Move fling implementation from renderer to browser:

content/browser/renderer_host/input/fling/flinger.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/fling/flinger.h"
+
+namespace content {
+
+const float kFrameRate = 60;
+
+Flinger::Flinger(FlingHelper* helper)
+    : helper_(helper),
+      fling_in_progress_(false),
+      ignore_next_tap_(false),
+      ignore_next_click_(false),
+      fling_start_time_secs_(0),
+      fling_source_(blink::WebGestureEvent::Touchscreen) {}
+
+bool Flinger::HandleGestureEvent(
+    const GestureEventWithLatencyInfo& gesture_event) {
+  switch (gesture_event.event.type) {
+    case blink::WebInputEvent::GestureTap:
+      if (ignore_next_tap_) {
+        ignore_next_tap_ = false;
+        return true;
+      }
+      break;
+    case blink::WebInputEvent::GestureFlingStart:
+      // Ignore zero velocity fling starts
+      if (gesture_event.event.data.flingStart.velocityX == 0 &&
+          gesture_event.event.data.flingStart.velocityY == 0)
+        return true;
+      fling_modifier_ = gesture_event.event.modifiers;
+      fling_start_position_ = gfx::Point(gesture_event.event.x,
+                                         gesture_event.event.y);
+      fling_start_global_position_ = gfx::Point(gesture_event.event.globalX,
+                                                gesture_event.event.globalY);
+      fling_start_time_secs_ = (base::TimeTicks::Now() -
+          base::TimeTicks()).InSecondsF();
+      fling_source_ = gesture_event.event.sourceDevice;
+      fling_curve_.reset(FlingCurve::Create(
+          gesture_event.event.sourceDevice,
+          gfx::PointF(gesture_event.event.data.flingStart.velocityX,
+                      gesture_event.event.data.flingStart.velocityY),
+          gfx::Point()));
+      fling_in_progress_ = true;
+      // TODO(varunjain): Use vsync instead of this timer.
+      StartCurveTimer();
+      return true;
+    case blink::WebInputEvent::GestureShowPress:
+    case blink::WebInputEvent::GestureTapDown:
+      return ignore_next_tap_;
+    case blink::WebInputEvent::GestureFlingCancel:
+      ignore_next_tap_ = false;
+      ignore_next_click_ = false;
+      if (fling_in_progress_) {
+        if (gesture_event.event.sourceDevice ==
+            blink::WebGestureEvent::Touchscreen)
+          ignore_next_tap_ = true;
+        else
+          ignore_next_click_ = true;
+      }
+      StopFlingAndCleanup();
+      return true;
+    default:
+      ignore_next_tap_ = false;
+      break;
+  }
+  return false;
+}
+
+bool Flinger::HandleMouseEvent(const MouseEventWithLatencyInfo& mouse_event) {
+  switch (mouse_event.event.type) {
+    case blink::WebInputEvent::MouseDown:
+    case blink::WebInputEvent::MouseUp:
+      return ignore_next_click_;
+    default:
+      StopFlingAndCleanup();
+      ignore_next_click_ = false;
+      break;
+  }
+  return false;
+}
+
+bool Flinger::HandleWheelEvent(
+    const MouseWheelEventWithLatencyInfo& wheel_event) {
+  StopFlingAndCleanup();
+  return false;
+}
+
+bool Flinger::HandleKeyboardEvent() {
+  StopFlingAndCleanup();
+  return false;
+}
+
+void Flinger::ProcessEventAck(blink::WebInputEvent::Type type,
+                              InputEventAckState ack_result,
+                              const ui::LatencyInfo& latency) {
+  if (!fling_in_progress_)
+    return;
+
+  if ((type == blink::WebInputEvent::GestureScrollUpdate ||
+      type == blink::WebInputEvent::MouseWheel) &&
+      ack_result == content::INPUT_EVENT_ACK_STATE_NOT_CONSUMED)
+    StopFlingAndCleanup();
+}
+
+void Flinger::ScrollBy(const gfx::PointF& delta) {
+  if (fling_source_ == blink::WebGestureEvent::Touchpad) {
+    blink::WebMouseWheelEvent synthetic_wheel;
+    const float tick_divisor = 120;
+    synthetic_wheel.type = blink::WebInputEvent::MouseWheel;
+    synthetic_wheel.deltaX = delta.x();
+    synthetic_wheel.deltaY = delta.y();
+    synthetic_wheel.wheelTicksX = delta.x() / tick_divisor;
+    synthetic_wheel.wheelTicksY = delta.y() / tick_divisor;
+    synthetic_wheel.hasPreciseScrollingDeltas = true;
+    synthetic_wheel.x = fling_start_position_.x();
+    synthetic_wheel.y = fling_start_position_.y();
+    synthetic_wheel.globalX = fling_start_global_position_.x();
+    synthetic_wheel.globalY = fling_start_global_position_.y();
+    synthetic_wheel.modifiers = fling_modifier_;
+    helper_->SendEventForFling(synthetic_wheel);
+  } else {
+    blink::WebGestureEvent synthetic_gesture;
+    synthetic_gesture.type = blink::WebInputEvent::GestureScrollUpdate;
+    synthetic_gesture.data.scrollUpdate.deltaX = delta.x();
+    synthetic_gesture.data.scrollUpdate.deltaY = delta.y();
+    synthetic_gesture.x = fling_start_position_.x();
+    synthetic_gesture.y = fling_start_position_.y();
+    synthetic_gesture.globalX = fling_start_global_position_.x();
+    synthetic_gesture.globalY = fling_start_global_position_.y();
+    synthetic_gesture.modifiers = fling_modifier_;
+    synthetic_gesture.sourceDevice = blink::WebGestureEvent::Touchscreen;
+    helper_->SendEventForFling(synthetic_gesture);
+  }
+}
+
+void Flinger::NotifyCurrentFlingVelocity(const gfx::PointF& velocity) {
+}
+
+void Flinger::StartCurveTimer() {
+  if (curve_timer_.IsRunning())
+    curve_timer_.Stop();
+  // TODO(varunjain): Use vsync instead of this timer.
+  curve_timer_.Start(FROM_HERE,
+                     base::TimeDelta::FromMilliseconds(1000.0 / kFrameRate),
+                     this,
+                     &Flinger::CurveTimerFired);
+}
+
+void Flinger::CurveTimerFired() {
+  if (!fling_in_progress_)
+    return;
+  double now = (base::TimeTicks::Now() - base::TimeTicks()).InSecondsF();
+  bool curve_done = !fling_curve_->Apply(now - fling_start_time_secs_, this);
+  if (!curve_done)
+    StartCurveTimer();
+  else
+    StopFlingAndCleanup();
+}
+
+void Flinger::StopFlingAndCleanup() {
+  if (!fling_in_progress_)
+    return;
+  curve_timer_.Stop();
+  fling_curve_.reset();
+  fling_in_progress_ = false;
+  helper_->FlingFinished(fling_source_);
+}
+
+}  // namespace content