1 // Copyright 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef DEVICE_NFC_NFC_TAG_H_ 6 #define DEVICE_NFC_NFC_TAG_H_ 7 8 #include "device/nfc/nfc_tag_technology.h" 9 10 namespace device { 11 12 // NfcTag represents a remote NFC tag. An NFC tag is a passive NFC device, 13 // powered by the NFC field of the local adapter while it is in range. Tags 14 // can come in many forms, such as stickers, key fobs, or even embedded in a 15 // more sofisticated device. 16 // 17 // Tags can have a wide range of capabilities. Simple tags just offer 18 // read/write semantics, and contain some one time programmable areas to make 19 // read-only. More complex tags offer math operations and per-sector access 20 // control and authentication. The most sophisticated tags contain operating 21 // environments allowing complex interactions with the code executing on the 22 // tag. 23 // 24 // The NfcTag class facilitates possible interactions with a tag. The most 25 // common usage of a tag is to exchange NDEF messages, but different kinds of 26 // I/O can be performed using the NfcTagTechnology classes. 27 class NfcTag { 28 public: 29 // NFC tag types. 30 enum TagType { 31 kTagType1, 32 kTagType2, 33 kTagType3, 34 kTagType4 35 }; 36 37 // NFC protocols that a tag can support. A tag will usually support only one 38 // of these. 39 enum Protocol { 40 kProtocolFelica, 41 kProtocolIsoDep, 42 kProtocolJewel, 43 kProtocolMifare, 44 kProtocolNfcDep 45 }; 46 47 // Interface for observing changes from NFC tags. 48 class Observer { 49 public: ~Observer()50 virtual ~Observer() {} 51 52 // This method will be called when an NDEF message |message|, stored on the 53 // NFC tag |tag| has been read. Although NDEF is the most common record 54 // storage format for NFC tags, not all tags support it. This method won't 55 // be called if there are no records on an NDEF compliant tag or if the tag 56 // doesn't support NDEF. RecordsReceived(NfcTag * tag,const NfcNdefMessage & message)57 virtual void RecordsReceived(NfcTag* tag, const NfcNdefMessage& message) {} 58 }; 59 60 virtual ~NfcTag(); 61 62 // Adds and removes observers for events on this NFC tag. If monitoring 63 // multiple tags, check the |tag| parameter of observer methods to determine 64 // which tag is issuing the event. 65 virtual void AddObserver(Observer* observer) = 0; 66 virtual void RemoveObserver(Observer* observer) = 0; 67 68 // Returns the unique identifier assigned to this tag. 69 virtual std::string GetIdentifier() const = 0; 70 71 // Returns the current tag's NFC forum specified "type". 72 virtual TagType GetType() const = 0; 73 74 // Returns true, if this tag is read-only and cannot be written to. 75 virtual bool IsReadOnly() const = 0; 76 77 // Returns the current tag's supported NFC protocol. 78 virtual Protocol GetSupportedProtocol() const = 0; 79 80 // Returns a bitmask of the tag I/O technologies supported by this tag. 81 virtual NfcTagTechnology::TechnologyTypeMask 82 GetSupportedTechnologies() const = 0; 83 84 protected: 85 NfcTag(); 86 87 private: 88 DISALLOW_COPY_AND_ASSIGN(NfcTag); 89 }; 90 91 } // namespace device 92 93 #endif // DEVICE_NFC_NFC_TAG_H_ 94