ash/wm/workspace/two_step_edge_cycler.cc

   1 // Copyright 2014 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 "ash/wm/workspace/two_step_edge_cycler.h"
   6
   7 #include <cstdlib>
   8
   9 namespace ash {
  10 namespace {
  11
  12 // We cycle to the second mode if any of the following happens while the mouse
  13 // is on the edge of the workspace:
  14 // . The user stops moving the mouse for |kMaxDelay| and then moves the mouse
  15 //   again in the preferred direction from the last paused location for at least
  16 //   |kMaxPixelsAfterPause| horizontal pixels.
  17 // . The mouse moves |kMaxPixels| horizontal pixels in the preferred direction.
  18 // . The mouse is moved |kMaxMoves| times since the last pause.
  19 const int kMaxDelay = 400;
  20 const int kMaxPixels = 100;
  21 const int kMaxPixelsAfterPause = 10;
  22 const int kMaxMoves = 25;
  23
  24 }  // namespace
  25
  26 TwoStepEdgeCycler::TwoStepEdgeCycler(const gfx::Point& start,
  27                                      TwoStepEdgeCycler::Direction direction)
  28     : second_mode_(false),
  29       time_last_move_(base::TimeTicks::Now()),
  30       num_moves_(0),
  31       start_x_(start.x()),
  32       paused_x_(start.x()),
  33       paused_(false),
  34       direction_(direction) {
  35 }
  36
  37 TwoStepEdgeCycler::~TwoStepEdgeCycler() {
  38 }
  39
  40 void TwoStepEdgeCycler::OnMove(const gfx::Point& location) {
  41   if (second_mode_)
  42     return;
  43
  44   if ((base::TimeTicks::Now() - time_last_move_).InMilliseconds() > kMaxDelay) {
  45     paused_ = true;
  46     paused_x_ = location.x();
  47     num_moves_ = 0;
  48   }
  49   time_last_move_ = base::TimeTicks::Now();
  50
  51   int compare_x = paused_ ? paused_x_ : start_x_;
  52   if (location.x() != compare_x &&
  53       (location.x() < compare_x) != (direction_ == DIRECTION_LEFT)) {
  54     return;
  55   }
  56
  57   ++num_moves_;
  58   bool moved_in_the_same_direction_after_pause =
  59       paused_ && std::abs(location.x() - paused_x_) >= kMaxPixelsAfterPause;
  60   second_mode_ = moved_in_the_same_direction_after_pause ||
  61                  std::abs(location.x() - start_x_) >= kMaxPixels ||
  62                  num_moves_ >= kMaxMoves;
  63 }
  64
  65 }  // namespace ash