arc: Show custom notification via notification surface

ui/arc/notification/arc_notification_surface_collection.cc

+// 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/arc/notification/arc_notification_surface_collection.h"
+
+#include <algorithm>
+
+#include "components/exo/display.h"
+#include "components/exo/notification_surface.h"
+#include "ui/arc/notification/arc_notification_manager.h"
+
+namespace arc {
+
+ArcNotificationSurfaceCollection::ArcNotificationSurfaceCollection() {

[yoshiki, 2016/06/15 11:47:20]

Can we ensure that no notification surface is added before this constructor?

[xiyuan, 2016/06/15 19:32:44]

This is created with ArcNotificationManager when we start ARC. There should be
no notification surfaces created before it.

But I get your point. I will make it more explicit by moving this class into exo
and make its lifetime the same as the exo system to ease the concern.

+  exo::Display::GetInstance()->AddObserver(this);
+}
+
+ArcNotificationSurfaceCollection::~ArcNotificationSurfaceCollection() {
+  exo::Display::GetInstance()->RemoveObserver(this);
+  for (auto& entry : notification_surface_map_)
+    entry.second->RemoveObserver(this);
+}
+
+exo::NotificationSurface* ArcNotificationSurfaceCollection::GetSurface(
+    const std::string& arc_notification_key) const {
+  auto it = notification_surface_map_.find(arc_notification_key);
+  return it == notification_surface_map_.end() ? nullptr : it->second;
+}
+
+void ArcNotificationSurfaceCollection::AddObserver(Observer* observer) {
+  observers_.AddObserver(observer);
+}
+
+void ArcNotificationSurfaceCollection::RemoveObserver(Observer* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+void ArcNotificationSurfaceCollection::AddSurface(
+    exo::NotificationSurface* surface) {
+  DCHECK(notification_surface_map_.find(surface->notification_id()) ==
+         notification_surface_map_.end());
+
+  notification_surface_map_[surface->notification_id()] = surface;
+  surface->AddObserver(this);
+
+  FOR_EACH_OBSERVER(Observer, observers_, OnNotificationSurfaceAdded(surface));
+}
+
+void ArcNotificationSurfaceCollection::OnNotificationSurfaceCreated(
+    exo::NotificationSurface* surface) {
+  AddSurface(surface);
+}
+
+void ArcNotificationSurfaceCollection::OnNotificationSurfaceDestroying(
+    exo::NotificationSurface* surface) {
+  auto it = notification_surface_map_.find(surface->notification_id());
+  if (it == notification_surface_map_.end()) {
+    NOTREACHED();
+    return;
+  }
+
+  surface->RemoveObserver(this);
+  notification_surface_map_.erase(it);
+}
+
+}  // namespace arc