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// Copyright 2018 The Chromium Authors
// 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_TIMING_EVENT_TIMING_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_TIMING_EVENT_TIMING_H_
#include <memory>
#include "base/time/time.h"
#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/timing/window_performance.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
namespace blink {
class Event;
// Event timing collects and records the event start time, processing start time
// and processing end time of long-latency events, providing a tool to evaluate
// input latency.
// See also: https://github.com/wicg/event-timing
class CORE_EXPORT EventTiming final {
STACK_ALLOCATED();
public:
// Processes an event that will be dispatched. Notifies the
// InteractiveDetector if it needs to be logged into input delay histograms.
// Returns an object only if the event is relevant for the EventTiming API.
// This object should be constructed before the event is dispatched and
// destructed after dispatch so that we can calculate the input delay and
// other latency values correctly.
static std::optional<EventTiming> TryCreate(LocalDOMWindow* window,
const Event& event,
EventTarget* hit_test_target);
~EventTiming();
EventTiming(const EventTiming&) = delete;
EventTiming& operator=(const EventTiming&) = delete;
EventTiming(EventTiming&&) = default;
EventTiming& operator=(EventTiming&&) = default;
static void HandleInputDelay(LocalDOMWindow* window,
const Event& event,
base::TimeTicks processing_start);
// The caller owns the |clock| which must outlive the EventTiming.
static void SetTickClockForTesting(const base::TickClock* clock);
// Returns true when the type of the event is included in the EventTiming.
static bool IsEventTypeForEventTiming(const Event& event);
private:
explicit EventTiming(base::TimeTicks processing_start,
WindowPerformance* performance,
const Event& event,
EventTarget* hit_test_target);
// Data members:
Persistent<WindowPerformance> performance_;
Persistent<const Event> event_;
};
} // namespace blink
#endif // THIRD_PARTY_BLINK_RENDERER_CORE_TIMING_EVENT_TIMING_H_
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