1. mInputManager = new InputManagerService(context, mInputMonitor);
在WMS的构造函数中进行初始化, mInputMonitor 继承InputManagerService.Callbacks,传给InputMangerService中的mCallbacks,WMS中的Context给mContext;
在InputManagerService的构造函数中,主要是初始化了变量,最后调用了Native的方法
public InputManagerService(Context context, Callbacks callbacks) {
this.mContext = context;
this.mCallbacks = callbacks;
this.mHandler = new InputManagerHandler();
Slog.i(TAG, "Initializing input manager");
mPtr = nativeInit(this, mContext, mHandler.getLooper().getQueue());
}
2. nativeInit (frameworks/base/services/jni/com_android_server_input_InputManagerService.cpp)
static jint nativeInit(JNIEnv* env, jclass clazz,
jobject serviceObj, jobject contextObj, jobject messageQueueObj) {
sp messageQueue = android_os_MessageQueue_getMessageQueue(env, messageQueueObj);
NativeInputManager* im = new NativeInputManager(contextObj, serviceObj,
messageQueue->getLooper());
im->incStrong(serviceObj);
return reinterpret_cast(im);
}
NativeInputManager::NativeInputManager(jobject contextObj,
jobject serviceObj, const sp& looper) :
mLooper(looper) {
... ...
sp eventHub = new EventHub();
mInputManager = new InputManager(eventHub, this, this);
在NativeInputManager的构造中,主要就是new出了一个EventHub, 然后作为构造参数给IputManager,最终最为一个参数传给InputReader。 并且和InputManagerHander共用同一个MessageQueue.
InputManager::InputManager(
const sp& eventHub,
const sp& readerPolicy,
const sp& dispatcherPolicy) {
mDispatcher = new InputDispatcher(dispatcherPolicy);
mReader = new InputReader(eventHub, readerPolicy, mDispatcher);
initialize();
}
void InputManager::initialize() {
mReaderThread = new InputReaderThread(mReader);
mDispatcherThread = new InputDispatcherThread(mDispatcher);
}
InputManager的构造函数中主要创建了InputReader 和 InputDispatcher对象并且保存在了mReader和mDispatcher中,InputDispatcher类是负责把键盘消息分发给当前激活的Activity窗口的,而InputReader类则是通过EventHub类来实现读取键盘事件的,后面我们会进一步分析。创建了这两个对象后,还要调用initialize函数来执行其它的初始化操作。
initialize()这个函数创建了一个InputReaderThread线程实例和一个InputDispatcherThread线程实例,并且分别保存在成员变量mReaderThread和mDispatcherThread中。这里的InputReader实列mReader就是通过这里的InputReaderThread线程实列mReaderThread来读取键盘事件的,而InputDispatcher实例mDispatcher则是通过这里的InputDispatcherThread线程实例mDisptacherThread来分发键盘消息的。
3. mInputManager.start()
InputManagerService 初始化完成之后,WMS就会去调用mInputManager.start() 来开始真正的检测键盘和touch事件。
public void start() {
Slog.i(TAG, "Starting input manager");
nativeStart(mPtr);
... ...
}
InputManagerServcie.start只是直接去调用Native的start方法。
static void nativeStart(JNIEnv* env, jclass clazz, jint ptr) {
NativeInputManager* im = reinterpret_cast(ptr);
status_t result = im->getInputManager()->start();
if (result) {
jniThrowRuntimeException(env, "Input manager could not be started.");
}
}
status_t InputManager::start() {
status_t result = mDispatcherThread->run("InputDispatcher", PRIORITY_URGENT_DISPLAY);
result = mReaderThread->run("InputReader", PRIORITY_URGENT_DISPLAY);
return OK;
}
所以我们直接进入到两个线程的threadLoop去查看一下是如何运行的。
4. InputReaderThread::threadLoop()
bool InputReaderThread::threadLoop() {
mReader->loopOnce();
return true;
}
InputReaderThread::threadLoop中通过调用mReader->loopOnce()来做每一次循环。 mReader是我们之前传进来的InputReader。
void InputReader::loopOnce() {
size_t count = mEventHub->getEvents(timeoutMillis, mEventBuffer, EVENT_BUFFER_SIZE);
{ // acquire lock
AutoMutex _l(mLock);
mReaderIsAliveCondition.broadcast();
if (count) {
processEventsLocked(mEventBuffer, count);
}
if (mNextTimeout != LLONG_MAX) {
nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
if (now >= mNextTimeout) {
mNextTimeout = LLONG_MAX;
timeoutExpiredLocked(now);
}
}
if (oldGeneration != mGeneration) {
inputDevicesChanged = true;
getInputDevicesLocked(inputDevices);
}
} // release lock
// Send out a message that the describes the changed input devices.
if (inputDevicesChanged) {
mPolicy->notifyInputDevicesChanged(inputDevices);
}
mQueuedListener->flush();
}
在这个函数中主要有两个操作,通过InputEent去getEents,然后processEventsLocked. getEent会去检测是否有Eent发生,如果就把Eents放到mEventBuffer中并且返回Event的个数,如果count是>0的数,说明是有Input发生的,然后交给processEventsLocked去处理。
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;
while (batchSize < count) {
if (rawEvent[batchSize].type >= EventHubInterface::FIRST_SYNTHETIC_EVENT
|| rawEvent[batchSize].deviceId != deviceId) {
break;
}
batchSize += 1;
}
#if DEBUG_RAW_EVENTS
ALOGD("BatchSize: %d Count: %d", batchSize, count);
#endif
processEventsForDeviceLocked(deviceId, rawEvent, batchSize);
} else {
switch (rawEvent->type) {
case EventHubInterface::DEVICE_ADDED:
addDeviceLocked(rawEvent->when, rawEvent->deviceId);
break;
case EventHubInterface::DEVICE_REMOVED:
removeDeviceLocked(rawEvent->when, rawEvent->deviceId);
break;
case EventHubInterface::FINISHED_DEVICE_SCAN:
handleConfigurationChangedLocked(rawEvent->when);
break;
default:
ALOG_ASSERT(false); // can't happen
break;
}
}
count -= batchSize;
rawEvent += batchSize;
}
}
struct RawEvent {
nsecs_t when;
int32_t deviceId;
int32_t type;
int32_t code;
int32_t value;
};
InputReader::processEventsForDeviceLocked
void InputReader::processEventsForDeviceLocked(int32_t deviceId,
const RawEvent* rawEvents, size_t count) {
ssize_t deviceIndex = mDevices.indexOfKey(deviceId);
InputDevice* device = mDevices.valueAt(deviceIndex);
if (device->isIgnored()) {
//ALOGD("Discarding event for ignored deviceId %d.", deviceId);
return;
}
device->process(rawEvents, count);
}
mDevices是一个Vector类型的集合变量,将deviceId和不同的device作为键值进行保存。通过传进来的deviceId值,就可一找到对应需要处理输入事件的device,之后调用device->process来用指定的device去处理事件。 Input device早在之前就通过 InputReader::addDeviceLocked 把自己加到了mDevices中。
void InputDevice::process(const RawEvent* rawEvents, size_t count) {
// Process all of the events in order for each mapper.
// We cannot simply ask each mapper to process them in bulk because mappers may
// have side-effects that must be interleaved. For example, joystick movement events and
// gamepad button presses are handled by different mappers but they should be dispatched
// in the order received.
size_t numMappers = mMappers.size();
for (const RawEvent* rawEvent = rawEvents; count--; rawEvent++) {
if (mDropUntilNextSync) {
if (rawEvent->type == EV_SYN && rawEvent->code == SYN_REPORT) {
mDropUntilNextSync = false;
} else {
}
} else if (rawEvent->type == EV_SYN && rawEvent->code == SYN_DROPPED) {
ALOGI("Detected input event buffer overrun for device %s.", getName().string());
mDropUntilNextSync = true;
reset(rawEvent->when);
} else {
for (size_t i = 0; i < numMappers; i++) {
InputMapper* mapper = mMappers[i];
mapper->process(rawEvent);
}
}
}
}
这边假设只是一个单击屏幕的事件,于是就会用TouchInputMapper::process
void TouchInputMapper::process(const RawEvent* rawEvent) {
mCursorButtonAccumulator.process(rawEvent);
mCursorScrollAccumulator.process(rawEvent);
mTouchButtonAccumulator.process(rawEvent);
if (rawEvent->type == EV_SYN && rawEvent->code == SYN_REPORT) {
sync(rawEvent->when);
}
}
void TouchInputMapper::sync(nsecs_t when) {
// Sync button state.
mCurrentButtonState = mTouchButtonAccumulator.getButtonState()
| mCursorButtonAccumulator.getButtonState();
// Sync scroll state.
mCurrentRawVScroll = mCursorScrollAccumulator.getRelativeVWheel();
mCurrentRawHScroll = mCursorScrollAccumulator.getRelativeHWheel();
mCursorScrollAccumulator.finishSync();
// Sync touch state.
bool havePointerIds = true;
mCurrentRawPointerData.clear();
syncTouch(when, &havePointerIds);
if (mDeviceMode == DEVICE_MODE_DISABLED) {
// Drop all input if the device is disabled.
mCurrentRawPointerData.clear();
mCurrentButtonState = 0;
} else {
// Preprocess pointer data.
if (!havePointerIds) {
assignPointerIds();
}
// Handle policy on initial down or hover events.
uint32_t policyFlags = 0;
bool initialDown = mLastRawPointerData.pointerCount == 0
&& mCurrentRawPointerData.pointerCount != 0;
bool buttonsPressed = mCurrentButtonState & ~mLastButtonState;
if (initialDown || buttonsPressed) {
// If this is a touch screen, hide the pointer on an initial down.
if (mDeviceMode == DEVICE_MODE_DIRECT) {
getContext()->fadePointer();
}
// Initial downs on external touch devices should wake the device.
// We don't do this for internal touch screens to prevent them from waking
// up in your pocket.
// TODO: Use the input device configuration to control this behavior more finely.
if (getDevice()->isExternal()) {
policyFlags |= POLICY_FLAG_WAKE_DROPPED;
}
}
// Synthesize key down from raw buttons if needed.
synthesizeButtonKeys(getContext(), AKEY_EVENT_ACTION_DOWN, when, getDeviceId(), mSource,
policyFlags, mLastButtonState, mCurrentButtonState);
// Consume raw off-screen touches before cooking pointer data.
// If touches are consumed, subsequent code will not receive any pointer data.
if (consumeRawTouches(when, policyFlags)) {
mCurrentRawPointerData.clear();
}
// Cook pointer data. This call populates the mCurrentCookedPointerData structure
// with cooked pointer data that has the same ids and indices as the raw data.
// The following code can use either the raw or cooked data, as needed.
cookPointerData();
// Dispatch the touches either directly or by translation through a pointer on screen.
if (mDeviceMode == DEVICE_MODE_POINTER) {
for (BitSet32 idBits(mCurrentRawPointerData.touchingIdBits); !idBits.isEmpty(); ) {
uint32_t id = idBits.clearFirstMarkedBit();
const RawPointerData::Pointer& pointer = mCurrentRawPointerData.pointerForId(id);
if (pointer.toolType == AMOTION_EVENT_TOOL_TYPE_STYLUS
|| pointer.toolType == AMOTION_EVENT_TOOL_TYPE_ERASER) {
mCurrentStylusIdBits.markBit(id);
} else if (pointer.toolType == AMOTION_EVENT_TOOL_TYPE_FINGER
|| pointer.toolType == AMOTION_EVENT_TOOL_TYPE_UNKNOWN) {
mCurrentFingerIdBits.markBit(id);
} else if (pointer.toolType == AMOTION_EVENT_TOOL_TYPE_MOUSE) {
mCurrentMouseIdBits.markBit(id);
}
}
for (BitSet32 idBits(mCurrentRawPointerData.hoveringIdBits); !idBits.isEmpty(); ) {
uint32_t id = idBits.clearFirstMarkedBit();
const RawPointerData::Pointer& pointer = mCurrentRawPointerData.pointerForId(id);
if (pointer.toolType == AMOTION_EVENT_TOOL_TYPE_STYLUS
|| pointer.toolType == AMOTION_EVENT_TOOL_TYPE_ERASER) {
mCurrentStylusIdBits.markBit(id);
}
}
// Stylus takes precedence over all tools, then mouse, then finger.
PointerUsage pointerUsage = mPointerUsage;
if (!mCurrentStylusIdBits.isEmpty()) {
mCurrentMouseIdBits.clear();
mCurrentFingerIdBits.clear();
pointerUsage = POINTER_USAGE_STYLUS;
} else if (!mCurrentMouseIdBits.isEmpty()) {
mCurrentFingerIdBits.clear();
pointerUsage = POINTER_USAGE_MOUSE;
} else if (!mCurrentFingerIdBits.isEmpty() || isPointerDown(mCurrentButtonState)) {
pointerUsage = POINTER_USAGE_GESTURES;
}
dispatchPointerUsage(when, policyFlags, pointerUsage);
} else {
if (mDeviceMode == DEVICE_MODE_DIRECT
&& mConfig.showTouches && mPointerController != NULL) {
mPointerController->setPresentation(PointerControllerInterface::PRESENTATION_SPOT);
mPointerController->fade(PointerControllerInterface::TRANSITION_GRADUAL);
mPointerController->setButtonState(mCurrentButtonState);
mPointerController->setSpots(mCurrentCookedPointerData.pointerCoords,
mCurrentCookedPointerData.idToIndex,
mCurrentCookedPointerData.touchingIdBits);
}
dispatchHoverExit(when, policyFlags);
dispatchTouches(when, policyFlags);
dispatchHoverEnterAndMove(when, policyFlags);
}
// Synthesize key up from raw buttons if needed.
synthesizeButtonKeys(getContext(), AKEY_EVENT_ACTION_UP, when, getDeviceId(), mSource,
policyFlags, mLastButtonState, mCurrentButtonState);
}
// Copy current touch to last touch in preparation for the next cycle.
mLastRawPointerData.copyFrom(mCurrentRawPointerData);
mLastCookedPointerData.copyFrom(mCurrentCookedPointerData);
mLastButtonState = mCurrentButtonState;
mLastFingerIdBits = mCurrentFingerIdBits;
mLastStylusIdBits = mCurrentStylusIdBits;
mLastMouseIdBits = mCurrentMouseIdBits;
// Clear some transient state.
mCurrentRawVScroll = 0;
mCurrentRawHScroll = 0;
}
如果这是单击事件,会走到mDeviceMode == DEVICE_MODE_DIRECT这个判断中,这里面已经开始去dispatchEvent了。
总要是这三句话,我没有跟下去看,dispatchTouches(when, policyFlags);
void TouchInputMapper::dispatchTouches(nsecs_t when, uint32_t policyFlags) {
BitSet32 currentIdBits = mCurrentCookedPointerData.touchingIdBits;
BitSet32 lastIdBits = mLastCookedPointerData.touchingIdBits;
int32_t metaState = getContext()->getGlobalMetaState();
int32_t buttonState = mCurrentButtonState;
if (currentIdBits == lastIdBits) {
if (!currentIdBits.isEmpty()) {
// No pointer id changes so this is a move event.
// The listener takes care of batching moves so we don't have to deal with that here.
dispatchMotion(when, policyFlags, mSource,
AMOTION_EVENT_ACTION_MOVE, 0, metaState, buttonState,
AMOTION_EVENT_EDGE_FLAG_NONE,
mCurrentCookedPointerData.pointerProperties,
mCurrentCookedPointerData.pointerCoords,
mCurrentCookedPointerData.idToIndex,
currentIdBits, -1,
mOrientedXPrecision, mOrientedYPrecision, mDownTime);
}
} else {
// There may be pointers going up and pointers going down and pointers moving
// all at the same time.
BitSet32 upIdBits(lastIdBits.value & ~currentIdBits.value);
BitSet32 downIdBits(currentIdBits.value & ~lastIdBits.value);
BitSet32 moveIdBits(lastIdBits.value & currentIdBits.value);
BitSet32 dispatchedIdBits(lastIdBits.value);
// Update last coordinates of pointers that have moved so that we observe the new
// pointer positions at the same time as other pointers that have just gone up.
bool moveNeeded = updateMovedPointers(
mCurrentCookedPointerData.pointerProperties,
mCurrentCookedPointerData.pointerCoords,
mCurrentCookedPointerData.idToIndex,
mLastCookedPointerData.pointerProperties,
mLastCookedPointerData.pointerCoords,
mLastCookedPointerData.idToIndex,
moveIdBits);
if (buttonState != mLastButtonState) {
moveNeeded = true;
}
// Dispatch pointer up events.
while (!upIdBits.isEmpty()) {
uint32_t upId = upIdBits.clearFirstMarkedBit();
dispatchMotion(when, policyFlags, mSource,
AMOTION_EVENT_ACTION_POINTER_UP, 0, metaState, buttonState, 0,
mLastCookedPointerData.pointerProperties,
mLastCookedPointerData.pointerCoords,
mLastCookedPointerData.idToIndex,
dispatchedIdBits, upId,
mOrientedXPrecision, mOrientedYPrecision, mDownTime);
dispatchedIdBits.clearBit(upId);
}
// Dispatch move events if any of the remaining pointers moved from their old locations.
// Although applications receive new locations as part of individual pointer up
// events, they do not generally handle them except when presented in a move event.
if (moveNeeded) {
ALOG_ASSERT(moveIdBits.value == dispatchedIdBits.value);
dispatchMotion(when, policyFlags, mSource,
AMOTION_EVENT_ACTION_MOVE, 0, metaState, buttonState, 0,
mCurrentCookedPointerData.pointerProperties,
mCurrentCookedPointerData.pointerCoords,
mCurrentCookedPointerData.idToIndex,
dispatchedIdBits, -1,
mOrientedXPrecision, mOrientedYPrecision, mDownTime);
}
// Dispatch pointer down events using the new pointer locations.
while (!downIdBits.isEmpty()) {
uint32_t downId = downIdBits.clearFirstMarkedBit();
dispatchedIdBits.markBit(downId);
if (dispatchedIdBits.count() == 1) {
// First pointer is going down. Set down time.
mDownTime = when;
}
dispatchMotion(when, policyFlags, mSource,
AMOTION_EVENT_ACTION_POINTER_DOWN, 0, metaState, buttonState, 0,
mCurrentCookedPointerData.pointerProperties,
mCurrentCookedPointerData.pointerCoords,
mCurrentCookedPointerData.idToIndex,
dispatchedIdBits, downId,
mOrientedXPrecision, mOrientedYPrecision, mDownTime);
}
}
void TouchInputMapper::dispatchMotion(nsecs_t when, uint32_t policyFlags, uint32_t source,
int32_t action, int32_t flags, int32_t metaState, int32_t buttonState, int32_t edgeFlags,
const PointerProperties* properties, const PointerCoords* coords,
const uint32_t* idToIndex, BitSet32 idBits,
int32_t changedId, float xPrecision, float yPrecision, nsecs_t downTime) {
PointerCoords pointerCoords[MAX_POINTERS];
PointerProperties pointerProperties[MAX_POINTERS];
uint32_t pointerCount = 0;
while (!idBits.isEmpty()) {
uint32_t id = idBits.clearFirstMarkedBit();
uint32_t index = idToIndex[id];
pointerProperties[pointerCount].copyFrom(properties[index]);
pointerCoords[pointerCount].copyFrom(coords[index]);
if (changedId >= 0 && id == uint32_t(changedId)) {
action |= pointerCount << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT;
}
pointerCount += 1;
}
ALOG_ASSERT(pointerCount != 0);
if (changedId >= 0 && pointerCount == 1) {
// Replace initial down and final up action.
// We can compare the action without masking off the changed pointer index
// because we know the index is 0.
if (action == AMOTION_EVENT_ACTION_POINTER_DOWN) {
action = AMOTION_EVENT_ACTION_DOWN;
} else if (action == AMOTION_EVENT_ACTION_POINTER_UP) {
action = AMOTION_EVENT_ACTION_UP;
} else {
// Can't happen.
ALOG_ASSERT(false);
}
}
NotifyMotionArgs args(when, getDeviceId(), source, policyFlags,
action, flags, metaState, buttonState, edgeFlags,
pointerCount, pointerProperties, pointerCoords, xPrecision, yPrecision, downTime);
getListener()->notifyMotion(&args);
inline InputListenerInterface* getListener() { return mContext->getListener(); }
去直接调用ContextImpl::getListener()
......
InputListenerInterface* InputReader::ContextImpl::getListener() {
return mReader->mQueuedListener.get();
}
而mQueuedListener在InputReader的构造中传进来的,这就是InputDispater,我们可以去查看什么时候创建InputReader的,上文也提到过。
......
InputReader::InputReader(const sp& eventHub,
const sp& policy,
const sp& listener) :
mContext(this), mEventHub(eventHub), mPolicy(policy),
mGlobalMetaState(0), mGeneration(1),
mDisableVirtualKeysTimeout(LLONG_MIN), mNextTimeout(LLONG_MAX),
mConfigurationChangesToRefresh(0) {
mQueuedListener = new QueuedInputListener(listener);
void InputDispatcher::notifyMotion(const NotifyMotionArgs* args) {
#if DEBUG_INBOUND_EVENT_DETAILS
uint32_t policyFlags = args->policyFlags;
policyFlags |= POLICY_FLAG_TRUSTED;
mPolicy->interceptMotionBeforeQueueing(args->eventTime, /*byref*/ policyFlags);
bool needWake;
{ // acquire lock
mLock.lock();
if (mInputFilterEnabled) {
mLock.unlock();
MotionEvent event;
event.initialize(args->deviceId, args->source, args->action, 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;
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->flags, args->metaState, args->buttonState,
args->edgeFlags, args->xPrecision, args->yPrecision, args->downTime,
args->pointerCount, args->pointerProperties, args->pointerCoords);
needWake = enqueueInboundEventLocked(newEntry);
mLock.unlock();
} // release lock
if (needWake) {
mLooper->wake();
}
}
在NotifyMotion中首先回去调用mPolicy->interceptMotionBeforeQueueing 通过查询policy判断此次事件是否要传给User端,如果需要则通过policyFlags |= POLICY_FLAG_PASS_TO_USER;就加个Flag。里面的其他 策略暂时不清楚。这里的mPolicy实际上就是NativeInputManager对象,NativeInputManager继承了InputDispatcherPolicyInterface和InputReaderPolicyInterface。
void NativeInputManager::interceptMotionBeforeQueueing(nsecs_t when, uint32_t& policyFlags) {
// Policy:
// - Ignore untrusted events and pass them along.
// - No special filtering for injected events required at this time.
// - Filter normal events based on screen state.
// - For normal events brighten (but do not wake) the screen if currently dim.
if ((policyFlags & POLICY_FLAG_TRUSTED) && !(policyFlags & POLICY_FLAG_INJECTED)) {
if (isScreenOn()) {
policyFlags |= POLICY_FLAG_PASS_TO_USER;
if (!isScreenBright()) {
policyFlags |= POLICY_FLAG_BRIGHT_HERE;
}
} else {
JNIEnv* env = jniEnv();
jint wmActions = env->CallIntMethod(mCallbacksObj,
gCallbacksClassInfo.interceptMotionBeforeQueueingWhenScreenOff,
policyFlags);
if (checkAndClearExceptionFromCallback(env,
"interceptMotionBeforeQueueingWhenScreenOff")) {
wmActions = 0;
}
policyFlags |= POLICY_FLAG_WOKE_HERE | POLICY_FLAG_BRIGHT_HERE;
handleInterceptActions(wmActions, when, /*byref*/ policyFlags);
}
} else {
policyFlags |= POLICY_FLAG_PASS_TO_USER;
}
}
之后就会走到mPolicy->filterInputEvent(&event, policyFlags), 看看此次event要不要呗filter掉,我们这边是MotionEvent,return ture说明不会被filter,所以继续走下去就到
bool InputDispatcher::enqueueInboundEventLocked(EventEntry* entry) {
bool needWake = mInboundQueue.isEmpty();
mInboundQueue.enqueueAtTail(entry);
traceInboundQueueLengthLocked();
switch (entry->type) {
case EventEntry::TYPE_KEY: {
......
}
case EventEntry::TYPE_MOTION: {
MotionEntry* motionEntry = static_cast(entry);
if (motionEntry->action == AMOTION_EVENT_ACTION_DOWN
&& (motionEntry->source & AINPUT_SOURCE_CLASS_POINTER)
&& mInputTargetWaitCause == INPUT_TARGET_WAIT_CAUSE_APPLICATION_NOT_READY
&& mInputTargetWaitApplicationHandle != NULL) {
int32_t x = int32_t(motionEntry->pointerCoords[0].
getAxisValue(AMOTION_EVENT_AXIS_X));
int32_t y = int32_t(motionEntry->pointerCoords[0].
getAxisValue(AMOTION_EVENT_AXIS_Y));
sp touchedWindowHandle = findTouchedWindowAtLocked(x, y);
if (touchedWindowHandle != NULL
&& touchedWindowHandle->inputApplicationHandle
!= mInputTargetWaitApplicationHandle) {
// User touched a different application than the one we are waiting on.
// Flag the event, and start pruning the input queue.
mNextUnblockedEvent = motionEntry;
needWake = true;
}
}
break;
}
}
return needWake;
}
在这个函数中会先把这个Event加到mInboundQueue中,然后去findTouchedWindowAtLock找到我们在Screen上面点击的是哪个Window,如果找到了对象的handle就把mNextUnblockedEvent = motionEntry; mNextUnblockedEvent 会在InputDispatcher的循环处理中被作为下一个要处理的Event。
之后返回needWake = true 给notifyMotion,就会触发mLooper->wake(); 通过一连串复杂的管道通信,最后会恢复dispatchOnce继续运行
void InputDispatcher::dispatchOnce() {
nsecs_t nextWakeupTime = LONG_LONG_MAX;
{ // acquire lock
AutoMutex _l(mLock);
dispatchOnceInnerLocked(&nextWakeupTime);
if (runCommandsLockedInterruptible()) {
nextWakeupTime = LONG_LONG_MIN; // force next poll to wake up immediately
}
} // release lock
// Wait for callback or timeout or wake. (make sure we round up, not down)
nsecs_t currentTime = now();
int timeoutMillis = toMillisecondTimeoutDelay(currentTime, nextWakeupTime);
mLooper->pollOnce(timeoutMillis);
}
dispatchOnce()也是直接调用dispatchOnceInnerLocked去完成具体的事物。
void InputDispatcher::dispatchOnceInnerLocked(nsecs_t* nextWakeupTime) {
nsecs_t currentTime = now();
// Optimize latency of app switches.
// Essentially we start a short timeout when an app switch key (HOME / ENDCALL) has
// been pressed. When it expires, we preempt dispatch and drop all other pending events.
bool isAppSwitchDue = mAppSwitchDueTime <= currentTime;
if (mAppSwitchDueTime < *nextWakeupTime) {
*nextWakeupTime = mAppSwitchDueTime;
}
// Ready to start a new event.
// If we don't already have a pending event, go grab one.
if (! mPendingEvent) {
if (mInboundQueue.isEmpty()) {
if (isAppSwitchDue) {
// The inbound queue is empty so the app switch key we were waiting
// for will never arrive. Stop waiting for it.
resetPendingAppSwitchLocked(false);
isAppSwitchDue = false;
}
// Synthesize a key repeat if appropriate.
if (mKeyRepeatState.lastKeyEntry) {
if (currentTime >= mKeyRepeatState.nextRepeatTime) {
mPendingEvent = synthesizeKeyRepeatLocked(currentTime);
} else {
if (mKeyRepeatState.nextRepeatTime < *nextWakeupTime) {
*nextWakeupTime = mKeyRepeatState.nextRepeatTime;
}
}
}
// Nothing to do if there is no pending event.
if (!mPendingEvent) {
return;
}
} else {
// Inbound queue has at least one entry.
mPendingEvent = mInboundQueue.dequeueAtHead();
traceInboundQueueLengthLocked();
}
// Poke user activity for this event.
if (mPendingEvent->policyFlags & POLICY_FLAG_PASS_TO_USER) {
pokeUserActivityLocked(mPendingEvent);
}
// Get ready to dispatch the event.
resetANRTimeoutsLocked();
}
// Now we have an event to dispatch.
// All events are eventually dequeued and processed this way, even if we intend to drop them.
switch (mPendingEvent->type) {
case EventEntry::TYPE_CONFIGURATION_CHANGED: {
.......
}
case EventEntry::TYPE_DEVICE_RESET: {
......
}
case EventEntry::TYPE_KEY: {
.......
}
case EventEntry::TYPE_MOTION: {
MotionEntry* typedEntry = static_cast(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;
}
done = dispatchMotionLocked(currentTime, typedEntry,
&dropReason, nextWakeupTime);
break;
}
if (done) {
if (dropReason != DROP_REASON_NOT_DROPPED) {
dropInboundEventLocked(mPendingEvent, dropReason);
}
releasePendingEventLocked();
*nextWakeupTime = LONG_LONG_MIN; // force next poll to wake up immediately
}
}
这个函数中,先通过mPendingEvent = mInboundQueue.dequeueAtHead();去取得当前InboundQueue的Head event付给mPengdingEvent. 然后根据mPendingEvent->type的类型去判断Event的类型,我们这边是TYPE_MOTION, 之后就调用对应的dispatch函数。
bool InputDispatcher::dispatchMotionLocked(
nsecs_t currentTime, MotionEntry* entry, DropReason* dropReason, nsecs_t* nextWakeupTime) {
// Clean up if dropping the event.
if (*dropReason != DROP_REASON_NOT_DROPPED) {
setInjectionResultLocked(entry, *dropReason == DROP_REASON_POLICY
? INPUT_EVENT_INJECTION_SUCCEEDED : INPUT_EVENT_INJECTION_FAILED);
return true;
}
bool isPointerEvent = entry->source & AINPUT_SOURCE_CLASS_POINTER;
// Identify targets.
Vector inputTargets;
bool conflictingPointerActions = false;
int32_t injectionResult;
if (isPointerEvent) {
// Pointer event. (eg. touchscreen)
injectionResult = findTouchedWindowTargetsLocked(currentTime,
entry, inputTargets, nextWakeupTime, &conflictingPointerActions);
} else {
// Non touch event. (eg. trackball)
......
}
ALOGD("injectionResult = %d !!!!!!!!!!!!!!!!!", injectionResult);
if (injectionResult == INPUT_EVENT_INJECTION_PENDING) {
return false;
}
setInjectionResultLocked(entry, injectionResult);
if (injectionResult != INPUT_EVENT_INJECTION_SUCCEEDED) {
return true;
}
addMonitoringTargetsLocked(inputTargets);
// Dispatch the motion.
if (conflictingPointerActions) {
CancelationOptions options(CancelationOptions::CANCEL_POINTER_EVENTS,
"conflicting pointer actions");
synthesizeCancelationEventsForAllConnectionsLocked(options);
}
dispatchEventLocked(currentTime, entry, inputTargets);
return true;
}
int32_t InputDispatcher::findTouchedWindowTargetsLocked(nsecs_t currentTime,
const MotionEntry* entry, Vector& inputTargets, nsecs_t* nextWakeupTime,
bool* outConflictingPointerActions) {
enum InjectionPermission {
INJECTION_PERMISSION_UNKNOWN,
INJECTION_PERMISSION_GRANTED,
INJECTION_PERMISSION_DENIED
};
nsecs_t startTime = now();
.......
// Success! Output targets.
injectionResult = INPUT_EVENT_INJECTION_SUCCEEDED;
for (size_t i = 0; i < mTempTouchState.windows.size(); i++) {
const TouchedWindow& touchedWindow = mTempTouchState.windows.itemAt(i);
addWindowTargetLocked(touchedWindow.windowHandle, touchedWindow.targetFlags,
touchedWindow.pointerIds, inputTargets);
}
// Drop the outside or hover touch windows since we will not care about them
// in the next iteration.
mTempTouchState.filterNonAsIsTouchWindows();
addWindowTargetLocked 将找到的找到的Window放到InputTargets中,在后面dispatchEvent的时候会从InputTargets中去查找。
void InputDispatcher::addWindowTargetLocked(const sp& windowHandle,
int32_t targetFlags, BitSet32 pointerIds, Vector& inputTargets) {
inputTargets.push();
const InputWindowInfo* windowInfo = windowHandle->getInfo();
InputTarget& target = inputTargets.editTop();
target.inputChannel = windowInfo->inputChannel;
target.flags = targetFlags;
target.xOffset = - windowInfo->frameLeft;
target.yOffset = - windowInfo->frameTop;
target.scaleFactor = windowInfo->scaleFactor;
target.pointerIds = pointerIds;
}
void InputDispatcher::addMonitoringTargetsLocked(Vector& inputTargets) {
for (size_t i = 0; i < mMonitoringChannels.size(); i++) {
inputTargets.push();
InputTarget& target = inputTargets.editTop();
target.inputChannel = mMonitoringChannels[i];
target.flags = InputTarget::FLAG_DISPATCH_AS_IS;
target.xOffset = 0;
target.yOffset = 0;
target.pointerIds.clear();
target.scaleFactor = 1.0f;
}
}
void InputDispatcher::dispatchEventLocked(nsecs_t currentTime,
EventEntry* eventEntry, const Vector& inputTargets) {
#if DEBUG_DISPATCH_CYCLE
ALOGD("dispatchEventToCurrentInputTargets");
#endif
ALOG_ASSERT(eventEntry->dispatchInProgress); // should already have been set to true
pokeUserActivityLocked(eventEntry);
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 = mConnectionsByFd.valueAt(connectionIndex);
prepareDispatchCycleLocked(currentTime, connection, eventEntry, &inputTarget);
} else {
#if DEBUG_FOCUS
ALOGD("Dropping event delivery to target with channel '%s' because it "
"is no longer registered with the input dispatcher.",
inputTarget.inputChannel->getName().string());
#endif
}
}
}
关于InputChannel和Connection之间的关系,我转了老罗博客中的一段话:前面我们在分析应用程序注册键盘消息接收通道的过程时,在Step 18中(InputDispatcher.registerInputChannel),把Server端的InputChannel封装成了一个Connection,然后以这个InputChannel中的Receive Pipe Fd作为键值把这个Connection对象保存在mConnectionsByReceiveFd中。这里,既然我们已经通过mCurrentInputTargets得到了表示当前需要接收键盘事件的Activity窗口的InputTarget对象,而且这个InputTarget对象的inputChannel就表示当初在InputDispatcher中注册的Server端InputChannel,因此,这里就可以把这个Connection对象取出来,最后调用prepareDispatchCycleLocked函数来进一步处理。
void InputDispatcher::prepareDispatchCycleLocked(nsecs_t currentTime,
const sp& connection, EventEntry* eventEntry, const InputTarget* inputTarget) {
// Skip this event if the connection status is not normal.
// We don't want to enqueue additional outbound events if the connection is broken.
if (connection->status != Connection::STATUS_NORMAL) {
return;
}
// Split a motion event if needed.
if (inputTarget->flags & InputTarget::FLAG_SPLIT) {
ALOG_ASSERT(eventEntry->type == EventEntry::TYPE_MOTION);
MotionEntry* originalMotionEntry = static_cast(eventEntry);
if (inputTarget->pointerIds.count() != originalMotionEntry->pointerCount) {
MotionEntry* splitMotionEntry = splitMotionEvent(
originalMotionEntry, inputTarget->pointerIds);
if (!splitMotionEntry) {
return; // split event was dropped
}
enqueueDispatchEntriesLocked(currentTime, connection,
splitMotionEntry, inputTarget);
splitMotionEntry->release();
return;
}
}
// Not splitting. Enqueue dispatch entries for the event as is.
enqueueDispatchEntriesLocked(currentTime, connection, eventEntry, inputTarget);
}
void InputDispatcher::enqueueDispatchEntriesLocked(nsecs_t currentTime,
const sp& 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);
}
}
在开始处理Touch事件之前,这个函数会检查一下传进来的参数connection中的outboundQueue事件队列是否为空,如果不为空,就要看看当前要处理的事件和outboundQueue队列中的最后一个事件是不是同一个motion事件,如果是的话,并且从上面传进来的resumeWithAppendedMotionSample参数为true,这时候就要以流水线的方式来处理这些motion事件了。
接下来,就会把当前的键盘事件封装成一个DispatchEntry对象,然后添加到connection对象的outboundQueue队列中去,表示当前键盘事件是一个待处理的键盘事件。
当connection中的outboundQueue事件队列不为空,即wasEmpty为false时,说明当前这个Activity窗口正在处键盘事件了,因此,就不需要调用startDispatchCycleLocked来启动Activity窗口来处理这个事件了,因为一旦这个Activity窗口正在处键盘事件,它就会一直处理下去,直到它里的connection对象的outboundQueue为空为止。当connection中的outboundQueue事件队列为空时,就需要调用startDispatchCycleLocked来通知这个Activity窗口来执行键盘事件处理的流程了。
void InputDispatcher::startDispatchCycleLocked(nsecs_t currentTime,
const sp& connection) {
#if DEBUG_DISPATCH_CYCLE
ALOGD("channel '%s' ~ startDispatchCycle",
connection->getInputChannelName());
#endif
while (connection->status == Connection::STATUS_NORMAL
&& !connection->outboundQueue.isEmpty()) {
DispatchEntry* dispatchEntry = connection->outboundQueue.head;
dispatchEntry->deliveryTime = currentTime;
// Publish the event.
status_t status;
EventEntry* eventEntry = dispatchEntry->eventEntry;
switch (eventEntry->type) {
case EventEntry::TYPE_KEY: {
.......
}
case EventEntry::TYPE_MOTION: {
MotionEntry* motionEntry = static_cast(eventEntry);
PointerCoords scaledCoords[MAX_POINTERS];
const PointerCoords* usingCoords = motionEntry->pointerCoords;
// Set the X and Y offset depending on the input source.
float xOffset, yOffset, scaleFactor;
if ((motionEntry->source & AINPUT_SOURCE_CLASS_POINTER)
&& !(dispatchEntry->targetFlags & InputTarget::FLAG_ZERO_COORDS)) {
scaleFactor = dispatchEntry->scaleFactor;
xOffset = dispatchEntry->xOffset * scaleFactor;
yOffset = dispatchEntry->yOffset * scaleFactor;
if (scaleFactor != 1.0f) {
for (size_t i = 0; i < motionEntry->pointerCount; i++) {
scaledCoords[i] = motionEntry->pointerCoords[i];
scaledCoords[i].scale(scaleFactor);
}
usingCoords = scaledCoords;
}
} else {
xOffset = 0.0f;
yOffset = 0.0f;
scaleFactor = 1.0f;
// We don't want the dispatch target to know.
if (dispatchEntry->targetFlags & InputTarget::FLAG_ZERO_COORDS) {
for (size_t i = 0; i < motionEntry->pointerCount; i++) {
scaledCoords[i].clear();
}
usingCoords = scaledCoords;
}
}
// Publish the motion event.
status = connection->inputPublisher.publishMotionEvent(dispatchEntry->seq,
motionEntry->deviceId, motionEntry->source,
dispatchEntry->resolvedAction, dispatchEntry->resolvedFlags,
motionEntry->edgeFlags, motionEntry->metaState, motionEntry->buttonState,
xOffset, yOffset,
motionEntry->xPrecision, motionEntry->yPrecision,
motionEntry->downTime, motionEntry->eventTime,
motionEntry->pointerCount, motionEntry->pointerProperties,
usingCoords);
break;
}
......
}
// Check the result.
if (status) {
if (status == WOULD_BLOCK) {
if (connection->waitQueue.isEmpty()) {
ALOGE("channel '%s' ~ Could not publish event because the pipe is full. "
"This is unexpected because the wait queue is empty, so the pipe "
"should be empty and we shouldn't have any problems writing an "
"event to it, status=%d", connection->getInputChannelName(), status);
abortBrokenDispatchCycleLocked(currentTime, connection, true /*notify*/);
} else {
// Pipe is full and we are waiting for the app to finish process some events
// before sending more events to it.
#if DEBUG_DISPATCH_CYCLE
ALOGD("channel '%s' ~ Could not publish event because the pipe is full, "
"waiting for the application to catch up",
connection->getInputChannelName());
#endif
connection->inputPublisherBlocked = true;
}
} else {
ALOGE("channel '%s' ~ Could not publish event due to an unexpected error, "
"status=%d", connection->getInputChannelName(), status);
abortBrokenDispatchCycleLocked(currentTime, connection, true /*notify*/);
}
return;
}
// Re-enqueue the event on the wait queue.
connection->outboundQueue.dequeue(dispatchEntry);
traceOutboundQueueLengthLocked(connection);
connection->waitQueue.enqueueAtTail(dispatchEntry);
traceWaitQueueLengthLocked(connection);
}
}
转自老罗的博客: 这个函数主要围绕传进来的Connection对象做两件事情,一是从它的outboundQueue队列中取出当前需要处理的键盘事件,然后把这个事件记录在它的内部对象inputPublisher中,二是通过它的内部对象inputPublisher通知它所关联的Activity窗口,现在有键盘事件需要处理了。第一件事情是通过调用它的InputPublisher对象的publishKeyEvent函数来完成的,而第二件事情是通过调用它的InputPublisher对象的sendDispatchSignal来完成的。我们先来看InputPublisher的成员函数publishKeyEvent的实现,然后再回来分析它的另外一个成员函数sendDispatchSignal的实现。
这里所谓的发送信号通知,其实是通过向其内部一个管道的写端写入一个字符来实现的。前面我们分析应用程序注册键盘消息接收通道的过程时,在Step 21中(NativeInputQueue.registerInputChannel),它把一个InputChannel注册到应用程序主线程中的Looper对象中,然后应用程序的主线程就通过这个Looper对象睡眠等待在这个InputChannel中的前向管道中有新的内容可读了,这里的mSendPipeFd就是对应这个前向管道的写端。现在既然向这个前向管道的写端写入新的内容了,于是,应用程序的主线程就被唤醒了。
InputPublisher 和 InputConsumer都在InputTransport.cpp中,在connection类中就有一个InputPublisher类型的变量。一个用于发布,一个用于接收。
int NativeInputEventReceiver::handleEvent(int receiveFd, int events, void* data) {
if (events & (ALOOPER_EVENT_ERROR | ALOOPER_EVENT_HANGUP)) {
ALOGE("channel '%s' ~ Publisher closed input channel or an error occurred. "
"events=0x%x", getInputChannelName(), events);
return 0; // remove the callback
}
if (!(events & ALOOPER_EVENT_INPUT)) {
ALOGW("channel '%s' ~ Received spurious callback for unhandled poll event. "
"events=0x%x", getInputChannelName(), events);
return 1;
}
JNIEnv* env = AndroidRuntime::getJNIEnv();
status_t status = consumeEvents(env, false /*consumeBatches*/, -1);
mMessageQueue->raiseAndClearException(env, "handleReceiveCallback");
return status == OK || status == NO_MEMORY ? 1 : 0;
}
status_t NativeInputEventReceiver::consumeEvents(JNIEnv* env,
bool consumeBatches, nsecs_t frameTime) {
bool skipCallbacks = false;
for (;;) {
uint32_t seq;
InputEvent* inputEvent;
status_t status = mInputConsumer.consume(&mInputEventFactory,
consumeBatches, frameTime, &seq, &inputEvent);
if (status) {
if (status == WOULD_BLOCK) {
if (!skipCallbacks && !mBatchedInputEventPending
&& mInputConsumer.hasPendingBatch()) {
// There is a pending batch. Come back later.
mBatchedInputEventPending = true;
env->CallVoidMethod(mReceiverObjGlobal,
gInputEventReceiverClassInfo.dispatchBatchedInputEventPending);
}
return OK;
}
return status;
}
if (!skipCallbacks) {
jobject inputEventObj;
switch (inputEvent->getType()) {
case AINPUT_EVENT_TYPE_KEY:
case AINPUT_EVENT_TYPE_MOTION:
#if DEBUG_DISPATCH_CYCLE
ALOGD("channel '%s' ~ Received motion event.", getInputChannelName());
#endif
inputEventObj = android_view_MotionEvent_obtainAsCopy(env,
static_cast(inputEvent));
break;
}
if (inputEventObj) {
env->CallVoidMethod(mReceiverObjGlobal,
gInputEventReceiverClassInfo.dispatchInputEvent, seq, inputEventObj);
} else {
}
最后通过一个JNI转到调用InputEventReceiver.dispatchInputEvent
// Called from native code.
@SuppressWarnings("unused")
private void dispatchInputEvent(int seq, InputEvent event) {
mSeqMap.put(event.getSequenceNumber(), seq);
onInputEvent(event);
}
void enqueueInputEvent(InputEvent event,
InputEventReceiver receiver, int flags, boolean processImmediately) {
QueuedInputEvent q = obtainQueuedInputEvent(event, receiver, flags);
// Always enqueue the input event in order, regardless of its time stamp.
// We do this because the application or the IME may inject key events
// in response to touch events and we want to ensure that the injected keys
// are processed in the order they were received and we cannot trust that
// the time stamp of injected events are monotonic.
QueuedInputEvent last = mFirstPendingInputEvent;
if (last == null) {
mFirstPendingInputEvent = q;
} else {
while (last.mNext != null) {
last = last.mNext;
}
last.mNext = q;
}
if (processImmediately) {
doProcessInputEvents();
} else {
scheduleProcessInputEvents();
}
}
void doProcessInputEvents() {
while (mCurrentInputEvent == null && mFirstPendingInputEvent != null) {
QueuedInputEvent q = mFirstPendingInputEvent;
mFirstPendingInputEvent = q.mNext;
q.mNext = null;
mCurrentInputEvent = q;
deliverInputEvent(q);
}
private void deliverPointerEvent(QueuedInputEvent q) {
Log.d(TAG, "deliverPointerEvent ######################");
final MotionEvent event = (MotionEvent)q.mEvent;
final boolean isTouchEvent = event.isTouchEvent();
if (mInputEventConsistencyVerifier != null) {
if (isTouchEvent) {
mInputEventConsistencyVerifier.onTouchEvent(event, 0);
} else {
mInputEventConsistencyVerifier.onGenericMotionEvent(event, 0);
}
}
// If there is no view, then the event will not be handled.
if (mView == null || !mAdded) {
finishInputEvent(q, false);
return;
}
// Translate the pointer event for compatibility, if needed.
if (mTranslator != null) {
mTranslator.translateEventInScreenToAppWindow(event);
}
// Enter touch mode on down or scroll.
final int action = event.getAction();
if (action == MotionEvent.ACTION_DOWN || action == MotionEvent.ACTION_SCROLL) {
ensureTouchMode(true);
}
// Offset the scroll position.
if (mCurScrollY != 0) {
event.offsetLocation(0, mCurScrollY);
}
if (MEASURE_LATENCY) {
lt.sample("A Dispatching PointerEvents", System.nanoTime() - event.getEventTimeNano());
}
// Remember the touch position for possible drag-initiation.
if (isTouchEvent) {
mLastTouchPoint.x = event.getRawX();
mLastTouchPoint.y = event.getRawY();
}
// Dispatch touch to view hierarchy.
boolean handled = mView.dispatchPointerEvent(event);
if (MEASURE_LATENCY) {
lt.sample("B Dispatched PointerEvents ", System.nanoTime() - event.getEventTimeNano());
}
if (handled) {
finishInputEvent(q, true);
return;
}
// Pointer event was unhandled.
finishInputEvent(q, false);
}
在deliverPointerEvent中会通过mView去做真正的dispatch的工作,
public final boolean dispatchPointerEvent(MotionEvent event) {
if (event.isTouchEvent()) {
return dispatchTouchEvent(event);
} else {
return dispatchGenericMotionEvent(event);
}
}
public boolean dispatchTouchEvent(MotionEvent event) {
if (mInputEventConsistencyVerifier != null) {
mInputEventConsistencyVerifier.onTouchEvent(event, 0);
}
if (onFilterTouchEventForSecurity(event)) {
//noinspection SimplifiableIfStatement
ListenerInfo li = mListenerInfo;
if (li != null && li.mOnTouchListener != null && (mViewFlags & ENABLED_MASK) == ENABLED
&& li.mOnTouchListener.onTouch(this, event)) {
return true;
}
if (onTouchEvent(event)) {
return true;
}
}
if (mInputEventConsistencyVerifier != null) {
mInputEventConsistencyVerifier.onUnhandledEvent(event, 0);
}
return false;
}
当mView.dispatchPointerEvent完成之后会返回一个handled值,代表是否被接受处理了, 然后去调 finishInputEvent (ViewRootImpl.java);
private void finishInputEvent(QueuedInputEvent q, boolean handled) {
if (q != mCurrentInputEvent) {
throw new IllegalStateException("finished input event out of order");
}
if (q.mReceiver != null) {
q.mReceiver.finishInputEvent(q.mEvent, handled);
} else {
q.mEvent.recycleIfNeededAfterDispatch();
}
recycleQueuedInputEvent(q);
mCurrentInputEvent = null;
if (mFirstPendingInputEvent != null) {
scheduleProcessInputEvents();
}
}
public final void finishInputEvent(InputEvent event, boolean handled) {
if (event == null) {
throw new IllegalArgumentException("event must not be null");
}
if (mReceiverPtr == 0) {
Log.w(TAG, "Attempted to finish an input event but the input event "
+ "receiver has already been disposed.");
} else {
int index = mSeqMap.indexOfKey(event.getSequenceNumber());
if (index < 0) {
Log.w(TAG, "Attempted to finish an input event that is not in progress.");
} else {
int seq = mSeqMap.valueAt(index);
mSeqMap.removeAt(index);
nativeFinishInputEvent(mReceiverPtr, seq, handled);
}
}
event.recycleIfNeededAfterDispatch();
}
status_t NativeInputEventReceiver::finishInputEvent(uint32_t seq, bool handled) {
#if DEBUG_DISPATCH_CYCLE
ALOGD("channel '%s' ~ Finished input event.", getInputChannelName());
#endif
status_t status = mInputConsumer.sendFinishedSignal(seq, handled);
if (status) {
ALOGW("Failed to send finished signal on channel '%s'. status=%d",
getInputChannelName(), status);
}
return status;
}
status_t InputConsumer::sendFinishedSignal(uint32_t seq, bool handled) {
#if DEBUG_TRANSPORT_ACTIONS
ALOGD("channel '%s' consumer ~ sendFinishedSignal: seq=%u, handled=%s",
mChannel->getName().string(), seq, handled ? "true" : "false");
#endif
if (!seq) {
ALOGE("Attempted to send a finished signal with sequence number 0.");
return BAD_VALUE;
}
// Send finished signals for the batch sequence chain first.
size_t seqChainCount = mSeqChains.size();
if (seqChainCount) {
uint32_t currentSeq = seq;
uint32_t chainSeqs[seqChainCount];
size_t chainIndex = 0;
for (size_t i = seqChainCount; i-- > 0; ) {
const SeqChain& seqChain = mSeqChains.itemAt(i);
if (seqChain.seq == currentSeq) {
currentSeq = seqChain.chain;
chainSeqs[chainIndex++] = currentSeq;
mSeqChains.removeAt(i);
}
}
status_t status = OK;
while (!status && chainIndex-- > 0) {
status = sendUnchainedFinishedSignal(chainSeqs[chainIndex], handled);
}
if (status) {
// An error occurred so at least one signal was not sent, reconstruct the chain.
do {
SeqChain seqChain;
seqChain.seq = chainIndex != 0 ? chainSeqs[chainIndex - 1] : seq;
seqChain.chain = chainSeqs[chainIndex];
mSeqChains.push(seqChain);
} while (chainIndex-- > 0);
return status;
}
}
// Send finished signal for the last message in the batch.
return sendUnchainedFinishedSignal(seq, handled);
}
status_t InputPublisher::receiveFinishedSignal(uint32_t* outSeq, bool* outHandled) {
#if DEBUG_TRANSPORT_ACTIONS
ALOGD("channel '%s' publisher ~ receiveFinishedSignal",
mChannel->getName().string());
#endif
InputMessage msg;
status_t result = mChannel->receiveMessage(&msg);
if (result) {
*outSeq = 0;
*outHandled = false;
return result;
}
if (msg.header.type != InputMessage::TYPE_FINISHED) {
ALOGE("channel '%s' publisher ~ Received unexpected message of type %d from consumer",
mChannel->getName().string(), msg.header.type);
return UNKNOWN_ERROR;
}
*outSeq = msg.body.finished.seq;
*outHandled = msg.body.finished.handled;
return OK;
}
InputDispatcher::handleReceiveCallback 里面有一个循环会去调用receiveFinishedSignal, 并且block在那里,等receiveFinishedSignal有返回值。
在前面分析应用程序注册键盘消息接收通道过程的Step 21中,我们也说过,当应用程序的主线程因为这个InputChannel中的前向管道的写端唤醒时,InputDispatcher的成员函数handleReceiveCallback就会被回调,因此,接下来,应用程序的主线程就会被唤醒,然后执行InputDispatcher的成员函数handleReceiveCallback。
int InputDispatcher::handleReceiveCallback(int fd, int events, void* data) {
InputDispatcher* d = static_cast(data);
{ // acquire lock
AutoMutex _l(d->mLock);
ALOGD(" InputDispatcher::handleReceiveCallback !!!!!!!!!!!!!!!~~~~~~~~");
ssize_t connectionIndex = d->mConnectionsByFd.indexOfKey(fd);
if (connectionIndex < 0) {
ALOGE("Received spurious receive callback for unknown input channel. "
"fd=%d, events=0x%x", fd, events);
return 0; // remove the callback
}
bool notify;
sp connection = d->mConnectionsByFd.valueAt(connectionIndex);
if (!(events & (ALOOPER_EVENT_ERROR | ALOOPER_EVENT_HANGUP))) {
if (!(events & ALOOPER_EVENT_INPUT)) {
ALOGW("channel '%s' ~ Received spurious callback for unhandled poll event. "
"events=0x%x", connection->getInputChannelName(), events);
return 1;
}
nsecs_t currentTime = now();
bool gotOne = false;
status_t status;
for (;;) {
uint32_t seq;
bool handled;
status = connection->inputPublisher.receiveFinishedSignal(&seq, &handled);
if (status) {
break;
}
d->finishDispatchCycleLocked(currentTime, connection, seq, handled);
gotOne = true;
}
if (gotOne) {
d->runCommandsLockedInterruptible();
if (status == WOULD_BLOCK) {
return 1;
}
}
notify = status != DEAD_OBJECT || !connection->monitor;
if (notify) {
ALOGE("channel '%s' ~ Failed to receive finished signal. status=%d",
connection->getInputChannelName(), status);
}
} else {
// Monitor channels are never explicitly unregistered.
// We do it automatically when the remote endpoint is closed so don't warn
// about them.
notify = !connection->monitor;
if (notify) {
ALOGW("channel '%s' ~ Consumer closed input channel or an error occurred. "
"events=0x%x", connection->getInputChannelName(), events);
}
}
// Unregister the channel.
d->unregisterInputChannelLocked(connection->inputChannel, notify);
return 0; // remove the callback
} // release lock
}
参考文章: 老罗的http://blog.csdn.net/luoshengyang/article/details/6882903
UML 图:
https://skydrive.live.com/redir?resid=6C8CF3BF78BE0A95!317&authkey=!ALzNjtukl5Lw73o