[CRD iOS] Move UI stuff into a subdirectory

remoting/client/fling_tracker.cc

Index: remoting/client/fling_tracker.cc
diff --git a/remoting/client/fling_tracker.cc b/remoting/client/fling_tracker.cc
deleted file mode 100644
index fb6bc7cb42adebc355554a649db5d57bb1a2e998..0000000000000000000000000000000000000000
--- a/remoting/client/fling_tracker.cc
+++ /dev/null
@@ -1,109 +0,0 @@
-// Copyright 2017 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 "remoting/client/fling_tracker.h"
-
-#include <cmath>
-
-namespace remoting {
-
-namespace {
-
-// TODO(yuweih): May need to tweak these numbers to get better smoothness.
-
-// Stop flinging if the speed drops below this.
-// 1px per 16ms. i.e. 1px/frame.
-// TODO(yuweih): The screen unit may not be in pixel. This needs to be
-//               normalized with the DPI.
-const float kMinTrackSpeed = 0.0625f;
-
-// The minimum fling duration (ms) needed to trigger the fling animation. This
-// is to prevent unintentional fling with low velocity.
-const float kMinFlingTime = 500.f;
-
-float GetExpFactor(float time_constant, float time_elapsed) {
-  return std::exp(-time_elapsed / time_constant);
-}
-
-float GetDisplacement(float initial_speed_rate, float exp_factor) {
-  // x = v0 * (1 - e^(-t / T))
-  // This comes from a solution to the linear drag equation F=-kv
-  return initial_speed_rate * (1.f - exp_factor);
-}
-
-float GetSpeed(float initial_speed_rate,
-               float time_constant,
-               float exp_factor) {
-  // v = (1 / T) * v0 * e^(-t / T).
-  // Derivative of the displacement.
-  return (1.f / time_constant) * initial_speed_rate * exp_factor;
-}
-
-}  // namespace
-
-FlingTracker::FlingTracker(float time_constant)
-    : time_constant_(time_constant) {}
-
-FlingTracker::~FlingTracker() {}
-
-void FlingTracker::StartFling(float velocity_x, float velocity_y) {
-  start_time_ = base::TimeTicks::Now();
-
-  initial_speed_rate_ =
-      std::sqrt(velocity_x * velocity_x + velocity_y * velocity_y);
-
-  if (GetSpeed(initial_speed_rate_, time_constant_,
-               GetExpFactor(time_constant_, kMinFlingTime)) < kMinTrackSpeed) {
-    StopFling();
-    return;
-  }
-
-  velocity_ratio_x_ = velocity_x / initial_speed_rate_;
-  velocity_ratio_y_ = velocity_y / initial_speed_rate_;
-
-  previous_position_x_ = 0;
-  previous_position_y_ = 0;
-}
-
-void FlingTracker::StopFling() {
-  initial_speed_rate_ = 0.f;
-}
-
-bool FlingTracker::IsFlingInProgress() const {
-  return initial_speed_rate_ > 0;
-}
-
-bool FlingTracker::TrackMovement(base::TimeDelta time_elapsed,
-                                 float* dx,
-                                 float* dy) {
-  if (!IsFlingInProgress()) {
-    return false;
-  }
-
-  float time_elapsed_ms = time_elapsed.InMilliseconds();
-
-  float exp_factor = GetExpFactor(time_constant_, time_elapsed_ms);
-
-  float speed = GetSpeed(initial_speed_rate_, time_constant_, exp_factor);
-
-  if (speed < kMinTrackSpeed) {
-    StopFling();
-    return false;
-  }
-
-  float displacement = GetDisplacement(initial_speed_rate_, exp_factor);
-
-  float position_x = displacement * velocity_ratio_x_;
-  float position_y = displacement * velocity_ratio_y_;
-
-  *dx = position_x - previous_position_x_;
-  *dy = position_y - previous_position_y_;
-
-  previous_position_x_ = position_x;
-  previous_position_y_ = position_y;
-
-  return true;
-}
-
-}  // namespace remoting