Class SVGDrawer

src/drawers/svgDrawer.ts:20–161

 * This class is immutable (but has internal state).
 */
export class SVGDrawer implements IDrawer {
  protected _className: string;
  protected _svgElementName: string;

  /**
   * The root element holding the visual elements. The SVGDrawer owns
   * this variable and manipulates it accordingly.
   */
  protected _root: d3.Selection<SVGElement, any, any, any>;

  /**
   * All of the DOM elements from the last draw.
   */
  private _selection: d3.Selection<Element, any, any, any>;

  /**
   * Cache of the _selection.nodes().
   */
  private _cachedVisualPrimitivesNodes: Element[];
  private _cachedVisualPrimitivesNodeMap: Utils.Map<number, Element>;

  /**
   * @param svgElementName an HTML/SVG tag name to be created, one per datum.
   * @param className CSS classes to be applied to the drawn primitives.
   * @param applyDefaultAttributes
   */
  constructor(svgElementName: string, className: string) {
    this._root = d3.select(document.createElementNS("http://www.w3.org/2000/svg", "g"));
    this._className = className;
    this._svgElementName = svgElementName;
  }

  public draw(data: any[], appliedDrawSteps: AppliedDrawStep[]) {
    /*
     * Draw to the DOM by clearing old DOM elements, adding new DOM elements,
     * and then passing those DOM elements to the animator, which will set the
     * appropriate attributes on the DOM.
     */
    this._createAndDestroyDOMElements(data);

    let delay = 0;
    const drawLength = appliedDrawSteps.length;
    for (let i = 0; i < drawLength; i++) {
      const drawStep = appliedDrawSteps[i];
      Utils.Window.setTimeout(() => this._drawStep(drawStep), delay);
      delay += drawStep.animator.totalTime(data.length);
    }
  }

  public getVisualPrimitives() {
    if (this._cachedVisualPrimitivesNodes == null) {
      this._cachedVisualPrimitivesNodes = this._selection.nodes();
    }
    return this._cachedVisualPrimitivesNodes;
  }

  public getVisualPrimitiveAtIndex(index: number) {
    if (this._cachedVisualPrimitivesNodeMap == null) {