SyntheticGestureTarget implementation for injecting synthetic input events

content/browser/renderer_host/input/synthetic_gesture_target_base.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_base.h"
+
+#include "content/browser/renderer_host/render_widget_host_impl.h"
+#include "content/browser/renderer_host/ui_events_helper.h"
+#include "content/common/input/input_event.h"
+#include "content/public/browser/render_widget_host_view.h"
+#include "ui/events/event.h"
+#include "ui/events/latency_info.h"
+
+using WebKit::WebInputEvent;
+using WebKit::WebTouchEvent;
+using WebKit::WebMouseWheelEvent;
+
+namespace content {
+
+namespace {
+
+// How many milliseconds apart synthetic scroll messages should be sent.
+const int kSyntheticGestureMessageIntervalMs = 7;

[Dominik Grewe, 2013/10/28 10:12:00]

I think we should change this to 16, so we're roughly sending one event per
frame. I remember having problems on Android with this value (the current
implementations on Android completely bypasses this mechanims).

Also, rename the constant so it's more in line with the method name
GetSyntheticGestureUpdateRate().

[kouhei (in TOK), 2013/10/29 03:30:43]

Done.

+
+}  // namespace
+
+SyntheticGestureTargetBase::SyntheticGestureTargetBase(
+    RenderWidgetHostView* render_view)
+    : render_view_(render_view) {
+}
+
+void SyntheticGestureTargetBase::QueueInputEventToPlatform(
+    const InputEvent& event) {
+  const WebInputEvent* web_event = event.web_event.get();
+  if (WebInputEvent::isTouchEventType(web_event->type)) {
+    DCHECK(SupportsSyntheticGestureSourceType(
+            SyntheticGestureParams::TOUCH_INPUT));
+
+    const WebTouchEvent* web_touch =
+        static_cast<const WebTouchEvent*>(web_event);
+    QueueWebTouchEventToPlatform(*web_touch, event.latency_info);
+  } else if (web_event->type == WebInputEvent::MouseWheel) {
+    DCHECK(SupportsSyntheticGestureSourceType(
+            SyntheticGestureParams::MOUSE_INPUT));
+
+    const WebMouseWheelEvent* web_wheel =
+        static_cast<const WebMouseWheelEvent*>(web_event);
+    QueueWebMouseWheelEventToPlatform(*web_wheel, event.latency_info);

[Dominik Grewe, 2013/10/28 10:12:00]

MOUSE_INPUT isn't necessarily a WebMouseWheelEvent, it could also be a
WebMouseEvent.

[kouhei (in TOK), 2013/10/29 03:30:43]

Done.

+  }
+    NOTREACHED();
+}
+
+void SyntheticGestureTargetBase::QueueWebTouchEventToPlatform(
+      const WebKit::WebTouchEvent& web_touch,
+      const ui::LatencyInfo& latency_info) {
+  RenderWidgetHostImpl* host = RenderWidgetHostImpl::From(
+      render_view_->GetRenderWidgetHost());
+  host->ForwardTouchEventWithLatencyInfo(web_touch, latency_info);
+}
+
+void SyntheticGestureTargetBase::QueueWebMouseWheelEventToPlatform(
+      const WebKit::WebMouseWheelEvent& web_wheel,
+      const ui::LatencyInfo& latency_info) {
+  RenderWidgetHostImpl* host = RenderWidgetHostImpl::From(
+      render_view_->GetRenderWidgetHost());
+  host->ForwardWheelEventWithLatencyInfo(
+      MouseWheelEventWithLatencyInfo(web_wheel, latency_info));
+}
+
+void SyntheticGestureTargetBase::OnSyntheticGestureCompleted(
+    SyntheticGestureNew::Result result) {
+}
+
+base::TimeDelta
+SyntheticGestureTargetBase::GetSyntheticGestureUpdateRate() const {
+  return base::TimeDelta::FromMilliseconds(kSyntheticGestureMessageIntervalMs);
+}
+
+SyntheticGestureParams::GestureSourceType
+SyntheticGestureTargetBase::GetDefaultSyntheticGestureSourceType() const {
+  return SyntheticGestureParams::MOUSE_INPUT;
+}
+
+bool SyntheticGestureTargetBase::SupportsSyntheticGestureSourceType(
+    SyntheticGestureParams::GestureSourceType gesture_source_type) const {
+  return gesture_source_type == SyntheticGestureParams::MOUSE_INPUT;

[Dominik Grewe, 2013/10/28 10:12:00]

Base also supports touch.

[kouhei (in TOK), 2013/10/29 03:30:43]

Done.

+}
+
+}  // namespace content