nfc: Add native NFC API definitions.

device/nfc/nfc_tag_technology.h

+// Copyright (c) 2013 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_NFC_NFC_TAG_TECHNOLOGY_H_
+#define DEVICE_NFC_NFC_TAG_TECHNOLOGY_H_
+
+#include "base/callback.h"
+#include "device/nfc/nfc_ndef_record.h"
+
+namespace device {
+
+class NfcTag;
+
+// NfcTagTechnology represents an NFC technology that allows a certain type of
+// I/O operation on an NFC tag. NFC tags can support a wide array of protocols.
+// The NfcTagTechnology hierarchy allows both raw and high-level I/O operations
+// on NFC tags.
+class NfcTagTechnology {
+ public:
+  // The various I/O technologies that an NFC tag can support.
+  enum TechnologyType {
+    kTechnologyTypeNfcA = 1 << 0,
+    kTechnologyTypeNfcB = 1 << 1,
+    kTechnologyTypeNfcF = 1 << 2,
+    kTechnologyTypeNfcV = 1 << 3,
+    kTechnologyTypeIsoDep = 1 << 4,
+    kTechnologyTypeNdef = 1 << 5
+  };
+  typedef uint32 TechnologyTypeMask;
+
+  virtual ~NfcTagTechnology();
+
+  // Returns true, if the underlying tag supports the NFC tag technology that
+  // this instance represents.
+  virtual bool IsSupportedByTag() const = 0;
+
+  // Returns a pointer to the associated NfcTag instance.
+  NfcTag* tag() const { return tag_; }
+
+ protected:
+  // Constructs a technology instance, where |tag| is the NFC tag that this
+  // instance will operate on. Clients aren't allowed to instantiate classes
+  // directly. They should use the static "Create" methods defined in each
+  // subclass to obtain the platform specific implementation.
+  explicit NfcTagTechnology(NfcTag* tag);
+
+ private:
+  NfcTagTechnology();
+
+  // The underlying NfcTag instance that data exchange operations through this
+  // instance are performed on.
+  NfcTag* tag_;
+
+  DISALLOW_COPY_AND_ASSIGN(NfcTagTechnology);
+};
+
+// NfcNdefTagTechnology allows reading and writing NDEF messages to a tag. This
+// is the most commonly used data exchange format in NFC.
+class NfcNdefTagTechnology : public NfcTagTechnology {
+ public:
+  // The ErrorCallback is used by methods to asynchronously report errors.
+  typedef base::Closure ErrorCallback;
+
+  virtual ~NfcNdefTagTechnology();
+
+  // NfcTagTechnology override.
+  virtual bool IsSupportedByTag() const OVERRIDE;
+
+  // Returns all NDEF records that were received from the tag in the form of an
+  // NDEF message. If the returned NDEF message contains no records, this only
+  // means that no records have yet been received from the tag. Users should
+  // use this method in conjunction with the NfcTag::Observer::RecordsReceived
+  // method to be notified when the records are ready.
+  virtual NfcNdefMessage GetNdefMessage() const = 0;
+
+  // Writes the given NDEF message to the underlying tag, overwriting any
+  // existing NDEF message on it. On success, |callback| will be invoked. On
+  // failure, |error_callback| will be invoked. This method can fail, if the
+  // underlying tag does not support NDEF as a technology.
+  virtual void WriteNdefMessage(const NfcNdefMessage& message,
+                                const base::Closure& callback,
+                                const ErrorCallback& error_callback) = 0;
+
+  // Static factory method for constructing an instance. The ownership of the
+  // returned instance belongs to the caller. Returns NULL, if NFC is not
+  // supported on the current platform.
+  static NfcNdefTagTechnology* Create(NfcTag* tag);
+
+ private:
+  // Constructs a technology instance, where |tag| is the NFC tag that this
+  // instance will operate on.
+  explicit NfcNdefTagTechnology(NfcTag* tag);
+
+  DISALLOW_COPY_AND_ASSIGN(NfcNdefTagTechnology);
+};
+
+}  // namespace device
+
+#endif  // DEVICE_NFC_NFC_TAG_TECHNOLOGY_H_