Function Controller

src/js/components/Controller/Controller.ts:44–403

( Splide: Splide, Components: Components, options: Options )

 * @return A Controller component object.
 */
export function Controller( Splide: Splide, Components: Components, options: Options ): ControllerComponent {
  const { on, emit } = EventInterface( Splide );
  const { Move } = Components;
  const { getPosition, getLimit, toPosition } = Move;
  const { isEnough, getLength } = Components.Slides;
  const { omitEnd } = options;
  const isLoop  = Splide.is( LOOP );
  const isSlide = Splide.is( SLIDE );
  const getNext = apply( getAdjacent, false );
  const getPrev = apply( getAdjacent, true );

  /**
   * The current index.
   */
  let currIndex = options.start || 0;

  /**
   * The latest end index.
   */
  let endIndex: number;

  /**
   * The previous index.
   */
  let prevIndex = currIndex;

  /**
   * The latest number of slides.
   */
  let slideCount: number;

  /**
   * The latest `perMove` value.
   */
  let perMove: number;

  /**
   * The latest `perMove` value.
   */
  let perPage: number;

  /**
   * Called when the component is mounted.
   */
  function mount(): void {
    init();
    on( [ EVENT_UPDATED, EVENT_REFRESH, EVENT_END_INDEX_CHANGED ], init );
    on( EVENT_RESIZED, onResized );
  }

  /**
   * Initializes some parameters.
   * Needs to check the number of slides since the current index may be out of the range after refresh.
   * The process order must be Elements -> Controller -> Move.
   */
  function init(): void {
    slideCount = getLength( true );
    perMove    = options.perMove;