Add EventForwarder for routing touch events

ui/android/event_handler.h

+// Copyright 2017 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 UI_ANDROID_EVENT_HANDLER_H_
+#define UI_ANDROID_EVENT_HANDLER_H_
+
+#include <jni.h>
+
+#include "base/android/scoped_java_ref.h"
+#include "ui/android/ui_android_export.h"
+
+namespace ui {
+
+class ViewAndroid;
+
+class UI_ANDROID_EXPORT EventHandler {
+ public:
+  EventHandler();

[Khushal, 2017/03/02 21:46:15]

Not used?

[Jinsuk Kim, 2017/03/03 06:29:21]

Removed.

+  base::android::ScopedJavaLocalRef<jobject> CreateJavaObject();

[Khushal, 2017/03/02 21:46:15]

Should this class cache the java object instead of creating a new one each time?
May be this should be called GetJavaObject instead? This way we should be able
to clean up the native pointer from the java object in the dtor as well.

[Jinsuk Kim, 2017/03/03 06:29:21]

Done.

+
+  static EventHandler* Create(ViewAndroid* view);

[Khushal, 2017/03/02 21:46:15]

nit: Do we need this Create method? We don't do any requisite initializations
there. Can the ctor just be public?

And if returning a raw ptr, please do mention that the ownership is passed to
the caller.

[boliu, 2017/03/02 22:02:16]

should return unique_ptr for passing ownership

[Khushal, 2017/03/02 22:08:59]

Agreed. That was just a general comment if for some reason you do end up
returning a raw ptr and expect the caller to take ownership. In this case we
should have the ctor be public.

[Jinsuk Kim, 2017/03/03 06:29:21]

Turned the ctor public. ViewAndroid is the owner and keeps a unique_ptr to it.

[Jinsuk Kim, 2017/03/03 06:29:21]

Removed the method.

[Jinsuk Kim, 2017/03/03 06:29:21]

Acknowledged.

+
+  jboolean OnTouchEvent(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj,
+      const base::android::JavaParamRef<jobject>& motion_event,
+      jlong time_ms,
+      jint android_action,
+      jint pointer_count,
+      jint history_size,
+      jint action_index,
+      jfloat pos_x_0,
+      jfloat pos_y_0,
+      jfloat pos_x_1,
+      jfloat pos_y_1,
+      jint pointer_id_0,
+      jint pointer_id_1,
+      jfloat touch_major_0,
+      jfloat touch_major_1,
+      jfloat touch_minor_0,
+      jfloat touch_minor_1,
+      jfloat orientation_0,
+      jfloat orientation_1,
+      jfloat tilt_0,
+      jfloat tilt_1,
+      jfloat raw_pos_x,
+      jfloat raw_pos_y,
+      jint android_tool_type_0,
+      jint android_tool_type_1,
+      jint android_button_state,
+      jint android_meta_state,
+      jboolean is_touch_handle_event);
+
+  void OnMouseEvent(JNIEnv* env,
+                    const base::android::JavaParamRef<jobject>& obj,
+                    jlong time_ms,
+                    jint android_action,
+                    jfloat x,
+                    jfloat y,
+                    jint pointer_id,
+                    jfloat pressure,
+                    jfloat orientation,
+                    jfloat tilt,
+                    jint android_changed_button,
+                    jint android_button_state,
+                    jint android_meta_state,
+                    jint tool_type);
+
+ private:
+  explicit EventHandler(ViewAndroid* view);
+
+  ViewAndroid* const view_;
+
+  DISALLOW_COPY_AND_ASSIGN(EventHandler);
+};
+
+bool RegisterEventHandler(JNIEnv* env);
+
+}  // namespace ui
+
+#endif  // UI_ANDROID_EVENT_HANDLER_H_