Refactors code for WebGestureCurve to ui/events/gestures/blink

content/child/web_gesture_curve_impl.cc

-// Copyright 2014 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/child/web_gesture_curve_impl.h"
-
-#include "base/logging.h"
-#include "base/metrics/histogram.h"
-#include "third_party/WebKit/public/platform/WebFloatSize.h"
-#include "third_party/WebKit/public/platform/WebGestureCurveTarget.h"
-#include "ui/events/gestures/fling_curve.h"
-#include "ui/gfx/geometry/safe_integer_conversions.h"
-#include "ui/gfx/geometry/vector2d.h"
-
-#if defined(OS_ANDROID)
-#include "ui/events/android/scroller.h"
-#endif
-
-using blink::WebGestureCurve;
-
-namespace content {
-namespace {
-
-scoped_ptr<ui::GestureCurve> CreateDefaultPlatformCurve(
-    const gfx::Vector2dF& initial_velocity) {
-  DCHECK(!initial_velocity.IsZero());
-#if defined(OS_ANDROID)
-  auto scroller = make_scoped_ptr(new ui::Scroller(ui::Scroller::Config()));
-  scroller->Fling(0,
-                  0,
-                  initial_velocity.x(),
-                  initial_velocity.y(),
-                  INT_MIN,
-                  INT_MAX,
-                  INT_MIN,
-                  INT_MAX,
-                  base::TimeTicks());
-  return scroller.Pass();
-#else
-  return make_scoped_ptr(
-      new ui::FlingCurve(initial_velocity, base::TimeTicks()));
-#endif
-}
-
-}  // namespace
-
-// static
-scoped_ptr<WebGestureCurve> WebGestureCurveImpl::CreateFromDefaultPlatformCurve(
-    const gfx::Vector2dF& initial_velocity,
-    const gfx::Vector2dF& initial_offset,
-    bool on_main_thread) {
-  return scoped_ptr<WebGestureCurve>(new WebGestureCurveImpl(
-      CreateDefaultPlatformCurve(initial_velocity), initial_offset,
-      on_main_thread ? ThreadType::MAIN : ThreadType::IMPL));
-}
-
-// static
-scoped_ptr<WebGestureCurve> WebGestureCurveImpl::CreateFromUICurveForTesting(
-    scoped_ptr<ui::GestureCurve> curve,
-    const gfx::Vector2dF& initial_offset) {
-  return scoped_ptr<WebGestureCurve>(
-      new WebGestureCurveImpl(curve.Pass(), initial_offset, ThreadType::TEST));
-}
-
-WebGestureCurveImpl::WebGestureCurveImpl(scoped_ptr<ui::GestureCurve> curve,
-                                         const gfx::Vector2dF& initial_offset,
-                                         ThreadType animating_thread_type)
-    : curve_(curve.Pass()),
-      last_offset_(initial_offset),
-      animating_thread_type_(animating_thread_type),
-      ticks_since_first_animate_(0),
-      first_animate_time_(0),
-      last_animate_time_(0) {
-}
-
-WebGestureCurveImpl::~WebGestureCurveImpl() {
-  if (ticks_since_first_animate_ <= 1)
-    return;
-
-  if (last_animate_time_ <= first_animate_time_)
-    return;
-
-  switch (animating_thread_type_) {
-    case ThreadType::MAIN:
-      UMA_HISTOGRAM_CUSTOM_COUNTS(
-          "Event.Frequency.Renderer.FlingAnimate",
-          gfx::ToRoundedInt(ticks_since_first_animate_ /
-                            (last_animate_time_ - first_animate_time_)),
-          1, 240, 120);
-      break;
-    case ThreadType::IMPL:
-      UMA_HISTOGRAM_CUSTOM_COUNTS(
-          "Event.Frequency.RendererImpl.FlingAnimate",
-          gfx::ToRoundedInt(ticks_since_first_animate_ /
-                            (last_animate_time_ - first_animate_time_)),
-          1, 240, 120);
-      break;
-    case ThreadType::TEST:
-      break;
-  }
-}
-
-bool WebGestureCurveImpl::apply(double time,
-                                blink::WebGestureCurveTarget* target) {
-  // If the fling has yet to start, simply return and report true to prevent
-  // fling termination.
-  if (time <= 0)
-    return true;
-
-  if (!first_animate_time_) {
-    first_animate_time_ = last_animate_time_ = time;
-  } else if (time != last_animate_time_) {
-    // Animation can occur multiple times a frame, but with the same timestamp.
-    // Suppress recording of such redundant animate calls, avoiding artificially
-    // inflated FPS computation.
-    last_animate_time_ = time;
-    ++ticks_since_first_animate_;
-  }
-
-  const base::TimeTicks time_ticks =
-      base::TimeTicks() + base::TimeDelta::FromSecondsD(time);
-  gfx::Vector2dF offset, velocity;
-  bool still_active =
-      curve_->ComputeScrollOffset(time_ticks, &offset, &velocity);
-
-  gfx::Vector2dF delta = offset - last_offset_;
-  last_offset_ = offset;
-
-  // As successive timestamps can be arbitrarily close (but monotonic!), don't
-  // assume that a zero delta means the curve has terminated.
-  if (delta.IsZero())
-    return still_active;
-
-  // scrollBy() could delete this curve if the animation is over, so don't touch
-  // any member variables after making that call.
-  bool did_scroll = target->scrollBy(blink::WebFloatSize(delta),
-                                     blink::WebFloatSize(velocity));
-  return did_scroll && still_active;
-}
-
-}  // namespace content