Function ensureHeaders

packages/sanddance/src/headers.ts:6–11

(presenter: Presenter, headers: Headers)

import { Presenter, PresenterElement } from '@msrvida/vega-deck.gl';

export function ensureHeaders(presenter: Presenter, headers: Headers) {
    const vegaControls = presenter.getElement(PresenterElement.vegaControls);
    conditionalHeader(!!vegaControls.querySelectorAll('.vega-bindings > *').length, vegaControls, headers.chart);
    const legend = presenter.getElement(PresenterElement.legend);
    conditionalHeader(!!legend.children.length, legend, headers.legend);
}

function conditionalHeader(condition: boolean, element: HTMLElement, header: string) {
    const existing = existingHeader(element, header);