SyntheticGestureTarget implementation for injecting synthetic input events

content/browser/renderer_host/input/synthetic_gesture_target_android.cc

+// Copyright 2013 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 "content/browser/renderer_host/input/synthetic_gesture_target_android.h"
+
+#include "content/browser/android/content_view_core_impl.h"
+#include "jni/SyntheticTouchEvent_jni.h"
+#include "third_party/WebKit/public/web/WebInputEvent.h"
+
+using WebKit::WebTouchEvent;
+
+namespace {
+bool g_jni_initialized = false;

[aelias_OOO_until_Jul13, 2013/10/31 01:47:48]

This isn't the usual way to do this.  Could you add this to the list in
content/browser/android/browser_jni_registrar.cc instead?

[kouhei (in TOK), 2013/10/31 04:26:36]

Done.

+
+void RegisterNativesIfNeeded(JNIEnv* env) {
+  if (!g_jni_initialized) {
+    content::RegisterNativesImpl(env);
+    g_jni_initialized = true;
+  }
+}
+}  // namespace
+
+namespace content {
+
+SyntheticGestureTargetAndroid::SyntheticGestureTargetAndroid(
+    RenderWidgetHostViewAndroid* render_view,
+    base::android::ScopedJavaLocalRef<jobject> java_touch_event)
+    : SyntheticGestureTargetBase(render_view),
+      java_touch_event_(java_touch_event) {
+  CHECK(!java_touch_event_.is_null());

[aelias_OOO_until_Jul13, 2013/10/31 01:47:48]

I don't see a strong reason for a CHECK here, please use DCHECK.

[kouhei (in TOK), 2013/10/31 04:26:36]

Done.

+
+  JNIEnv* env = base::android::AttachCurrentThread();
+  RegisterNativesIfNeeded(env);
+}
+
+SyntheticGestureTargetAndroid::~SyntheticGestureTargetAndroid() {
+}
+
+void SyntheticGestureTargetAndroid::TouchSetPointer(
+    JNIEnv* env, int index, int x, int y, int id) {
+

[aelias_OOO_until_Jul13, 2013/10/31 01:47:48]

nit: extra newline

[kouhei (in TOK), 2013/10/31 04:26:36]

Done.

+  Java_SyntheticTouchEvent_setPointer(env, java_touch_event_.obj(),
+                                      index, x, y, id);
+}
+
+void SyntheticGestureTargetAndroid::TouchInject(
+    JNIEnv* env, Action action, int pointer_count) {
+  Java_SyntheticTouchEvent_inject(env, java_touch_event_.obj(),
+                                  static_cast<int>(action), pointer_count);
+}
+
+void SyntheticGestureTargetAndroid::QueueWebTouchEventToPlatform(
+    const WebKit::WebTouchEvent& web_touch, const ui::LatencyInfo&) {
+  JNIEnv* env = base::android::AttachCurrentThread();
+
+  SyntheticGestureTargetAndroid::Action action =
+      SyntheticGestureTargetAndroid::ActionInvalid;
+  switch (web_touch.type) {
+    case WebKit::WebInputEvent::TouchStart:
+      action = SyntheticGestureTargetAndroid::ActionStart;
+      break;
+    case WebKit::WebInputEvent::TouchMove:
+      action = SyntheticGestureTargetAndroid::ActionMove;
+      break;
+    case WebKit::WebInputEvent::TouchCancel:
+      action = SyntheticGestureTargetAndroid::ActionCancel;
+      break;
+    case WebKit::WebInputEvent::TouchEnd:
+      action = SyntheticGestureTargetAndroid::ActionEnd;
+      break;
+    default:
+      NOTREACHED();
+  }
+  const unsigned num_touches = web_touch.touchesLength;
+  for (unsigned i = 0; i < num_touches; ++i) {
+    const WebKit::WebTouchPoint* point = &web_touch.touches[i];
+    TouchSetPointer(env, i, point->position.x, point->position.y, point->id);
+  }
+
+  TouchInject(env, action, num_touches);
+}
+
+SyntheticGestureParams::GestureSourceType
+SyntheticGestureTargetAndroid::GetDefaultSyntheticGestureSourceType() const {
+  return SyntheticGestureParams::TOUCH_INPUT;
+}
+
+bool SyntheticGestureTargetAndroid::SupportsSyntheticGestureSourceType(
+    SyntheticGestureParams::GestureSourceType gesture_source_type) const {
+  return gesture_source_type == SyntheticGestureParams::TOUCH_INPUT;
+}
+
+}  // namespace content