chromium/src/third_party/blink/renderer/core/paint/paint_timing_visualizer.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_PAINT_PAINT_TIMING_VISUALIZER_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_PAINT_PAINT_TIMING_VISUALIZER_H_

#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/layout/layout_object.h"
#include "third_party/blink/renderer/platform/instrumentation/tracing/traced_value.h"

namespace blink {

class IntRect;
class LocalFrameView;

// While Largest Contentful Paint only concerns about the largest contentful
// rect, the smaller rects used in its computation are helpful for debugging
// purpose. This helper class generates debugging traces that contains these
// intermediate rects. These debugging events, as well as their intermediate
// rects, can be visualized by third-party visualization tools.
class CORE_EXPORT PaintTimingVisualizer {
 public:
  static bool IsTracingEnabled();

  void DumpTextDebuggingRect(const LayoutObject&, const FloatRect&);
  void DumpImageDebuggingRect(const LayoutObject&,
                              const FloatRect&,
                              const ImageResourceContent&);
  void RecordMainFrameViewport(LocalFrameView& frame_view);
  inline void OnViewportChanged() { need_recording_viewport = true; }

 private:
  void RecordObject(const LayoutObject&, std::unique_ptr<TracedValue>&);
  void RecordRects(const IntRect& rect, std::unique_ptr<TracedValue>&);
  void RecordMainFrameViewport(const IntRect&);
  void DumpTrace(std::unique_ptr<TracedValue>);

  bool need_recording_viewport = true;
};
}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_PAINT_PAINT_TIMING_VISUALIZER_H_