1// Copyright 2014 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "ui/gfx/display_change_notifier.h"
6
7#include "ui/gfx/display.h"
8#include "ui/gfx/display_observer.h"
9
10namespace gfx {
11
12namespace {
13
14class DisplayComparator {
15 public:
16  explicit DisplayComparator(const Display& display)
17    : display_id_(display.id())
18  {}
19
20  bool operator()(const Display& display) const {
21    return display.id() == display_id_;
22  }
23
24 private:
25  int64 display_id_;
26};
27
28} // anonymous namespace
29
30DisplayChangeNotifier::DisplayChangeNotifier() {
31}
32
33DisplayChangeNotifier::~DisplayChangeNotifier() {
34}
35
36void DisplayChangeNotifier::AddObserver(DisplayObserver* obs) {
37  observer_list_.AddObserver(obs);
38}
39
40void DisplayChangeNotifier::RemoveObserver(DisplayObserver* obs) {
41  observer_list_.RemoveObserver(obs);
42}
43
44void DisplayChangeNotifier::NotifyDisplaysChanged(
45    const std::vector<Display>& old_displays,
46    const std::vector<Display>& new_displays) {
47  // Display present in old_displays but not in new_displays has been removed.
48  std::vector<Display>::const_iterator old_it = old_displays.begin();
49  for (; old_it != old_displays.end(); ++old_it) {
50    if (std::find_if(new_displays.begin(), new_displays.end(),
51                     DisplayComparator(*old_it)) == new_displays.end()) {
52      FOR_EACH_OBSERVER(DisplayObserver, observer_list_,
53                        OnDisplayRemoved(*old_it));
54    }
55  }
56
57  // Display present in new_displays but not in old_displays has been added.
58  // Display present in both might have been modified.
59  for (std::vector<Display>::const_iterator new_it =
60          new_displays.begin(); new_it != new_displays.end(); ++new_it) {
61    std::vector<Display>::const_iterator old_it = std::find_if(
62        old_displays.begin(), old_displays.end(), DisplayComparator(*new_it));
63
64    if (old_it == old_displays.end()) {
65      FOR_EACH_OBSERVER(DisplayObserver, observer_list_,
66                        OnDisplayAdded(*new_it));
67      continue;
68    }
69
70    uint32_t metrics = DisplayObserver::DISPLAY_METRIC_NONE;
71
72    if (new_it->bounds() != old_it->bounds())
73      metrics |= DisplayObserver::DISPLAY_METRIC_BOUNDS;
74
75    if (new_it->rotation() != old_it->rotation())
76      metrics |= DisplayObserver::DISPLAY_METRIC_ROTATION;
77
78    if (new_it->work_area() != old_it->work_area())
79      metrics |= DisplayObserver::DISPLAY_METRIC_WORK_AREA;
80
81    if (new_it->device_scale_factor() != old_it->device_scale_factor())
82      metrics |= DisplayObserver::DISPLAY_METRIC_DEVICE_SCALE_FACTOR;
83
84    if (metrics != DisplayObserver::DISPLAY_METRIC_NONE) {
85      FOR_EACH_OBSERVER(DisplayObserver,
86                        observer_list_,
87                        OnDisplayMetricsChanged(*new_it, metrics));
88    }
89  }
90}
91
92} // namespace gfx
93