chromium/content/browser/attribution_reporting/attribution_input_event_tracker_android.h

// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_ATTRIBUTION_REPORTING_ATTRIBUTION_INPUT_EVENT_TRACKER_ANDROID_H_
#define CONTENT_BROWSER_ATTRIBUTION_REPORTING_ATTRIBUTION_INPUT_EVENT_TRACKER_ANDROID_H_

#include <jni.h>
#include <stdint.h>

#include <optional>

#include "base/android/scoped_java_ref.h"
#include "base/time/time.h"
#include "content/common/content_export.h"
#include "ui/android/event_forwarder.h"

namespace ui {
class MotionEventAndroid;
}  // namespace ui

namespace content {

class WebContents;

// A class that observes motion events per web contents and keeps track of the
// most recent event. An event filter may be applied to filter out invalid
// events.
class CONTENT_EXPORT AttributionInputEventTrackerAndroid
    : public ui::EventForwarder::Observer {
 public:
  static constexpr base::TimeDelta kEventExpiry = base::Seconds(5);

  struct InputEvent {
    std::optional<uint32_t> id;
    base::android::ScopedJavaGlobalRef<jobject> event;

    InputEvent(std::optional<uint32_t> id,
               base::android::ScopedJavaGlobalRef<jobject> event);
    ~InputEvent();
  };

  explicit AttributionInputEventTrackerAndroid(WebContents* web_contents);

  AttributionInputEventTrackerAndroid(
      const AttributionInputEventTrackerAndroid&) = delete;
  AttributionInputEventTrackerAndroid& operator=(
      const AttributionInputEventTrackerAndroid&) = delete;

  AttributionInputEventTrackerAndroid(AttributionInputEventTrackerAndroid&&) =
      delete;
  AttributionInputEventTrackerAndroid& operator=(
      AttributionInputEventTrackerAndroid&&) = delete;

  ~AttributionInputEventTrackerAndroid() override;

  // Returns the most recent input event. The input event expires `kEventExpiry`
  // after it was pushed, and expired event may be dropped.
  InputEvent GetMostRecentEvent();

  void RemoveObserverForTesting(WebContents* web_contents);

 private:
  friend class AttributionInputEventTrackerAndroidTest;

  // ui::EventForwarder::Observer:
  void OnTouchEvent(const ui::MotionEventAndroid& event) override;

  void PushEvent(const ui::MotionEventAndroid& event);

  base::android::ScopedJavaGlobalRef<jobject> most_recent_event_;
  std::optional<uint32_t> most_recent_event_id_;

  // The time that the most recent event was pushed and cached.
  base::TimeTicks most_recent_event_cache_time_;
};

}  // namespace content

#endif  // CONTENT_BROWSER_ATTRIBUTION_REPORTING_ATTRIBUTION_INPUT_EVENT_TRACKER_ANDROID_H_