content/browser/renderer_host/smooth_scroll_calculator.cc

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/browser/renderer_host/smooth_scroll_calculator.h"
   6
   7 namespace content {
   8
   9 SmoothScrollCalculator::SmoothScrollCalculator() {
  10 }
  11
  12 SmoothScrollCalculator::~SmoothScrollCalculator() {
  13 }
  14
  15 double SmoothScrollCalculator::GetScrollDelta(
  16     base::TimeTicks now, base::TimeDelta desired_interval) {
  17   double position_delta = 10;
  18   if (!last_tick_time_.is_null()) {
  19     double velocity = 10 / desired_interval.InMillisecondsF();
  20     double time_delta = (now - last_tick_time_).InMillisecondsF();
  21     position_delta = velocity * time_delta;
  22   }
  23
  24   last_tick_time_ = now;
  25   return position_delta;
  26 }
  27
  28 }  // namespace content