Android 事件处理流程
2010-03-19 07:14:00 来源:WEB开发网}
for(i = 1; i < mFDCount; i++) {
if(mFDs[i].revents) {
LOGV("revents for %d = 0x%08x", i, mFDs[i].revents);
if(mFDs[i].revents & POLLIN) {
res = read(mFDs[i].fd, &iev, sizeof(iev));
if (res == sizeof(iev)) {
LOGV("%s got: t0=%d, t1=%d, type=%d, code=%d, v=%d",
mDevices[i]->path.string(),
(int) iev.time.tv_sec, (int) iev.time.tv_usec,
iev.type, iev.code, iev.value);
*outDeviceId = mDevices[i]->id;
if (*outDeviceId == mFirstKeyboardId) *outDeviceId = 0;
*outType = iev.type;
*outScancode = iev.code;
if (iev.type == EV_KEY) {
err = mDevices[i]->layoutMap->map(iev.code, outKeycode, outFlags);
LOGV("iev.code=%d outKeycode=%d outFlags=0x%08x err=%d ",
iev.code, *outKeycode, *outFlags, err);
if (err != 0) {
*outKeycode = 0;
*outFlags = 0;
}
} else {
*outKeycode = iev.code;
}
*outValue = iev.value;
*outWhen = s2ns(iev.time.tv_sec) + us2ns(iev.time.tv_usec);
return true;
} else {
if (res<0) {
LOGW("could not get event (errno=%d)", errno);
} else {
LOGE("could not get event (wrong size: %d)", res);
}
continue;
}
}
}
}
...
}
对于按键事件,调用mDevices[i]->layoutMap->map进行映射。映射实际是由 KeyLayoutMap::map完成的,KeyLayoutMap类里读取配置文件qwerty.kl,由配置 文件 qwerty.kl 决定键值的映射关系。你可以通过修 改./development/emulator/keymaps/qwerty.kl来改变键值的映射关系。
JNI 函数
在frameworks/base/services/jni /com_android_server_KeyInputQueue.cpp文 件中,向 JAVA提供了函数android_server_KeyInputQueue_readEvent,用于读 取输入设备事件。
赞助商链接