Refactors std::vector<Display> out of ScreenMus

ui/views/mus/screen_mus.cc

Index: ui/views/mus/screen_mus.cc
diff --git a/ui/views/mus/screen_mus.cc b/ui/views/mus/screen_mus.cc
index b2a84a7ff77dd2a2ecc8e7693145f1f1340ff058..227170606ae384220c29741a26a67bb5f15a9fe2 100644
--- a/ui/views/mus/screen_mus.cc
+++ b/ui/views/mus/screen_mus.cc
@@ -36,7 +36,6 @@ namespace views {
 
 ScreenMus::ScreenMus(ScreenMusDelegate* delegate)
     : delegate_(delegate),
-      primary_display_index_(0),
       display_manager_observer_binding_(this) {
 }
 
@@ -59,64 +58,28 @@ void ScreenMus::Init(shell::Connector* connector) {
   // The WaitForIncomingMethodCall() should have supplied the set of Displays,
   // unless mus is going down, in which case encountered_error() is true, or the
   // call to WaitForIncomingMethodCall() failed.
-  if (displays_.empty()) {
+  if (display_list_.displays().empty()) {
     DCHECK(display_manager_.encountered_error() || !success);
     // In this case we install a default display and assume the process is
     // going to exit shortly so that the real value doesn't matter.
-    displays_.push_back(
-        display::Display(0xFFFFFFFF, gfx::Rect(0, 0, 801, 802)));
+    display_list_.AddDisplay(
+        display::Display(0xFFFFFFFF, gfx::Rect(0, 0, 801, 802)),
+        DisplayList::Type::PRIMARY);
   }
 }
 
-int ScreenMus::FindDisplayIndexById(int64_t id) const {
-  for (size_t i = 0; i < displays_.size(); ++i) {
-    if (displays_[i].id() == id)
-      return static_cast<int>(i);
-  }
-  return -1;
-}
-
 void ScreenMus::ProcessDisplayChanged(const display::Display& changed_display,
                                       bool is_primary) {
-  const int display_index = FindDisplayIndexById(changed_display.id());
-  if (display_index == -1) {
-    displays_.push_back(changed_display);
-    if (is_primary)
-      primary_display_index_ = static_cast<int>(displays_.size()) - 1;
-    FOR_EACH_OBSERVER(display::DisplayObserver, observers_,
-                      OnDisplayAdded(changed_display));
+  if (display_list_.FindDisplayById(changed_display.id()) ==
+      display_list_.displays().end()) {
+    display_list_.AddDisplay(changed_display,
+                             is_primary ? DisplayList::Type::PRIMARY
+                                        : DisplayList::Type::NOT_PRIMARY);
     return;
   }
-
-  display::Display* local_display = &displays_[display_index];
-  uint32_t changed_values = 0;
-  if (is_primary && display_index != primary_display_index_) {
-    primary_display_index_ = display_index;
-    // ash::DisplayManager only notifies for the Display gaining primary, not
-    // the one losing it.
-    changed_values |= display::DisplayObserver::DISPLAY_METRIC_PRIMARY;
-  }
-  if (local_display->bounds() != changed_display.bounds()) {
-    local_display->set_bounds(changed_display.bounds());
-    changed_values |= display::DisplayObserver::DISPLAY_METRIC_BOUNDS;
-  }
-  if (local_display->work_area() != changed_display.work_area()) {
-    local_display->set_work_area(changed_display.work_area());
-    changed_values |= display::DisplayObserver::DISPLAY_METRIC_WORK_AREA;
-  }
-  if (local_display->rotation() != changed_display.rotation()) {
-    local_display->set_rotation(changed_display.rotation());
-    changed_values |= display::DisplayObserver::DISPLAY_METRIC_ROTATION;
-  }
-  if (local_display->device_scale_factor() !=
-      changed_display.device_scale_factor()) {
-    local_display->set_device_scale_factor(
-        changed_display.device_scale_factor());
-    changed_values |=
-        display::DisplayObserver::DISPLAY_METRIC_DEVICE_SCALE_FACTOR;
-  }
-  FOR_EACH_OBSERVER(display::DisplayObserver, observers_,
-                    OnDisplayMetricsChanged(*local_display, changed_values));
+  display_list_.UpdateDisplay(
+      changed_display,
+      is_primary ? DisplayList::Type::PRIMARY : DisplayList::Type::NOT_PRIMARY);
 }
 
 gfx::Point ScreenMus::GetCursorScreenPoint() {
@@ -144,58 +107,64 @@ gfx::NativeWindow ScreenMus::GetWindowAtScreenPoint(const gfx::Point& point) {
 }
 
 display::Display ScreenMus::GetPrimaryDisplay() const {
-  return displays_[primary_display_index_];
+  return *display_list_.GetPrimaryDisplayIterator();
 }
 
 display::Display ScreenMus::GetDisplayNearestWindow(
     gfx::NativeView view) const {
   //NOTIMPLEMENTED();
-  return GetPrimaryDisplay();
+  return *display_list_.GetPrimaryDisplayIterator();
 }
 
 display::Display ScreenMus::GetDisplayNearestPoint(
     const gfx::Point& point) const {
-  return *display::FindDisplayNearestPoint(displays_, point);
+  return *display::FindDisplayNearestPoint(display_list_.displays(), point);
 }
 
 int ScreenMus::GetNumDisplays() const {
-  return static_cast<int>(displays_.size());
+  return static_cast<int>(display_list_.displays().size());
 }
 
 std::vector<display::Display> ScreenMus::GetAllDisplays() const {
-  return displays_;
+  return display_list_.displays();
 }
 
 display::Display ScreenMus::GetDisplayMatching(
     const gfx::Rect& match_rect) const {
-  const display::Display* match =
-      display::FindDisplayWithBiggestIntersection(displays_, match_rect);
+  const display::Display* match = display::FindDisplayWithBiggestIntersection(
+      display_list_.displays(), match_rect);
   return match ? *match : GetPrimaryDisplay();
 }
 
 void ScreenMus::AddObserver(display::DisplayObserver* observer) {
-  observers_.AddObserver(observer);
+  display_list_.AddObserver(observer);
 }
 
 void ScreenMus::RemoveObserver(display::DisplayObserver* observer) {
-  observers_.RemoveObserver(observer);
+  display_list_.RemoveObserver(observer);
 }
 
-void ScreenMus::OnDisplays(mojo::Array<mus::mojom::DisplayPtr> displays) {
+void ScreenMus::OnDisplays(
+    mojo::Array<mus::mojom::DisplayPtr> transport_displays) {
   // This should only be called once from Init() before any observers have been
   // added.
-  DCHECK(displays_.empty());
-  displays_ = displays.To<std::vector<display::Display>>();
-  DCHECK(!displays_.empty());
+  DCHECK(display_list_.displays().empty());
+  std::vector<display::Display> displays =
+      transport_displays.To<std::vector<display::Display>>();
   for (size_t i = 0; i < displays.size(); ++i) {
-    if (displays[i]->is_primary) {
-      primary_display_index_ = static_cast<int>(i);
+    const bool is_primary = transport_displays[i]->is_primary;
+    display_list_.AddDisplay(displays[i], is_primary
+                                              ? DisplayList::Type::PRIMARY
+                                              : DisplayList::Type::NOT_PRIMARY);
+    if (is_primary) {
       // TODO(sky): Make WindowManagerFrameValues per display.
       WindowManagerFrameValues frame_values =
-          displays[i]->frame_decoration_values.To<WindowManagerFrameValues>();
+          transport_displays[i]
+              ->frame_decoration_values.To<WindowManagerFrameValues>();
       WindowManagerFrameValues::SetInstance(frame_values);
     }
   }
+  DCHECK(!display_list_.displays().empty());
 }
 
 void ScreenMus::OnDisplaysChanged(
@@ -216,14 +185,7 @@ void ScreenMus::OnDisplaysChanged(
 }
 
 void ScreenMus::OnDisplayRemoved(int64_t id) {
-  const int index = FindDisplayIndexById(id);
-  DCHECK_NE(-1, index);
-  // Another display must become primary before the existing primary is
-  // removed.
-  DCHECK_NE(index, primary_display_index_);
-  const display::Display display = displays_[index];
-  FOR_EACH_OBSERVER(display::DisplayObserver, observers_,
-                    OnDisplayRemoved(display));
+  display_list_.RemoveDisplay(id);
 }
 
 }  // namespace views