Add EventForwarder for routing touch events

ui/android/event_forwarder.cc

Index: ui/android/event_forwarder.cc
diff --git a/ui/android/event_forwarder.cc b/ui/android/event_forwarder.cc
new file mode 100644
index 0000000000000000000000000000000000000000..361ce3421da39c8b3686c5eafd5373450bf3a102
--- /dev/null
+++ b/ui/android/event_forwarder.cc
@@ -0,0 +1,112 @@
+// 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.
+
+#include "ui/android/event_forwarder.h"
+
+#include "jni/EventForwarder_jni.h"
+#include "ui/android/view_android.h"
+#include "ui/android/view_client.h"
+#include "ui/events/android/motion_event_android.h"
+
+namespace ui {
+
+using base::android::JavaParamRef;
+using base::android::ScopedJavaLocalRef;
+
+EventForwarder::EventForwarder(ViewAndroid* view) : view_(view) {}
+
+EventForwarder::~EventForwarder() {
+  if (!java_obj_.is_null()) {
+    Java_EventForwarder_destroy(base::android::AttachCurrentThread(),
+                                java_obj_);
+    java_obj_.Reset();
+  }
+}
+
+ScopedJavaLocalRef<jobject> EventForwarder::GetJavaObject() {
+  if (java_obj_.is_null()) {
+    java_obj_.Reset(
+        Java_EventForwarder_create(base::android::AttachCurrentThread(),
+                                   reinterpret_cast<intptr_t>(this)));
+  }
+  return ScopedJavaLocalRef<jobject>(java_obj_);
+}
+
+jboolean EventForwarder::OnTouchEvent(JNIEnv* env,
+                                      const JavaParamRef<jobject>& obj,
+                                      const 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) {
+  ui::MotionEventAndroid::Pointer pointer0(
+      pointer_id_0, pos_x_0, pos_y_0, touch_major_0, touch_minor_0,
+      orientation_0, tilt_0, android_tool_type_0);
+  ui::MotionEventAndroid::Pointer pointer1(
+      pointer_id_1, pos_x_1, pos_y_1, touch_major_1, touch_minor_1,
+      orientation_1, tilt_1, android_tool_type_1);
+  ui::MotionEventAndroid event(
+      1.f / view_->GetDipScale(), env, motion_event.obj(), time_ms,
+      android_action, pointer_count, history_size, action_index,
+      0 /* action_button */, android_button_state, android_meta_state,
+      raw_pos_x - pos_x_0, raw_pos_y - pos_y_0, &pointer0, &pointer1);
+  return view_->OnTouchEvent(event, is_touch_handle_event);
+}
+
+void EventForwarder::OnMouseEvent(JNIEnv* env,
+                                  const JavaParamRef<jobject>& obj,
+                                  jlong time_ms,
+                                  jint android_action,
+                                  jfloat x,
+                                  jfloat y,
+                                  jint pointer_id,
+                                  jfloat orientation,
+                                  jfloat pressure,
+                                  jfloat tilt,
+                                  jint android_action_button,
+                                  jint android_button_state,
+                                  jint android_meta_state,
+                                  jint android_tool_type) {
+  // Construct a motion_event object minimally, only to convert the raw
+  // parameters to ui::MotionEvent values. Since we used only the cached values
+  // at index=0, it is okay to even pass a null event to the constructor.
+  ui::MotionEventAndroid::Pointer pointer(
+      pointer_id, x, y, 0.0f /* touch_major */, 0.0f /* touch_minor */,
+      orientation, tilt, android_tool_type);
+  ui::MotionEventAndroid event(
+      1.f / view_->GetDipScale(), env, nullptr /* event */, time_ms,
+      android_action, 1 /* pointer_count */, 0 /* history_size */,
+      0 /* action_index */, android_action_button, android_button_state,
+      android_meta_state, 0 /* raw_offset_x_pixels */,
+      0 /* raw_offset_y_pixels */, &pointer, nullptr);
+  view_->OnMouseEvent(event);
+}
+
+bool RegisterEventForwarder(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+}  // namespace ui