Bug 811261 - Implement WakeLockListener on Linux to disable screensaver while video is playing r=karl

widget/gtk/Makefile.in

@@ -11,3 +11,6 @@ CXXFLAGS        += $(MOZ_CAIRO_CFLAGS) $(MOZ_STARTUP_NOTIFICATION_CFLAGS)
 CFLAGS          += $(TK_CFLAGS)
 CXXFLAGS        += $(TK_CFLAGS)
 
+ifdef MOZ_ENABLE_DBUS
+CXXFLAGS        += $(MOZ_DBUS_GLIB_CFLAGS)
+endif

widget/gtk/WakeLockListener.cpp

@@ -0,0 +1,365 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:expandtab:shiftwidth=2:tabstop=2:
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <dbus/dbus.h>
+#include <dbus/dbus-glib-lowlevel.h>
+
+#include "WakeLockListener.h"
+
+#ifdef MOZ_ENABLE_DBUS
+
+#define FREEDESKTOP_SCREENSAVER_TARGET    "org.freedesktop.ScreenSaver"
+#define FREEDESKTOP_SCREENSAVER_OBJECT    "/ScreenSaver"
+#define FREEDESKTOP_SCREENSAVER_INTERFACE "org.freedesktop.ScreenSaver"
+
+#define SESSION_MANAGER_TARGET            "org.gnome.SessionManager"
+#define SESSION_MANAGER_OBJECT            "/org/gnome/SessionManager"
+#define SESSION_MANAGER_INTERFACE         "org.gnome.SessionManager"
+
+#define DBUS_TIMEOUT                      (-1)
+
+using namespace mozilla;
+
+NS_IMPL_ISUPPORTS(WakeLockListener, nsIDOMMozWakeLockListener)
+
+WakeLockListener* WakeLockListener::sSingleton = nullptr;
+
+
+enum DesktopEnvironment {
+  FreeDesktop,
+  GNOME,
+  Unsupported,
+};
+
+class WakeLockTopic
+{
+public:
+  WakeLockTopic(const nsAString& aTopic, DBusConnection* aConnection)
+    : mTopic(NS_ConvertUTF16toUTF8(aTopic))
+    , mConnection(aConnection)
+    , mDesktopEnvironment(FreeDesktop)
+    , mInhibitRequest(0)
+    , mShouldInhibit(false)
+    , mWaitingForReply(false)
+  {
+  }
+
+  nsresult InhibitScreensaver(void);
+  nsresult UninhibitScreensaver(void);
+
+private:
+  bool SendInhibit();
+  bool SendUninhibit();
+
+  bool SendFreeDesktopInhibitMessage();
+  bool SendGNOMEInhibitMessage();
+  bool SendMessage(DBusMessage* aMessage);
+
+  static void ReceiveInhibitReply(DBusPendingCall* aPending, void* aUserData);
+  void InhibitFailed();
+  void InhibitSucceeded(uint32_t aInhibitRequest);
+
+  nsAutoCString mTopic;
+  DBusConnection* mConnection;
+
+  DesktopEnvironment mDesktopEnvironment;
+
+  uint32_t mInhibitRequest;
+
+  bool mShouldInhibit;
+  bool mWaitingForReply;
+};
+
+
+bool
+WakeLockTopic::SendMessage(DBusMessage* aMessage)
+{
+  // send message and get a handle for a reply
+  DBusPendingCall* reply;
+  dbus_connection_send_with_reply(mConnection, aMessage, &reply,
+                                  DBUS_TIMEOUT);
+  dbus_message_unref(aMessage);
+
+  if (!reply) {
+    return false;
+  }
+
+  dbus_pending_call_set_notify(reply, &ReceiveInhibitReply, this, NULL);
+  dbus_pending_call_unref(reply);
+
+  return true;
+}
+
+bool
+WakeLockTopic::SendFreeDesktopInhibitMessage()
+{
+  DBusMessage* message =
+    dbus_message_new_method_call(FREEDESKTOP_SCREENSAVER_TARGET,
+                                 FREEDESKTOP_SCREENSAVER_OBJECT,
+                                 FREEDESKTOP_SCREENSAVER_INTERFACE,
+                                 "Inhibit");
+
+  if (!message) {
+    return false;
+  }
+
+  const char* app = g_get_prgname();
+  const char* topic = mTopic.get();
+  dbus_message_append_args(message,
+                           DBUS_TYPE_STRING, &app,
+                           DBUS_TYPE_STRING, &topic,
+                           DBUS_TYPE_INVALID);
+
+  return SendMessage(message);
+}
+
+bool
+WakeLockTopic::SendGNOMEInhibitMessage()
+{
+  DBusMessage* message =
+    dbus_message_new_method_call(SESSION_MANAGER_TARGET,
+                                 SESSION_MANAGER_OBJECT,
+                                 SESSION_MANAGER_INTERFACE,
+                                 "Inhibit");
+
+  if (!message) {
+    return false;
+  }
+
+  static const uint32_t xid = 0;
+  static const uint32_t flags = (1 << 3); // Inhibit idle
+  const char* app = g_get_prgname();
+  const char* topic = mTopic.get();
+  dbus_message_append_args(message,
+                           DBUS_TYPE_STRING, &app,
+                           DBUS_TYPE_UINT32, &xid,
+                           DBUS_TYPE_STRING, &topic,
+                           DBUS_TYPE_UINT32, &flags,
+                           DBUS_TYPE_INVALID);
+
+  return SendMessage(message);
+}
+
+
+bool
+WakeLockTopic::SendInhibit()
+{
+  bool sendOk = false;
+
+  switch (mDesktopEnvironment)
+  {
+  case FreeDesktop:
+    sendOk = SendFreeDesktopInhibitMessage();
+    break;
+  case GNOME:
+    sendOk = SendGNOMEInhibitMessage();
+    break;
+  case Unsupported:
+    return false;
+  }
+
+  if (sendOk) {
+    mWaitingForReply = true;
+  }
+
+  return sendOk;
+}
+
+bool
+WakeLockTopic::SendUninhibit()
+{
+  DBusMessage* message = nullptr;
+
+  if (mDesktopEnvironment == FreeDesktop) {
+    message =
+      dbus_message_new_method_call(FREEDESKTOP_SCREENSAVER_TARGET,
+                                   FREEDESKTOP_SCREENSAVER_OBJECT,
+                                   FREEDESKTOP_SCREENSAVER_INTERFACE,
+                                   "UnInhibit");
+  } else if (mDesktopEnvironment == GNOME) {
+    message =
+      dbus_message_new_method_call(SESSION_MANAGER_TARGET,
+                                   SESSION_MANAGER_OBJECT,
+                                   SESSION_MANAGER_INTERFACE,
+                                   "Uninhibit");
+  }
+
+  if (!message) {
+    return false;
+  }
+
+  dbus_message_append_args(message,
+                           DBUS_TYPE_UINT32, &mInhibitRequest,
+                           DBUS_TYPE_INVALID);
+
+  dbus_connection_send(mConnection, message, nullptr);
+  dbus_connection_flush(mConnection);
+  dbus_message_unref(message);
+
+  mInhibitRequest = 0;
+
+  return true;
+}
+
+nsresult
+WakeLockTopic::InhibitScreensaver()
+{
+  NS_ASSERTION(!mShouldInhibit, "Screensaver is already inhibited");
+  mShouldInhibit = true;
+
+  if (mWaitingForReply) {
+    // We already have a screensaver inhibit request pending. This can happen
+    // if InhibitScreensaver is called, then UninhibitScreensaver, then
+    // InhibitScreensaver again quickly.
+    return NS_OK;
+  }
+
+  return SendInhibit() ? NS_OK : NS_ERROR_FAILURE;
+}
+
+nsresult
+WakeLockTopic::UninhibitScreensaver()
+{
+  if (!mShouldInhibit) {
+    // Screensaver isn't inhibited. Nothing to do here.
+    return NS_OK;
+  }
+
+  mShouldInhibit = false;
+
+  if (mWaitingForReply) {
+    // If we're still waiting for a response to our inhibit request, we can't
+    // do anything until we get a dbus message back. The callbacks below will
+    // check |mShouldInhibit| and act accordingly.
+    return NS_OK;
+  }
+
+  return SendUninhibit() ? NS_OK : NS_ERROR_FAILURE;
+}
+
+void
+WakeLockTopic::InhibitFailed()
+{
+  mWaitingForReply = false;
+
+  if (mDesktopEnvironment == FreeDesktop) {
+    mDesktopEnvironment = GNOME;
+  } else {
+    NS_ASSERTION(mDesktopEnvironment == GNOME, "Unknown desktop environment");
+    mDesktopEnvironment = Unsupported;
+    mShouldInhibit = false;
+  }
+
+  if (!mShouldInhibit) {
+    // We were interrupted by UninhibitScreensaver() before we could find the
+    // correct desktop environment.
+    return;
+  }
+
+  SendInhibit();
+}
+
+void
+WakeLockTopic::InhibitSucceeded(uint32_t aInhibitRequest)
+{
+  mWaitingForReply = false;
+  mInhibitRequest = aInhibitRequest;
+
+  if (!mShouldInhibit) {
+    // We successfully inhibited the screensaver, but UninhibitScreensaver()
+    // was called while we were waiting for a reply.
+    SendUninhibit();
+  }
+}
+
+/* static */ void
+WakeLockTopic::ReceiveInhibitReply(DBusPendingCall* pending, void* user_data)
+{
+  if (!WakeLockListener::GetSingleton(false)) {
+    // The WakeLockListener (and therefore our topic) was deleted while we were
+    // waiting for a reply.
+    return;
+  }
+
+  WakeLockTopic* self = static_cast<WakeLockTopic*>(user_data);
+
+  DBusMessage* msg = dbus_pending_call_steal_reply(pending);
+  if (!msg) {
+    return;
+  }
+
+  if (dbus_message_get_type(msg) == DBUS_MESSAGE_TYPE_METHOD_RETURN) {
+    uint32_t inhibitRequest;
+
+    if (dbus_message_get_args(msg, nullptr, DBUS_TYPE_UINT32,
+                              &inhibitRequest, DBUS_TYPE_INVALID)) {
+      self->InhibitSucceeded(inhibitRequest);
+    }
+  } else {
+    self->InhibitFailed();
+  }
+
+  dbus_message_unref(msg);
+}
+
+
+WakeLockListener::WakeLockListener()
+  : mConnection(dbus_bus_get(DBUS_BUS_SESSION, nullptr))
+{
+  if (mConnection) {
+    dbus_connection_set_exit_on_disconnect(mConnection, false);
+    dbus_connection_setup_with_g_main(mConnection, nullptr);
+  }
+}
+
+WakeLockListener::~WakeLockListener()
+{
+  if (mConnection) {
+    dbus_connection_unref(mConnection);
+  }
+}
+
+/* static */ WakeLockListener*
+WakeLockListener::GetSingleton(bool aCreate)
+{
+  if (!sSingleton && aCreate) {
+    sSingleton = new WakeLockListener();
+    sSingleton->AddRef();
+  }
+
+  return sSingleton;
+}
+
+/* static */ void
+WakeLockListener::Shutdown()
+{
+  sSingleton->Release();
+  sSingleton = nullptr;
+}
+
+nsresult
+WakeLockListener::Callback(const nsAString& topic, const nsAString& state)
+{
+  if (!mConnection) {
+    return NS_ERROR_FAILURE;
+  }
+
+  WakeLockTopic* topicLock = mTopics.Get(topic);
+  if (!topicLock) {
+    topicLock = new WakeLockTopic(topic, mConnection);
+    mTopics.Put(topic, topicLock);
+  }
+
+  // Treat "locked-background" the same as "unlocked" on desktop linux.
+  bool shouldLock = state.EqualsLiteral("locked-foreground");
+
+  return shouldLock ?
+    topicLock->InhibitScreensaver() :
+    topicLock->UninhibitScreensaver();
+}
+
+#endif

widget/gtk/WakeLockListener.h

@@ -0,0 +1,47 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:expandtab:shiftwidth=2:tabstop=2:
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <unistd.h>
+
+#ifndef __WakeLockListener_h__
+#define __WakeLockListener_h__
+
+#include "nsHashKeys.h"
+#include "nsClassHashtable.h"
+
+#include "nsIDOMWakeLockListener.h"
+
+struct DBusConnection;
+class WakeLockTopic;
+
+/**
+ * Receives WakeLock events and simply passes it on to the right WakeLockTopic
+ * to inhibit the screensaver.
+ */
+class WakeLockListener MOZ_FINAL : public nsIDOMMozWakeLockListener
+{
+public:
+  NS_DECL_ISUPPORTS;
+
+  static WakeLockListener* GetSingleton(bool aCreate = true);
+  static void Shutdown();
+
+  nsresult Callback(const nsAString& topic, const nsAString& state);
+
+private:
+  WakeLockListener();
+  ~WakeLockListener();
+
+  static WakeLockListener* sSingleton;
+
+  DBusConnection* mConnection;
+  // Map of topic names to |WakeLockTopic|s.
+  // We assume a small, finite-sized set of topics.
+  nsClassHashtable<nsStringHashKey, WakeLockTopic> mTopics;
+};
+
+#endif // __WakeLockListener_h__

widget/gtk/moz.build

@@ -29,6 +29,7 @@ UNIFIED_SOURCES += [
     'nsScreenManagerGtk.cpp',
     'nsSound.cpp',
     'nsToolkit.cpp',
+    'WakeLockListener.cpp',
     'WidgetTraceEvent.cpp',
 ]
 

widget/gtk/nsAppShell.cpp

@@ -17,6 +17,10 @@
 #include "mozilla/HangMonitor.h"
 #include "mozilla/unused.h"
 #include "GeckoProfiler.h"
+#include "nsIPowerManagerService.h"
+#ifdef MOZ_ENABLE_DBUS
+#include "WakeLockListener.h"
+#endif
 
 using mozilla::unused;
 
@@ -82,6 +86,17 @@ nsAppShell::Init()
         gWidgetDrawLog = PR_NewLogModule("WidgetDraw");
 #endif
 
+#ifdef MOZ_ENABLE_DBUS
+    nsCOMPtr<nsIPowerManagerService> powerManagerService =
+      do_GetService(POWERMANAGERSERVICE_CONTRACTID);
+
+    if (powerManagerService) {
+        powerManagerService->AddWakeLockListener(WakeLockListener::GetSingleton());
+    } else {
+        NS_WARNING("Failed to retrieve PowerManagerService, wakelocks will be broken!");
+    }
+#endif
+
     if (!sPollFunc) {
         sPollFunc = g_main_context_get_poll_func(nullptr);
         g_main_context_set_poll_func(nullptr, &PollWrapper);

widget/gtk/nsWidgetFactory.cpp

@@ -26,6 +26,7 @@
 #include "nsBidiKeyboard.h"
 #include "nsScreenManagerGtk.h"
 #include "nsGTKToolkit.h"
+#include "WakeLockListener.h"
 
 #ifdef NS_PRINTING
 #include "nsPrintOptionsGTK.h"
@@ -280,6 +281,9 @@ nsWidgetGtk2ModuleDtor()
   nsWindow::ReleaseGlobals();
   nsGTKToolkit::Shutdown();
   nsAppShellShutdown();
+#ifdef MOZ_ENABLE_DBUS
+  WakeLockListener::Shutdown();
+#endif
 }
 
 static const mozilla::Module kWidgetModule = {