src/ui/input/lib/hid-input-report/device.h

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef SRC_UI_INPUT_LIB_HID_INPUT_REPORT_DEVICE_H_
#define SRC_UI_INPUT_LIB_HID_INPUT_REPORT_DEVICE_H_

#include <stddef.h>
#include <stdint.h>

#include <hid-parser/parser.h>
#include <hid-parser/report.h>
#include <hid-parser/units.h>

#include "src/ui/input/lib/hid-input-report/axis.h"

namespace hid_input_report {

enum class ParseResult : uint32_t {
  kOk = 0,
  kNoMemory = 1,
  kTooManyItems = 2,
  kReportSizeMismatch = 3,
  kNoCollection = 4,
  kBadReport = 5,
  kNotImplemented = 6,
  kItemNotFound = 7,
};

enum class DeviceType : uint32_t {
  kMouse = 1,
  kSensor = 2,
  kTouch = 3,
  kKeyboard = 4,
  kConsumerControl = 5,
};

template <typename T>
fidl::ObjectView<T> Extract(const uint8_t* data, size_t len, hid::Attributes attr,
                            fidl::AnyAllocator& allocator) {
  double value;
  if (!hid::ExtractAsUnitType(data, len, attr, &value)) {
    return fidl::ObjectView<T>();
  }
  return fidl::ObjectView<T>(allocator, value);
}

class Device {
 public:
  virtual ~Device() = default;

  virtual ParseResult ParseReportDescriptor(const hid::ReportDescriptor& hid_report_descriptor) = 0;

  virtual ParseResult SetOutputReport(const fuchsia_input_report::wire::OutputReport* report,
                                      uint8_t* data, size_t data_size, size_t* data_out_size) {
    return ParseResult::kNotImplemented;
  }

  virtual ParseResult CreateDescriptor(fidl::AnyAllocator& allocator,
                                       fuchsia_input_report::wire::DeviceDescriptor& descriptor) {
    return ParseResult::kNotImplemented;
  }

  virtual ParseResult ParseInputReport(const uint8_t* data, size_t len,
                                       fidl::AnyAllocator& allocator,
                                       fuchsia_input_report::wire::InputReport& input_report) {
    return ParseResult::kNotImplemented;
  }

  virtual uint8_t InputReportId() const = 0;
  virtual DeviceType GetDeviceType() const = 0;
};

// Create `out_device` from a HID descriptor. `out_device` is returned fully formed,
// it does not need any additional initialization.
ParseResult CreateDevice(const hid::ReportDescriptor* descriptor,
                         std::unique_ptr<Device>* out_device);

}  // namespace hid_input_report

#endif  // SRC_UI_INPUT_LIB_HID_INPUT_REPORT_DEVICE_H_