SyntheticGestureTarget implementation for injecting synthetic input events

content/browser/renderer_host/input/touch_scroll_smooth_gesture.cc

+// Copyright (c) 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/touch_scroll_smooth_gesture.h"
+#include "content/browser/renderer_host/render_widget_host_impl.h"
+#include "content/common/input/input_event.h"
+#include "content/port/browser/render_widget_host_view_port.h"
+
+#include "third_party/WebKit/public/web/WebInputEvent.h"
+
+namespace content {
+
+TouchSmoothScrollGesture::TouchSmoothScrollGesture(bool scroll_down,
+                                                   int pixels_to_scroll,
+                                                   int mouse_event_x,
+                                                   int mouse_event_y)
+    : scroll_down_(scroll_down),
+      pixels_to_scroll_(pixels_to_scroll),
+      pixels_scrolled_(0),
+      mouse_event_x_(mouse_event_x),
+      mouse_event_y_(mouse_event_y) {
+}
+
+TouchSmoothScrollGesture::~TouchSmoothScrollGesture() {}
+
+namespace {
+
+void InjectTouchEvent(
+    RenderWidgetHostViewPort* view,
+    WebKit::WebInputEvent::Type type,
+    WebKit::WebTouchPoint::State state,
+    int x, int y) {
+  WebKit::WebTouchEvent touch_event;
+  touch_event.type = type;
+  touch_event.touchesLength = 1;
+  touch_event.touches[0].id = 1;
+  touch_event.touches[0].state = state;
+  // screenPosition is unused for RWHV::QueueInputEventToPlatform
+  touch_event.touches[0].screenPosition.x = 0;
+  touch_event.touches[0].screenPosition.y = 0;
+  touch_event.touches[0].position.x = x;
+  touch_event.touches[0].position.y = y;
+  touch_event.touches[0].radiusX = 1;
+  touch_event.touches[0].radiusY = 1;
+  touch_event.touches[0].rotationAngle = 1.0f;
+  touch_event.touches[0].force = 1.0f;
+
+  InputEvent input_event(touch_event, ui::LatencyInfo(), false);
+  view->QueueInputEventToPlatform(input_event);
+}
+
+}  // namespace
+
+bool TouchSmoothScrollGesture::ForwardInputEvents(
+    base::TimeTicks now,
+    RenderWidgetHost* host) {
+  if (pixels_scrolled_ >= pixels_to_scroll_)
+    return false;
+
+  RenderWidgetHostImpl* host_impl = RenderWidgetHostImpl::From(host);
+  float position_delta = synthetic_gesture_calculator_.GetDelta(now,
+      host_impl->GetSyntheticGestureMessageInterval());
+
+  // Note: we will be able to get this directly in the new I/F
+  RenderWidgetHostViewPort* view =
+      RenderWidgetHostViewPort::FromRWHV(host->GetView());
+  if (!view)
+    return false;
+
+  if (pixels_scrolled_ == 0) {
+    InjectTouchEvent(view,
+                     WebKit::WebInputEvent::TouchStart,
+                     WebKit::WebTouchPoint::StatePressed,
+                     mouse_event_x_, mouse_event_y_);
+  }
+
+  mouse_event_y_ += scroll_down_ ? -position_delta : position_delta;
+
+  InjectTouchEvent(view,
+                   WebKit::WebInputEvent::TouchMove,
+                   WebKit::WebTouchPoint::StateMoved,
+                   mouse_event_x_, mouse_event_y_);
+
+  pixels_scrolled_ += abs(position_delta);
+
+  if (pixels_scrolled_ >= pixels_to_scroll_) {
+    InjectTouchEvent(view,
+                     WebKit::WebInputEvent::TouchEnd,
+                     WebKit::WebTouchPoint::StateReleased,
+                     mouse_event_x_, mouse_event_y_);
+  }
+
+  return true;
+}
+
+}  // namespace content