src/content/browser/battery_status/battery_status_message_filter.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/browser/battery_status/battery_status_message_filter.h"
   6
   7 #include "content/common/battery_status_messages.h"
   8
   9 namespace content {
  10
  11 BatteryStatusMessageFilter::BatteryStatusMessageFilter()
  12     : BrowserMessageFilter(BatteryStatusMsgStart),
  13       is_started_(false) {
  14   callback_ = base::Bind(&BatteryStatusMessageFilter::SendBatteryChange,
  15                          base::Unretained(this));
  16 }
  17
  18 BatteryStatusMessageFilter::~BatteryStatusMessageFilter() {
  19   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  20   if (is_started_)
  21     subscription_.reset();
  22 }
  23
  24 bool BatteryStatusMessageFilter::OnMessageReceived(
  25     const IPC::Message& message) {
  26   bool handled = true;
  27   IPC_BEGIN_MESSAGE_MAP(BatteryStatusMessageFilter, message)
  28     IPC_MESSAGE_HANDLER(BatteryStatusHostMsg_Start, OnBatteryStatusStart)
  29     IPC_MESSAGE_HANDLER(BatteryStatusHostMsg_Stop, OnBatteryStatusStop)
  30     IPC_MESSAGE_UNHANDLED(handled = false)
  31   IPC_END_MESSAGE_MAP()
  32   return handled;
  33 }
  34
  35 void BatteryStatusMessageFilter::OnBatteryStatusStart() {
  36   DCHECK(!is_started_);
  37   if (is_started_)
  38     return;
  39   is_started_ = true;
  40   subscription_ = BatteryStatusService::GetInstance()->AddCallback(callback_);
  41 }
  42
  43 void BatteryStatusMessageFilter::OnBatteryStatusStop() {
  44   DCHECK(is_started_);
  45   if (!is_started_)
  46     return;
  47   is_started_ = false;
  48   subscription_.reset();
  49 }
  50
  51 void BatteryStatusMessageFilter::SendBatteryChange(
  52     const blink::WebBatteryStatus& status) {
  53   Send(new BatteryStatusMsg_DidChange(status));
  54 }
  55
  56 }  // namespace content