1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #define LOG_TAG "MouseInputMapper"
18 //#define LOG_NDEBUG 0
19 
20 #include "MouseInputMapper.h"
21 
22 #include <linux/input.h>
23 #include <hardware/input.h>
24 #include <utils/Log.h>
25 #include <utils/misc.h>
26 
27 #include "InputHost.h"
28 #include "InputHub.h"
29 
30 
31 namespace android {
32 
33 // Map scancodes to input HAL usages.
34 // The order of these definitions MUST remain in sync with the order they are
35 // defined in linux/input.h.
36 static struct {
37     int32_t scancode;
38     InputUsage usage;
39 } codeMap[] = {
40     {BTN_LEFT, INPUT_USAGE_BUTTON_PRIMARY},
41     {BTN_RIGHT, INPUT_USAGE_BUTTON_SECONDARY},
42     {BTN_MIDDLE, INPUT_USAGE_BUTTON_TERTIARY},
43     {BTN_SIDE, INPUT_USAGE_BUTTON_UNKNOWN},
44     {BTN_EXTRA, INPUT_USAGE_BUTTON_UNKNOWN},
45     {BTN_FORWARD, INPUT_USAGE_BUTTON_FORWARD},
46     {BTN_BACK, INPUT_USAGE_BUTTON_BACK},
47     {BTN_TASK, INPUT_USAGE_BUTTON_UNKNOWN},
48 };
49 
50 
configureInputReport(InputDeviceNode * devNode,InputReportDefinition * report)51 bool MouseInputMapper::configureInputReport(InputDeviceNode* devNode,
52         InputReportDefinition* report) {
53     setInputReportDefinition(report);
54     getInputReportDefinition()->addCollection(INPUT_COLLECTION_ID_MOUSE, 1);
55 
56     // Configure mouse axes
57     if (!devNode->hasRelativeAxis(REL_X) || !devNode->hasRelativeAxis(REL_Y)) {
58         ALOGE("Device %s is missing a relative x or y axis. Device cannot be configured.",
59                 devNode->getPath().c_str());
60         return false;
61     }
62     getInputReportDefinition()->declareUsage(INPUT_COLLECTION_ID_MOUSE, INPUT_USAGE_AXIS_X,
63             INT32_MIN, INT32_MAX, 1.0f);
64     getInputReportDefinition()->declareUsage(INPUT_COLLECTION_ID_MOUSE, INPUT_USAGE_AXIS_Y,
65             INT32_MIN, INT32_MAX, 1.0f);
66     if (devNode->hasRelativeAxis(REL_WHEEL)) {
67         getInputReportDefinition()->declareUsage(INPUT_COLLECTION_ID_MOUSE,
68                 INPUT_USAGE_AXIS_VSCROLL, -1, 1, 0.0f);
69     }
70     if (devNode->hasRelativeAxis(REL_HWHEEL)) {
71         getInputReportDefinition()->declareUsage(INPUT_COLLECTION_ID_MOUSE,
72                 INPUT_USAGE_AXIS_HSCROLL, -1, 1, 0.0f);
73     }
74 
75     // Configure mouse buttons
76     InputUsage usages[NELEM(codeMap)];
77     int numUsages = 0;
78     for (int32_t i = 0; i < NELEM(codeMap); ++i) {
79         if (devNode->hasKey(codeMap[i].scancode)) {
80             usages[numUsages++] = codeMap[i].usage;
81         }
82     }
83     if (numUsages == 0) {
84         ALOGW("MouseInputMapper found no buttons for %s", devNode->getPath().c_str());
85     }
86     getInputReportDefinition()->declareUsages(INPUT_COLLECTION_ID_MOUSE, usages, numUsages);
87     return true;
88 }
89 
process(const InputEvent & event)90 void MouseInputMapper::process(const InputEvent& event) {
91     ALOGV("processing mouse event. type=%d code=%d value=%d",
92             event.type, event.code, event.value);
93     switch (event.type) {
94         case EV_KEY:
95             processButton(event.code, event.value);
96             break;
97         case EV_REL:
98             processMotion(event.code, event.value);
99             break;
100         case EV_SYN:
101             if (event.code == SYN_REPORT) {
102                 sync(event.when);
103             }
104             break;
105         default:
106             ALOGV("unknown mouse event type: %d", event.type);
107     }
108 }
109 
processMotion(int32_t code,int32_t value)110 void MouseInputMapper::processMotion(int32_t code, int32_t value) {
111     switch (code) {
112         case REL_X:
113             mRelX = value;
114             break;
115         case REL_Y:
116             mRelY = value;
117             break;
118         case REL_WHEEL:
119             mRelWheel = value;
120             break;
121         case REL_HWHEEL:
122             mRelHWheel = value;
123             break;
124         default:
125             // Unknown code. Ignore.
126             break;
127     }
128 }
129 
130 // Map evdev button codes to bit indices. This function assumes code >=
131 // BTN_MOUSE.
buttonToBit(int32_t code)132 uint32_t buttonToBit(int32_t code) {
133     return static_cast<uint32_t>(code - BTN_MOUSE);
134 }
135 
processButton(int32_t code,int32_t value)136 void MouseInputMapper::processButton(int32_t code, int32_t value) {
137     // Mouse buttons start at BTN_MOUSE and end before BTN_JOYSTICK. There isn't
138     // really enough room after the mouse buttons for another button class, so
139     // the risk of a button type being inserted after mouse is low.
140     if (code >= BTN_MOUSE && code < BTN_JOYSTICK) {
141         if (value) {
142             mButtonValues.markBit(buttonToBit(code));
143         } else {
144             mButtonValues.clearBit(buttonToBit(code));
145         }
146         mUpdatedButtonMask.markBit(buttonToBit(code));
147     }
148 }
149 
sync(nsecs_t when)150 void MouseInputMapper::sync(nsecs_t when) {
151     // Process updated button states.
152     while (!mUpdatedButtonMask.isEmpty()) {
153         auto bit = mUpdatedButtonMask.clearFirstMarkedBit();
154         getInputReport()->setBoolUsage(INPUT_COLLECTION_ID_MOUSE, codeMap[bit].usage,
155                 mButtonValues.hasBit(bit), 0);
156     }
157 
158     // Process motion and scroll changes.
159     if (mRelX != 0) {
160         getInputReport()->setIntUsage(INPUT_COLLECTION_ID_MOUSE, INPUT_USAGE_AXIS_X, mRelX, 0);
161     }
162     if (mRelY != 0) {
163         getInputReport()->setIntUsage(INPUT_COLLECTION_ID_MOUSE, INPUT_USAGE_AXIS_Y, mRelY, 0);
164     }
165     if (mRelWheel != 0) {
166         getInputReport()->setIntUsage(INPUT_COLLECTION_ID_MOUSE, INPUT_USAGE_AXIS_VSCROLL,
167                 mRelWheel, 0);
168     }
169     if (mRelHWheel != 0) {
170         getInputReport()->setIntUsage(INPUT_COLLECTION_ID_MOUSE, INPUT_USAGE_AXIS_HSCROLL,
171                 mRelHWheel, 0);
172     }
173 
174     // Report and reset.
175     getInputReport()->reportEvent(getDeviceHandle());
176     mUpdatedButtonMask.clear();
177     mButtonValues.clear();
178     mRelX = 0;
179     mRelY = 0;
180     mRelWheel = 0;
181     mRelHWheel = 0;
182 }
183 
184 }  // namespace android
185