device_class.hpp

#pragma once
 
#include <cstddef>
#include <cstdint>
 
#include "libxr_type.hpp"
#include "usb/core/desc_cfg.hpp"
 
namespace LibXR::USB
{
class DeviceComposition;
class DeviceCore;
 
class DeviceClass : public ConfigDescriptorItem
{
 public:
  DeviceClass() = default;
 
  virtual const char* GetInterfaceString(size_t local_interface_index) const
  {
    UNUSED(local_interface_index);
    return nullptr;
  }
 
  size_t GetBosCapabilityCount() override { return 0u; }
 
  BosCapability* GetBosCapability(size_t index) override
  {
    UNUSED(index);
    return nullptr;
  }
 
 protected:
  [[nodiscard]] uint8_t GetInterfaceStringIndex(size_t local_interface_index) const;
 
  struct ControlTransferResult
  {
    RawData read_data{nullptr, 0};  
    ConstRawData write_data{nullptr, 0};  
    bool read_zlp = false;   
    bool write_zlp = false;  
 
    RawData& OutData() { return read_data; }
    const RawData& OutData() const { return read_data; }
 
    ConstRawData& InData() { return write_data; }
    const ConstRawData& InData() const { return write_data; }
 
    bool& ExpectStatusOutZLP() { return read_zlp; }
    bool ExpectStatusOutZLP() const { return read_zlp; }
 
    bool& SendStatusInZLP() { return write_zlp; }
    bool SendStatusInZLP() const { return write_zlp; }
  };
 
  virtual ErrorCode OnGetDescriptor(bool in_isr, uint8_t bRequest, uint16_t wValue,
                                    uint16_t wLength, ConstRawData& out_data)
  {
    UNUSED(in_isr);
    UNUSED(bRequest);
    UNUSED(wValue);
    UNUSED(wLength);
    UNUSED(out_data);
    return ErrorCode::NOT_SUPPORT;
  }
 
  virtual ErrorCode OnClassRequest(bool in_isr, uint8_t bRequest, uint16_t wValue,
                                   uint16_t wLength, uint16_t wIndex,
                                   ControlTransferResult& result)
  {
    UNUSED(in_isr);
    UNUSED(bRequest);
    UNUSED(wValue);
    UNUSED(wLength);
    UNUSED(wIndex);
    UNUSED(result);
    return ErrorCode::NOT_SUPPORT;
  }
 
  virtual ErrorCode OnClassData(bool in_isr, uint8_t bRequest, LibXR::ConstRawData& data)
  {
    UNUSED(in_isr);
    UNUSED(bRequest);
    UNUSED(data);
    return ErrorCode::NOT_SUPPORT;
  }
 
  virtual void OnClassInDataStatusComplete(bool in_isr, uint8_t bRequest)
  {
    UNUSED(in_isr);
    UNUSED(bRequest);
  }
 
  virtual ErrorCode OnVendorRequest(bool in_isr, uint8_t bRequest, uint16_t wValue,
                                    uint16_t wLength, uint16_t wIndex,
                                    ControlTransferResult& result)
  {
    UNUSED(in_isr);
    UNUSED(bRequest);
    UNUSED(wValue);
    UNUSED(wLength);
    UNUSED(wIndex);
    UNUSED(result);
    return ErrorCode::NOT_SUPPORT;
  }
 
 private:
  // These helpers are driven by DeviceComposition during initialization-time string
  // registration and are not part of the public class contract.
  // 这些辅助函数只在初始化期由 DeviceComposition 调用，不属于对外类接口。
  void SetInterfaceStringBaseIndex(uint8_t string_index);
 
  friend class DeviceComposition;
  friend class DeviceCore;
 
  uint8_t interface_string_base_index_ =
      0u;  
};
 
}  // namespace LibXR::USB