device/usb/usb_device.h

// Copyright 2014 The Chromium 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 DEVICE_USB_USB_DEVICE_H_
#define DEVICE_USB_USB_DEVICE_H_

#include "base/basictypes.h"
#include "base/callback.h"
#include "base/memory/ref_counted.h"
#include "base/observer_list.h"
#include "base/strings/string16.h"

namespace device {

class UsbDeviceHandle;
struct UsbConfigDescriptor;

// A UsbDevice object represents a detected USB device, providing basic
// information about it. For further manipulation of the device, a
// UsbDeviceHandle must be created from Open() method.
class UsbDevice : public base::RefCountedThreadSafe<UsbDevice> {
 public:
  class Observer {
   public:
    virtual void OnDisconnect(scoped_refptr<UsbDevice> device) = 0;
  };

  // Accessors to basic information.
  uint16 vendor_id() const { return vendor_id_; }
  uint16 product_id() const { return product_id_; }
  uint32 unique_id() const { return unique_id_; }

#if defined(OS_CHROMEOS)
  // On ChromeOS, if an interface of a claimed device is not claimed, the
  // permission broker can change the owner of the device so that the unclaimed
  // interfaces can be used. If this argument is missing, permission broker will
  // not be used and this method fails if the device is claimed.
  virtual void RequestUsbAccess(
      int interface_id,
      const base::Callback<void(bool success)>& callback) = 0;
#endif  // OS_CHROMEOS

  // Creates a UsbDeviceHandle for further manipulation.
  // Blocking method. Must be called on FILE thread.
  virtual scoped_refptr<UsbDeviceHandle> Open() = 0;

  // Explicitly closes a device handle. This method will be automatically called
  // by the destructor of a UsbDeviceHandle as well.
  // Closing a closed handle is a safe
  // Blocking method. Must be called on FILE thread.
  virtual bool Close(scoped_refptr<UsbDeviceHandle> handle) = 0;

  // Gets the UsbConfigDescriptor for the active device configuration.
  // Blocking method. Must be called on FILE thread.
  virtual const UsbConfigDescriptor& GetConfiguration() = 0;

  // Gets the manufacturer string of the device, or returns false.
  // Blocking method. Must be called on FILE thread.
  virtual bool GetManufacturer(base::string16* manufacturer) = 0;

  // Gets the product string of the device, or returns false.
  // Blocking method. Must be called on FILE thread.
  virtual bool GetProduct(base::string16* product) = 0;

  // Gets the serial number string of the device, or returns false.
  // Blocking method. Must be called on FILE thread.
  virtual bool GetSerialNumber(base::string16* serial) = 0;

  void AddObserver(Observer* obs) { observer_list_.AddObserver(obs); }
  void RemoveObserver(Observer* obs) { observer_list_.RemoveObserver(obs); }

 protected:
  UsbDevice(uint16 vendor_id, uint16 product_id, uint32 unique_id);
  virtual ~UsbDevice();

  void NotifyDisconnect();

 private:
  friend class base::RefCountedThreadSafe<UsbDevice>;

  const uint16 vendor_id_;
  const uint16 product_id_;
  const uint32 unique_id_;

  ObserverList<Observer> observer_list_;

  DISALLOW_COPY_AND_ASSIGN(UsbDevice);
};

}  // namespace device

#endif  // DEVICE_USB_USB_DEVICE_H_