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// Copyright 2016 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_FIRST_MEANINGFUL_PAINT_DETECTOR_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_PAINT_FIRST_MEANINGFUL_PAINT_DETECTOR_H_
#include "base/macros.h"
#include "third_party/blink/public/platform/web_layer_tree_view.h"
#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/paint/paint_event.h"
#include "third_party/blink/renderer/platform/heap/handle.h"
#include "third_party/blink/renderer/platform/timer.h"
#include "third_party/blink/renderer/platform/wtf/time.h"
namespace blink {
class Document;
class PaintTiming;
// FirstMeaningfulPaintDetector observes layout operations during page load
// until network stable (2 seconds of no network activity), and computes the
// layout-based First Meaningful Paint.
// See https://goo.gl/vpaxv6 and http://goo.gl/TEiMi4 for more details.
class CORE_EXPORT FirstMeaningfulPaintDetector
: public GarbageCollectedFinalized<FirstMeaningfulPaintDetector> {
public:
// Used by FrameView to keep track of the number of layout objects created
// in the frame.
class LayoutObjectCounter {
public:
void Reset() { count_ = 0; }
void Increment() { count_++; }
unsigned Count() const { return count_; }
private:
unsigned count_ = 0;
};
static FirstMeaningfulPaintDetector& From(Document&);
FirstMeaningfulPaintDetector(PaintTiming*, Document&);
virtual ~FirstMeaningfulPaintDetector() = default;
void MarkNextPaintAsMeaningfulIfNeeded(const LayoutObjectCounter&,
int contents_height_before_layout,
int contents_height_after_layout,
int visible_height);
void NotifyInputEvent();
void NotifyPaint();
void CheckNetworkStable();
void ReportSwapTime(PaintEvent,
WebLayerTreeView::SwapResult,
base::TimeTicks);
void NotifyFirstContentfulPaint(TimeTicks swap_stamp);
void Trace(blink::Visitor*);
enum HadUserInput { kNoUserInput, kHadUserInput, kHadUserInputEnumMax };
private:
friend class FirstMeaningfulPaintDetectorTest;
enum DeferFirstMeaningfulPaint {
kDoNotDefer,
kDeferOutstandingSwapPromises,
kDeferFirstContentfulPaintNotSet
};
// The page is n-quiet if there are no more than n active network requests for
// this duration of time.
static constexpr double kNetwork2QuietWindowSeconds = 0.5;
static constexpr double kNetwork0QuietWindowSeconds = 0.5;
Document* GetDocument();
int ActiveConnections();
void SetNetworkQuietTimers(int active_connections);
void Network0QuietTimerFired(TimerBase*);
void Network2QuietTimerFired(TimerBase*);
void ReportHistograms();
void RegisterNotifySwapTime(PaintEvent);
void SetFirstMeaningfulPaint(TimeTicks stamp, TimeTicks swap_stamp);
bool next_paint_is_meaningful_ = false;
HadUserInput had_user_input_ = kNoUserInput;
HadUserInput had_user_input_before_provisional_first_meaningful_paint_ =
kNoUserInput;
Member<PaintTiming> paint_timing_;
TimeTicks provisional_first_meaningful_paint_;
TimeTicks provisional_first_meaningful_paint_swap_;
double max_significance_so_far_ = 0.0;
double accumulated_significance_while_having_blank_text_ = 0.0;
unsigned prev_layout_object_count_ = 0;
bool seen_first_meaningful_paint_candidate_ = false;
bool network0_quiet_reached_ = false;
bool network2_quiet_reached_ = false;
TimeTicks first_meaningful_paint0_quiet_;
TimeTicks first_meaningful_paint2_quiet_;
unsigned outstanding_swap_promise_count_ = 0;
DeferFirstMeaningfulPaint defer_first_meaningful_paint_ = kDoNotDefer;
TaskRunnerTimer<FirstMeaningfulPaintDetector> network0_quiet_timer_;
TaskRunnerTimer<FirstMeaningfulPaintDetector> network2_quiet_timer_;
DISALLOW_COPY_AND_ASSIGN(FirstMeaningfulPaintDetector);
};
} // namespace blink
#endif
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