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 "base/android/scoped_java_ref.h"
+#include "ui/android/ui_android_export.h"
+
+namespace ui {
+
+class ViewAndroid;
+
+class UI_ANDROID_EXPORT EventHandler {

[boliu, 2017/03/03 22:01:32]

I think now that the native side EventHandler is no longer "public" part of ui/,
can remove this export?

[Jinsuk Kim, 2017/03/06 04:07:33]

Done.

+ public:
+  explicit EventHandler(ViewAndroid* view);
+  ~EventHandler();
+
+  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:
+  base::android::ScopedJavaLocalRef<jobject> GetJavaObject();
+
+  ViewAndroid* const view_;
+  base::android::ScopedJavaGlobalRef<jobject> java_obj_;
+
+  friend class ViewAndroid;

[boliu, 2017/03/03 22:01:31]

nit: move friend line right below "private:"

[Khushal, 2017/03/03 23:36:07]

I think you need the other way around. ViewAndroid needs to add EventHandler as
a friend to expose the OnTouch methods.

And now that we are going with really limiting the access to this class for
anyone, might as well make the ctor for this private. VA is the only one that
can construct an EventHandler for itself.

[Jinsuk Kim, 2017/03/06 04:07:34]

Done.

[Jinsuk Kim, 2017/03/06 04:07:34]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(EventHandler);
+};
+
+bool RegisterEventHandler(JNIEnv* env);
+
+}  // namespace ui
+
+#endif  // UI_ANDROID_EVENT_HANDLER_H_