Snap to bounds

snap-to-bounds.js

rflect.ui.MomentumScroller.prototype.snapToBounds = function() {
  const transition = rflect.browser.css.getSelectorCasedProperty('transform') +
    ' ' + 500 + 'ms ease-out';
  this.setTransitionAll(transition);

  // Different out of bounds cases:
  // 1. If content is lower than frame upper border
  if (this.contentOffsetY > 0) {
    this.contentOffsetY = 0;
    rflect.browser.css.setTransform(this.getScrollBarContainer(),
        `translate3d(0, ${(this.getScrollBarLineHeight() / 2)}px, 0)`);
  }
  else {
  // 2. If content is higher that frame lower border.
    this.contentOffsetY = this.getLowestContentPosition();
    rflect.browser.css.setTransform(this.getScrollBarContainer(),
        `translate3d(0, ${this.frameElementSize.height -
        this.getScrollBarLineHeight() / 2}px, 0)`);
  }

  rflect.browser.css.setTransform(this.element,
      `translate3d(0, ${this.contentOffsetY}px, 0)`);
  rflect.browser.css.setTransform(this.getScrollBarLine(),
      `scaleY(${this.getScrollBarLineHeight()})`);

  this.isDecelerating_ = true;
}