Method _mouseDown

src/dd-draggable.ts:148–183

@internal call when mouse goes down before a dragstart happens

(e: MouseEvent)

  /** @internal call when mouse goes down before a dragstart happens */
  protected _mouseDown(e: MouseEvent): boolean {
    // if real brower event (trusted:true vs false for our simulated ones) and we didn't correctly clear the last touch event, clear things up
    if (DDTouch.touchHandled && e.isTrusted) DDTouch.touchHandled = false;

    // don't let more than one widget handle mouseStart
    if (DDManager.mouseHandled) return;
    if (e.button !== 0) return true; // only left click

    // make sure we are not clicking on known object that handles mouseDown, or ones supplied by the user
    if (!this.dragEls.find(el => el === e.target) && (e.target as HTMLElement).closest(skipMouseDown)) return true;
    if (this.option.cancel) {
      if ((e.target as HTMLElement).closest(this.option.cancel)) return true;
    }

    this.mouseDownEvent = e;
    delete this.dragging;
    delete DDManager.dragElement;
    delete DDManager.dropElement;
    delete this._autoScrollMaxSpeed;
    delete this._autoScrollContainer;
    // document handler so we can continue receiving moves as the item is 'fixed' position, and capture=true so WE get a first crack
    document.addEventListener('mousemove', this._mouseMove, { capture: true, passive: true }); // true=capture, not bubble
    document.addEventListener('mouseup', this._mouseUp, true);
    if (isTouch) {
      e.currentTarget.addEventListener('touchmove', touchmove);
      e.currentTarget.addEventListener('touchend', touchend);
    }

    e.preventDefault();
    // preventDefault() prevents blur event which occurs just after mousedown event.
    // if an editable content has focus, then blur must be call
    if (document.activeElement) (document.activeElement as HTMLElement).blur();

    DDManager.mouseHandled = true;
    return true;
  }

  /** @internal method to call actual drag event */
  public _callDrag(e: DragEvent): void {