Android InputManager分析
本篇爲雞生蛋系列第二篇文章java
主要講一下inputmanager相關的，即驅動把數據上報到用戶空間後，用戶空間到應用這麼個流程，
在上一遍講內核的input子系統時候，咱們採起的反向分析，即由驅動出發，最後到input core，input子系統架構這麼個由點到面的分析方法，
那分析inputmanager是否可採用這種方法如何呢？實際上，對於Android上層(Native framework/framework, c++/java)的分析，我通常
採用的是由上而下的分析，即從其初始化(main,構造，onFirstRef())開始, 一般在其初始化時候，會重一些很重要的上下層的鏈接，若是由下往上看，會麻煩點，
而後再結合實例，看看他的數據流向是如何的，或者一些重要的API, 例如對於Audio來講，能夠結合播放音樂流程來分析整個系統架構。android
簡單說來，input到應用的流程爲
EventHub監控並讀取/dev/input下數據 --> 給InputReader 加工處理 --> 到InputDispacher --> 找到focused窗口並經過input channel發出去c++
參考文檔:
十分鐘瞭解Android觸摸事件原理（InputManagerService）
https://www.jianshu.com/p/f05...
android控件系統:輸入事件在控件樹中的傳遞
https://blog.csdn.net/renshug...
https://blog.csdn.net/renshug...
InputManagerService分析一：IMS的啓動與事件傳遞
https://blog.csdn.net/lilian0...segmentfault
相關代碼目錄:
Android 9.0 http://androidxref.com/9.0.0_r3/
frameworks/base/services/java/com/android/server/SystemServer.java
frameworks/base/services/core/java/com/android/server/input/InputManagerService.java
frameworks/base/services/core/jni/com_android_server_input_InputManagerService.cpp
frameworks/native/services/inputflinger/架構
1.1 初始化
frameworks/base/services/java/com/android/server/SystemServer.java
startOtherServices() {
inputManager = new InputManagerService(context);
....
wm = WindowManagerService.main(context, inputManager,
ServiceManager.addService(Context.INPUT_SERVICE, inputManager,
/* allowIsolated= */ false, DUMP_FLAG_PRIORITY_CRITICAL);
....
inputManager.setWindowManagerCallbacks(wm.getInputMonitor());
inputManager.start();
......
}
IMS(InputManagerService)的初始化，是從SystemServer開始的，經過搜索代碼（如上），咱們能夠看到構造了一個實例，
並作爲參數傳給了WMS, 由此咱們也猜測，會和WMS有緊密的關係，而後
IMS設置了setWindowManagerCallbacks()並經過start()函數啓動了，
SystemServer裏有關IMS的就這麼幾個地方，咱們再看下構造和start()具體的流程，與WMS的關聯不分析。app
frameworks/base/services/core/java/com/android/server/input/InputManagerService.java
// Pointer to native input manager service object.
private final long mPtr;
public InputManagerService(Context context) {
this.mContext = context;
this.mHandler = new InputManagerHandler(DisplayThread.get().getLooper());
// config_useDevInputEventForAudioJack配置爲true, 耳機事件可經過input上報
mUseDevInputEventForAudioJack =
context.getResources().getBoolean(R.bool.config_useDevInputEventForAudioJack);
......
mPtr = nativeInit(this, mContext, mHandler.getLooper().getQueue());
......
LocalServices.addService(InputManagerInternal.class, new LocalService());
}
public void start() {
Slog.i(TAG, "Starting input manager");
nativeStart(mPtr);
....
}
InputManagerService構造和start()主要也是調到JNI的 nativeInit() nativeStart().socket
frameworks/base/services/core/jni/com_android_server_input_InputManagerService.cpp
static jlong nativeInit(JNIEnv* env, jclass /* clazz */,
jobject serviceObj, jobject contextObj, jobject messageQueueObj) {
....
NativeInputManager* im = new NativeInputManager(contextObj, serviceObj,
messageQueue->getLooper());
im->incStrong(0);
return reinterpret_cast<jlong>(im);
}
static void nativeStart(JNIEnv* env, jclass /* clazz */, jlong ptr) {
......
status_t result = im->getInputManager()->start();
......
}
nativeInit()又構造了一個 NativeInputManager(),該類可認爲是上層JAVA和下層EventHub InputManager的橋樑，
nativeStart()經過 NativeInputManager最終調到 InputManager 的 start()方法ide
NativeInputManager::NativeInputManager(jobject contextObj,
jobject serviceObj, const sp<Looper>& looper) :
mLooper(looper), mInteractive(true) {
......
sp<EventHub> eventHub = new EventHub();
mInputManager = new InputManager(eventHub, this, this);
}
NativeInputManager()的構造又new了 EventHub 和 InputManager ， 其中
eventHub作爲參數傳給了 InputManager()函數
frameworks/native/services/inputflinger/EventHub.cpp
EventHub::EventHub(void) :
......{
acquire_wake_lock(PARTIAL_WAKE_LOCK, WAKE_LOCK_ID);
mEpollFd = epoll_create(EPOLL_SIZE_HINT); // epoll機制
LOG_ALWAYS_FATAL_IF(mEpollFd < 0, "Could not create epoll instance. errno=%d", errno);
mINotifyFd = inotify_init(); // inotify機制
int result = inotify_add_watch(mINotifyFd, DEVICE_PATH, IN_DELETE | IN_CREATE); // 利用inotify監控 DEVICE_PATH(/dev/input)建立和刪除
......
eventItem.events = EPOLLIN;
eventItem.data.u32 = EPOLL_ID_INOTIFY;
result = epoll_ctl(mEpollFd, EPOLL_CTL_ADD, mINotifyFd, &eventItem); // 將inotify的fd添加到Epoll監控中
LOG_ALWAYS_FATAL_IF(result != 0, "Could not add INotify to epoll instance. errno=%d", errno);
int wakeFds[2];
result = pipe(wakeFds); //讀寫pipe, InputReader有事件時喚醒
LOG_ALWAYS_FATAL_IF(result != 0, "Could not create wake pipe. errno=%d", errno);
mWakeReadPipeFd = wakeFds[0];
mWakeWritePipeFd = wakeFds[1];
......
result = epoll_ctl(mEpollFd, EPOLL_CTL_ADD, mWakeReadPipeFd, &eventItem);
......
}
EventHub至關於一個集線器，把底層的USB, TOUCH,鼠標等事件統一收集上來，再給上層。
其構造函數當中利用inotify機制監控"/dev/input" 目錄下設備的建立和刪除，這樣當有設備變動時就能夠收到通知了，
構造函數也建立了所須要的mEpollFd，這個做爲IO多路複用的機制，不清楚的能夠查下如何使用，
構造裏將mINotifyFd添加到了epoll裏，在後續input設備建立的時候，也會把input設備的fd添加進去，這樣當有數據或者設備變化時，
EventHub就可獲取這些事件，進一步處理。
構造還建立了兩個pipe,做爲wakeup的讀端和寫端，當InputReader.cpp有事件(配置變動，monitor, 超時請求等)喚醒EventHub處理。oop
InputManager::InputManager(
const sp<EventHubInterface>& eventHub,
const sp<InputReaderPolicyInterface>& readerPolicy,
const sp<InputDispatcherPolicyInterface>& dispatcherPolicy) {
mDispatcher = new InputDispatcher(dispatcherPolicy);
mReader = new InputReader(eventHub, readerPolicy, mDispatcher); // eventHub又傳給了 InputReader,最終他們倆是緊密聯繫在一塊兒的
initialize(); // eventHub又傳給了
}
void InputManager::initialize() {
mReaderThread = new InputReaderThread(mReader);
mDispatcherThread = new InputDispatcherThread(mDispatcher);
}
InputManager(),建立了InputDispatcher和InputReader實例並與對應的InputDispatcherThread InputReaderThread 線程關聯
具體的咱們不往下跟了，有興趣的能夠再看看，
至此，初始化流程告一段落。
InputManagerService.java的 start方法，最終到InputManager::start(),
status_t InputManager::start() {
status_t result = mDispatcherThread->run("InputDispatcher", PRIORITY_URGENT_DISPLAY);
......
result = mReaderThread->run("InputReader", PRIORITY_URGENT_DISPLAY);
......
}
start() 方法目的就是讓這兩個線程跑起來，這樣就能夠不斷的獲取，處理消息了。
1.2 小結
startOtherServices()/SystemServer.java
+ new InputManagerService(context) --> nativeInit(...) --> new NativeInputManager(...)
+ + new EventHub() --> inotify監控/dev/input + epoll + wake pipe
+ + new InputManager(eventHub,...)
+ + new InputDispatcher()
+ + new InputReader(eventHub,...)
+ + initialize()
+ + new InputReaderThread(mReader)
+ + new InputDispatcherThread(mDispatcher)
+
+ ^
+ +
+ inputManager.start() --> nativeStart(mPtr) --> im->getInputManager()->start() --> mDispatcherThread->run() mReaderThread->run()
2. 讀取數據
bool InputReaderThread::threadLoop() {
mReader->loopOnce();
return true;
}
bool InputDispatcherThread::threadLoop() {
mDispatcher->dispatchOnce();
return true;
}
上一小節講到IMS經過start()函數，最終讓InputReaderThread InputDispatcherThread兩個線程跑起來了，
線程跑起來後，他們由於返回值爲true, 因此他們會不斷的loop, 即不斷的讀取，分發，讀取，分發……
看上面幾行代碼，以爲整個過程很簡單清晰，然而當咱們繼續跟下去看細節的時候，你能 哇～～哇～～哇～～
這一節咱們看看 mReader->loopOnce()， 下一節繼續看Dispatcher過程
void InputReader::loopOnce() {
......
size_t count = mEventHub->getEvents(timeoutMillis, mEventBuffer, EVENT_BUFFER_SIZE);
......
if (count) {
processEventsLocked(mEventBuffer, count);
}
......// 通知dispather分發
mQueuedListener->flush();
}
InputReader的loopOnce()經過
EventHub getEvents()
得到元數據，而後經過
processEventsLocked()
進一步的處理，
而後再經過
mQueuedListener->flush()
通知InputDispatcher有數據了，該處理了
2.1 InputReader::loopOnce()之 EventHub->getEvents()
size_t EventHub::getEvents(int timeoutMillis, RawEvent* buffer, size_t bufferSize) {
......
for (;;) {
nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
// Reopen input devices if needed.
......
// Report any devices that had last been added/removed.
while (mClosingDevices) {
......
}
// 掃描設備
if (mNeedToScanDevices) {
mNeedToScanDevices = false;
scanDevicesLocked();
mNeedToSendFinishedDeviceScan = true;
}
......
// Grab the next input event.
bool deviceChanged = false;
while (mPendingEventIndex < mPendingEventCount) {
const struct epoll_event& eventItem = mPendingEventItems[mPendingEventIndex++];
......
ssize_t deviceIndex = mDevices.indexOfKey(eventItem.data.u32);
......
Device* device = mDevices.valueAt(deviceIndex);
if (eventItem.events & EPOLLIN) { //epoll事件
// 讀取數據
int32_t readSize = read(device->fd, readBuffer,
sizeof(struct input_event) * capacity);
......
event->deviceId = deviceId; // <-- 設備id
event->type = iev.type;
event->code = iev.code;
event->value = iev.value;
event += 1;
......
// Return now if we have collected any events or if we were explicitly awoken.
if (event != buffer || awoken) {
break;
}
// Poll for events. Mind the wake lock dance!
......
int pollResult = epoll_wait(mEpollFd, mPendingEventItems, EPOLL_MAX_EVENTS, timeoutMillis);
......
return event - buffer;
}
getEvents()會檢查是否須要掃描設備，若是須要的話，則會創建設備KeyedVector向量表，
以後如有數據到來則經過read()函數讀取數據， 返回RawEvent* buffer給processEventsLocked()進行下一步處理，
若啥事都沒有經過epoll_wait()阻塞等待。
原本數據的讀取(read())比較簡單, 這裏只列下設備掃描流程，做爲我的筆記，有興趣的能夠看下
EventHub::scanDevicesLocked() --> scanDirLocked(DEVICE_PATH) "/dev/input" --> while處理 openDeviceLocked() -->
status_t EventHub::openDeviceLocked(const char *devicePath) {
......
int fd = open(devicePath, O_RDWR | O_CLOEXEC | O_NONBLOCK);
......//一大堆ioctl的信息獲取
if(ioctl(......)) {
......//生成惟一的 deviceId,和device, 作爲mdevices的 key, value. 之後的操做會經常使用到這個deviceId
// Allocate device. (The device object takes ownership of the fd at this point.)
int32_t deviceId = mNextDeviceId++;
Device* device = new Device(fd, deviceId, String8(devicePath), identifier);
......
// Load the configuration file for the device.
// 加載這個設備的 idc(Input Device Configuration)配置文件
loadConfigurationLocked(device);
......//能力獲取和分類
// Figure out the kinds of events the device reports.
ioctl(fd, EVIOCGBIT(EV_KEY, sizeof(device->keyBitmask)), device->keyBitmask);
ioctl(fd, EVIOCGBIT(EV_ABS, sizeof(device->absBitmask)), device->absBitmask);
ioctl(fd, EVIOCGBIT(EV_REL, sizeof(device->relBitmask)), device->relBitmask);
...... // 設備分類
device->classes |= ......;
......
//加入到epoll當中
if (registerDeviceForEpollLocked(device) != OK) {
......
configureFd(device);
......//加入mDevices並更新 mOpeningDevices 鏈表
addDeviceLocked(device);
return OK;
}
// 對於咱們的觸屏來講class爲
// See if this is a touch pad.
// Is this a new modern multi-touch driver?
if (test_bit(ABS_MT_POSITION_X, device->absBitmask)
&& test_bit(ABS_MT_POSITION_Y, device->absBitmask)) {
......
if (test_bit(BTN_TOUCH, device->keyBitmask) || !haveGamepadButtons) {
device->classes |= INPUT_DEVICE_CLASS_TOUCH | INPUT_DEVICE_CLASS_TOUCH_MT;
}
......//以後還會加載虛擬key.
// Configure virtual keys.
if ((device->classes & INPUT_DEVICE_CLASS_TOUCH)) {
// Load the virtual keys for the touch screen, if any.
// We do this now so that we can make sure to load the keymap if necessary.
status_t status = loadVirtualKeyMapLocked(device);
status_t EventHub::loadVirtualKeyMapLocked(Device* device) {
// The virtual key map is supplied by the kernel as a system board property file.
......
path.append("/sys/board_properties/virtualkeys.");
path.append(device->identifier.name);
......
return VirtualKeyMap::load(path, &device->virtualKeyMap);
addDeviceLocked()即添加到
EventHub.h KeyedVector<int32_t, Device*> mDevices;
並更新鏈表mOpeningDevices
void EventHub::addDeviceLocked(Device* device) {
mDevices.add(device->id, device);
device->next = mOpeningDevices;
mOpeningDevices = device;
}
另外要注意一點的是，在scanDevicesLocked()時候也會建立虛擬鍵盤。
void EventHub::scanDevicesLocked() {
status_t res = scanDirLocked(DEVICE_PATH);
.......
// 建立虛擬鍵盤
if (mDevices.indexOfKey(VIRTUAL_KEYBOARD_ID) < 0) {
createVirtualKeyboardLocked();
}
}
2.2 InputReader::loopOnce()之 processEventsLocked
mEventHub->getEvents(), 反回元數據後，傳給 processEventsLocked()進一步處理
元數據的定義以下，主要記錄了時間，設備id, type, code, value.
struct RawEvent {
nsecs_t when;
int32_t deviceId;
int32_t type;
int32_t code;
int32_t value;
};
其中的deviceId起了個鏈接做用，用於標識eventhub和iputreader中的設備，
void InputReader::processEventsLocked(const RawEvent* rawEvents, size_t count) {
for (const RawEvent* rawEvent = rawEvents; count;) {
int32_t type = rawEvent->type;
size_t batchSize = 1;
if (type < EventHubInterface::FIRST_SYNTHETIC_EVENT) {
int32_t deviceId = rawEvent->deviceId;
......
processEventsForDeviceLocked(deviceId, rawEvent, batchSize);
......
case EventHubInterface::DEVICE_ADDED:
addDeviceLocked(rawEvent->when, rawEvent->deviceId);
case EventHubInterface::DEVICE_REMOVED:
......
case EventHubInterface::FINISHED_DEVICE_SCAN:
......
}
}
processEventsLocked()函數有個
processEventsForDeviceLocked() 對於對數據的處理，
另外還根據type, 處理了對設備添加移除，掃描的處理，
你們就有點奇怪了，咦，eventhub掃描設備的時候，不是有處理添加設備嗎？
咋這兒又有添加設備了？ 並且看代碼，二者都有個mDevices變量
EventHub.h KeyedVector<int32_t, Device*> mDevices; InputReader.h KeyedVector<int32_t, InputDevice*> mDevices;
上面可看到二者value類型不一樣，他們之間的key 即deviceID是相同的，
其實我我的認爲EventHub中的Device爲設備的自己屬性，是下層設備的實例化，
而InputReader中的InputDevice爲更高層次的抽象，主要用於往上層處理數據，
addDeviceLocked()過程當中還會根據input設備的不一樣屬性設置不一樣的Mapper事件轉換器。
咱們先看下processEventsForDeviceLocked()過程:
void InputReader::processEventsForDeviceLocked(int32_t deviceId,
const RawEvent* rawEvents, size_t count) {
ssize_t deviceIndex = mDevices.indexOfKey(deviceId);
......
InputDevice* device = mDevices.valueAt(deviceIndex);
......
device->process(rawEvents, count);
}
void InputDevice::process(const RawEvent* rawEvents, size_t count) {
// Process all of the events in order for each mapper.
......
// 可能會有多個mapper
size_t numMappers = mMappers.size();
for (const RawEvent* rawEvent = rawEvents; count != 0; rawEvent++) {
......
for (size_t i = 0; i < numMappers; i++) {
InputMapper* mapper = mMappers[i];
mapper->process(rawEvent);
}
......
}
processEventsForDeviceLocked() --> device->process() --> mapper->process()
最終數據的處理也是經過mapper來處理的，因此咱們還得看下mapper咋添加的
Mapper添加
mapper的添加是根據分類來添加的, 以觸屏爲例
frameworks/native/services/inputflinger/InputReader.cpp
InputReader::processEventsLocked() --> addDeviceLocked() --> createDeviceLocked() -->
// Touchscreens and touchpad devices.
if (classes & INPUT_DEVICE_CLASS_TOUCH_MT) {
device->addMapper(new MultiTouchInputMapper(device));
} else if (classes & INPUT_DEVICE_CLASS_TOUCH) {
device->addMapper(new SingleTouchInputMapper(device));
}
因此觸屏的最後數據處理函數會調到
MultiTouchInputMapper的process函數再也不詳細看
void MultiTouchInputMapper::process(const RawEvent* rawEvent) {
TouchInputMapper::process(rawEvent);
mMultiTouchMotionAccumulator.process(rawEvent);
}
2.3 InputReader數據如何到InputDispatcher的？
InputReader::loopOnce() 數據處理完後便調用 mQueuedListener->flush() 通知 InputDispatcher 該處理數據了。
void QueuedInputListener::flush() {
size_t count = mArgsQueue.size();
for (size_t i = 0; i < count; i++) {
NotifyArgs* args = mArgsQueue[i];
args->notify(mInnerListener);
delete args;
}
mArgsQueue.clear();
}
flush()方法即把mArgsQueue Vector一個個取出來，而後再調用notify()方法，
那咱們確定想要知道
1. 數據是咋壓入 mArgsQueue的？
2. notify() 後續流程咋把數據給到 InputDispatcher
1.
void QueuedInputListener::notifyConfigurationChanged(
const NotifyConfigurationChangedArgs* args) {
mArgsQueue.push(new NotifyConfigurationChangedArgs(*args));
}
void QueuedInputListener::notifyKey(const NotifyKeyArgs* args) {
mArgsQueue.push(new NotifyKeyArgs(*args));
}
void QueuedInputListener::notifyMotion(const NotifyMotionArgs* args) {
mArgsQueue.push(new NotifyMotionArgs(*args));
}
void QueuedInputListener::notifySwitch(const NotifySwitchArgs* args) {
mArgsQueue.push(new NotifySwitchArgs(*args));
}
void QueuedInputListener::notifyDeviceReset(const NotifyDeviceResetArgs* args) {
mArgsQueue.push(new NotifyDeviceResetArgs(*args));
}
在QueuedInputListener中看到 notifyConfigurationChanged() notifyKey() notifyMotion() notifySwitch() notifyDeviceReset()
當有配置變化或事件時，都會新建立個notify args實例(都繼承自NotifyArgs)，而後push到mArgsQueue，
以觸屏事件爲例，push流程爲:
TouchInputMapper::sync() --> processRawTouches() --> cookAndDispatch() --> dispatchTouches() --> dispatchMotion()
--> NotifyMotionArgs args(...) getListener()->notifyMotion(&args) -->
frameworks/native/services/inputflinger/InputListener.cpp
void QueuedInputListener::notifyMotion(const NotifyMotionArgs* args) {
mArgsQueue.push(new NotifyMotionArgs(*args));
}
- InputReader::loopOnce() --> QueuedInputListener::flush() --> for args->notify(mInnerListener);
以觸屏NotifyMotionArgs爲例，其調用到
void NotifyMotionArgs::notify(const sp<InputListenerInterface>& listener) const {
listener->notifyMotion(this);
}
注意其 listener 爲 InputDispatcher (InputDispatcher 繼承自 InputDispatcherInterface class InputDispatcher : public InputDispatcherInterface),
frameworks/native/services/inputflinger/InputManager.cpp mDispatcher = new InputDispatcher(dispatcherPolicy); mReader = new InputReader(..., ..., mDispatcher); --> InputReader::InputReader(..., ..., ...listener) --> new QueuedInputListener(listener);
因此最終就調到了
InputDispatcher::notifyMotion()
void InputDispatcher::notifyMotion(const NotifyMotionArgs* args) {
......// 合法性檢查
if (!validateMotionEvent(args->action, args->actionButton,
args->pointerCount, args->pointerProperties)) {
......// 預處理
mPolicy->interceptMotionBeforeQueueing(args->eventTime, /*byref*/ policyFlags);
......
if (shouldSendMotionToInputFilterLocked(args)) {
mLock.unlock();
MotionEvent event;
event.initialize(args->deviceId, args->source, args->action, args->actionButton,
args->flags, args->edgeFlags, args->metaState, args->buttonState,
0, 0, args->xPrecision, args->yPrecision,
args->downTime, args->eventTime,
args->pointerCount, args->pointerProperties, args->pointerCoords);
policyFlags |= POLICY_FLAG_FILTERED;
// 過濾
if (!mPolicy->filterInputEvent(&event, policyFlags)) {
return; // event was consumed by the filter
}
mLock.lock();
}
// Just enqueue a new motion event.
MotionEntry* newEntry = new MotionEntry(args->eventTime,
args->deviceId, args->source, policyFlags,
args->action, args->actionButton, args->flags,
args->metaState, args->buttonState,
args->edgeFlags, args->xPrecision, args->yPrecision, args->downTime,
args->displayId,
args->pointerCount, args->pointerProperties, args->pointerCoords, 0, 0);
// 入隊
needWake = enqueueInboundEventLocked(newEntry);
mLock.unlock();
} // release lock
if (needWake) {
// 喚醒
mLooper->wake();
}
}
notifyMotion()會先檢查合法性，而後預處理，若是須要過濾則進行過濾處理，
不然構建 MotionEntry，併入隊，隨後將looper喚醒。
bool InputDispatcher::enqueueInboundEventLocked(EventEntry* entry) {
bool needWake = mInboundQueue.isEmpty();
// 入隊
mInboundQueue.enqueueAtTail(entry);
......
}
InputReader這一側大至就分析完了，數據從InputReader傳到InputDispatcher也清楚了，
接下來看看數據分發。
3. 分發數據
在開頭也講到，InputDispatcherThread裏不斷的loop,調用dispatchOnce()進行數據的分發。
frameworks/native/services/inputflinger/InputDispatcher.cpp
void InputDispatcher::dispatchOnce() {
......
// Run a dispatch loop if there are no pending commands.
// The dispatch loop might enqueue commands to run afterwards.
if (!haveCommandsLocked()) {
// 若是命令列隊爲空， 進行事件分發
dispatchOnceInnerLocked(&nextWakeupTime);
}
//若是looper裏沒有信息，會阻塞，直到timeoutMillis超時
mLooper->pollOnce(timeoutMillis);
}
dispatchOnce()裏若是命令處理完了，纔會調用dispatchOnceInnerLocked()進行事件處理。
void InputDispatcher::dispatchOnceInnerLocked(nsecs_t* nextWakeupTime) {
.....//若是沒有event,抓取一個
// Ready to start a new event.
// If we don't already have a pending event, go grab one.
if (! mPendingEvent) {
if (mInboundQueue.isEmpty()) {
......
} else {
// Inbound queue has at least one entry.
mPendingEvent = mInboundQueue.dequeueAtHead(); //<---從mInboundQueue隊頭抓個
traceInboundQueueLengthLocked();
}
......//一些錯誤處理，包括anr時間重置，略過
switch (mPendingEvent->type) {
case EventEntry::TYPE_CONFIGURATION_CHANGED: ....
case EventEntry::TYPE_DEVICE_RESET: ....
case EventEntry::TYPE_KEY: .....
......//對咱們的touch來講是motion事件
case EventEntry::TYPE_MOTION: {
MotionEntry* typedEntry = static_cast<MotionEntry*>(mPendingEvent);
if (dropReason == DROP_REASON_NOT_DROPPED && isAppSwitchDue) {
dropReason = DROP_REASON_APP_SWITCH;
}
if (dropReason == DROP_REASON_NOT_DROPPED
&& isStaleEventLocked(currentTime, typedEntry)) {
dropReason = DROP_REASON_STALE;
}
if (dropReason == DROP_REASON_NOT_DROPPED && mNextUnblockedEvent) {
dropReason = DROP_REASON_BLOCKED;
}
//分發事件
done = dispatchMotionLocked(currentTime, typedEntry,
&dropReason, nextWakeupTime);
break;
}
......
}
dispatchOnceInnerLocked從mInboundQueue隊列中取出以前的MotionEntry，
而後錯誤處理，對於觸屏事件作dispatchMotionLocked()
bool InputDispatcher::dispatchMotionLocked(
nsecs_t currentTime, MotionEntry* entry, DropReason* dropReason, nsecs_t* nextWakeupTime) {
......// 是否爲 point event
bool isPointerEvent = entry->source & AINPUT_SOURCE_CLASS_POINTER;
// Identify targets.
Vector<InputTarget> inputTargets;
......
if (isPointerEvent) {
// Pointer event. (eg. touchscreen)
injectionResult = findTouchedWindowTargetsLocked(currentTime,
entry, inputTargets, nextWakeupTime, &conflictingPointerActions);
} else {
// Non touch event. (eg. trackball)
injectionResult = findFocusedWindowTargetsLocked(currentTime,
entry, inputTargets, nextWakeupTime);
}
......
dispatchEventLocked(currentTime, entry, inputTargets);
return true;
}
對於point event，會先用
findTouchedWindowTargetsLocked() 找到目標窗口，不然用
findFocusedWindowTargetsLocked() 找到目標窗口
對咱們的觸屏來講，包含有該屬性
frameworks/native/include/android/input.h
AINPUT_SOURCE_TOUCHSCREEN = 0x00001000 | AINPUT_SOURCE_CLASS_POINTER,
找到目標窗口後，再用 dispatchEventLocked() 發給目標窗口
dispatchEventLocked() --> prepareDispatchCycleLocked() --> enqueueDispatchEntriesLocked()
void InputDispatcher::dispatchEventLocked(nsecs_t currentTime,
EventEntry* eventEntry, const Vector<InputTarget>& inputTargets) {
......
for (size_t i = 0; i < inputTargets.size(); i++) {
const InputTarget& inputTarget = inputTargets.itemAt(i);
ssize_t connectionIndex = getConnectionIndexLocked(inputTarget.inputChannel);
if (connectionIndex >= 0) {
sp<Connection> connection = mConnectionsByFd.valueAt(connectionIndex);
prepareDispatchCycleLocked(currentTime, connection, eventEntry, &inputTarget);
......
}
void InputDispatcher::prepareDispatchCycleLocked(nsecs_t currentTime,
......
// Not splitting. Enqueue dispatch entries for the event as is.
enqueueDispatchEntriesLocked(currentTime, connection, eventEntry, inputTarget);
}
void InputDispatcher::enqueueDispatchEntriesLocked(nsecs_t currentTime,
const sp<Connection>& connection, EventEntry* eventEntry, const InputTarget* inputTarget) {
bool wasEmpty = connection->outboundQueue.isEmpty();
// Enqueue dispatch entries for the requested modes.
enqueueDispatchEntryLocked(connection, eventEntry, inputTarget,
InputTarget::FLAG_DISPATCH_AS_HOVER_EXIT);
enqueueDispatchEntryLocked(connection, eventEntry, inputTarget,
InputTarget::FLAG_DISPATCH_AS_OUTSIDE);
enqueueDispatchEntryLocked(connection, eventEntry, inputTarget,
InputTarget::FLAG_DISPATCH_AS_HOVER_ENTER);
enqueueDispatchEntryLocked(connection, eventEntry, inputTarget,
InputTarget::FLAG_DISPATCH_AS_IS);
enqueueDispatchEntryLocked(connection, eventEntry, inputTarget,
InputTarget::FLAG_DISPATCH_AS_SLIPPERY_EXIT);
enqueueDispatchEntryLocked(connection, eventEntry, inputTarget,
InputTarget::FLAG_DISPATCH_AS_SLIPPERY_ENTER);
// If the outbound queue was previously empty, start the dispatch cycle going.
if (wasEmpty && !connection->outboundQueue.isEmpty()) {
startDispatchCycleLocked(currentTime, connection);
}
}
enqueueDispatchEntryLocked()會根據flag mode進行比較，而後加入到connection的outboundQueue裏
connection->outboundQueue.enqueueAtTail(dispatchEntry);
而後再調用
startDispatchCycleLocked()最終經過socket把事件發出去
void InputDispatcher::startDispatchCycleLocked(nsecs_t currentTime,
const sp<Connection>& connection) {
......
case EventEntry::TYPE_MOTION: {
......
// Publish the motion event.
status = connection->inputPublisher.publishMotionEvent(dispatchEntry->seq,
motionEntry->deviceId, motionEntry->source, motionEntry->displayId,
dispatchEntry->resolvedAction, motionEntry->actionButton,
dispatchEntry->resolvedFlags, motionEntry->edgeFlags,
motionEntry->metaState, motionEntry->buttonState,
xOffset, yOffset, motionEntry->xPrecision, motionEntry->yPrecision,
motionEntry->downTime, motionEntry->eventTime,
motionEntry->pointerCount, motionEntry->pointerProperties,
usingCoords);
break;
}
......
frameworks/native/libs/input/InputTransport.cpp
status_t InputPublisher::publishMotionEvent(
......
InputMessage msg;
msg.header.type = InputMessage::TYPE_MOTION;
...... // 經過socket發送
return mChannel->sendMessage(&msg);
}
4. 數據接收
數據發送後，又被誰接收到了呢？以後流程又如何呢？
input數據主要有兩種，一個應用，一個MonitoringChannel，
這裏僅簡單的列舉下，詳細的請看看參考文檔
4.1 App 接收
對於應用的接收，須要看input channel是咋創建的，
而後看看findTouchedWindowTargetsLocked()，咋找到目錄窗口，該函數很複雜，
但有個比較重要的是查詢 mWindowHandles, 該變量在setInputWindows()設置,
WindowManagerService.java
mInputMonitor.updateInputWindowsLw(false /*force*/); in addWindow() -+
mInputMonitor.updateInputWindowsLw(true /*force*/); in postWindowRemoveCleanupLocked() +
mInputMonitor.updateInputWindowsLw(true /*force*/); in relayoutWindow() +
mInputMonitor.updateInputWindowsLw(true /*force*/); in relayoutWindow() +--> updateInputWindowsLw() -->
mInputMonitor.updateInputWindowsLw(true /*force*/); in removeWindowToken() +
mInputMonitor.updateInputWindowsLw(true /*force*/); in startPositioningLocked() +
mInputMonitor.updateInputWindowsLw(true /*force*/); in startPositioningLocked() +
mInputMonitor.updateInputWindowsLw(true /*force*/); in finishPositioning() -+
InputMonitor.java updateInputWindowsLw()
+--> mUpdateInputForAllWindowsConsumer.updateInputWindows(inDrag)
+--> updateInputWindows()
+--> InputManagerService.java setInputWindows()
+--> nativeSetInputWindows()
+--> im->setInputWindows (NativeInputManager::setInputWindows())
+--> mInputManager->getDispatcher()->setInputWindows()
+-->
void InputDispatcher::setInputWindows(const Vector<sp<InputWindowHandle> >& inputWindowHandles) {
......
mWindowHandles = inputWindowHandles;
應用添加窗口設置mWindowHandles如上。在addWindow() relayoutWindow()...過程當中均可能設置該變量
frameworks/base/core/java/android/view/ViewRootImpl.java
public void setView(View view, WindowManager.LayoutParams attrs, View panelParentView) {
...... // addToDisplay() 將調用WMS mService.addWindow()
res = mWindowSession.addToDisplay(mWindow, mSeq, mWindowAttributes,
getHostVisibility(), mDisplay.getDisplayId(), mWinFrame,
mAttachInfo.mContentInsets, mAttachInfo.mStableInsets,
mAttachInfo.mOutsets, mAttachInfo.mDisplayCutout, mInputChannel);
...... //
mInputEventReceiver = new WindowInputEventReceiver(mInputChannel,
Looper.myLooper());
}
對應用來講在setView() 時會調用mWindowSession.addToDisplay(),很後調用addWindow(), 而後win.openInputChannel(outInputChannel)等創建channel操做
addToDisplay() 之會，會將mInputChannel looper，經過 WindowInputEventReceiver綁在一塊兒，
這樣當有數據到來時在looper裏面處理。
WindowInputEventReceiver()流程以下
WindowInputEventReceiver() --> InputEventReceiver.java InputEventReceiver() --> nativeInit() -->
frameworks/base/core/jni/android_view_InputEventReceiver.cpp
static jlong nativeInit(JNIEnv* env, jclass clazz, jobject receiverWeak,
jobject inputChannelObj, jobject messageQueueObj) {
......
sp<NativeInputEventReceiver> receiver = new NativeInputEventReceiver(env,
receiverWeak, inputChannel, messageQueue);
status_t status = receiver->initialize();
......
}
initialize() (NativeInputEventReceiver::initialize())--> setFdEvents(ALOOPER_EVENT_INPUT) -->
// 注意事件類型爲 ALOOPER_EVENT_INPUT
void NativeInputEventReceiver::setFdEvents(int events) {
if (mFdEvents != events) {
mFdEvents = events;
int fd = mInputConsumer.getChannel()->getFd();
if (events) {
mMessageQueue->getLooper()->addFd(fd, 0, events, this, NULL);
system/core/libutils/Looper.cpp
int Looper::addFd(int fd, int ident, int events, const sp<LooperCallback>& callback, void* data) {
......// 將input channel的fd加入到epoll監控中
int epollResult = epoll_ctl(mEpollFd, EPOLL_CTL_ADD, fd, & eventItem);
** 當socket接收到數據時，經過handle來處理
android_view_InputEventReceiver.cpp
int NativeInputEventReceiver::handleEvent(int receiveFd, int events, void* data) {
......// ALOOPER_EVENT_INPUT 事件
if (events & ALOOPER_EVENT_INPUT) {
JNIEnv* env = AndroidRuntime::getJNIEnv();
status_t status = consumeEvents(env, false /*consumeBatches*/, -1, NULL);
mMessageQueue->raiseAndClearException(env, "handleReceiveCallback");
return status == OK || status == NO_MEMORY ? 1 : 0;
}
......
}
handleEvent() --> consumeEvents() -->
status_t NativeInputEventReceiver::consumeEvents(JNIEnv* env,
bool consumeBatches, nsecs_t frameTime, bool* outConsumedBatch) {
......
status_t status = mInputConsumer.consume(&mInputEventFactory, //取數據
......
if (inputEventObj) {
...
env->CallVoidMethod(receiverObj.get(),
gInputEventReceiverClassInfo.dispatchInputEvent, seq, inputEventObj, //調用 dispatchInputEvent()
......
}
-->
frameworks/base/core/java/android/view/InputEventReceiver.java dispatchInputEvent() --> onInputEvent() -->
final class WindowInputEventReceiver extends InputEventReceiver {
......
@Override
public void onInputEvent(InputEvent event, int displayId) {
enqueueInputEvent(event, this, 0, true);
}
void enqueueInputEvent(InputEvent event,
InputEventReceiver receiver, int flags, boolean processImmediately) {
......
if (processImmediately) {
doProcessInputEvents(); // --> deliverInputEvent(q);
} else {
scheduleProcessInputEvents();
}
}
ViewRootImpl.java
private void deliverInputEvent(QueuedInputEvent q) {
......
InputStage stage;
if (q.shouldSendToSynthesizer()) {
stage = mSyntheticInputStage;
} else {
// mFirstPostImeInputStage = earlyPostImeStage; new EarlyPostImeInputStage(nativePostImeStage); 注意參數爲nativePostImeStage，在 apply(q, onProcess(q)) 返回forward時會用到
stage = q.shouldSkipIme() ? mFirstPostImeInputStage : mFirstInputStage;
}
......
if (stage != null) {
handleWindowFocusChanged();
stage.deliver(q);
......
}
stage.deliver --> apply(q, onProcess(q)) --> EarlyPostImeInputStage onProcess() --> processPointerEvent() --> (EarlyPostImeInputStage-->NativePostImeInputStage-->ViewPostImeInputStage-->SyntheticInputStage;)
ViewPostImeInputStage mView.dispatchPointerEvent(event)
View.java dispatchPointerEvent() +-->View.java dispatchTouchEvent() --> li.mOnTouchListener.onTouch(this, event) onTouchEvent(event)
+
+--> ViewGroup.java dispatchTouchEvent()
4.2 input monitor筆記
在分發input數據時，會把 mMonitoringChannels 加入到目標中，而後經過socket也發給該目標，
InputDispatcher::dispatchMotionLocked() --> addMonitoringTargetsLocked() --> for mMonitoringChannels
在WMS時構造，會經過monitorInput()建立，
以後別的服務可經過WMS registerPointerEventListener() unregisterPointerEventListener() 以listener方式獲取數據
frameworks/base/services/core/java/com/android/server/wm/WindowManagerService.java
private WindowManagerService(......) {
......
if(mInputManager != null) {
final InputChannel inputChannel = mInputManager.monitorInput(TAG_WM);
mPointerEventDispatcher = inputChannel != null
? new PointerEventDispatcher(inputChannel) : null;
@Override
public void registerPointerEventListener(PointerEventListener listener) {
mPointerEventDispatcher.registerInputEventListener(listener);
}
@Override
public void unregisterPointerEventListener(PointerEventListener listener) {
mPointerEventDispatcher.unregisterInputEventListener(listener);
}
monitorInput()流程以下：
InputManagerService.java monitorInput()
+--> nativeRegisterInputChannel(......, true);
+--> NativeInputManager::registerInputChannel()
+--> mInputManager->getDispatcher()->registerInputChannel() -->
status_t InputDispatcher::registerInputChannel(const sp<InputChannel>& inputChannel,
const sp<InputWindowHandle>& inputWindowHandle, bool monitor) {
......
if (monitor) {
mMonitoringChannels.push(inputChannel);
}
......
}
我的筆記
數據的轉存
從slot --> RawPointerData --> cookAndDispatch() cookPointerData()進一步處理將值給
mCurrentCookedState.cookedPointerData，主要爲
cookedPointerData.pointerCoords cookedPointerData.pointerProperties
dispatchMotion()時參數傳入cookedPointerData,進一步將數據封裝爲
NotifyMotionArgs
dispatchMotion(when, policyFlags, mSource,
......
mCurrentCookedStat.cookedPointerData.pointerProperties,
mCurrentCookedStat.cookedPointerData.pointerCoords,
mCurrentCookedStat.cookedPointerData.idToIndex,
......
TouchInputMapper::sync()
+-> syncTouch(when, next); --> 數據從slot到outState->rawPointerData.pointers[outCount];
+-> processRawTouches() --> cookAndDispatch() --> dispatchTouches() --> dispatchMotion()
數據處理完後將 NotifyMotionArgs 壓入mArgsQueue
TouchInputMapper::dispatchMotion() --> getListener()->notifyMotion(&args) -->
frameworks/native/services/inputflinger/InputListener.cpp
void NotifyMotionArgs::notify(const sp<InputListenerInterface>& listener) const {
listener->notifyMotion(this);
}
void QueuedInputListener::notifyMotion(const NotifyMotionArgs* args) {
mArgsQueue.push(new NotifyMotionArgs(*args));
}
數據從MultiTouchMotionAccumulator::Slot 轉到 RawPointerData::Pointer
void MultiTouchInputMapper::syncTouch(nsecs_t when, RawState* outState) {
size_t inCount = mMultiTouchMotionAccumulator.getSlotCount();
......
for (size_t inIndex = 0; inIndex < inCount; inIndex++) {
const MultiTouchMotionAccumulator::Slot* inSlot =
mMultiTouchMotionAccumulator.getSlot(inIndex);
......
RawPointerData::Pointer& outPointer = outState->rawPointerData.pointers[outCount];
outPointer.x = inSlot->getX();
outPointer.y = inSlot->getY();
......
}
加工數據
void TouchInputMapper::processRawTouches(bool timeout) {
....//在處理mRawStatesPending數據時，一個一個取出給mCurrentRawState，而後 cookAndDispatch進一步處理
for(count = 0; count < N; count++) {
const RawState& next = mRawStatesPending[count];
......//給mCurrentRawState
mCurrentRawState.copyFrom(next);
......//cookAndDispatch加工並分發
cookAndDispatch(mCurrentRawState.when);
void TouchInputMapper::cookPointerData() {
uint32_t currentPointerCount = mCurrentRawState.rawPointerData.pointerCount;
mCurrentCookedState.cookedPointerData.clear();
......//將數據進一步的處理，例如，計算旋轉後的值
// Walk through the the active pointers and map device coordinates onto
// surface coordinates and adjust for display orientation.
for (uint32_t i = 0; i < currentPointerCount; i++) {
const RawPointerData::Pointer& in = mCurrentRawState.rawPointerData.pointers[i];
......
case DISPLAY_ORIENTATION_90:
x = float(yTransformed - mRawPointerAxes.y.minValue) * mYScale + mYTranslate;
y = float(mRawPointerAxes.x.maxValue - xTransformed) * mXScale + mXTranslate;
......//將值給 cookedPointerData.pointerCoords
// Write output coords.
PointerCoords& out = mCurrentCookedState.cookedPointerData.pointerCoords[i];
out.clear();
out.setAxisValue(AMOTION_EVENT_AXIS_X, x);
out.setAxisValue(AMOTION_EVENT_AXIS_Y, y);
out.setAxisValue(AMOTION_EVENT_AXIS_PRESSURE, pressure);
......//將值給 cookedPointerData.pointerProperties
// Write output properties.
PointerProperties& properties =
mCurrentCookedState.cookedPointerData.pointerProperties[i];
uint32_t id = in.id;
properties.clear();
properties.id = id;
properties.toolType = in.toolType;
// Write id index.
mCurrentCookedState.cookedPointerData.idToIndex[id] = i;
......
相關文章
- 1. Unity 常用腳本：InputManager視圖
- 2. Android lowmemorykiller分析
- 3. Android SparseArray 分析
- 4. Android ServiceManager分析
- 5. Android ANR 分析
- 6. Android framworks分析
- 7. android classloader 分析
- 8. Android -- WifiMonitor分析
- 9. Android tombstone 分析
- 10. Android SystemServer 分析
- 更多相關文章...
- • Kotlin Android 環境搭建 - Kotlin 教程
- • 互聯網系統應用架構基礎分析 - 紅包項目實戰
- • Git五分鐘教程
- • 算法總結-二分查找法
相關標籤/搜索
每日一句
-
每一个你不满意的现在，都有一个你没有努力的曾经。
歡迎關注本站公眾號,獲取更多信息
