Android加载键盘布局文件过程 无法加载日语键盘布局

一、系统启动过程中SystemServer添加WindowManagerService
Slog.i(TAG, "WindowManager");
wm = WindowManagerService.main(context, power,
factoryTest !=SystemServer.FACTORY_TEST_LOW_LEVEL);
ServiceManager.addService(Context.WINDOW_SERVICE, wm);

((ActivityManagerService)ServiceManager.getService("activity"))
.setWindowManager(wm);

mInputManager = newInputManager(context,this);//构造InputManager实例

PolicyThread thr= new PolicyThread(mPolicy, this, context, pm);
thr.start();

synchronized (thr){
while(!thr.mRunning) {
try {
thr.wait();
} catch (InterruptedException e) {
}
}
}

mInputManager.start();//调用InputManager.java start()函数

// Add ourself to the Watchdog monitors.
Watchdog.getInstance().addMonitor(this);
}

三、InputManager.java是本地c代码的包装类，对com_android_server_InputManager.cpp接口函数进行包装，以提供其他java文件调取。
1.初始化，InputManager.java构造函数中的init()最后调用nativeInit(mCallbacks)，
publicInputManager(Context context,WindowManagerService windowManagerService) {
this.mContext =context;
this.mWindowManagerService = windowManagerService;

this.mCallbacks =new Callbacks();

init();//调用init()函数
}

private void init(){
Slog.i(TAG, "Initializing input manager");
nativeInit(mCallbacks);//java接口，由本地函数实现
}

2.启动，InputManager.java的start()最后调用nativeStart()：
public void start(){
Slog.i(TAG, "Starting input manager");
nativeStart();//java接口，由本地函数实现
}

四、com_android_server_InputManager.cpp实现InutManager.java的nativeInit(mCallbacks和nativeStart()，当然还实现了其他功能的接口函数，这里不再介绍，对于android如何实现java和c之间的转换，我想对于了解jni的来说不难理解。不懂的可以看此文章学习：http://hi.baidu.com/kellyvivian/blog/item/09cfb541179d2f3387947397.html
1.初始化，android_server_InputManager_nativeInit在被执行的时候会new一个NativeInputManager(callbacks)实例，NativeInputManager(callbacks)接着又会new一个InputManager(eventHub,this, this)实例
static voidandroid_server_InputManager_nativeInit(JNIEnv* env, jclass clazz,
jobject callbacks) {
if (gNativeInputManager == NULL) {
gNativeInputManager= new NativeInputManager(callbacks);
} else {
LOGE("Input manager alreadyinitialized.");
jniThrowRuntimeException(env, "Inputmanager already initialized.");
}
}

NativeInputManager::NativeInputManager(jobjectcallbacksObj) :
mFilterTouchEvents(-1),mFilterJumpyTouchEvents(-1),mVirtualKeyQuietTime(-1),
mMaxEventsPerSecond(-1){
JNIEnv* env = jniEnv();

mCallbacksObj = env->NewGlobalRef(callbacksObj);

…….
sp eventHub = newEventHub();
mInputManager = newInputManager(eventHub, this,this);
}

2.启动，android_server_InputManager_nativeStart中gNativeInputManager->getInputManager()->start()最终调用的是InputManager.cpp的start()函数
static voidandroid_server_InputManager_nativeStart(JNIEnv* env, jclass clazz) {
if (checkInputManagerUnitialized(env)) {
return;
}

status_t result= gNativeInputManager->getInputManager()->start();
if (result) {
jniThrowRuntimeException(env, "Inputmanager could not be started.");
}
}

五、InputManager.cpp中主要有三个函数：initialize()初始化函数，在构造函数中调用；start()开启线程函数；stop()取消线程函数，在虚构函数中调用。
1.初始化，InputManager.cpp构造函数调用initialize()，期间new一个InputReaderThread线程
InputManager::InputManager(
const sp& eventHub,
const sp& readerPolicy,
const sp& dispatcherPolicy) {
mDispatcher = newInputDispatcher(dispatcherPolicy);
mReader = newInputReader(eventHub,readerPolicy, mDispatcher);
initialize();
}

voidInputManager::initialize() {
mReaderThread = newInputReaderThread(mReader);
mDispatcherThread = newInputDispatcherThread(mDispatcher);
}

2.启动，mReaderThread->run("InputReader",PRIORITY_URGENT_DISPLAY)开启初始化时new的InputReaderThread线程
status_t InputManager::start(){
……..

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

mDispatcherThread->requestExit();
returnresult;
}

returnOK;
}

六、InputReader.cpp中定义了InputReaderThread类，继承于Thread类
1.初始化，InputReaderThread构造函数，初始化一个Thread类
InputReaderThread::InputReaderThread(constsp& reader) :
Thread( true),mReader(reader){
}

2.启动，run启动线程，Threadrun()方法又调用InputReaderThread的虚函数threadLoop()，接着调用InputReader的loopOnce()方法，最后调用EventHub.cpp的getEvent(& rawEvent)方法
boolInputReaderThread::threadLoop() {
mReader->loopOnce();
return true;
}
void InputReader::loopOnce(){
RawEvent rawEvent;
mEventHub->getEvent(&rawEvent);

#ifDEBUG_RAW_EVENTS
LOGD("Input event: device=%dtype=0x%x scancode=%d keycode=%d value=%d",
rawEvent.deviceId, rawEvent.type, rawEvent.scanCode,rawEvent.keyCode,
rawEvent.value);
#endif

process(&rawEvent);
}

七、EventHub.cpp是android输入系统的硬件抽象层，维护输入设备的运行，包括Keyboard、TouchScreen、TraceBall等。
EventHub.cpp中依次执行getEvent()–>openPlatformInput()–>scanDir(DEVICE_PATH)–> openDevice(devname)

boolEventHub::openPlatformInput(void) {

int res, fd;
………
// Reserve fd index 0 for inotify.
struct pollfd pollfd;
pollfd.fd = fd;
pollfd.events =POLLIN;

pollfd.revents =0;
mFds.push(pollfd);
mDevices.push(NULL);

res = scanDir(DEVICE_PATH);//DEVICE_PATH ="/dev/input"
if(res < 0) {
LOGE("scan dir failed for%sn",DEVICE_PATH);
}

returntrue;
}

intEventHub::scanDir(const char*dirname)
{
……
openDevice(devname);
}
closedir(dir);
return 0;
}

openDevice方法会打开/dev/input目录下的所有设备文件，读取name、version、id等设备信息，然后执行loadConfiguration()方法，如果键盘设备就会执行loadKeyMap()这个方法
intEventHub::openDevice(const char*devicePath) {
……

// Load the configuration file for the device.
loadConfiguration(device);

……

if((device->classes &INPUT_DEVICE_CLASS_KEYBOARD) !=0) {
// Load the keymap for the device.
status_t status= loadKeyMap(device);

……
}

……
}

Honeycomb与之前版本不同之处是加入loadConfiguration()方法，它获取与当前设备驱动Vendor、Product、Version匹配的配置文件名，或者是Vendor、Product匹配的配置文件名，具体可查看Input.cpp中getInputDeviceConfigurationFilePathByDeviceIdentifie和getInputDeviceConfigurationFilePathByName方法。
如： kernel/drivers/input/keyboard/atkbd.c键盘驱动中定义了input_dev->id.vendor = 0×0001;input_dev->id.product = 0×0001;input_dev->id.version = 0xab41，那么与之对应的配置名为Vendor_0001_Product_0001_Version_ad41.idc，返回这个文件的全路径并赋值给device->configurationFile。如果/system/user/idc下存在此文件，接下来调用PropertyMap.cpp的load()方法解析该配置文件并将解析后的信息保存到device->configuration中。
voidEventHub::loadConfiguration(Device* device) {
device->configurationFile = getInputDeviceConfigurationFilePathByDeviceIdentifier(
device->identifier,INPUT_DEVICE_CONFIGURATION_FILE_TYPE_CONFIGURATION);
if (device->configurationFile.isEmpty()){
LOGD("No input deviceconfiguration file found for device ‘%s’.",
device->identifier.name.string());
} else {
status_t status= PropertyMap::load(device->configurationFile,
&device->configuration);
if(status) {
LOGE("Error loading inputdevice configuration file for device ‘%s’."
"Using defaultconfiguration.",
device->identifier.name.string());
}
}
}

EventHub.cpp中loadKeyMap又调用了Keyboard.cpp的KeyMap::load()方法
status_tEventHub::loadKeyMap(Device*device) {
return device->keyMap.load(device->identifier,device->configuration);
}

八、在Keyboard.cpp的load方法中，首先判断deviceConfiguration参数是否为空，deviceConfiguration的赋值就是上面loadConfiguration()方法所做的工作。
如果有.idc的配置文件，那么获取key为keyboard.layout的value给keyLayoutName和key为keyboard.characterMap的value给keyCharacterMapName，最后调用loadKeyLayout和loadKeyCharacterMap方法加载此键盘布局文件；如果没有对应的.idc配置文件，则deviceConfiguration为空，就会接着执行probeKeyMap(deviceIdenfifier,String8("Generic"))方法
status_tKeyMap::load(constInputDeviceIdentifier& deviceIdenfifier,
const PropertyMap* deviceConfiguration) {
// Use the configured key layout if available.
if (deviceConfiguration) {
String8 keyLayoutName;
if(deviceConfiguration->tryGetProperty(String8("keyboard.layout"),
keyLayoutName)) {
status_t status= loadKeyLayout(deviceIdenfifier, keyLayoutName);
if(status == NAME_NOT_FOUND) {
LOGE("Configuration forkeyboard device ‘%s’ requested keyboard layout ‘%s’ but"
"it was not found.",
deviceIdenfifier.name.string(),keyLayoutName.string());
}
}

String8 keyCharacterMapName;
if(deviceConfiguration->tryGetProperty(String8("keyboard.characterMap"),
keyCharacterMapName)) {
status_t status= loadKeyCharacterMap(deviceIdenfifier,keyCharacterMapName);
if(status == NAME_NOT_FOUND) {
LOGE("Configuration forkeyboard device ‘%s’ requested keyboard character "
"map ‘%s’ but it was notfound.",
deviceIdenfifier.name.string(),keyLayoutName.string());
}
}

if(isComplete()) {
returnOK;
}
}

……
if (probeKeyMap(deviceIdenfifier, String8("Generic"))) {
returnOK;
}
……
}

probeKeyMap方法判断名为Gerneric的布局文件是否存在，若存在就会调用loadKeyLayout和loadKeyCharacterMap方法加载此键盘布局文件
boolKeyMap::probeKeyMap(constInputDeviceIdentifier& deviceIdentifier,
const String8& keyMapName) {
if (!haveKeyLayout()) {
loadKeyLayout(deviceIdentifier,keyMapName);
}
if (!haveKeyCharacterMap()) {
loadKeyCharacterMap(deviceIdentifier, keyMapName);
}
return isComplete();
}

至此，AndroidHoneycomb已经正确加载了键盘布局文件，那么我们如何定制和使用自己的键盘布局文件呢？

#
# Emulatorkeyboard configuration file #1.
#

touch.deviceType= touchScreen
touch.orientationAware= 1

keyboard.layout = qwerty
keyboard.characterMap= qwerty
keyboard.orientationAware= 1
keyboard.builtIn = 1

cursor.mode = navigation
cursor.orientationAware= 1

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