Move low battery notification to Message Center.

ash/system/chromeos/power/battery_notification.cc

+// Copyright 2015 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 "ash/system/chromeos/power/battery_notification.h"
+
+#include "ash/system/chromeos/power/power_status.h"
+#include "ash/system/system_notifier.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/time/time.h"
+#include "grit/ash_resources.h"
+#include "grit/ash_strings.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/base/l10n/time_format.h"
+#include "ui/base/resource/resource_bundle.h"
+#include "ui/gfx/image/image.h"
+#include "ui/message_center/message_center.h"
+#include "ui/message_center/notification.h"
+
+using message_center::MessageCenter;
+using message_center::Notification;
+
+namespace ash {
+
+namespace {
+
+const char kBatteryNotificationId[] = "battery";
+
+gfx::Image& GetBatteryImage(TrayPower::NotificationState notification_state) {
+  int resource_id;
+  if (PowerStatus::Get()->IsUsbChargerConnected()) {
+    resource_id = IDR_AURA_NOTIFICATION_BATTERY_FLUCTUATING;

[Mr4D (OOO till 08-26), 2015/03/17 17:04:37]

?? What is this? The USB charger has not enough power?

[michaelpg, 2015/03/17 18:32:45]

When a USB charger is connected we assume it probably only supports a low
charging rate -- this is usually the case. We only show this notification if the
battery level is low or critical.

So we know you have a low battery, and we're not sure how long it will last or
whether you're likely to charge or discharge (or both depending on load). We
show the fluctuating icon added to this CL for that (which is a larger version
of a similar status area icon).

+  } else if (notification_state == TrayPower::NOTIFICATION_LOW_POWER) {
+    resource_id = IDR_AURA_NOTIFICATION_BATTERY_LOW;
+  } else if (notification_state == TrayPower::NOTIFICATION_CRITICAL) {
+    resource_id = IDR_AURA_NOTIFICATION_BATTERY_CRITICAL;
+  } else {
+    NOTREACHED();
+    resource_id = 0;
+  }
+
+  return ui::ResourceBundle::GetSharedInstance().GetImageNamed(resource_id);
+}
+
+scoped_ptr<Notification> CreateNotification(
+    TrayPower::NotificationState notification_state) {
+  const PowerStatus& status = *PowerStatus::Get();
+
+  base::string16 message = l10n_util::GetStringFUTF16(
+      IDS_ASH_STATUS_TRAY_BATTERY_PERCENT,
+      base::IntToString16(status.GetRoundedBatteryPercent()));
+
+  const base::TimeDelta time = status.IsBatteryCharging()
+                                   ? status.GetBatteryTimeToFull()
+                                   : status.GetBatteryTimeToEmpty();
+  base::string16 time_message;
+  if (status.IsUsbChargerConnected()) {

[Mr4D (OOO till 08-26), 2015/03/17 17:04:37]

Is the meaning of "IsUsbChargerConnected()" really more like
"IsLowPowerUsbChargerConnected"? If so - would it be possible to rename that?

[michaelpg, 2015/03/17 18:32:45]

No -- there's just a note in the comments that a USB charger is usually
low-power (but not always).

This is the same logic currently used for the system tray notification, it's
just being used for the notification here. This CL shouldn't result in
functional changes besides moving the notification.

[Mr4D (OOO till 08-26), 2015/03/17 22:25:04]

Okay. Somehow this is confusing however. Think about the Pixel2 for example. It
only charges through USB. So the name of the function is misleading. But okay -
we could possibly change it later.

[michaelpg, 2015/03/17 23:10:39]

derat@ is the person to talk to about this. Raiden ports are treated as
low-power USB unless they're connected to a USB-PD device like the Pixel
charger, then we consider that mains rather than USB charger (so the unreliable
charger notification doesn't show). But it's outside the scope of this CL.

+    time_message = l10n_util::GetStringUTF16(
+        IDS_ASH_STATUS_TRAY_BATTERY_CHARGING_UNRELIABLE);
+  } else if (PowerStatus::ShouldDisplayBatteryTime(time) &&
+             !status.IsBatteryDischargingOnLinePower()) {
+    int hour = 0, min = 0;
+    PowerStatus::SplitTimeIntoHoursAndMinutes(time, &hour, &min);
+    if (status.IsBatteryCharging()) {
+      time_message = l10n_util::GetStringFUTF16(
+          IDS_ASH_STATUS_TRAY_BATTERY_TIME_UNTIL_FULL,
+          base::IntToString16(hour), base::IntToString16(min));
+    } else {
+      // This is a low battery warning prompting the user in minutes.
+      time_message = ui::TimeFormat::Simple(
+          ui::TimeFormat::FORMAT_REMAINING, ui::TimeFormat::LENGTH_LONG,
+          base::TimeDelta::FromMinutes(hour * 60 + min));
+    }
+  }
+
+  if (!time_message.empty())
+    message = message + base::ASCIIToUTF16("\n") + time_message;
+
+  scoped_ptr<Notification> notification(new Notification(
+      message_center::NOTIFICATION_TYPE_SIMPLE, kBatteryNotificationId,
+      base::string16(), message, GetBatteryImage(notification_state),
+      base::string16(),
+      message_center::NotifierId(message_center::NotifierId::SYSTEM_COMPONENT,
+                                 system_notifier::kNotifierBattery),
+      message_center::RichNotificationData(), NULL));
+  notification->SetSystemPriority();
+  return notification;
+}
+
+}  // namespace
+
+BatteryNotification::BatteryNotification(MessageCenter* message_center)
+    : message_center_(message_center) {
+}
+
+void BatteryNotification::Show(
+    TrayPower::NotificationState notification_state) {
+  // Should only be called when the state changes, so ensure any older
+  // notifications are dismissed. Otherwise we might update a "low battery"
+  // notification to "critical" without it being shown again.
+  if (message_center_->FindVisibleNotificationById(kBatteryNotificationId)) {

[Mr4D (OOO till 08-26), 2015/03/17 17:04:37]

Don't need {}

[michaelpg, 2015/03/17 18:32:45]

Will do.

[michaelpg, 2015/03/17 23:10:39]

Done.

+    message_center_->RemoveNotification(kBatteryNotificationId, false);
+  }
+  message_center_->AddNotification(
+      CreateNotification(notification_state).Pass());
+}
+
+void BatteryNotification::Hide() {
+  message_center_->RemoveNotification(kBatteryNotificationId, false);
+}
+
+void BatteryNotification::Update(
+    TrayPower::NotificationState notification_state) {
+  if (message_center_->FindVisibleNotificationById(kBatteryNotificationId)) {
+    message_center_->UpdateNotification(
+        kBatteryNotificationId, CreateNotification(notification_state).Pass());
+  }
+}
+
+}  // namespace ash