Post notification after fetching articles

chrome/browser/android/ntp/content_suggestions_notifier_service.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 "chrome/browser/android/ntp/content_suggestions_notifier_service.h"
+
+#include <algorithm>
+
+#include "base/memory/ptr_util.h"
+#include "chrome/browser/android/ntp/content_suggestions_notification_helper.h"
+#include "chrome/browser/notifications/notification.h"
+#include "chrome/browser/notifications/notification_handler.h"
+#include "chrome/browser/profiles/profile.h"
+#include "components/ntp_snippets/content_suggestions_service.h"
+#include "components/pref_registry/pref_registry_syncable.h"
+#include "components/prefs/pref_service.h"
+#include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/image/image_skia.h"
+#include "ui/gfx/image/image_skia_operations.h"
+
+using ntp_snippets::Category;
+using ntp_snippets::CategoryStatus;
+using ntp_snippets::ContentSuggestion;
+using ntp_snippets::ContentSuggestionsNotificationHelper;
+using ntp_snippets::ContentSuggestionsService;
+using ntp_snippets::KnownCategories;
+
+namespace {
+
+const char kNotificationIDWithinCategory[] =
+    "ContentSuggestionsNotificationIDWithinCategory";
+
+gfx::Image CropSquare(const gfx::Image& image) {
+  if (image.IsEmpty()) {
+    return image;
+  }
+  const gfx::ImageSkia* skimage = image.ToImageSkia();
+  gfx::Rect bounds{{0, 0}, skimage->size()};
+  int size = std::min(bounds.width(), bounds.height());
+  bounds.ClampToCenteredSize({size, size});
+  return gfx::Image(gfx::ImageSkiaOperations::CreateTiledImage(
+      *skimage, bounds.x(), bounds.y(), bounds.width(), bounds.height()));
+}
+
+}  // namespace
+
+class ContentSuggestionsNotifierService::NotifyingObserver
+    : public ContentSuggestionsService::Observer {
+ public:
+  NotifyingObserver(ContentSuggestionsService* service,
+                    Profile* profile,
+                    PrefService* prefs)
+      : service_(service), prefs_(prefs), weak_ptr_factory_(this) {}
+
+  void OnNewSuggestions(Category category) override {
+    if (!category.IsKnownCategory(KnownCategories::ARTICLES)) {
+      return;
+    }
+    const auto& suggestions = service_->GetSuggestionsForCategory(category);
+    if (!suggestions.empty()) {
+      const auto& suggestion = suggestions[0];
+      service_->FetchSuggestionImage(
+          suggestions[0].id(),
+          base::Bind(&NotifyingObserver::ImageFetched,
+                     weak_ptr_factory_.GetWeakPtr(), suggestion.id(),
+                     suggestion.url(), suggestion.title(),
+                     suggestion.publisher_name()));
+    }
+  }
+
+  void OnCategoryStatusChanged(Category category,
+                               CategoryStatus new_status) override {
+    if (!category.IsKnownCategory(KnownCategories::ARTICLES)) {
+      return;
+    }
+    switch (new_status) {
+      case CategoryStatus::AVAILABLE:
+      case CategoryStatus::AVAILABLE_LOADING:
+        break;  // nothing to do
+      case CategoryStatus::INITIALIZING:
+      case CategoryStatus::ALL_SUGGESTIONS_EXPLICITLY_DISABLED:
+      case CategoryStatus::CATEGORY_EXPLICITLY_DISABLED:
+      case CategoryStatus::LOADING_ERROR:
+      case CategoryStatus::NOT_PROVIDED:
+      case CategoryStatus::SIGNED_OUT:
+        ContentSuggestionsNotificationHelper::HideNotification();
+        break;
+    }
+  }
+
+  void OnSuggestionInvalidated(
+      const ContentSuggestion::ID& suggestion_id) override {
+    if (suggestion_id.category().IsKnownCategory(KnownCategories::ARTICLES) &&
+        (suggestion_id.id_within_category() ==
+         prefs_->GetString(kNotificationIDWithinCategory))) {
+      ContentSuggestionsNotificationHelper::HideNotification();
+    }
+  }
+
+  void OnFullRefreshRequired() override {
+    ContentSuggestionsNotificationHelper::HideNotification();
+  }
+
+  void ContentSuggestionsServiceShutdown() override {
+    ContentSuggestionsNotificationHelper::HideNotification();
+  }
+
+ private:
+  void ImageFetched(const ContentSuggestion::ID& id,
+                    const GURL& url,
+                    const base::string16& title,
+                    const base::string16& publisher,
+                    const gfx::Image& image) {
+    // check if suggestion is still valid.
+    DVLOG(1) << "Fetched " << image.Size().width() << "x"
+             << image.Size().height() << " image for " << url.spec();
+    prefs_->SetString(kNotificationIDWithinCategory, id.id_within_category());
+    ContentSuggestionsNotificationHelper::SendNotification(
+        url, title, publisher, CropSquare(image));
+  }
+
+  ContentSuggestionsService* const service_;
+  PrefService* const prefs_;
+
+  base::WeakPtrFactory<NotifyingObserver> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(NotifyingObserver);
+};
+
+ContentSuggestionsNotifierService::ContentSuggestionsNotifierService(
+    Profile* profile,
+    ContentSuggestionsService* suggestions,
+    PrefService* prefs)
+    : observer_(base::MakeUnique<NotifyingObserver>(suggestions,
+                                                    profile,
+                                                    profile->GetPrefs())) {
+  suggestions->AddObserver(observer_.get());
+}
+
+ContentSuggestionsNotifierService::~ContentSuggestionsNotifierService() =
+    default;
+
+void ContentSuggestionsNotifierService::RegisterProfilePrefs(
+    user_prefs::PrefRegistrySyncable* registry) {
+  registry->RegisterStringPref(kNotificationIDWithinCategory, "");

[Bernhard Bauer, 2017/01/03 17:38:59]

Nit: use an empty std::string() constructor to save some instructions.

[sfiera, 2017/01/03 23:13:55]

Done.

+}