Gamepad API support for chrome on android

content/browser/android/gamepad_reader_impl.h

+// Copyright 2014 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.
+
+#ifndef CONTENT_BROWSER_ANDROID_GAMEPAD_READER_H_
+#define CONTENT_BROWSER_ANDROID_GAMEPAD_READER_H_
+
+#include <jni.h>
+#include <string>
+#include <vector>
+
+#include "base/android/jni_array.h"
+#include "base/android/jni_helper.h"
+#include "base/android/scoped_java_ref.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/singleton.h"
+#include "third_party/WebKit/public/platform/WebGamepads.h"
+
+namespace content {
+using std::string;
+// This class interacts with JNI and calls GamepadList. It creates a
+// GamepadsReader java object and pings GamepadList for updates.
+
+// The simplified flow is:
+// 1. GamepadDataFetcher runs on a Polling Thread and it tries to fetch data
+// via low-level data fetcher from the framework for android platform.
+// 2. GamepadPlatformDataFetcherAndroid access a singleton GamepadsReader
+// GamepadsReader makes JNI calls and uses singleton GamepadList on the java
+// side to get the updated gamepad state. We then bounce these updates to the
+// GamepadProvider which writes to GamepadHardwareBuffer.
+
+// Note that GamepadsReader is a singleton and there's at most only
+// one GamepadsReader that has made calls to GamepadList.
+
+class GamepadsReader {
+ public:
+  // Registers the JNI methods for GamepadsReader.
+  static bool RegisterGamepadsReader(JNIEnv* env);
+  // Returns our singleton.
+  static GamepadsReader* GetInstance();
+
+  // Native methods that are called from GamepadList.
+  void SetGamepadData(JNIEnv* env,
+                      jobject obj,
+                      int index,
+                      bool connected,
+                      jstring devicename,
+                      int64 timestamp,
+                      jfloatArray jaxes,
+                      jfloatArray jbuttons);
+
+  void UpdateDeviceCount(JNIEnv* env, jobject obj, int devicecount);
+
+  // Called on Polling thread.
+  void GetGamepadData(blink::WebGamepads* pads);
+
+  // Called to update GamepadList for Gamepad access and release by
+  // low level gamepad data fetcher.
+  void NotifyForGamepadsAccess(bool isaccesspaused);
+
+ private:
+  friend struct DefaultSingletonTraits<GamepadsReader>;
+  GamepadsReader();
+  ~GamepadsReader();
+
+  void CreateJavaObject(JNIEnv* env);
+
+  // Data to fetch into.
+  blink::WebGamepads* gamepads_data_;
+
+  base::android::ScopedJavaGlobalRef<jobject> java_gamepadList_object_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_ANDROID_GAMEPAD_READER_H_