ui/events/ozone/evdev/touch_noise/touch_noise_finder.h

   1 // Copyright 2015 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 #ifndef UI_EVENTS_OZONE_EVDEV_TOUCH_NOISE_TOUCH_NOISE_FINDER_H_
   6 #define UI_EVENTS_OZONE_EVDEV_TOUCH_NOISE_TOUCH_NOISE_FINDER_H_
   7
   8 #include <bitset>
   9 #include <vector>
  10
  11 #include "base/basictypes.h"
  12 #include "base/time/time.h"
  13 #include "ui/events/ozone/evdev/events_ozone_evdev_export.h"
  14 #include "ui/events/ozone/evdev/touch_evdev_types.h"
  15
  16 namespace ui {
  17 class TouchNoiseFilter;
  18
  19 // Finds touches which are likely touch noise.
  20 class EVENTS_OZONE_EVDEV_EXPORT TouchNoiseFinder {
  21  public:
  22   TouchNoiseFinder();
  23   ~TouchNoiseFinder();
  24
  25   // Updates which ABS_MT_SLOTs are noise. |touches| should contain all of the
  26   // in-progress touches at |time| (including noisy touches).
  27   // |touches| should have at most one entry per ABS_MT_SLOT.
  28   void HandleTouches(const std::vector<InProgressTouchEvdev>& touches,
  29                      base::TimeDelta time);
  30
  31   // Returns whether the in-progress touch at ABS_MT_SLOT |slot| is noise.
  32   bool SlotHasNoise(size_t slot) const;
  33
  34  private:
  35   // Records how frequently noisy touches occur to UMA.
  36   void RecordUMA(bool had_noise, base::TimeDelta time);
  37
  38   friend class TouchEventConverterEvdevTouchNoiseTest;
  39
  40   // The slots which are noise.
  41   std::bitset<kNumTouchEvdevSlots> slots_with_noise_;
  42
  43   // The time of the previous noise occurence in any of the slots.
  44   base::TimeDelta last_noise_time_;
  45
  46   std::vector<TouchNoiseFilter*> filters_;
  47
  48   DISALLOW_COPY_AND_ASSIGN(TouchNoiseFinder);
  49 };
  50
  51 }  // namespace ui
  52
  53 #endif  // UI_EVENTS_OZONE_EVDEV_TOUCH_NOISE_TOUCH_NOISE_FINDER_H_