docs: private int getSwipeDuration(MotionEvent ev, int velocity) {
          int sx = getScrollX();
          int dx = (int)(ev.getX() - sx);
          final int width = mSwipeCurrentHorizontal.getMenuWidth();
          final int halfWidth = width / 2;
          final float distanceRatio = Math.min(1f, 1.0f * Math.abs(dx) / width);
          final float distance = halfWidth + halfWidth * distanceInfluenceForSnapDuration(distanceRatio);
          int duration;
          if (velocity > 0) {
              duration = 4 * Math.round(1000 * Math.abs(distance / velocity));
          } else {
              final float pageDelta = (float)Math.abs(dx) / width;
              duration = (int)((pageDelta + 1) * 100);
          }
          duration = Math.min(duration, mScrollerDuration);
          return duration;
      }