ui/gfx/display_change_notifier.cc

   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
  10 namespace gfx {
  11
  12 namespace {
  13
  14 class 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
  30 DisplayChangeNotifier::DisplayChangeNotifier() {
  31 }
  32
  33 DisplayChangeNotifier::~DisplayChangeNotifier() {
  34 }
  35
  36 void DisplayChangeNotifier::AddObserver(DisplayObserver* obs) {
  37   observer_list_.AddObserver(obs);
  38 }
  39
  40 void DisplayChangeNotifier::RemoveObserver(DisplayObserver* obs) {
  41   observer_list_.RemoveObserver(obs);
  42 }
  43
  44 void 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