Gamepad API: add support for connection events

content/browser/gamepad/gamepad_service.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 "content/browser/gamepad/gamepad_service.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/singleton.h"
+#include "content/browser/gamepad/gamepad_consumer.h"
 #include "content/browser/gamepad/gamepad_data_fetcher.h"
 #include "content/browser/gamepad/gamepad_provider.h"
+#include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_process_host.h"
 
 namespace content {
 
-GamepadService::GamepadService() : num_readers_(0) {
+GamepadService::GamepadService() {
 }
 
 GamepadService::GamepadService(scoped_ptr<GamepadDataFetcher> fetcher)
-    : num_readers_(0),
-      provider_(new GamepadProvider(fetcher.Pass())) {
+    : provider_(new GamepadProvider(fetcher.Pass())) {
   thread_checker_.DetachFromThread();
 }
 
 GamepadService::~GamepadService() {
 }
 
 GamepadService* GamepadService::GetInstance() {
   return Singleton<GamepadService,
                    LeakySingletonTraits<GamepadService> >::get();
 }
 
-void GamepadService::AddConsumer() {
+void GamepadService::AddConsumer(GamepadConsumer* consumer) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
-  num_readers_++;
-  DCHECK(num_readers_ > 0);
+  DCHECK(consumers_.count(ConsumerInfo(consumer)) == 0);
+  consumers_.insert(ConsumerInfo(consumer));
   if (!provider_)
     provider_.reset(new GamepadProvider);
+  provider_->RegisterForUserGesture(
+      base::Bind(&GamepadService::OnUserGesture,
+                 base::Unretained(this)));
   provider_->Resume();
 }
 
-void GamepadService::RemoveConsumer() {
+void GamepadService::OnUserGesture() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
-  --num_readers_;
-  DCHECK(num_readers_ >= 0);
+  if (!provider_)
+    return;
 
-  if (num_readers_ == 0)
+  for (ConsumerSet::iterator it = consumers_.begin();
+       it != consumers_.end(); ++it) {
+    if (!it->did_observe_user_gesture) {
+      ConsumerInfo& info = const_cast<ConsumerInfo&>(*it);
+      info.did_observe_user_gesture = true;
+      blink::WebGamepads gamepads;
+      provider_->GetCurrentGamepadData(&gamepads);
+      for (unsigned i = 0; i < blink::WebGamepads::itemsLengthCap; ++i) {
+        const blink::WebGamepad& pad = gamepads.items[i];
+        if (pad.connected)
+          info.consumer->OnGamepadConnected(i, pad);
+      }
+    }
+  }
+}
+
+void GamepadService::RemoveConsumer(GamepadConsumer* consumer) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  DCHECK(consumers_.count(ConsumerInfo(consumer)) > 0);
+  consumers_.erase(ConsumerInfo(consumer));
+  if (consumers_.size() == 0)
     provider_->Pause();
 }
 
 void GamepadService::RegisterForUserGesture(const base::Closure& closure) {
-  DCHECK(num_readers_ > 0);
+  DCHECK(consumers_.size() > 0);
   DCHECK(thread_checker_.CalledOnValidThread());
   provider_->RegisterForUserGesture(closure);
 }
 
 void GamepadService::Terminate() {
   provider_.reset();
 }
 
+void GamepadService::OnGamepadConnected(
+    int index,
+    const blink::WebGamepad& pad) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  for (ConsumerSet::iterator it = consumers_.begin();
+       it != consumers_.end(); ++it) {
+    if (it->did_observe_user_gesture)
+      it->consumer->OnGamepadConnected(index, pad);
+  }
+}
+
+void GamepadService::OnGamepadDisconnected(
+    int index,
+    const blink::WebGamepad& pad) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  for (ConsumerSet::iterator it = consumers_.begin();
+       it != consumers_.end(); ++it) {
+    if (it->did_observe_user_gesture)
+      it->consumer->OnGamepadDisconnected(index, pad);
+  }
+}
+
 base::SharedMemoryHandle GamepadService::GetSharedMemoryHandleForProcess(
     base::ProcessHandle handle) {
   DCHECK(thread_checker_.CalledOnValidThread());
   return provider_->GetSharedMemoryHandleForProcess(handle);
 }
 
 }  // namespace content