chromeos: Add power supply info reading capability

chrome/browser/chromeos/dbus/power_manager_client.cc

 // Copyright (c) 2011 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/dbus/power_manager_client.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
+#include "base/format_macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/stringprintf.h"
+#include "base/time.h"
+#include "base/timer.h"
 #include "chrome/browser/chromeos/system/runtime_environment.h"
 #include "dbus/bus.h"
 #include "dbus/message.h"
 #include "dbus/object_proxy.h"
 #include "third_party/cros_system_api/dbus/service_constants.h"
 
 namespace chromeos {
 
+PowerSupplyStatus::PowerSupplyStatus()
+    : line_power_on(false),
+      battery_is_present(false),
+      battery_is_full(false),
+      battery_seconds_to_empty(0),
+      battery_seconds_to_full(0),
+      battery_percentage(0) {
+}
+
+const std::string& PowerSupplyStatus::ToString() const {
+  static std::string result = "";
+  base::StringAppendF(&result,
+                      "line_power_on = %s ",
+                      line_power_on ? "true" : "false");
+  base::StringAppendF(&result,
+                      "battery_is_present = %s ",
+                      battery_is_present ? "true" : "false");
+  base::StringAppendF(&result,
+                      "battery_is_full = %s ",
+                      battery_is_full ? "true" : "false");
+  base::StringAppendF(&result,
+                      "battery_percentage = %f ",
+                      battery_percentage);
+  base::StringAppendF(&result,
+                      "battery_seconds_to_empty = %"PRId64" ",
+                      battery_seconds_to_empty);
+  base::StringAppendF(&result,
+                      "battery_seconds_to_full = %"PRId64" ",
+                      battery_seconds_to_full);

[Nico, 2011/11/20 22:38:21]

This will append "line_power_on" to result every time this function runs, and
since result is static, the string will get longer and longer. Is that intended?
If not, the best fix is probably to make result not static and let the function
return by copy instead of by const reference.

[satorux1, 2011/11/21 17:28:05]

Good catch! I wasn't able to catch this. Simon, please create a patch to remove
'static', and change the return value type to std::string as Nico suggested.

+  return result;
+}
+
 // The PowerManagerClient implementation used in production.
 class PowerManagerClientImpl : public PowerManagerClient {
  public:
   explicit PowerManagerClientImpl(dbus::Bus* bus)
       : power_manager_proxy_(NULL),
         weak_ptr_factory_(this) {
     power_manager_proxy_ = bus->GetObjectProxy(
         power_manager::kPowerManagerServiceName,
         power_manager::kPowerManagerServicePath);
 
     // Monitor the D-Bus signal for brightness changes. Only the power
     // manager knows the actual brightness level. We don't cache the
     // brightness level in Chrome as it'll make things less reliable.
     power_manager_proxy_->ConnectToSignal(
         power_manager::kPowerManagerInterface,
         power_manager::kBrightnessChangedSignal,
         base::Bind(&PowerManagerClientImpl::BrightnessChangedReceived,
                    weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&PowerManagerClientImpl::BrightnessChangedConnected,
+        base::Bind(&PowerManagerClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+
+    // Monitor the D-Bus signal for power supply polling signals.
+    power_manager_proxy_->ConnectToSignal(
+        power_manager::kPowerManagerInterface,
+        power_manager::kPowerSupplyPollSignal,
+        base::Bind(&PowerManagerClientImpl::PowerSupplyPollReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&PowerManagerClientImpl::SignalConnected,
                    weak_ptr_factory_.GetWeakPtr()));
   }
 
   virtual ~PowerManagerClientImpl() {
   }
 
   // PowerManagerClient override.
   virtual void AddObserver(Observer* observer) {
     observers_.AddObserver(observer);
   }
@@ skipping 23 matching lines @@
     dbus::MethodCall method_call(
         power_manager::kPowerManagerInterface,
         power_manager::kIncreaseScreenBrightness);
     power_manager_proxy_->CallMethod(
         &method_call,
         dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
         base::Bind(&PowerManagerClientImpl::OnIncreaseScreenBrightness,
                    weak_ptr_factory_.GetWeakPtr()));
   }
 
+  virtual void RequestStatusUpdate() OVERRIDE {
+    // TODO(stevenjb): chromeos::RetrievePowerInformation has been deprecated;
+    // we should add a mechanism to immediately request an update, probably
+    // when we migrate the DBus code from libcros to here.
+  }
+
+ private:
+  // Called when a dbus signal is initially connected.
+  void SignalConnected(const std::string& interface_name,
+                       const std::string& signal_name,
+                       bool success) {
+    LOG_IF(WARNING, !success) << "Failed to connect to signal "
+                              << signal_name << ".";
+  }
+
   // Called when a brightness change signal is received.
   void BrightnessChangedReceived(dbus::Signal* signal) {
     dbus::MessageReader reader(signal);
     int32 brightness_level = 0;
     bool user_initiated = 0;
     if (!(reader.PopInt32(&brightness_level) &&
           reader.PopBool(&user_initiated))) {
       LOG(ERROR) << "Brightness changed signal had incorrect parameters: "
                  << signal->ToString();
       return;
     }
     VLOG(1) << "Brightness changed to " << brightness_level
             << ": user initiated " << user_initiated;
     FOR_EACH_OBSERVER(Observer, observers_,
                       BrightnessChanged(brightness_level, user_initiated));
   }
 
-  // Called when the brightness change signal is initially connected.
-  void BrightnessChangedConnected(const std::string& interface_name,
-                                  const std::string& signal_name,
-                                  bool success) {
-    LOG_IF(WARNING, !success)
-        << "Failed to connect to brightness changed signal.";
-  }
-
   // Called when a response for DecreaseScreenBrightness() is received.
   void OnDecreaseScreenBrightness(dbus::Response* response) {
     if (!response) {
       LOG(ERROR) << "Failed to decrease screen brightness";
       return;
     }
     VLOG(1) << "screen brightness increased: " << response->ToString();
   }
 
   // Called when a response for IncreaseScreenBrightness() is received.
   void OnIncreaseScreenBrightness(dbus::Response* response) {
     if (!response) {
       LOG(ERROR) << "Failed to increase screen brightness";
       return;
     }
     VLOG(1) << "screen brightness increased: " << response->ToString();
   }
 
+  // Called when a power supply polling signal is received.
+  void PowerSupplyPollReceived(dbus::Signal* signal) {
+    dbus::MessageReader reader(signal);
+    VLOG(1) << "Received power supply poll signal.";
+    GetPowerSupplyInfo();
+  }
+
+  // Gets the state of the power supply (line power and battery) from power
+  // manager.
+  void GetPowerSupplyInfo() {
+    dbus::MethodCall method_call(power_manager::kPowerManagerInterface,
+                                 power_manager::kGetAllPropertiesMethod);
+    power_manager_proxy_->CallMethod(
+        &method_call,
+        dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+        base::Bind(&PowerManagerClientImpl::OnGetAllPropertiesMethod,
+                   weak_ptr_factory_.GetWeakPtr()));
+  }
+
+  // Called when GetAllPropertiesMethod call is complete.
+  void OnGetAllPropertiesMethod(dbus::Response* response) {
+    if (!response) {
+      LOG(ERROR) << "Error calling " << power_manager::kGetAllPropertiesMethod;
+      return;
+    }
+    dbus::MessageReader reader(response);
+    PowerSupplyStatus status;
+    double unused_battery_voltage = 0.0;
+    double unused_battery_energy = 0.0;
+    double unused_battery_energy_rate = 0.0;
+    if (!reader.PopBool(&status.line_power_on) ||
+        !reader.PopDouble(&unused_battery_energy) ||
+        !reader.PopDouble(&unused_battery_energy_rate) ||
+        !reader.PopDouble(&unused_battery_voltage) ||
+        !reader.PopInt64(&status.battery_seconds_to_empty) ||
+        !reader.PopInt64(&status.battery_seconds_to_full) ||
+        !reader.PopDouble(&status.battery_percentage) ||
+        !reader.PopBool(&status.battery_is_present) ||
+        !reader.PopBool(&status.battery_is_full)) {
+      LOG(ERROR) << "Error reading response from powerd: "
+                 << response->ToString();
+      return;
+    }
+
+    VLOG(1) << "Power status: " << status.ToString();
+    FOR_EACH_OBSERVER(Observer, observers_, PowerChanged(status));
+  }
+
   dbus::ObjectProxy* power_manager_proxy_;
   ObserverList<Observer> observers_;
   base::WeakPtrFactory<PowerManagerClientImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PowerManagerClientImpl);
 };
 
 // The PowerManagerClient implementation used on Linux desktop,
 // which does nothing.
 class PowerManagerClientStubImpl : public PowerManagerClient {
+ public:
+  PowerManagerClientStubImpl()
+      : discharging_(true),
+        battery_percentage_(80),
+        pause_count_(0) {
+  }
+
+  virtual ~PowerManagerClientStubImpl() {}
+
   // PowerManagerClient override.
-  virtual void AddObserver(Observer* observer) {
+  virtual void AddObserver(Observer* observer) OVERRIDE {
+    observers_.AddObserver(observer);
   }
 
   // PowerManagerClient override.
-  virtual void RemoveObserver(Observer* observer) {
+  virtual void RemoveObserver(Observer* observer) OVERRIDE {
+    observers_.RemoveObserver(observer);
   }
 
   // PowerManagerClient override.
-  virtual void DecreaseScreenBrightness(bool allow_off) {
+  virtual void DecreaseScreenBrightness(bool allow_off) OVERRIDE {
     VLOG(1) << "Requested to descrease screen brightness";
   }
 
   // PowerManagerClient override.
-  virtual void IncreaseScreenBrightness() {
+  virtual void IncreaseScreenBrightness() OVERRIDE {
     VLOG(1) << "Requested to increase screen brightness";
   }
+
+  virtual void RequestStatusUpdate() OVERRIDE {
+    if (!timer_.IsRunning()) {
+      timer_.Start(
+          FROM_HERE,
+          base::TimeDelta::FromMilliseconds(100),
+          this,
+          &PowerManagerClientStubImpl::Update);
+    } else {
+      timer_.Stop();
+    }
+  }
+
+ private:
+  void Update() {
+    // We pause at 0 and 100% so that it's easier to check those conditions.
+    if (pause_count_ > 1) {
+      pause_count_--;
+      return;
+    }
+
+    if (battery_percentage_ == 0 || battery_percentage_ == 100) {
+      if (pause_count_) {
+        pause_count_ = 0;
+        discharging_ = !discharging_;
+      } else {
+        pause_count_ = 20;
+        return;
+      }
+    }
+    battery_percentage_ += (discharging_ ? -1 : 1);
+
+    PowerSupplyStatus status;
+    status.line_power_on = !discharging_;
+    status.battery_is_present = true;
+    status.battery_percentage = battery_percentage_;
+    status.battery_seconds_to_empty =
+        std::max(1, battery_percentage_ * 180 / 100);
+    status.battery_seconds_to_full =
+        std::max(static_cast<int64>(1), 180 - status.battery_seconds_to_empty);
+
+    FOR_EACH_OBSERVER(Observer, observers_, PowerChanged(status));
+  }
+
+  bool discharging_;
+  int battery_percentage_;
+  int pause_count_;
+  ObserverList<Observer> observers_;
+  base::RepeatingTimer<PowerManagerClientStubImpl> timer_;
 };
 
 PowerManagerClient::PowerManagerClient() {
 }
 
 PowerManagerClient::~PowerManagerClient() {
 }
 
 PowerManagerClient* PowerManagerClient::Create(dbus::Bus* bus) {
   if (system::runtime_environment::IsRunningOnChromeOS()) {
     return new PowerManagerClientImpl(bus);
   } else {
     return new PowerManagerClientStubImpl();
   }
 }
 
 }  // namespace chromeos