Refactors std::vector<Display> out of ScreenMus

ui/views/mus/display_list.cc

Index: ui/views/mus/display_list.cc
diff --git a/ui/views/mus/display_list.cc b/ui/views/mus/display_list.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5be844ca52f3043b3fdaa37f8882e8798d7c6c74
--- /dev/null
+++ b/ui/views/mus/display_list.cc
@@ -0,0 +1,109 @@
+// 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.
+
+#include "ui/views/mus/display_list.h"
+
+#include "ui/display/display_finder.h"
+#include "ui/display/display_observer.h"
+
+namespace views {
+
+DisplayList::DisplayList() {}
+
+DisplayList::~DisplayList() {}
+
+void DisplayList::AddObserver(display::DisplayObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void DisplayList::RemoveObserver(display::DisplayObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+DisplayList::Displays::const_iterator DisplayList::FindDisplayById(
+    int64_t id) const {
+  for (auto iter = displays_.begin(); iter != displays_.end(); ++iter) {
+    if (iter->id() == id)
+      return iter;
+  }
+  return displays_.end();
+}
+
+DisplayList::Displays::iterator DisplayList::FindDisplayById(int64_t id) {
+  for (auto iter = displays_.begin(); iter != displays_.end(); ++iter) {
+    if (iter->id() == id)
+      return iter;
+  }
+  return displays_.end();
+}
+
+DisplayList::Displays::const_iterator DisplayList::GetPrimaryDisplayIterator()
+    const {
+  return primary_display_index_ == -1
+             ? displays_.end()
+             : displays_.begin() + primary_display_index_;
+}
+
+void DisplayList::UpdateDisplay(const display::Display& display, Type type) {
+  auto iter = FindDisplayById(display.id());
+  DCHECK(iter != displays_.end());
+
+  display::Display* local_display = &(*iter);
+  uint32_t changed_values = 0;
+  if (type == Type::PRIMARY &&
+      static_cast<int>(iter - displays_.begin()) !=
+          static_cast<int>(GetPrimaryDisplayIterator() - displays_.begin())) {
+    primary_display_index_ = static_cast<int>(iter - displays_.begin());
+    // 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() != display.bounds()) {
+    local_display->set_bounds(display.bounds());
+    changed_values |= display::DisplayObserver::DISPLAY_METRIC_BOUNDS;
+  }
+  if (local_display->work_area() != display.work_area()) {
+    local_display->set_work_area(display.work_area());
+    changed_values |= display::DisplayObserver::DISPLAY_METRIC_WORK_AREA;
+  }
+  if (local_display->rotation() != display.rotation()) {
+    local_display->set_rotation(display.rotation());
+    changed_values |= display::DisplayObserver::DISPLAY_METRIC_ROTATION;
+  }
+  if (local_display->device_scale_factor() != display.device_scale_factor()) {
+    local_display->set_device_scale_factor(display.device_scale_factor());
+    changed_values |=
+        display::DisplayObserver::DISPLAY_METRIC_DEVICE_SCALE_FACTOR;
+  }
+  FOR_EACH_OBSERVER(display::DisplayObserver, observers_,
+                    OnDisplayMetricsChanged(*local_display, changed_values));
+}
+
+void DisplayList::AddDisplay(const display::Display& display, Type type) {
+  DCHECK(displays_.end() == FindDisplayById(display.id()));
+  displays_.push_back(display);
+  if (type == Type::PRIMARY)
+    primary_display_index_ = static_cast<int>(displays_.size()) - 1;
+  FOR_EACH_OBSERVER(display::DisplayObserver, observers_,
+                    OnDisplayAdded(display));
+}
+
+void DisplayList::RemoveDisplay(int64_t id) {
+  auto iter = FindDisplayById(id);
+  DCHECK(displays_.end() != iter);
+  if (primary_display_index_ == static_cast<int>(iter - displays_.begin())) {
+    // We expect the primary to change before removing it. The only case we
+    // allow removal of the primary is if it is the list display.
+    DCHECK_EQ(1u, displays_.size());
+    primary_display_index_ = -1;
+  } else if (primary_display_index_ >
+             static_cast<int>(iter - displays_.begin())) {
+    primary_display_index_--;
+  }
+  const display::Display display = *iter;
+  displays_.erase(iter);
+  FOR_EACH_OBSERVER(display::DisplayObserver, observers_,
+                    OnDisplayRemoved(display));
+}
+}  // namespace views