third_party/blink/renderer/core/loader/lazy_image_helper.h

// Copyright 2019 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.

#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_LOADER_LAZY_IMAGE_HELPER_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_LOADER_LAZY_IMAGE_HELPER_H_

#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"

namespace blink {

class Element;
class HTMLImageElement;
class LocalFrame;
class KURL;

// Contains helper functions to deal with the lazy loading logic of images.
class LazyImageHelper final {
  STATIC_ONLY(LazyImageHelper);

 public:
  enum class Eligibility {
    kDisabled,
    kEnabledFullyDeferred,
    kEnabledFetchPlaceholder,
  };

  static void StartMonitoring(Element* element);
  static void StopMonitoring(Element* element);

  static Eligibility DetermineEligibilityAndTrackVisibilityMetrics(
      const LocalFrame& frame,
      HTMLImageElement* html_image,
      const KURL& url);

  static void RecordMetricsOnLoadFinished(HTMLImageElement* image_element);
};

}  // namespace blink
#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_LOADER_LAZY_IMAGE_HELPER_H_