android 触摸事件传递(一)

android 触摸事件传递

1、主要相关代码路径

基于展讯7.0源码

native

frameworks/base/services/core/jni/com_android_server_input_InputManagerService.cpp
frameworks/native/services/inputflinger/EventHub.cpp
frameworks/native/services/inputflinger/InputDispatcher.cpp
frameworks/native/services/inputflinger/InputManager.cpp
frameworks/native/services/inputflinger/InputReader.cpp
frameworks/native/services/inputflinger/InputListener.cpp
frameworks/native/services/inputflinger/InputWindow.cpp

java

frameworks/base/services/java/com/android/server/SystemServer.java
frameworks/base/services/core/java/com/android/server/input/InputManagerService.java

RawEvent

struct RawEvent {
    nsecs_t when;
    int32_t deviceId;
    int32_t type;
    int32_t code;
    int32_t value;
};

NotifyArgs

struct NotifyArgs {
    virtual ~NotifyArgs() { }

    virtual void notify(const sp<InputListenerInterface>& listener) const = 0;
};

/* Describes a configuration change event. */
struct NotifyConfigurationChangedArgs : public NotifyArgs {}
/* Describes a key event. */
struct NotifyKeyArgs : public NotifyArgs {}
/* Describes a motion event. */
struct NotifyMotionArgs : public NotifyArgs {}
/* Describes a switch event. */
struct NotifySwitchArgs : public NotifyArgs {}
/* Describes a device reset event, such as when a device is added,
 * reconfigured, or removed. */
struct NotifyDeviceResetArgs : public NotifyArgs {}

InputManagerService 启动

/**
 * Starts a miscellaneous grab bag of stuff that has yet to be refactored
 * and organized.
 */
    private void startOtherServices() {
        ...
        inputManager = new InputManagerService(context);
        inputManager.setWindowManagerCallbacks(wm.getInputMonitor());
        inputManager.start();
        ...

    }

public InputManagerService(Context context) {
        this.mContext = context;
        this.mHandler = new InputManagerHandler(DisplayThread.get().getLooper());

        mUseDevInputEventForAudioJack =
                context.getResources().getBoolean(R.bool.config_useDevInputEventForAudioJack);
        //初始化native层        
        mPtr = nativeInit(this, mContext, mHandler.getLooper().getQueue());

        LocalServices.addService(InputManagerInternal.class, new LocalService());
    }

native层初始化

static jlong nativeInit(JNIEnv* env, jclass /* clazz */,
        jobject serviceObj, jobject contextObj, jobject messageQueueObj) {
    sp<MessageQueue> messageQueue = android_os_MessageQueue_getMessageQueue(env, messageQueueObj);
    if (messageQueue == NULL) {
        jniThrowRuntimeException(env, "MessageQueue is not initialized.");
        return 0;
    }
    //创建NativeInputManager
    NativeInputManager* im = new NativeInputManager(contextObj, serviceObj,
            messageQueue->getLooper());
    im->incStrong(0);
    //NativeInputManager服务对象的指针
    return reinterpret_cast<jlong>(im);
}

NativeInputManager::NativeInputManager(jobject contextObj,
        jobject serviceObj, const sp<Looper>& looper) :
        mLooper(looper), mInteractive(true) {
        .....
        //创建eventhub
    sp<EventHub> eventHub = new EventHub();
    mInputManager = new InputManager(eventHub, this, this);
}

创建事件分发和读取

InputManager::InputManager(
        const sp<EventHubInterface>& eventHub,
        const sp<InputReaderPolicyInterface>& readerPolicy,
        const sp<InputDispatcherPolicyInterface>& dispatcherPolicy) {
    mDispatcher = new InputDispatcher(dispatcherPolicy);
    mReader = new InputReader(eventHub, readerPolicy, mDispatcher);
    initialize();
}
void InputManager::initialize() {
    mReaderThread = new InputReaderThread(mReader);
    mDispatcherThread = new InputDispatcherThread(mDispatcher);
}

在SystemServer启动时inputManager.start();将会启动input的线程工作

public void start() {
        Slog.i(TAG, "Starting input manager");
        nativeStart(mPtr);
        .....
}        

static void nativeStart(JNIEnv* env, jclass /* clazz */, jlong ptr) {
    NativeInputManager* im = reinterpret_cast<NativeInputManager*>(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);
    if (result) {
        ALOGE("Could not start InputDispatcher thread due to error %d.", result);
        return result;
    }

    result = mReaderThread->run("InputReader", PRIORITY_URGENT_DISPLAY);
    if (result) {
        ALOGE("Could not start InputReader thread due to error %d.", result);

        mDispatcherThread->requestExit();
        return result;
    }

    return OK;
}