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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 UI_DISPLAY_DISPLAY_LIST_H_
#define UI_DISPLAY_DISPLAY_LIST_H_
#include <stdint.h>
#include <memory>
#include <vector>
#include "base/observer_list.h"
#include "ui/display/display.h"
#include "ui/display/display_export.h"
namespace display {
class Display;
class DisplayList;
class DisplayObserver;
// See description in DisplayLock::SuspendObserverUpdates.
class DISPLAY_EXPORT DisplayListObserverLock {
public:
~DisplayListObserverLock();
private:
friend class DisplayList;
explicit DisplayListObserverLock(DisplayList* display_list);
DisplayList* display_list_;
DISALLOW_COPY_AND_ASSIGN(DisplayListObserverLock);
};
// Maintains an ordered list of display::Displays as well as operations to add,
// remove and update said list. Additionally maintains display::DisplayObservers
// and updates them as appropriate.
class DISPLAY_EXPORT DisplayList {
public:
using Displays = std::vector<display::Display>;
enum class Type {
PRIMARY,
NOT_PRIMARY,
};
DisplayList();
~DisplayList();
void AddObserver(display::DisplayObserver* observer);
void RemoveObserver(display::DisplayObserver* observer);
const Displays& displays() const { return displays_; }
Displays::const_iterator FindDisplayById(int64_t id) const;
Displays::iterator FindDisplayById(int64_t id);
Displays::const_iterator GetPrimaryDisplayIterator() const;
// Internally increments a counter that while non-zero results in observers
// not being called for any changes to the displays. It is assumed once
// callers release the last lock they call the observers appropriately.
std::unique_ptr<DisplayListObserverLock> SuspendObserverUpdates();
// Updates the cached id based on display.id() as well as whether the Display
// is the primary display.
void UpdateDisplay(const display::Display& display, Type type);
// Adds a new Display.
void AddDisplay(const display::Display& display, Type type);
// Removes the Display with the specified id.
void RemoveDisplay(int64_t id);
base::ObserverList<display::DisplayObserver>* observers() {
return &observers_;
}
private:
friend class DisplayListObserverLock;
bool should_notify_observers() const {
return observer_suspend_lock_count_ == 0;
}
void IncrementObserverSuspendLockCount();
void DecrementObserverSuspendLockCount();
std::vector<display::Display> displays_;
int primary_display_index_ = -1;
base::ObserverList<display::DisplayObserver> observers_;
int observer_suspend_lock_count_ = 0;
DISALLOW_COPY_AND_ASSIGN(DisplayList);
};
} // namespace display
#endif // UI_DISPLAY_DISPLAY_LIST_H_