path: root/ui/base/x/device_data_manager.h

// Copyright 2013 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.

#ifndef UI_BASE_X_DEVICE_DATA_MANAGER_H_
#define UI_BASE_X_DEVICE_DATA_MANAGER_H_

#include <X11/extensions/XInput2.h>

#include <bitset>
#include <map>
#include <vector>

#include "base/basictypes.h"
#include "base/event_types.h"
#include "ui/base/events/event_constants.h"
#include "ui/base/ui_export.h"
#include "ui/base/x/x11_atom_cache.h"

template <typename T> struct DefaultSingletonTraits;

typedef union _XEvent XEvent;

namespace ui {

// A class that extracts and tracks the input events data. It currently handles
// mouse, touchpad and touchscreen devices.
class UI_EXPORT DeviceDataManager {
 public:
  // Enumerate additional data that one might be interested on an input event,
  // which are usually wrapped in X valuators. If you modify any of this,
  // make sure to update the kCachedAtoms data structure in the source file
  // and the k*Type[Start/End] constants used by IsCMTDataType and
  // IsTouchDataType.
  enum DataType {
    // Define the valuators used the CrOS CMT driver. Used by mice and CrOS
    // touchpads.
    DT_CMT_SCROLL_X = 0,  // Scroll amount on the X (horizontal) direction.
    DT_CMT_SCROLL_Y,      // Scroll amount on the Y (vertical) direction.
    DT_CMT_ORDINAL_X,     // Original (unaccelerated) value on the X direction.
                          // Can be used both for scrolls and flings.
    DT_CMT_ORDINAL_Y,     // Original (unaccelerated) value on the Y direction.
                          // Can be used both for scrolls and flings.
    DT_CMT_START_TIME,    // Gesture start time.
    DT_CMT_END_TIME,      // Gesture end time.
    DT_CMT_FLING_X,       // Fling amount on the X (horizontal) direction.
    DT_CMT_FLING_Y,       // Fling amount on the Y (vertical) direction.
    DT_CMT_FLING_STATE,   // The state of fling gesture (whether the user just
                          // start flinging or that he/she taps down).
    DT_CMT_FINGER_COUNT,  // Finger counts in the current gesture. A same type
                          // of gesture can have very different meanings based
                          // on that (e.g. 2f scroll v.s. 3f swipe).

    // End of CMT data types.
    // Beginning of touch data types.

    // Define the valuators following the Multi-touch Protocol. Used by
    // touchscreen devices.
    DT_TOUCH_MAJOR,       // Length of the touch area.
    DT_TOUCH_MINOR,       // Width of the touch area.
    DT_TOUCH_ORIENTATION, // Angle between the X-axis and the major axis of the
                          // touch area.
    DT_TOUCH_PRESSURE,    // Pressure of the touch contact.

    // NOTE: A touch event can have multiple touch points. So when we receive a
    // touch event, we need to determine which point triggered the event.
    // A touch point can have both a 'Slot ID' and a 'Tracking ID', and they can
    // be (in fact, usually are) different. The 'Slot ID' ranges between 0 and
    // (X - 1), where X is the maximum touch points supported by the device. The
    // 'Tracking ID' can be any 16-bit value. With XInput 2.0, an XI_Motion
    // event that comes from a currently-unused 'Slot ID' indicates the creation
    // of a new touch point, and any event that comes with a 0 value for
    // 'Tracking ID' marks the removal of a touch point. During the lifetime of
    // a touchpoint, we use the 'Slot ID' as its identifier. The XI_ButtonPress
    // and XI_ButtonRelease events are ignored.
#if !defined(USE_XI2_MT)
    DT_TOUCH_SLOT_ID,     // ID of the finger that triggered a touch event
                          // (useful when tracking multiple simultaneous
                          // touches).
#endif
    // NOTE for XInput MT: 'Tracking ID' is provided in every touch event to
    // track individual touch. 'Tracking ID' is an unsigned 32-bit value and
    // is increased for each new touch. It will wrap back to 0 when reaching
    // the numerical limit.
    DT_TOUCH_TRACKING_ID, // ID of the touch point.

    // Kernel timestamp from touch screen (if available).
    DT_TOUCH_RAW_TIMESTAMP,

    // End of touch data types.

    DT_LAST_ENTRY         // This must come last.
  };

  // Data struct to store extracted data from an input event.
  typedef std::map<int, double> EventData;

  // We use int because enums can be casted to ints but not vice versa.
  static bool IsCMTDataType(const int type);
  static bool IsTouchDataType(const int type);

  // Returns the DeviceDataManager singleton.
  static DeviceDataManager* GetInstance();

  // Natural scroll setter/getter.
  bool natural_scroll_enabled() const { return natural_scroll_enabled_; }
  void set_natural_scroll_enabled(bool enabled) {
    natural_scroll_enabled_ = enabled;
  }

  // Get the natural scroll direction multiplier (1.0f or -1.0f).
  float GetNaturalScrollFactor(int sourceid) const;

  // Updates the list of devices.
  void UpdateDeviceList(Display* display);

  // Get all event data in one pass. We extract only data types that we know
  // about (defined in enum DataType). The data is not processed (e.g. not
  // filled in by cached values) as in GetEventData.
  void GetEventRawData(const XEvent& xev, EventData* data);

  // Get a datum of the specified type. Return true and the value
  // is updated if the data is found, false and value unchanged if the data is
  // not found. In the case of MT-B/XI2.2, the value can come from a previously
  // cached one (see the comment above last_seen_valuator_).
  bool GetEventData(const XEvent& xev, const DataType type, double* value);

  // Check if the event comes from touchpad devices.
  bool IsTouchpadXInputEvent(const base::NativeEvent& native_event) const;

  // Check if the event comes from devices running CMT driver or using
  // CMT valuators (e.g. mouses). Note that doesn't necessarily mean the event
  // is a CMT event (e.g. it could be a mouse pointer move).
  bool IsCMTDeviceEvent(const base::NativeEvent& native_event) const;

  // Check if the event is one of the CMT gesture events (scroll, fling,
  // metrics etc.).
  bool IsCMTGestureEvent(const base::NativeEvent& native_event) const;

  // Returns true if the event is of the specific type, false if not.
  bool IsScrollEvent(const base::NativeEvent& native_event) const;
  bool IsFlingEvent(const base::NativeEvent& native_event) const;

  // Returns true if the event has CMT start/end timestamps.
  bool HasGestureTimes(const base::NativeEvent& native_event) const;

  // Extract data from a scroll event (a motion event with the necessary
  // valuators). User must first verify the event type with IsScrollEvent.
  // Pointers shouldn't be NULL.
  void GetScrollOffsets(const base::NativeEvent& native_event,
                        float* x_offset,
                        float* y_offset,
                        float* x_offset_ordinal,
                        float* y_offset_ordinal,
                        int* finger_count);

  // Extract data from a fling event. User must first verify the event type
  // with IsFlingEvent. Pointers shouldn't be NULL.
  void GetFlingData(const base::NativeEvent& native_event,
                    float* vx,
                    float* vy,
                    float* vx_ordinal,
                    float* vy_ordinal,
                    bool* is_cancel);

  // Extract the start/end timestamps from CMT events. User must first verify
  // the event with HasGestureTimes. Pointers shouldn't be NULL.
  void GetGestureTimes(const base::NativeEvent& native_event,
                       double* start_time,
                       double* end_time);

  // Normalize the data value on deviceid to fall into [0, 1].
  // *value = (*value - min_value_of_tp) / (max_value_of_tp - min_value_of_tp)
  // Returns true and sets the normalized value in|value| if normalization is
  // successful. Returns false and |value| is unchanged otherwise.
  bool NormalizeData(unsigned int deviceid,
                     const DataType type,
                     double* value);

  // Extract the range of the data type. Return true if the range is available
  // and written into min & max, false if the range is not available.
  bool GetDataRange(unsigned int deviceid,
                    const DataType type,
                    double* min,
                    double* max);

 private:
  // Requirement for Singleton.
  friend struct DefaultSingletonTraits<DeviceDataManager>;

  DeviceDataManager();
  ~DeviceDataManager();

  // Check if an XI event contains data of the specified type.
  bool HasEventData(const XIDeviceEvent* xiev, const DataType type) const;

  static const int kMaxDeviceNum = 128;
  bool natural_scroll_enabled_;

  // A quick lookup table for determining if events from the pointer device
  // should be processed.
  std::bitset<kMaxDeviceNum> cmt_devices_;
  std::bitset<kMaxDeviceNum> touchpads_;

  // Number of valuators on the specific device.
  int valuator_count_[kMaxDeviceNum];

  // Index table to find the valuator for DataType on the specific device
  // by valuator_lookup_[device_id][data_type].
  std::vector<int> valuator_lookup_[kMaxDeviceNum];

  // Index table to find the DataType for valuator on the specific device
  // by data_type_lookup_[device_id][valuator].
  std::vector<int> data_type_lookup_[kMaxDeviceNum];

  // Index table to find the min & max value of the Valuator on a specific
  // device.
  std::vector<double> valuator_min_[kMaxDeviceNum];
  std::vector<double> valuator_max_[kMaxDeviceNum];

  // Table to keep track of the last seen value for the specified valuator for
  // a device. Defaults to 0 if the valuator was not specified in an earlier
  // event. With MT-B/XI2.2, valuators in an XEvent are not reported if the
  // values haven't changed from the previous event. So it is necessary to
  // remember these valuators so that chrome doesn't think X/device doesn't
  // know about the valuators. We currently use this only on touchscreen
  // devices.
  std::vector<double> last_seen_valuator_[kMaxDeviceNum];

  // X11 atoms cache.
  X11AtomCache atom_cache_;

  DISALLOW_COPY_AND_ASSIGN(DeviceDataManager);
};

}  // namespace ui

#endif  // UI_BASE_X_DEVICE_DATA_MANAGER_H_