1 #include "VirtualTouchpadEvdev.h"
2
3 #include <android/input.h>
4 #include <inttypes.h>
5 #include <linux/input.h>
6 #include <log/log.h>
7
8 // References:
9 // [0] Multi-touch (MT) Protocol,
10 // https://www.kernel.org/doc/Documentation/input/multi-touch-protocol.txt
11
12 namespace android {
13 namespace dvr {
14
15 namespace {
16
17 // Virtual evdev device properties. The name is arbitrary, but Android can
18 // use it to look up device configuration, so it must be unique. Vendor and
19 // product values must be 0 to indicate an internal device and prevent a
20 // similar lookup that could conflict with a physical device.
21 static const char* const kDeviceNameFormat = "vr-virtual-touchpad-%d";
22 static constexpr int16_t kDeviceBusType = BUS_VIRTUAL;
23 static constexpr int16_t kDeviceVendor = 0;
24 static constexpr int16_t kDeviceProduct = 0;
25 static constexpr int16_t kDeviceVersion = 0x0001;
26
27 static constexpr int32_t kWidth = 0x10000;
28 static constexpr int32_t kHeight = 0x10000;
29 static constexpr int32_t kSlots = 2;
30
31 static constexpr float kScrollScale = 100.0f;
32
scale_relative_scroll(float x)33 int32_t scale_relative_scroll(float x) {
34 return kScrollScale * x;
35 }
36
37 } // anonymous namespace
38
Create()39 std::unique_ptr<VirtualTouchpad> VirtualTouchpadEvdev::Create() {
40 std::unique_ptr<VirtualTouchpadEvdev> touchpad(new VirtualTouchpadEvdev());
41 touchpad->Reset();
42 return touchpad;
43 }
44
Reset()45 void VirtualTouchpadEvdev::Reset() {
46 for (auto& touchpad : touchpad_) {
47 if (touchpad.injector) {
48 touchpad.injector->Close();
49 }
50 touchpad.injector = nullptr;
51 touchpad.owned_injector.reset();
52 touchpad.last_device_x = INT32_MIN;
53 touchpad.last_device_y = INT32_MIN;
54 touchpad.touches = 0;
55 touchpad.last_motion_event_buttons = 0;
56 }
57 }
58
Attach()59 status_t VirtualTouchpadEvdev::Attach() {
60 status_t status = OK;
61 for (int i = 0; i < kTouchpads; ++i) {
62 Touchpad& touchpad = touchpad_[i];
63 if (!touchpad.injector) {
64 touchpad.owned_injector.reset(new EvdevInjector());
65 touchpad.injector = touchpad.owned_injector.get();
66 }
67 String8 DeviceName;
68 DeviceName.appendFormat(kDeviceNameFormat, i);
69 touchpad.injector->ConfigureBegin(DeviceName, kDeviceBusType,
70 kDeviceVendor, kDeviceProduct,
71 kDeviceVersion);
72 touchpad.injector->ConfigureInputProperty(INPUT_PROP_DIRECT);
73 touchpad.injector->ConfigureMultiTouchXY(0, 0, kWidth - 1, kHeight - 1);
74 touchpad.injector->ConfigureAbsSlots(kSlots);
75 touchpad.injector->ConfigureRel(REL_WHEEL);
76 touchpad.injector->ConfigureRel(REL_HWHEEL);
77 touchpad.injector->ConfigureKey(BTN_TOUCH);
78 touchpad.injector->ConfigureKey(BTN_BACK);
79 touchpad.injector->ConfigureEnd();
80 if (const status_t configuration_status = touchpad.injector->GetError()) {
81 status = configuration_status;
82 }
83 }
84 return status;
85 }
86
Detach()87 status_t VirtualTouchpadEvdev::Detach() {
88 Reset();
89 return OK;
90 }
91
Touch(int touchpad_id,float x,float y,float pressure)92 int VirtualTouchpadEvdev::Touch(int touchpad_id, float x, float y,
93 float pressure) {
94 if (touchpad_id < 0 || touchpad_id >= kTouchpads) {
95 return EINVAL;
96 }
97 int32_t device_x = x * kWidth;
98 int32_t device_y = y * kHeight;
99 Touchpad& touchpad = touchpad_[touchpad_id];
100 touchpad.touches = ((touchpad.touches & 1) << 1) | (pressure > 0);
101 ALOGV("(%f,%f) %f -> (%" PRId32 ",%" PRId32 ") %d", x, y, pressure, device_x,
102 device_y, touchpad.touches);
103
104 if (!touchpad.injector) {
105 return EvdevInjector::ERROR_SEQUENCING;
106 }
107 touchpad.injector->ResetError();
108 switch (touchpad.touches) {
109 case 0b00: // Hover continues.
110 if (device_x != touchpad.last_device_x ||
111 device_y != touchpad.last_device_y) {
112 touchpad.injector->SendMultiTouchXY(0, 0, device_x, device_y);
113 touchpad.injector->SendSynReport();
114 }
115 break;
116 case 0b01: // Touch begins.
117 // Press.
118 touchpad.injector->SendMultiTouchXY(0, 0, device_x, device_y);
119 touchpad.injector->SendKey(BTN_TOUCH, EvdevInjector::KEY_PRESS);
120 touchpad.injector->SendSynReport();
121 break;
122 case 0b10: // Touch ends.
123 touchpad.injector->SendKey(BTN_TOUCH, EvdevInjector::KEY_RELEASE);
124 touchpad.injector->SendMultiTouchLift(0);
125 touchpad.injector->SendSynReport();
126 break;
127 case 0b11: // Touch continues.
128 if (device_x != touchpad.last_device_x ||
129 device_y != touchpad.last_device_y) {
130 touchpad.injector->SendMultiTouchXY(0, 0, device_x, device_y);
131 touchpad.injector->SendSynReport();
132 }
133 break;
134 }
135 touchpad.last_device_x = device_x;
136 touchpad.last_device_y = device_y;
137
138 return touchpad.injector->GetError();
139 }
140
ButtonState(int touchpad_id,int buttons)141 int VirtualTouchpadEvdev::ButtonState(int touchpad_id, int buttons) {
142 if (touchpad_id < 0 || touchpad_id >= kTouchpads) {
143 return EINVAL;
144 }
145 Touchpad& touchpad = touchpad_[touchpad_id];
146 const int changes = touchpad.last_motion_event_buttons ^ buttons;
147 if (!changes) {
148 return 0;
149 }
150 if (buttons & ~AMOTION_EVENT_BUTTON_BACK) {
151 return ENOTSUP;
152 }
153 ALOGV("change %X from %X to %X", changes, touchpad.last_motion_event_buttons,
154 buttons);
155
156 if (!touchpad.injector) {
157 return EvdevInjector::ERROR_SEQUENCING;
158 }
159 touchpad.injector->ResetError();
160 if (changes & AMOTION_EVENT_BUTTON_BACK) {
161 touchpad.injector->SendKey(BTN_BACK, (buttons & AMOTION_EVENT_BUTTON_BACK)
162 ? EvdevInjector::KEY_PRESS
163 : EvdevInjector::KEY_RELEASE);
164 touchpad.injector->SendSynReport();
165 }
166 touchpad.last_motion_event_buttons = buttons;
167 return touchpad.injector->GetError();
168 }
169
Scroll(int touchpad_id,float x,float y)170 int VirtualTouchpadEvdev::Scroll(int touchpad_id, float x, float y) {
171 if (touchpad_id < 0 || touchpad_id >= kTouchpads) {
172 return EINVAL;
173 }
174 if ((x < -1.0f) || (x > 1.0f) || (y < -1.0f) || (y > 1.0f)) {
175 return EINVAL;
176 }
177 Touchpad& touchpad = touchpad_[touchpad_id];
178 if (!touchpad.injector) {
179 return EvdevInjector::ERROR_SEQUENCING;
180 }
181 touchpad.injector->ResetError();
182 const int32_t scaled_x = scale_relative_scroll(x);
183 const int32_t scaled_y = scale_relative_scroll(y);
184 ALOGV("(%f,%f) -> (%" PRId32 ",%" PRId32 ")", x, y, scaled_x, scaled_y);
185 if (scaled_x) {
186 touchpad.injector->SendRel(REL_HWHEEL, scaled_x);
187 }
188 if (scaled_y) {
189 touchpad.injector->SendRel(REL_WHEEL, scaled_y);
190 }
191 if (scaled_x || scaled_y) {
192 touchpad.injector->SendSynReport();
193 }
194 return touchpad.injector->GetError();
195 }
196
dumpInternal(String8 & result)197 void VirtualTouchpadEvdev::dumpInternal(String8& result) {
198 for (int i = 0; i < kTouchpads; ++i) {
199 const auto& touchpad = touchpad_[i];
200 result.appendFormat("[virtual touchpad %d]\n", i);
201 if (!touchpad.injector) {
202 result.append("injector = none\n");
203 return;
204 }
205 result.appendFormat("injector = %s\n",
206 touchpad.owned_injector ? "normal" : "test");
207 result.appendFormat("touches = %d\n", touchpad.touches);
208 result.appendFormat("last_position = (%" PRId32 ", %" PRId32 ")\n",
209 touchpad.last_device_x, touchpad.last_device_y);
210 result.appendFormat("last_buttons = 0x%" PRIX32 "\n",
211 touchpad.last_motion_event_buttons);
212 touchpad.injector->dumpInternal(result);
213 result.append("\n");
214 }
215 }
216
217 } // namespace dvr
218 } // namespace android
219