Class Legend

src/plugins/plugin.legend.js:41–553

const itemsEqual = (a, b) => a !== null && b !== null && a.datasetIndex === b.datasetIndex && a.index === b.index;

export class Legend extends Element {

  /**
	 * @param {{ ctx: any; options: any; chart: any; }} config
	 */
  constructor(config) {
    super();

    this._added = false;

    // Contains hit boxes for each dataset (in dataset order)
    this.legendHitBoxes = [];

    /**
 		 * @private
 		 */
    this._hoveredItem = null;

    // Are we in doughnut mode which has a different data type
    this.doughnutMode = false;

    this.chart = config.chart;
    this.options = config.options;
    this.ctx = config.ctx;
    this.legendItems = undefined;
    this.columnSizes = undefined;
    this.lineWidths = undefined;
    this.maxHeight = undefined;
    this.maxWidth = undefined;
    this.top = undefined;
    this.bottom = undefined;
    this.left = undefined;
    this.right = undefined;
    this.height = undefined;
    this.width = undefined;
    this._margins = undefined;
    this.position = undefined;
    this.weight = undefined;
    this.fullSize = undefined;
  }

  update(maxWidth, maxHeight, margins) {
    this.maxWidth = maxWidth;
    this.maxHeight = maxHeight;
    this._margins = margins;

    this.setDimensions();
    this.buildLabels();
    this.fit();
  }

  setDimensions() {
    if (this.isHorizontal()) {
      this.width = this.maxWidth;
      this.left = this._margins.left;
      this.right = this.width;
    } else {
      this.height = this.maxHeight;