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// Copyright 2020 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_SCREEN_DETAILS_SCREEN_CHANGE_MONITOR_H_
#define CONTENT_BROWSER_SCREEN_DETAILS_SCREEN_CHANGE_MONITOR_H_
#include <vector>
#include "base/functional/callback.h"
#include "ui/display/display_observer.h"
namespace content {
// Monitors system screen information and runs a callback on changes.
class ScreenChangeMonitor : public display::DisplayObserver {
public:
// The callback is run on any screen changes; the bool parameter is true iff
// the plurality of connected screens changed (e.g. 1 screen <-> 2 screens).
explicit ScreenChangeMonitor(base::RepeatingCallback<void(bool)> callback);
~ScreenChangeMonitor() override;
ScreenChangeMonitor(const ScreenChangeMonitor&) = delete;
ScreenChangeMonitor& operator=(const ScreenChangeMonitor&) = delete;
private:
// Run the callback if a meaningful display change took place.
void OnScreensChange();
// display::DisplayObserver:
void OnDisplayAdded(const display::Display& new_display) override;
void OnDisplaysRemoved(const display::Displays& removed_displays) override;
void OnDisplayMetricsChanged(const display::Display& display,
uint32_t changed_metrics) override;
display::ScopedOptionalDisplayObserver display_observer_{this};
// The callback to run on screen change events.
base::RepeatingCallback<void(bool)> callback_;
// The most recent display information, cached to detect meaningful changes.
std::vector<display::Display> cached_displays_;
};
} // namespace content
#endif // CONTENT_BROWSER_SCREEN_DETAILS_SCREEN_CHANGE_MONITOR_H_
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