.pro 文件概述

设备可以拥有自己的pro 文件用来映射自己特殊的键值，它的作用是将Linux scancode 转化为Openharmony keycode,scancode 就是硬件直接扫描到的数字，而这些数字会通过这个 pro文件找到对应的字符串也就是keycode.

配置文件示例

cat /vendor/etc/keymap/32002_2_3_BluetoothHID.pro
KEY_VOLUME_UP 115 17 HOS_KEY_VOLUME_DOWN     //  KEY_VOLUME_UP 115 Linux驱动键值   17 HOS_KEY_VOLUME_DOWN openharony 对应的系统键值
KEY_VOLUME_DOWN 114 16 HOS_KEY_VOLUME_DOWN

详细的Linux键值与openharony 系统键值对应关系可以参考

foundation/multimodalinput/input/service/event_handler/src/key_event_value_transformation.cpp 参考此结构体MAP_KEY_EVENT_VALUE_TRANSFORMATION
   {314, {"KEY_BUTTON_SELECT", 314, 2311, HOS_KEY_BUTTON_SELECT}},

   314：为nativeKeyValue 驱动上报键值
   KEY_BUTTON_SELECT：linux键值上报描述
   2311： openharmony 系统键值
   HOS_KEY_BUTTON_SELECT： 系统键值描述

流程图

配置文件解析流程

监听配置文件事件

foundation/multimodalinput/input/service/event_handler/src/event_normalize_handler.cpp
void EventNormalizeHandler::HandleEvent(libinput_event* event, int64_t frameTime)
{

    switch (type) {
        case LIBINPUT_EVENT_DEVICE_ADDED: {
            OnEventDeviceAdded(event);  // 设备添加信号
            break;
        }
    }

}

int32_t EventNormalizeHandler::OnEventDeviceAdded(libinput_event *event)
{
    CHKPR(event, ERROR_NULL_POINTER);
    auto device = libinput_event_get_device(event);
    CHKPR(device, ERROR_NULL_POINTER);
    InputDevMgr->OnInputDeviceAdded(device);
    KeyMapMgr->ParseDeviceConfigFile(device);    // 查找键值映射文件
    KeyRepeat->AddDeviceConfig(device);
#ifdef OHOS_BUILD_ENABLE_KEYBOARD
    KeyEventHdr->ResetKeyEvent(device);
#endif // OHOS_BUILD_ENABLE_KEYBOARD
    return RET_OK;
}

void KeyMapManager::ParseDeviceConfigFile(struct libinput_device *device)
{
    CHKPV(device);
    std::string fileName = GetKeyEventFileName(device);  // 获取设备号，配置文件
    if (fileName.empty()) {
        MMI_HILOGE("Get fileName is empty");
        return;
    }
    int32_t deviceId = InputDevMgr->FindInputDeviceId(device);
    GetConfigKeyValue(fileName, deviceId);   // 解析配置文件参数
}

void KeyMapManager::GetConfigKeyValue(const std::string &fileName, int32_t deviceId)
{
    CALL_DEBUG_ENTER;
    std::string filePath = GetProFilePath(fileName);
    ReadProFile(filePath, deviceId, configKeyValue_);
    MMI_HILOGD("Number of loaded config files:%{public}zu", configKeyValue_.size());
}

按键事件上报流程，解析配置文件

foundation/multimodalinput/input/service/key_event_normalize/src/key_event_normalize.cpp
int32_t KeyEventNormalize::Normalize(struct libinput_event *event, std::shared_ptr<KeyEvent> keyEvent)
{
    CALL_DEBUG_ENTER;
    CHKPR(event, PARAM_INPUT_INVALID);
    CHKPR(keyEvent, ERROR_NULL_POINTER);
    keyEvent->UpdateId();
    auto data = libinput_event_get_keyboard_event(event);
    CHKPR(data, ERROR_NULL_POINTER);

    auto device = libinput_event_get_device(event);
    CHKPR(device, ERROR_NULL_POINTER);
    int32_t deviceId = InputDevMgr->FindInputDeviceId(device);
    int32_t keyCode = static_cast<int32_t>(libinput_event_keyboard_get_key(data));
    MMI_HILOGD("The linux input keyCode:%{public}d", keyCode);
    keyCode = KeyMapMgr->TransferDeviceKeyValue(device, keyCode);  // 解析Linux键值，对应的系统键值
    int32_t keyAction = (libinput_event_keyboard_get_key_state(data) == 0) ?
        (KeyEvent::KEY_ACTION_UP) : (KeyEvent::KEY_ACTION_DOWN);
    auto preAction = keyEvent->GetAction();
    if (preAction == KeyEvent::KEY_ACTION_UP) {
        std::optional<KeyEvent::KeyItem> preUpKeyItem = keyEvent->GetKeyItem();
        if (preUpKeyItem) {
            keyEvent->RemoveReleasedKeyItems(*preUpKeyItem);
        } else {
            MMI_HILOGE("The preUpKeyItem is nullopt");
        }
    }
}

foundation/multimodalinput/input/service/event_handler/src/key_map_manager.cpp
int32_t KeyMapManager::TransferDeviceKeyValue(struct libinput_device *device,
    int32_t inputKey)
{
    CALL_DEBUG_ENTER;
    if (device == nullptr) {
        return TransferDefaultKeyValue(inputKey);
    }
    int32_t deviceId = InputDevMgr->FindInputDeviceId(device);
    if (auto itr = configKeyValue_.find(deviceId); itr != configKeyValue_.end()) {   // 有没有overrd 的键值，有返回
        if (auto devKey = itr->second.find(inputKey); devKey != itr->second.end()) {
            return devKey->second;
        }
    }
    return TransferDefaultKeyValue(inputKey);                                      //  没有返回默认键值
}