// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "third_party/blink/renderer/core/scroll/scroll_customization.h"

namespace blink {
namespace ScrollCustomization {

ScrollDirection GetScrollDirectionFromDeltas(double delta_x, double delta_y) {
  // TODO(ekaramad, tdresser): Find out the right value for kEpsilon here (see
  // https://crbug.com/510550).
  const double kEpsilon = 0.1f;

  ScrollDirection direction = kScrollDirectionNone;
  if (delta_x > kEpsilon)
    direction |= kScrollDirectionPanRight;
  if (delta_x < -kEpsilon)
    direction |= kScrollDirectionPanLeft;
  if (delta_y > kEpsilon)
    direction |= kScrollDirectionPanDown;
  if (delta_y < -kEpsilon)
    direction |= kScrollDirectionPanUp;

  if (!direction) {
    // TODO(ekaramad, sahel): Remove this and perhaps replace with a DCHECK when
    // issue https://crbug.com/728214 is fixed.
    return kScrollDirectionAuto;
  }

  return direction;
}

}  // namespace ScrollCustomization
}  // namespace blink