1
    2
    3
    4
    5
    6
    7
    8
    9
   10
   11
   12
   13
   14
   15
   16
   17
   18
   19
   20
   21
   22
   23
   24
   25
   26
   27
   28
   29
   30
   31
   32
   33
   34
   35
   36
   37
   38
   39
   40
   41
   42
   43
   44
   45
   46
   47
   48
   49
   50
   51
   52
   53
   54
   55
   56
   57
   58
   59
   60
   61
   62
   63
   64
   65
   66
   67
   68
   69
   70
   71
   72
   73
   74
   75
   76
   77
   78
   79
   80
   81
   82
   83
   84
   85
   86
   87
   88
   89
   90
   91
   92
   93
   94
   95
   96
   97
   98
   99
  100
  101
  102
  103
  104
  105
  106
  107
  108
  109
  110
  111
  112
  113
  114
  115
  116
  117
  118
  119
  120
  121
  122
  123
  124
  125
  126
  127
  128
  129
  130
  131
  132
  133
  134
  135
  136


ash / accessibility / mouse_keys / mouse_keys_controller.h [blame]

// Copyright 2024 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef ASH_ACCESSIBILITY_MOUSE_KEYS_MOUSE_KEYS_CONTROLLER_H_
#define ASH_ACCESSIBILITY_MOUSE_KEYS_MOUSE_KEYS_CONTROLLER_H_

#include "ash/ash_export.h"
#include "base/timer/timer.h"
#include "ui/events/event.h"
#include "ui/events/event_handler.h"
#include "ui/events/types/event_type.h"
#include "ui/gfx/geometry/point.h"

namespace ash {

// Mouse keys is an accessibility feature that allows you to control your mouse
// cursor with the keyboard.  To do this, MouseKeysController ingests key events
// and generates mouse events.
class ASH_EXPORT MouseKeysController : public ui::EventHandler {
 public:
  // TODO(259372916): Find a good base speed/acceleration.
  // Base movement speed in DIP/s.
  static constexpr int kBaseSpeedDIPPerSecond = 80;
  static constexpr int kBaseAccelerationDIPPerSecondSquared = 80;

  // The default acceleration as a scale factor ranging from 0-1 for mouse keys
  // movement.
  static constexpr double kDefaultAcceleration = 0.2;

  // The default max speed as a factor of the minimum speed for mouse keys
  // movement.  Ranges from 0-10.
  static constexpr double kDefaultMaxSpeed = 5;

  // Frequency that the position is updated in Hz.
  static constexpr double kUpdateFrequencyInSeconds = 0.05;

  MouseKeysController();

  MouseKeysController(const MouseKeysController&) = delete;
  MouseKeysController& operator=(const MouseKeysController&) = delete;

  ~MouseKeysController() override;

  // Pause or unpause mouse keys.
  void Toggle();

  // Returns true if the event should be cancelled.
  bool RewriteEvent(const ui::Event& event);

  void set_enabled(bool enabled);
  bool enabled() { return enabled_; }

  void set_paused(bool paused) { paused_ = paused; }
  bool paused() { return paused_; }

  void set_use_primary_keys(bool use_primary_keys) {
    use_primary_keys_ = use_primary_keys;
  }
  bool use_primary_keys() { return use_primary_keys_; }

  void set_left_handed(bool left_handed) { left_handed_ = left_handed; }
  bool left_handed() { return left_handed_; }

  void set_acceleration(double acceleration) { acceleration_ = acceleration; }
  void SetMaxSpeed(double factor) {
    max_speed_ = factor * kBaseSpeedDIPPerSecond * kUpdateFrequencyInSeconds;
  }

  enum MouseKey {
    kKeyUpLeft = 0,
    kKeyUp,
    kKeyUpRight,
    kKeyLeft,
    kKeyRight,
    kKeyDownLeft,
    kKeyDown,
    kKeyDownRight,
    kKeyClick,
    kKeyDoubleClick,
    kKeyDragStart,
    kKeyDragStop,
    kKeySelectLeftButton,
    kKeySelectRightButton,
    kKeySelectBothButtons,
    kKeySelectNextButton,
    kKeyCount,
  };

  enum MouseButton {
    kLeft,
    kRight,
    kBoth,
  };

 private:
  // ui::EventHandler:
  void OnMouseEvent(ui::MouseEvent* event) override;

  void SendMouseEventToLocation(ui::EventType type,
                                const gfx::Point& location,
                                int flags = 0);
  void MoveMouse(const gfx::Vector2d& move_delta_dip);
  void CenterMouseIfUninitialized();

  // Returns true if the event was consumed.
  bool CheckFlagsAndMaybeSendEvent(const ui::KeyEvent& key_event,
                                   ui::DomCode input,
                                   MouseKey output);
  void PressKey(MouseKey key);
  void ReleaseKey(MouseKey key);
  void SelectNextButton();
  void RefreshVelocity();
  void UpdateState();
  void ResetMovement();

  bool enabled_ = false;
  bool paused_ = false;
  bool use_primary_keys_ = false;
  bool left_handed_ = false;
  double acceleration_ = kDefaultAcceleration;
  double max_speed_;
  gfx::Vector2d move_direction_;
  double speed_ = 0;
  MouseButton current_mouse_button_ = kLeft;

  bool pressed_keys_[kKeyCount];
  bool dragging_ = false;
  gfx::Point last_mouse_position_dips_ = gfx::Point(-1, -1);
  int event_flags_ = 0;
  base::RepeatingTimer update_timer_;
};

}  // namespace ash

#endif  // ASH_ACCESSIBILITY_MOUSE_KEYS_MOUSE_KEYS_CONTROLLER_H_