Emulate Android joystick scroll with synthetic mouse wheel event

content/browser/android/joystick_scroll_provider.h

+// Copyright 2016 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_JOYSTICK_SCROLL_PROVIDER_H_
+#define CONTENT_BROWSER_ANDROID_JOYSTICK_SCROLL_PROVIDER_H_
+
+#include "base/android/jni_android.h"
+#include "base/android/jni_weak_ref.h"
+
+namespace content {
+
+class WebContentsImpl;
+
+class JoystickScrollProvider {
+ public:
+  JoystickScrollProvider(JNIEnv* env,
+                         const base::android::JavaRef<jobject>& obj,
+                         WebContentsImpl* web_contents);
+
+  ~JoystickScrollProvider();
+
+  void ScrollBy(JNIEnv* env,
+                const base::android::JavaParamRef<jobject>& obj,
+                jlong time_ms,
+                jfloat dx_dip,
+                jfloat dy_dip);
+
+ private:
+  class UserData;
+
+  // A weak reference to the Java JoystickScrollProvider object.
+  JavaObjectWeakGlobalRef java_ref_;
+
+  WebContentsImpl* web_contents_;
+
+  DISALLOW_COPY_AND_ASSIGN(JoystickScrollProvider);
+};
+
+bool RegisterJoystickScrollProvider(JNIEnv* env);
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_ANDROID_JOYSTICK_SCROLL_PROVIDER_H_