Show notifications on low disk space.

chrome/browser/chromeos/ui/low_disk_notification.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/chromeos/ui/low_disk_notification.h"
+
+#include <stdint.h>
+
+#include "ash/common/system/system_notifier.h"
+#include "base/bind.h"
+#include "base/macros.h"
+#include "base/strings/utf_string_conversions.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/profiles/profile_manager.h"
+#include "chrome/browser/ui/chrome_pages.h"
+#include "chrome/grit/generated_resources.h"
+#include "chromeos/dbus/cryptohome_client.h"
+#include "chromeos/dbus/dbus_thread_manager.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/base/resource/resource_bundle.h"
+#include "ui/chromeos/resources/grit/ui_chromeos_resources.h"
+#include "ui/message_center/message_center.h"
+#include "ui/message_center/notification.h"
+#include "ui/message_center/notification_types.h"
+#include "ui/message_center/notifier_settings.h"
+
+namespace {

[satorux1, 2016/06/27 07:46:39]

nit: add a blank line?

[dspaid1, 2016/06/28 00:39:05]

Done.

+const char kLowDiskId[] = "low_disk";
+const char kStoragePage[] = "storage";
+const uint64_t kNotificationThreshold = 1 << 30;          // 1GB
+const uint64_t kNotificationSevereThreshold = 512 << 20;  // 512MB
+constexpr base::TimeDelta kNotificationInterval =
+    base::TimeDelta::FromMinutes(2);
+
+class LowDiskNotificationDelegate
+    : public message_center::NotificationDelegate {
+ public:
+  LowDiskNotificationDelegate() {}
+
+  // message_center::NotificationDelegate
+  void ButtonClick(int button_index) override {
+    chrome::ShowSettingsSubPageForProfile(
+        ProfileManager::GetActiveUserProfile(), kStoragePage);
+  }
+
+ private:
+  ~LowDiskNotificationDelegate() override {}

[yoshiki, 2016/06/27 08:14:02]

nit: please add DISALLOW_COPY_AND_ASSIGN(LowDiskNotificationDelegate);

[dspaid1, 2016/06/28 00:39:06]

Done.

+};
+
+}  // namespace
+
+namespace chromeos {
+
+LowDiskNotification::LowDiskNotification()
+    : message_center_(g_browser_process->message_center()),
+      notification_interval_(kNotificationInterval),
+      weak_ptr_factory_(this) {
+  DCHECK(DBusThreadManager::Get()->GetCryptohomeClient());
+  DBusThreadManager::Get()->GetCryptohomeClient()->SetLowDiskSpaceHandler(
+      base::Bind(&LowDiskNotification::OnLowDiskSpace,
+                 weak_ptr_factory_.GetWeakPtr()));
+}
+
+LowDiskNotification::~LowDiskNotification() {
+  DCHECK(DBusThreadManager::Get()->GetCryptohomeClient());
+  DBusThreadManager::Get()->GetCryptohomeClient()->ResetLowDiskSpaceHandler();
+}
+
+void LowDiskNotification::OnLowDiskSpace(uint64_t free_disk_bytes) {

[yoshiki, 2016/06/27 08:14:02]

I don't know much about DBusThreadManager, but is that this callback method
called on the UI thread? Notification methods must be called on the UI thread.
Please double-check.

Adding the following check might help.
DCHECK_CURRENTLY_ON(BrowserThread::UI);

[dspaid1, 2016/06/28 00:39:06]

As far as I can tell based on comments this should be on the UI thread (and
things seem to be working without warnings/errors, so I assume that is the
case).  I've added the DCHECK to be safe.

+  LOG(ERROR) << "LowDiskNotification received";
+  Severity severity = GetSeverity(free_disk_bytes);
+  base::Time now = base::Time::Now();
+  if (severity != last_notification_severity_ ||
+      now - last_notification_time_ > notification_interval_) {
+    message_center_->AddNotification(CreateNotification(severity));
+    last_notification_time_ = now;
+    last_notification_severity_ = severity;
+  }
+}
+
+std::unique_ptr<message_center::Notification>
+LowDiskNotification::CreateNotification(Severity severity) {
+  base::string16 title;
+  base::string16 message;
+  gfx::Image icon;
+  switch (severity) {
+    case HIGH:
+      title =
+          l10n_util::GetStringUTF16(IDS_CRITICALLY_LOW_DISK_NOTIFICATION_TITLE);
+      message = l10n_util::GetStringUTF16(
+          IDS_CRITICALLY_LOW_DISK_NOTIFICATION_MESSAGE);
+      icon = gfx::Image(ui::ResourceBundle::GetSharedInstance().GetImageNamed(
+          IDR_DISK_SPACE_NOTIFICATION_CRITICAL));
+      break;
+    default:
+      title = l10n_util::GetStringUTF16(IDS_LOW_DISK_NOTIFICATION_TITLE);
+      message = l10n_util::GetStringUTF16(IDS_LOW_DISK_NOTIFICATION_MESSAGE);
+      icon = gfx::Image(ui::ResourceBundle::GetSharedInstance().GetImageNamed(
+          IDR_DISK_SPACE_NOTIFICATION_LOW));
+  }
+
+  message_center::ButtonInfo storage_settings(
+      l10n_util::GetStringUTF16(IDS_LOW_DISK_NOTIFICATION_BUTTON));
+  storage_settings.icon = ui::ResourceBundle::GetSharedInstance().GetImageNamed(
+      IDR_STORAGE_MANAGER_BUTTON);
+  message_center::RichNotificationData optional_fields;
+  optional_fields.buttons.push_back(storage_settings);
+
+  message_center::NotifierId notifier_id(
+      message_center::NotifierId::SYSTEM_COMPONENT,
+      ash::system_notifier::kNotifierDisk);
+
+  std::unique_ptr<message_center::Notification> notification(
+      new message_center::Notification(
+          message_center::NOTIFICATION_TYPE_SIMPLE, kLowDiskId, title, message,
+          icon, base::string16(), GURL(), notifier_id, optional_fields,
+          new LowDiskNotificationDelegate()));
+  notification->set_pinned(true);

[yoshiki, 2016/06/27 08:14:02]

If you use pinned notification, you need to add the code removing the
notification. This is because user can't remove a pinned notification from the
message center manually. (sorry for lack of my explanation)

You need do either of:
- Add the code removing the notification when disk gets enough space
- Make the notification non-pinned

[dspaid1, 2016/06/28 00:39:05]

Since we don't have an easy way to determine when there is enough space I've
opted for making it non-pinned.

+
+  return notification;
+}
+
+LowDiskNotification::Severity LowDiskNotification::GetSeverity(
+    uint64_t free_disk_bytes) {
+  if (free_disk_bytes < kNotificationSevereThreshold)
+    return Severity::HIGH;
+  if (free_disk_bytes < kNotificationThreshold)
+    return Severity::MEDIUM;
+  return Severity::NONE;
+}
+
+void LowDiskNotification::SetMessageCenterForTest(
+    message_center::MessageCenter* message_center) {
+  message_center_ = message_center;
+}
+
+void LowDiskNotification::SetNotificationIntervalForTest(
+    base::TimeDelta notification_interval) {
+  notification_interval_ = notification_interval;
+}
+
+}  // namespace chromeos