input text 流程
sendMessage前
调用命令 input text 'helo world',会进入到函数 nativeInjectInputEvent
static jint nativeInjectInputEvent(JNIEnv* env, jclass /* clazz */,
jlong ptr, jobject inputEventObj, jint displayId, jint injectorPid, jint injectorUid,
jint syncMode, jint timeoutMillis, jint policyFlags) {
NativeInputManager* im = reinterpret_cast<NativeInputManager*>(ptr);
if (env->IsInstanceOf(inputEventObj, gKeyEventClassInfo.clazz)) { //KeyEvent类型
KeyEvent keyEvent;
// Java KeyEvent 转换 native层的
status_t status = android_view_KeyEvent_toNative(env, inputEventObj, & keyEvent);
if (status) {
jniThrowRuntimeException(env, "Could not read contents of KeyEvent object.");
return INPUT_EVENT_INJECTION_FAILED;
}
// injectInputEvent
return (jint) im->getInputManager()->getDispatcher()->injectInputEvent(
& keyEvent, displayId, injectorPid, injectorUid, syncMode, timeoutMillis,
uint32_t(policyFlags));
} else if (env->IsInstanceOf(inputEventObj, gMotionEventClassInfo.clazz)) { //MotionEvent类型
const MotionEvent* motionEvent = android_view_MotionEvent_getNativePtr(env, inputEventObj);
if (!motionEvent) {
jniThrowRuntimeException(env, "Could not read contents of MotionEvent object.");
return INPUT_EVENT_INJECTION_FAILED;
}
return (jint) im->getInputManager()->getDispatcher()->injectInputEvent(
motionEvent, displayId, injectorPid, injectorUid, syncMode, timeoutMillis,
uint32_t(policyFlags));
} else {
jniThrowRuntimeException(env, "Invalid input event type.");
return INPUT_EVENT_INJECTION_FAILED;
}
}
input text是KeyEvent类型,所以我们关注函数android_view_KeyEvent_toNative
// frameworks/base/core/jni/android_view_KeyEvent.cpp
status_t android_view_KeyEvent_toNative(JNIEnv* env, jobject eventObj,
KeyEvent* event) {
jint deviceId = env->GetIntField(eventObj, gKeyEventClassInfo.mDeviceId);
jint source = env->GetIntField(eventObj, gKeyEventClassInfo.mSource);
jint metaState = env->GetIntField(eventObj, gKeyEventClassInfo.mMetaState);
jint action = env->GetIntField(eventObj, gKeyEventClassInfo.mAction);
jint keyCode = env->GetIntField(eventObj, gKeyEventClassInfo.mKeyCode);
jint scanCode = env->GetIntField(eventObj, gKeyEventClassInfo.mScanCode);
jint repeatCount = env->GetIntField(eventObj, gKeyEventClassInfo.mRepeatCount);
jint flags = env->GetIntField(eventObj, gKeyEventClassInfo.mFlags);
jlong downTime = env->GetLongField(eventObj, gKeyEventClassInfo.mDownTime);
jlong eventTime = env->GetLongField(eventObj, gKeyEventClassInfo.mEventTime);
event->initialize(deviceId, source, action, flags, keyCode, scanCode, metaState, repeatCount,
milliseconds_to_nanoseconds(downTime),
milliseconds_to_nanoseconds(eventTime));
return OK;
}
android_view_KeyEvent_toNative函数实际是将Java的KeyEvent转换成Native的KeyEvent类型
// frameworks/native/services/inputflinger/InputDispatcher.cpp
int32_t InputDispatcher::injectInputEvent(const InputEvent* event, int32_t displayId,
int32_t injectorPid, int32_t injectorUid, int32_t syncMode, int32_t timeoutMillis,
uint32_t policyFlags) {
...
EventEntry* firstInjectedEntry;
EventEntry* lastInjectedEntry;
switch (event->getType()) {
case AINPUT_EVENT_TYPE_KEY: {
const KeyEvent* keyEvent = static_cast<const KeyEvent*>(event);
int32_t action = keyEvent->getAction();
if (! validateKeyEvent(action)) {
return INPUT_EVENT_INJECTION_FAILED;
}
int32_t flags = keyEvent->getFlags();
if (flags & AKEY_EVENT_FLAG_VIRTUAL_HARD_KEY) {
policyFlags |= POLICY_FLAG_VIRTUAL;
}
if (!(policyFlags & POLICY_FLAG_FILTERED)) {
mPolicy->interceptKeyBeforeQueueing(keyEvent, /*byref*/ policyFlags);
}
mLock.lock();
firstInjectedEntry = new KeyEntry(keyEvent->getEventTime(),
keyEvent->getDeviceId(), keyEvent->getSource(),
policyFlags, action, flags,
keyEvent->getKeyCode(), keyEvent->getScanCode(), keyEvent->getMetaState(),
keyEvent->getRepeatCount(), keyEvent->getDownTime());
lastInjectedEntry = firstInjectedEntry;
break;
}
case AINPUT_EVENT_TYPE_MOTION: {
...
}
bool needWake = false;
for (EventEntry* entry = firstInjectedEntry; entry != NULL; ) {
EventEntry* nextEntry = entry->next;
needWake |= enqueueInboundEventLocked(entry);
entry = nextEntry;
}
if (needWake) {
mLooper->wake();
}
...
}
injectInputEvent 函数中创建 KeyEntry, 调用enqueueInboundEventLocked(entry),将 entry放入队列
void InputDispatcher::dispatchOnceInnerLocked(nsecs_t* nextWakeupTime) {
...
case EventEntry::TYPE_KEY: {
KeyEntry* typedEntry = static_cast<KeyEntry*>(mPendingEvent);
if (isAppSwitchDue) {
if (isAppSwitchKeyEventLocked(typedEntry)) {
resetPendingAppSwitchLocked(true);
isAppSwitchDue = false;
} else if (dropReason == DROP_REASON_NOT_DROPPED) {
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;
}
// dispatch事件
done = dispatchKeyLocked(currentTime, typedEntry, &dropReason, nextWakeupTime);
break;
}
...
if (done) {
if (dropReason != DROP_REASON_NOT_DROPPED) {
dropInboundEventLocked(mPendingEvent, dropReason);
}
mLastDropReason = dropReason;
releasePendingEventLocked();
*nextWakeupTime = LONG_LONG_MIN; // force next poll to wake up immediately
}
}
前面只是添加到队列,但是处理队列的是 dispatchOnceInnerLocked 函数根据事件类型,再调用 dispatchKeyLocked
bool InputDispatcher::dispatchKeyLocked(nsecs_t currentTime, KeyEntry* entry,
DropReason* dropReason, nsecs_t* nextWakeupTime) {
...
// Identify targets.
Vector<InputTarget> inputTargets;
int32_t injectionResult = findFocusedWindowTargetsLocked(currentTime,
entry, inputTargets, nextWakeupTime);
if (injectionResult == INPUT_EVENT_INJECTION_PENDING) {
return false;
}
setInjectionResultLocked(entry, injectionResult);
if (injectionResult != INPUT_EVENT_INJECTION_SUCCEEDED) {
return true;
}
addMonitoringTargetsLocked(inputTargets);
// Dispatch the key.
dispatchEventLocked(currentTime, entry, inputTargets);
return true;
}
dispatchKeyLocked 中会根据某些条件判断是否丢掉事件, 如果不丢掉事件会继续向下调用 dispatchEventLocked 函数
void InputDispatcher::dispatchEventLocked(nsecs_t currentTime,
EventEntry* eventEntry, const Vector<InputTarget>& inputTargets) {
...
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> 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
}
}
}
从代码来看dispatchEventLocked中有两个函数,分别是pokeUserActivityLocked和prepareDispatchCycleLocked
其中pokeUserActivityLocked(eventEntry)方法最终会调用到Java层的PowerManagerService.java中的userActivityFromNative()方法
根据inputChannel的fd从mConnectionsByFd队列中查询目标connection.然后调用prepareDispatchCycleLocked
void InputDispatcher::prepareDispatchCycleLocked(nsecs_t currentTime,
const sp<Connection>& connection, EventEntry* eventEntry, const InputTarget* inputTarget) {
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);
}
}
prepareDispatchCycleLocked 最终会调用到 startDispatchCycleLocked
void InputDispatcher::startDispatchCycleLocked(nsecs_t currentTime,
const sp<Connection>& connection) {
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: {
KeyEntry* keyEntry = static_cast<KeyEntry*>(eventEntry);
// Publish the key event.
status = connection->inputPublisher.publishKeyEvent(dispatchEntry->seq,
keyEntry->deviceId, keyEntry->source,
dispatchEntry->resolvedAction, dispatchEntry->resolvedFlags,
keyEntry->keyCode, keyEntry->scanCode,
keyEntry->metaState, keyEntry->repeatCount, keyEntry->downTime,
keyEntry->eventTime);
break;
}
...
// Check the result.
if (status) { //正常情况应该为null
// 错误检查
return;
}
// Re-enqueue the event on the wait queue.
connection->outboundQueue.dequeue(dispatchEntry);
traceOutboundQueueLengthLocked(connection);
connection->waitQueue.enqueueAtTail(dispatchEntry);
traceWaitQueueLengthLocked(connection);
}
}
如果publishKeyEvent没有失败,则从outboundQueue中取出事件,放入到waitQueue队列中
// frameworks/native/libs/input/InputTransport.cpp
status_t InputPublisher::publishKeyEvent(
uint32_t seq,
int32_t deviceId,
int32_t source,
int32_t action,
int32_t flags,
int32_t keyCode,
int32_t scanCode,
int32_t metaState,
int32_t repeatCount,
nsecs_t downTime,
nsecs_t eventTime) {
#if DEBUG_TRANSPORT_ACTIONS
ALOGD("channel '%s' publisher ~ publishKeyEvent: seq=%u, deviceId=%d, source=0x%x, "
"action=0x%x, flags=0x%x, keyCode=%d, scanCode=%d, metaState=0x%x, repeatCount=%d,"
"downTime=%lld, eventTime=%lld",
mChannel->getName().string(), seq,
deviceId, source, action, flags, keyCode, scanCode, metaState, repeatCount,
downTime, eventTime);
#endif
if (!seq) {
ALOGE("Attempted to publish a key event with sequence number 0.");
return BAD_VALUE;
}
InputMessage msg;
msg.header.type = InputMessage::TYPE_KEY;
msg.body.key.seq = seq;
msg.body.key.deviceId = deviceId;
msg.body.key.source = source;
msg.body.key.action = action;
msg.body.key.flags = flags;
msg.body.key.keyCode = keyCode;
msg.body.key.scanCode = scanCode;
msg.body.key.metaState = metaState;
msg.body.key.repeatCount = repeatCount;
msg.body.key.downTime = downTime;
msg.body.key.eventTime = eventTime;
return mChannel->sendMessage(&msg);
}
sendMessage 向UI主线程发送input事件, 利用安卓消息机制,到nativePollOnce中
sendMessage前调用流程
// 接收event 放入Inbound队列
nativeInjectInputEvent --> android_view_KeyEvent_toNative --> InputDispatcher::injectInputEvent()
// 处理key event
dispatchKeyLocked --> dispatchEventLocked(currentTime, entry, inputTargets); --> dispatchEventLocked -->
prepareDispatchCycleLocked --> startDispatchCycleLocked --> publishKeyEvent --> mChannel->sendMessage(&msg) //到UI线程
sendMessage后
// system/core/libutils/Looper.cpp
// android_os_MessageQueue.cpp
MessageQueue.next() --> android_os_MessageQueue_nativePollOnce --> NativeMessageQueue::pollOnce() -- > Looper::pollOnce() --> Looper::pollInner() //轮询
int Looper::pollInner(int timeoutMillis) {
// Invoke all response callbacks.
for (size_t i = 0; i < mResponses.size(); i++) {
Response& response = mResponses.editItemAt(i);
if (response.request.ident == POLL_CALLBACK) {
int fd = response.request.fd;
int events = response.events;
void* data = response.request.data;
#if DEBUG_POLL_AND_WAKE || DEBUG_CALLBACKS
ALOGD("%p ~ pollOnce - invoking fd event callback %p: fd=%d, events=0x%x, data=%p",
this, response.request.callback.get(), fd, events, data);
#endif
// callback 初始化在
int callbackResult = response.request.callback->handleEvent(fd, events, data);
if (callbackResult == 0) {
removeFd(fd, response.request.seq);
}
// Clear the callback reference in the response structure promptly because we
// will not clear the response vector itself until the next poll.
response.request.callback.clear();
result = POLL_CALLBACK;
}
}
return result;
}
response.request.callback的赋值在Looper::addFd() 函数中,这段在完成InputManagerService.registerInputChannel()中调用,具体流程
WindowManagerService.addWindow() --> mInputManager.registerInputChannel() --> nativeRegisterInputChannel()
--> NativeInputManager::registerInputChannel() --> InputDispatcher::registerInputChannel() --> mLooper->addFd()
inputChannel 在 nativeRegisterInputChannel中创建的,其实取得是inputChannelObj的一个字段
static void nativeRegisterInputChannel(JNIEnv* env, jclass /* clazz */, jlong ptr, jobject inputChannelObj, jobject inputWindowHandleObj, jboolean monitor) {
NativeInputManager* im = reinterpret_cast<NativeInputManager*>(ptr);
// inputChannel在这创建的
sp<InputChannel> inputChannel = android_view_InputChannel_getInputChannel(env,
inputChannelObj);
sp<InputWindowHandle> inputWindowHandle =
android_server_InputWindowHandle_getHandle(env, inputWindowHandleObj);
status_t status = im->registerInputChannel(
env, inputChannel, inputWindowHandle, monitor);
...
if (! monitor) {
android_view_InputChannel_setDisposeCallback(env, inputChannelObj,
handleInputChannelDisposed, im);
}
}
// InputDispatcher::registerInputChannel
status_t InputDispatcher::registerInputChannel(const sp<InputChannel>& inputChannel,
const sp<InputWindowHandle>& inputWindowHandle, bool monitor) {
#if DEBUG_REGISTRATION
ALOGD("channel '%s' ~ registerInputChannel - monitor=%s", inputChannel->getName().string(),
toString(monitor));
#endif
{ // acquire lock
AutoMutex _l(mLock);
if (getConnectionIndexLocked(inputChannel) >= 0) {
ALOGW("Attempted to register already registered input channel '%s'",
inputChannel->getName().string());
return BAD_VALUE;
}
sp<Connection> connection = new Connection(inputChannel, inputWindowHandle, monitor);
// 从inputChannel取出fd
int fd = inputChannel->getFd();
mConnectionsByFd.add(fd, connection);
if (monitor) {
mMonitoringChannels.push(inputChannel);
}
mLooper->addFd(fd, 0, ALOOPER_EVENT_INPUT, handleReceiveCallback, this);
} // release lock
// Wake the looper because some connections have changed.
mLooper->wake();
return OK;
}
handleEvent 实际是NativeInputEventReceiver.handleEvent();
NativeInputEventReceiver的创建流程
ViewRootImpl.setView() --> new WindowInputEventReceiver() --> new InputEventReceiver() --> nativeInit() --> new NativeInputEventReceiver()
// frameworks/base/core/jni/android_view_InputEventReceiver.cpp
int NativeInputEventReceiver::handleEvent(int receiveFd, int events, void* data) {
...
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;
}
if (events & ALOOPER_EVENT_OUTPUT) {
for (size_t i = 0; i < mFinishQueue.size(); i++) {
const Finish& finish = mFinishQueue.itemAt(i);
status_t status = mInputConsumer.sendFinishedSignal(finish.seq, finish.handled);
...
}
mFinishQueue.clear();
setFdEvents(ALOOPER_EVENT_INPUT);
return 1;
}
...
}
handleEvent中有2个函数 consumeEvents 和 sendFinishedSignal
status_t NativeInputEventReceiver::consumeEvents(JNIEnv* env,
bool consumeBatches, nsecs_t frameTime, bool* outConsumedBatch) {
...
ScopedLocalRef<jobject> receiverObj(env, NULL);
bool skipCallbacks = false;
for (;;) {
uint32_t seq;
InputEvent* inputEvent;
int32_t displayId;
status_t status = mInputConsumer.consume(&mInputEventFactory,
consumeBatches, frameTime, &seq, &inputEvent, &displayId);
if (status) {
if (status == WOULD_BLOCK) {
if (!skipCallbacks && !mBatchedInputEventPending
&& mInputConsumer.hasPendingBatch()) {
if (!receiverObj.get()) {
receiverObj.reset(jniGetReferent(env, mReceiverWeakGlobal));
if (!receiverObj.get()) {
ALOGW("channel '%s' ~ Receiver object was finalized "
"without being disposed.", getInputChannelName());
return DEAD_OBJECT;
}
}
mBatchedInputEventPending = true;
// 调用java层的dispatchBatchedInputEventPending
env->CallVoidMethod(receiverObj.get(),
gInputEventReceiverClassInfo.dispatchBatchedInputEventPending);
if (env->ExceptionCheck()) {
ALOGE("Exception dispatching batched input events.");
mBatchedInputEventPending = false; // try again later
}
}
return OK;
}
ALOGE("channel '%s' ~ Failed to consume input event. status=%d",
getInputChannelName(), status);
return status;
}
assert(inputEvent);
if (!skipCallbacks) {
...
jobject inputEventObj;
switch (inputEvent->getType()) {
case AINPUT_EVENT_TYPE_KEY:
if (kDebugDispatchCycle) {
ALOGD("channel '%s' ~ Received key event.", getInputChannelName());
}
inputEventObj = android_view_KeyEvent_fromNative(env,
static_cast<KeyEvent*>(inputEvent));
break;
...
if (inputEventObj) {
// //执行Java层的InputEventReceiver.dispachInputEvent
env->CallVoidMethod(receiverObj.get(),
gInputEventReceiverClassInfo.dispatchInputEvent, seq, inputEventObj,
displayId);
if (env->ExceptionCheck()) {
ALOGE("Exception dispatching input event.");
skipCallbacks = true;
}
env->DeleteLocalRef(inputEventObj);
} else {
skipCallbacks = true;
}
}
if (skipCallbacks) {
mInputConsumer.sendFinishedSignal(seq, false);
}
}
}
如果inputEventObj不为null, 调用java层的InputEventReceiver.dispachInputEvent()
// frameworks/base/core/java/android/view/InputEventReceiver.java
// Called from native code.
@SuppressWarnings("unused")
private void dispatchInputEvent(int seq, InputEvent event, int displayId) {
mSeqMap.put(event.getSequenceNumber(), seq);
onInputEvent(eventdisplayId);
}
sendMessage后的流程
NativeInputEventReceiver::handleEvent() --> consumeEvents --> WindowInputEventReceiver.onInputEvent()
--> ViewRootImpl.enqueueInputEvent() --> ViewRootImpl.doProcessInputEvents() --> ViewRootImpl.deliverInputEvent()