Implement the gamepad API in the IPC proxy

content/browser/gamepad/gamepad_provider.cc

 // Copyright (c) 2012 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 <cmath>
 #include <set>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
+#include "base/message_loop_proxy.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_restrictions.h"
-#include "content/browser/gamepad/data_fetcher.h"
+#include "content/browser/gamepad/gamepad_data_fetcher.h"
 #include "content/browser/gamepad/gamepad_provider.h"
-#include "content/browser/gamepad/platform_data_fetcher.h"
+#include "content/browser/gamepad/gamepad_platform_data_fetcher.h"
 #include "content/common/gamepad_hardware_buffer.h"
 #include "content/common/gamepad_messages.h"
+#include "content/common/gamepad_user_gesture.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace content {
 
 GamepadProvider::GamepadProvider()
     : is_paused_(true),
       have_scheduled_do_poll_(false),
       devices_changed_(true) {
-  size_t data_size = sizeof(GamepadHardwareBuffer);
-  base::SystemMonitor* monitor = base::SystemMonitor::Get();
-  if (monitor)
-    monitor->AddDevicesChangedObserver(this);
-  bool res = gamepad_shared_memory_.CreateAndMapAnonymous(data_size);
-  CHECK(res);
-  GamepadHardwareBuffer* hwbuf = SharedMemoryAsHardwareBuffer();
-  memset(hwbuf, 0, sizeof(GamepadHardwareBuffer));
-
-  polling_thread_.reset(new base::Thread("Gamepad polling thread"));
-  polling_thread_->StartWithOptions(
-      base::Thread::Options(MessageLoop::TYPE_IO, 0));
+  Initialize(scoped_ptr<GamepadDataFetcher>());
 }
 
-void GamepadProvider::SetDataFetcher(GamepadDataFetcher* fetcher) {
-  MessageLoop* polling_loop = polling_thread_->message_loop();
-  polling_loop->PostTask(
-      FROM_HERE,
-      base::Bind(&GamepadProvider::DoInitializePollingThread,
-                 Unretained(this),
-                 fetcher));
+GamepadProvider::GamepadProvider(scoped_ptr<GamepadDataFetcher> fetcher)
+    : is_paused_(true),
+      have_scheduled_do_poll_(false),
+      devices_changed_(true) {
+  Initialize(fetcher.Pass());
 }
 
 GamepadProvider::~GamepadProvider() {
   base::SystemMonitor* monitor = base::SystemMonitor::Get();
   if (monitor)
     monitor->RemoveDevicesChangedObserver(this);
 
   polling_thread_.reset();
   data_fetcher_.reset();
 }
 
-base::SharedMemoryHandle GamepadProvider::GetRendererSharedMemoryHandle(
+base::SharedMemoryHandle GamepadProvider::GetSharedMemoryHandleForProcess(
     base::ProcessHandle process) {
   base::SharedMemoryHandle renderer_handle;
   gamepad_shared_memory_.ShareToProcess(process, &renderer_handle);
   return renderer_handle;
 }
 
 void GamepadProvider::Pause() {
   {
     base::AutoLock lock(is_paused_lock_);
     is_paused_ = true;
@@ skipping 14 matching lines @@
 
   MessageLoop* polling_loop = polling_thread_->message_loop();
   polling_loop->PostTask(
       FROM_HERE,
       base::Bind(&GamepadProvider::SendPauseHint, Unretained(this), false));
   polling_loop->PostTask(
       FROM_HERE,
       base::Bind(&GamepadProvider::ScheduleDoPoll, Unretained(this)));
 }
 
+void GamepadProvider::RegisterForUserGesture(const base::Closure& closure) {

[raymes, 2012/09/05 23:37:13]

This must be called from the IO thread, right? Should we add a dcheck here?

[raymes, 2012/09/06 04:07:53]

Nevermind I see this is protected and can be called from any thread.

+  base::AutoLock lock(user_gesture_lock_);
+  ClosureAndThread closure_and_thread;
+  closure_and_thread.closure = closure;
+  closure_and_thread.message_loop =
+      MessageLoop::current()->message_loop_proxy();
+  user_gesture_observers_.push_back(closure_and_thread);
+}
+
 void GamepadProvider::OnDevicesChanged(base::SystemMonitor::DeviceType type) {
   base::AutoLock lock(devices_changed_lock_);
   devices_changed_ = true;
 }
 
-void GamepadProvider::DoInitializePollingThread(GamepadDataFetcher* fetcher) {
+void GamepadProvider::Initialize(scoped_ptr<GamepadDataFetcher> fetcher) {
+  size_t data_size = sizeof(GamepadHardwareBuffer);
+  base::SystemMonitor* monitor = base::SystemMonitor::Get();
+  if (monitor)
+    monitor->AddDevicesChangedObserver(this);
+  bool res = gamepad_shared_memory_.CreateAndMapAnonymous(data_size);
+  CHECK(res);
+  GamepadHardwareBuffer* hwbuf = SharedMemoryAsHardwareBuffer();
+  memset(hwbuf, 0, sizeof(GamepadHardwareBuffer));
+
+  polling_thread_.reset(new base::Thread("Gamepad polling thread"));
+  polling_thread_->StartWithOptions(
+      base::Thread::Options(MessageLoop::TYPE_IO, 0));
+
+  polling_thread_->message_loop()->PostTask(
+      FROM_HERE,
+      base::Bind(&GamepadProvider::DoInitializePollingThread,
+                 base::Unretained(this),
+                 base::Passed(&fetcher)));
+}
+
+void GamepadProvider::DoInitializePollingThread(
+    scoped_ptr<GamepadDataFetcher> fetcher) {
   DCHECK(MessageLoop::current() == polling_thread_->message_loop());
+  DCHECK(!data_fetcher_.get());  // Should only initialize once.
 
-  if (data_fetcher_ != NULL) {
-    // Already initialized.
-    return;
-  }
-
-  if (fetcher == NULL)
-    fetcher = new GamepadPlatformDataFetcher;
-
-  // Pass ownership of fetcher to provider_.
-  data_fetcher_.reset(fetcher);
+  if (!fetcher.get())
+    fetcher.reset(new GamepadPlatformDataFetcher);
+  data_fetcher_ = fetcher.Pass();
 }
 
 void GamepadProvider::SendPauseHint(bool paused) {
   DCHECK(MessageLoop::current() == polling_thread_->message_loop());
   if (data_fetcher_.get())
     data_fetcher_->PauseHint(paused);
 }
 
 void GamepadProvider::DoPoll() {
   DCHECK(MessageLoop::current() == polling_thread_->message_loop());
@@ skipping 13 matching lines @@
     changed = devices_changed_;
     devices_changed_ = false;
   }
 
   // Acquire the SeqLock. There is only ever one writer to this data.
   // See gamepad_hardware_buffer.h.
   hwbuf->sequence.WriteBegin();
   data_fetcher_->GetGamepadData(&hwbuf->buffer, changed);
   hwbuf->sequence.WriteEnd();
 
+  CheckForUserGesture();
+
   // Schedule our next interval of polling.
   ScheduleDoPoll();
 }
 
 void GamepadProvider::ScheduleDoPoll() {
   DCHECK(MessageLoop::current() == polling_thread_->message_loop());
   if (have_scheduled_do_poll_)
     return;
 
   {
     base::AutoLock lock(is_paused_lock_);
     if (is_paused_)
       return;
   }
 
   MessageLoop::current()->PostDelayedTask(
       FROM_HERE,
       base::Bind(&GamepadProvider::DoPoll, Unretained(this)),
       base::TimeDelta::FromMilliseconds(kDesiredSamplingIntervalMs));
   have_scheduled_do_poll_ = true;
 }
 
 GamepadHardwareBuffer* GamepadProvider::SharedMemoryAsHardwareBuffer() {
   void* mem = gamepad_shared_memory_.memory();
   CHECK(mem);
   return static_cast<GamepadHardwareBuffer*>(mem);
 }
 
+void GamepadProvider::CheckForUserGesture() {
+  base::AutoLock lock(user_gesture_lock_);
+  if (user_gesture_observers_.empty())
+    return;  // Don't need to check if nobody is listening.
+
+  if (GamepadsHaveUserGesture(SharedMemoryAsHardwareBuffer()->buffer)) {
+    for (size_t i = 0; i < user_gesture_observers_.size(); i++) {
+      user_gesture_observers_[i].message_loop->PostTask(FROM_HERE,
+          user_gesture_observers_[i].closure);
+    }
+    user_gesture_observers_.clear();
+  }
+}
+
 }  // namespace content