Method _getActiveElements

src/plugins/plugin.tooltip.js:1183–1207

* Helper for determining the active elements for event * @param {ChartEvent} e - The event to handle * @param {InteractionItem[]} lastActive - Previously active elements * @param {boolean} [replay] - This is a replayed event (from update) * @param {boolean} [inChartArea] - The event is insid

(e, lastActive, replay, inChartArea)

	 * @private
	 */
  _getActiveElements(e, lastActive, replay, inChartArea) {
    const options = this.options;

    if (e.type === 'mouseout') {
      return [];
    }

    if (!inChartArea) {
      // Let user control the active elements outside chartArea. Eg. using Legend.
      // But make sure that active elements are still valid.
      return lastActive.filter(i =>
        this.chart.data.datasets[i.datasetIndex] &&
        this.chart.getDatasetMeta(i.datasetIndex).controller.getParsed(i.index) !== undefined
      );
    }

    // Find Active Elements for tooltips
    const active = this.chart.getElementsAtEventForMode(e, options.mode, options, replay);

    if (options.reverse) {
      active.reverse();
    }

    return active;
  }

  /**
	 * Determine if the active elements + event combination changes the