 0;
}
options.segment = this.options.segment;
this.updateElement(line, undefined, {
animated: !animationsDisabled,
options
}, mode);
// Update Points
this.updateElements(points, start, count, mode);
}
updateElements(points, start, count, mode) {
const reset = mode === 'reset';
const {iScale, vScale, _stacked, _dataset} = this._cachedMeta;
const {sharedOptions, includeOptions} = this._getSharedOptions(start, mode);
const iAxis = iScale.axis;
const vAxis = vScale.axis;
const {spanGaps, segment} = this.options;
const maxGapLength = isNumber(spanGaps) ? spanGaps : Number.POSITIVE_INFINITY;
const directUpdate = this.chart._animationsDisabled || reset || mode === 'none';
const end = start + count;
const pointsCount = points.length;
let prevParsed = start > 0 && this.getParsed(start - 1);
for (let i = 0; i < pointsCount; ++i) {
const point = points[i];
const properties = directUpdate ? point : {};
if (i < start || i >= end) {
properties.skip = true;
continue;
}
const parsed = this.getParsed(i);
const nullData = isNullOrUndef(parsed[vAxis]);
const iPixel = properties[iAxis] = iScale.getPixelForValue(parsed[iAxis], i);
const vPixel = properties[vAxis] = reset || nullData ? vScale.getBasePixel() : vScale.getPixelForValue(_stacked ? this.applyStack(vScale, parsed, _stacked) : parsed[vAxis], i);
properties.skip = isNaN(iPixel) || isNaN(vPixel) || nullData;
properties.stop = i > 0 && (Math.abs(parsed[iAxis] - prevParsed[iAxis])) > maxGapLength;
if (segment) {
properties.parsed = parsed;
properties.raw = _dataset.data[i];
}
if (includeOptions) {
properties.options = sharedOptions || this.resolveDataElementOptions(i, point.active ? 'active' : mode);
}
if (!directUpdate) {
this.updateElement(point, i, properties, mode);
}
prevParsed = parsed;
}
}
/**
* @protected
*/
getMaxOverflow() {
const meta = this._cachedMeta;
const dataset = meta.dataset;
const border = dataset.options && dataset.options.borderWidth || 0;
const data = meta.data || [];
if (!data.length) {
return border;
}
const firstPoint = data[0].size(this.resolveDataElementOptions(0));
const lastPoint = data[data.length - 1].size(this.resolveDataElementOptions(data.length - 1));
return Math.max(border, firstPoint, lastPoint) / 2;
}
draw() {
const meta = this._cachedMeta;
meta.dataset.updateControlPoints(this.chart.chartArea, meta.iScale.axis);
super.draw();
}
}