10.10 Android input System _app get and process input event flow

App's registration process for Fd/inputchannel:

The Dispatchinputevent function of the new Windowinputeventreceiver extends Inputeventreceiver//inputeventreceiver class calls Oninputevent

The Oninputevent function is called after the event is received//called by the dispatchinputevent of the parent class

Call Nativeinit in the constructor of Inputeventreceiver

nativeinit//from Java into C + +

New Nativeinputeventreceiver

consumeevents//calls the Java layer's function dispatchinputevent

Dispatchinputevent

Finally, we'll add FD to the Epoll to monitor

App gets and handles input event flow

Pollonce

Polinner

epoll_wait//waiting for events to happen

Pushresponse (Events,mrequests.valueat (REQUESTINDEX)) constructs response into a buffer

response& Response = Mresponses.edititemat (i)//Remove from buffer Response

int callbackresult = response.request.callback->handleevent (fd,events,data)

Consumeevents (Env,false,-1,null)

Minputconsumer.consume (..., &seq,&inputevent)

Mchannel->receivemessage (&MMSG)

Nread =:: Recv (Mfd,msg,sizeof (inputmessage), msg_dontwait)

Initializekeyevent (KEYEVENT,&MMSG)

*outseq = MMsg.body.key.seq

*outevent = KeyEvent

Inputeventobj = Android_view_keyevent_fromnative (env,static_cast<keyevent*> (inputEvent))

Env->callvoidmethod (Receiverobj.get (), ginputeventreceivrrclassinfo.dispatchinputevent,seq,inputeventobj)

Oninputevent (Event)

Enqueueinputevent (Event,this,0,true)

Mpendinginputeventtail =q

doprocessinputevents//handles a multitude of input events

queueinputevent q = mpendinginputeventhead;

Mpendinginputeventhead = Q.mnext

Deliverinputevent (q)

stage = Q.shouldskipime ()? mfirstpostimeinputstage:mfirstinputstage;//if the application uses an input method, start processing from mfirstinputstage if the input method is not used , start processing from mfirstpostimeinputstage.

Stage.deliver (q)

The analysis of Inputstage stage

If your application uses input methods, start processing from mfirstinputstage, and if you do not use an IME, start processing from mfirstpostimeinputstage

　　

10.10 Android input System _app get and process input event flow