VirtualTouchpadEvdev.h revision 4b64dd48b6896d6b963f0a3a0259d3d2a7076a9e 
1#ifndef ANDROID_DVR_VIRTUAL_TOUCHPAD_EVDEV_H
2#define ANDROID_DVR_VIRTUAL_TOUCHPAD_EVDEV_H
3
4#include <memory>
5
6#include "VirtualTouchpad.h"
7#include "EvdevInjector.h"
8
9namespace android {
10namespace dvr {
11
12class EvdevInjector;
13
14// VirtualTouchpadEvdev implements a VirtualTouchpad by injecting evdev events.
15//
16class VirtualTouchpadEvdev : public VirtualTouchpad {
17 public:
18  static sp<VirtualTouchpad> Create();
19
20  // VirtualTouchpad implementation:
21  status_t Attach() override;
22  status_t Detach() override;
23  status_t Touch(int touchpad, float x, float y, float pressure) override;
24  status_t ButtonState(int touchpad, int buttons) override;
25  void dumpInternal(String8& result) override;
26
27 protected:
28  VirtualTouchpadEvdev() {}
29  ~VirtualTouchpadEvdev() override {}
30
31  // Must be called only between construction and Attach().
32  inline void SetEvdevInjectorForTesting(EvdevInjector* injector) {
33    injector_ = injector;
34  }
35
36 private:
37  // Except for testing, the |EvdevInjector| used to inject evdev events.
38  std::unique_ptr<EvdevInjector> owned_injector_;
39
40  // Active pointer to |owned_injector_| or to a testing injector.
41  EvdevInjector* injector_ = nullptr;
42
43  // Previous (x, y) position in device space, to suppress redundant events.
44  int32_t last_device_x_ = INT32_MIN;
45  int32_t last_device_y_ = INT32_MIN;
46
47  // Records current touch state (0=up 1=down) in bit 0, and previous state
48  // in bit 1, to track transitions.
49  int touches_ = 0;
50
51  // Previous injected button state, to detect changes.
52  int32_t last_motion_event_buttons_ = 0;
53
54  VirtualTouchpadEvdev(const VirtualTouchpadEvdev&) = delete;
55  void operator=(const VirtualTouchpadEvdev&) = delete;
56};
57
58}  // namespace dvr
59}  // namespace android
60
61#endif  // ANDROID_DVR_VIRTUAL_TOUCHPAD_EVDEV_H
62