Gamepad API support for chrome on android

content/browser/android/gamepad_reader_impl.h

+/*
+ * Copyright (c) 2014, NVIDIA CORPORATION. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *  * Neither the name of NVIDIA CORPORATION nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef CONTENT_BROWSER_ANDROID_GAMEPAD_READER_H_
+#define CONTENT_BROWSER_ANDROID_GAMEPAD_READER_H_
+
+#include <jni.h>
+#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"
+
+namespace content {
+using std::string;
+// Interacts with JNI and calls GamepadList.
+// This class creates a GamepadsReader java object and pings GamepadList for
+// updates.
+// The simplified flow is:
+// GamepadDataFetcher runs on a Polling Thread and it tries to fetch data from
+// the framework for android platform.
+// GamepadPlatformDataFetcherAndroid access a singleton GamepadsReader
+// GamepadsReader calls via JNI and uses the singleton GamepadList
+// in the java side to get the updated gamepad state. We then bounce these
+// updates to the GamepadProvider which writes to GamepadHardwareBuffer.
+// GamepadHardwareBuffer structure is stored in shared memory that's shared
+// between a writer that does hardware polling, and the various consumers of
+// the gamepad.
+
+// Note that GamepadsReader is a singleton and there's at most only
+// one GamepadsReader that has called updateGamepadList().
+
+class GamepadsReader{

[scottmg, 2014/01/13 19:42:43]

There's a lot of code that doesn't follow the style guide in this patch
(spacing, indent, method case, comment format, etc). Did you see presubmit
warnings when uploading?

[SaurabhK, 2014/01/15 16:57:08]

WIll update in next patchset.

+public:
+
+    // Registers the JNI methods for GamepadsReader.
+    static bool RegisterGamepadsReader(JNIEnv* env);
+
+    // Returns our singleton.
+    static GamepadsReader* GetInstance();
+
+    // Methods called to update GamepadList for Gamepad access and release by
+    // navigator object.
+    void notifyForGamepadsAccess(bool);
+    // Methods called on the Polling thread.
+    int updateGamepadsCount();
+    bool isDeviceConnected(int);
+    std::string getDeviceName(int);
+    long getDeviceTimestamp(int);
+    std::vector<float> getDeviceAxes(int);
+    std::vector<float> getDeviceButtons(int);
+    bool isGamepadLayoutKnown(int);
+
+private:
+    friend struct DefaultSingletonTraits<GamepadsReader>;
+    GamepadsReader();
+    ~GamepadsReader();
+
+    void CreateJavaObject(JNIEnv* env);
+
+    base::android::ScopedJavaGlobalRef<jobject>
+            java_gamepadList_object_;
+};
+
+}  // namespace content
+#endif      // CONTENT_BROWSER_ANDROID_GAMEPAD_READER_H_