Add chrome://nfc-debug for debugging NFC on Chrome OS.

chrome/browser/ui/webui/chromeos/nfc_debug_ui.cc

+// 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.
+
+#include "chrome/browser/ui/webui/chromeos/nfc_debug_ui.h"
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/values.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/common/url_constants.h"
+#include "content/public/browser/web_ui.h"
+#include "content/public/browser/web_ui_data_source.h"
+#include "content/public/browser/web_ui_message_handler.h"
+#include "device/nfc/nfc_adapter.h"
+#include "device/nfc/nfc_adapter_factory.h"
+#include "device/nfc/nfc_peer.h"
+#include "device/nfc/nfc_tag.h"
+#include "grit/browser_resources.h"
+#include "grit/generated_resources.h"
+
+using device::NfcAdapter;
+using device::NfcAdapterFactory;
+using device::NfcNdefMessage;
+using device::NfcNdefRecord;
+using device::NfcNdefTagTechnology;
+using device::NfcPeer;
+using device::NfcTag;
+using device::NfcTagTechnology;
+
+namespace chromeos {
+
+namespace {
+
+// Keys for various NFC properties that are used by JS.
+const char kAdapterPeersProperty[] = "peers";
+const char kAdapterPollingProperty[] = "polling";
+const char kAdapterPoweredProperty[] = "powered";
+const char kAdapterPresentProperty[] = "present";
+const char kAdapterTagsProperty[] = "tags";
+
+const char kPeerIdentifierProperty[] = "identifier";
+const char kPeerRecordsProperty[] = "records";
+
+const char kTagIdentifierProperty[] = "identifier";
+const char kTagTypeProperty[] = "type";
+const char kTagReadOnlyProperty[] = "readOnly";
+const char kTagRecordsProperty[] = "records";
+const char kTagSupportedProtocolProperty[] = "supportedProtocol";
+const char kTagSupportedTechnologiesProperty[] = "supportedTechnologies";
+const char kRecordTypeProperty[] = "type";
+
+// Tag types.
+const char kTagType1[] = "TYPE-1";
+const char kTagType2[] = "TYPE-2";
+const char kTagType3[] = "TYPE-3";
+const char kTagType4[] = "TYPE-4";
+const char kTagTypeUnknown[] = "UNKNOWN";
+
+// NFC transfer protocols.
+const char kTagProtocolFelica[] = "FELICA";
+const char kTagProtocolIsoDep[] = "ISO-DEP";
+const char kTagProtocolJewel[] = "JEWEL";
+const char kTagProtocolMifare[] = "MIFARE";
+const char kTagProtocolNfcDep[] = "NFC-DEP";
+const char kTagProtocolUnknown[] = "UNKNOWN";
+
+// NFC tag technologies.
+const char kTagTechnologyNfcA[] = "NFC-A";
+const char kTagTechnologyNfcB[] = "NFC-B";
+const char kTagTechnologyNfcF[] = "NFC-F";
+const char kTagTechnologyNfcV[] = "NFC-V";
+const char kTagTechnologyIsoDep[] = "ISO-DEP";
+const char kTagTechnologyNdef[] = "NDEF";
+
+// NDEF types.
+const char kTypeHandoverCarrier[] = "HANDOVER_CARRIER";
+const char kTypeHandoverRequest[] = "HANDOVER_REQUEST";
+const char kTypeHandoverSelect[] = "HANDOVER_SELECT";
+const char kTypeSmartPoster[] = "SMART_POSTER";
+const char kTypeText[] = "TEXT";
+const char kTypeURI[] = "URI";
+const char kTypeUnknown[] = "UNKNOWN";
+
+// JavaScript callback constants.
+const char kInitializeCallback[] = "initialize";
+const char kSetAdapterPowerCallback[] = "setAdapterPower";
+const char kSetAdapterPollingCallback[] = "setAdapterPolling";
+const char kSubmitRecordFormCallback[] = "submitRecordForm";
+
+// Constants for JavaScript functions that we can call.
+const char kOnNfcAdapterInfoChangedFunction[] =
+    "nfc_debug.NfcDebugUI.onNfcAdapterInfoChanged";
+const char kOnNfcAvailabilityDeterminedFunction[] =
+    "nfc_debug.NfcDebugUI.onNfcAvailabilityDetermined";
+const char kOnNfcPeerDeviceInfoChangedFunction[] =
+    "nfc_debug.NfcDebugUI.onNfcPeerDeviceInfoChanged";
+const char kOnNfcTagInfoChangedFunction[] =
+    "nfc_debug.NfcDebugUI.onNfcTagInfoChanged";
+const char kOnSetAdapterPollingFailedFunction[] =
+    "nfc_debug.NfcDebugUI.onSetAdapterPollingFailed";
+const char kOnSetAdapterPowerFailedFunction[] =
+    "nfc_debug.NfcDebugUI.onSetAdapterPowerFailed";
+const char kOnSubmitRecordFormFailedFunction[] =
+    "nfc_debug.NfcDebugUI.onSubmitRecordFormFailed";
+
+std::string RecordTypeToString(NfcNdefRecord::Type type) {
+  switch (type) {
+    case NfcNdefRecord::kTypeHandoverCarrier:
+      return kTypeHandoverCarrier;
+    case NfcNdefRecord::kTypeHandoverRequest:
+      return kTypeHandoverRequest;
+    case NfcNdefRecord::kTypeHandoverSelect:
+      return kTypeHandoverSelect;
+    case NfcNdefRecord::kTypeSmartPoster:
+      return kTypeSmartPoster;
+    case NfcNdefRecord::kTypeText:
+      return kTypeText;
+    case NfcNdefRecord::kTypeURI:
+      return kTypeURI;
+    default:

[stevenjb, 2014/01/23 21:57:57]

remove default so that compiler will catch addition of new types; return
kTypeUnknown outside the switch.

[armansito, 2014/01/24 20:50:33]

Done.

+      return kTypeUnknown;
+  }
+}
+
+NfcNdefRecord::Type RecordTypeStringValueToEnum(const std::string& type) {
+  if (type == kTypeHandoverCarrier)
+    return NfcNdefRecord::kTypeHandoverCarrier;
+  if (type == kTypeHandoverRequest)
+    return NfcNdefRecord::kTypeHandoverRequest;
+  if (type == kTypeHandoverSelect)
+    return NfcNdefRecord::kTypeHandoverSelect;
+  if (type == kTypeSmartPoster)
+    return NfcNdefRecord::kTypeSmartPoster;
+  if (type == kTypeText)
+    return NfcNdefRecord::kTypeText;
+  if (type == kTypeURI)
+    return NfcNdefRecord::kTypeURI;
+  return NfcNdefRecord::kTypeUnknown;
+}
+
+std::string TagTypeToString(NfcTag::TagType type) {
+  switch (type) {
+    case NfcTag::kTagType1:
+      return kTagType1;
+    case NfcTag::kTagType2:
+      return kTagType2;
+    case NfcTag::kTagType3:
+      return kTagType3;
+    case NfcTag::kTagType4:
+      return kTagType4;
+    default:
+      return kTagTypeUnknown;

[stevenjb, 2014/01/23 21:57:57]

Same here.

[armansito, 2014/01/24 20:50:33]

Done.

+  }
+}
+
+std::string TagProtocolToString(NfcTag::Protocol protocol) {
+  switch (protocol) {
+    case NfcTag::kProtocolFelica:
+      return kTagProtocolFelica;
+    case NfcTag::kProtocolIsoDep:
+      return kTagProtocolIsoDep;
+    case NfcTag::kProtocolJewel:
+      return kTagProtocolJewel;
+    case NfcTag::kProtocolMifare:
+      return kTagProtocolMifare;
+    case NfcTag::kProtocolNfcDep:
+      return kTagProtocolNfcDep;
+    default:
+      return kTagProtocolUnknown;

[stevenjb, 2014/01/23 21:57:57]

Same here.

[armansito, 2014/01/24 20:50:33]

Done.

+  }
+}
+
+// content::WebUIMessageHandler implementation for this page.
+class NfcDebugMessageHandler : public content::WebUIMessageHandler,
+                               public NfcAdapter::Observer,
+                               public NfcNdefTagTechnology::Observer,
+                               public NfcPeer::Observer,
+                               public NfcTag::Observer {
+ public:
+  NfcDebugMessageHandler();
+  virtual ~NfcDebugMessageHandler();
+
+  // WebUIMessageHandler implementation.
+  virtual void RegisterMessages() OVERRIDE;
+
+  // NfcAdapter::Observer overrides.
+  virtual void AdapterPresentChanged(
+      NfcAdapter* adapter, bool present) OVERRIDE;

[stevenjb, 2014/01/23 21:57:57]

one line per arg unless entire declaration fits on one line, here and below.

[armansito, 2014/01/24 20:50:33]

Done.

+  virtual void AdapterPoweredChanged(
+      NfcAdapter* adapter, bool powered) OVERRIDE;
+  virtual void AdapterPollingChanged(
+      NfcAdapter* adapter, bool polling) OVERRIDE;
+  virtual void TagFound(NfcAdapter* adapter, NfcTag* tag) OVERRIDE;
+  virtual void TagLost(NfcAdapter*adapter, NfcTag* tag) OVERRIDE;
+  virtual void PeerFound(NfcAdapter* adaper, NfcPeer* peer) OVERRIDE;
+  virtual void PeerLost(NfcAdapter* adapter, NfcPeer* peer) OVERRIDE;
+
+  // NfcNdefTagTechnology::Observer override.
+  virtual void RecordReceived(
+      NfcTag* tag, const NfcNdefRecord* record) OVERRIDE;
+
+  // NfcPeer::Observer override.
+  virtual void RecordReceived(
+      NfcPeer* peer, const NfcNdefRecord* record) OVERRIDE;
+
+  // NfcTag::Observer override.
+  virtual void TagReady(NfcTag* tag) OVERRIDE;
+
+ private:
+  // Called by the UI when the page loads. This method requests information
+  // about NFC availability on the current platform and requests the underlying
+  // Adapter object. The UI is notified once the information is available.
+  void Initialize(const base::ListValue* args);
+
+  // Called by the UI to toggle the adapter power. |args| will contain one
+  // boolean that indicates whether the power should be set to ON or OFF.
+  void SetAdapterPower(const base::ListValue* args);
+  void OnSetAdapterPowerError();
+
+  // Called by the UI set the adapter's poll status. |args| will contain one
+  // boolean that indicates whether polling should be started or stopped.
+  void SetAdapterPolling(const base::ListValue* args);
+  void OnSetAdapterPollingError();
+
+  // Called by the UI to push an NDEF record to a remote device or tag. |args|
+  // will contain one dictionary that contains the record data.
+  void SubmitRecordForm(const base::ListValue* args);
+  void OnSubmitRecordFormFailed(const std::string& error_message);
+
+  // Callback passed to NfcAdapterFactory::GetAdapter.
+  void OnGetAdapter(scoped_refptr<NfcAdapter> adapter);
+
+  // Stores the properties of the NFC adapter in |out|, mapping these to keys
+  // that will be read by JS.
+  void GetAdapterProperties(base::DictionaryValue* out);
+
+  // Stores the properties of the NFC peer in |out|, mapping these to keys
+  // that will be read by JS. |out| will not be modified, if no peer is known.
+  void GetPeerProperties(base::DictionaryValue* out);
+
+  // Stores the properties of the NFC tag in |out|, mapping these to keys
+  // that will be read by JS. |out| will not be modified, if no tag is known.
+  void GetTagProperties(base::DictionaryValue* out);
+
+  // Returns the records in |message| by populating |out|, in which
+  // they have been converted to a JS friendly format.
+  void GetRecordList(const NfcNdefMessage& message, base::ListValue* out);
+
+  // Updates the data displayed in the UI for the current adapter.
+  void UpdateAdapterInfo();
+
+  // Updates the data displayed in the UI for the current peer.
+  void UpdatePeerInfo();
+
+  // Updates the data displayed in the UI for the current tag.
+  void UpdateTagInfo();
+
+  // The NfcAdapter object.
+  scoped_refptr<NfcAdapter> nfc_adapter_;
+
+  // The cached identifier of the most recent NFC peer device found.
+  std::string peer_identifier_;
+
+  // The cached identifier of the most recent NFC tag found.
+  std::string tag_identifier_;
+
+  DISALLOW_COPY_AND_ASSIGN(NfcDebugMessageHandler);
+};
+
+NfcDebugMessageHandler::NfcDebugMessageHandler() {
+}
+
+NfcDebugMessageHandler::~NfcDebugMessageHandler() {
+}
+
+void NfcDebugMessageHandler::AdapterPresentChanged(
+    NfcAdapter* adapter, bool present) {
+  UpdateAdapterInfo();
+}
+
+void NfcDebugMessageHandler::AdapterPoweredChanged(
+    NfcAdapter* adapter, bool powered) {
+  UpdateAdapterInfo();
+}
+
+void NfcDebugMessageHandler::AdapterPollingChanged(
+    NfcAdapter* adapter, bool polling) {
+  UpdateAdapterInfo();
+}
+
+void NfcDebugMessageHandler::TagFound(NfcAdapter* adapter, NfcTag* tag) {
+  VLOG(1) << "Found NFC tag: " << tag->GetIdentifier();
+  tag->AddObserver(this);
+  tag_identifier_ = tag->GetIdentifier();
+  tag->GetNdefTagTechnology()->AddObserver(this);
+  UpdateAdapterInfo();
+}
+
+void NfcDebugMessageHandler::TagLost(NfcAdapter*adapter, NfcTag* tag) {
+  VLOG(1) << "Lost NFC tag: " << tag->GetIdentifier();
+  tag->RemoveObserver(this);
+  tag->GetNdefTagTechnology()->RemoveObserver(this);
+  tag_identifier_.clear();
+  UpdateAdapterInfo();
+  UpdateTagInfo();
+}
+
+void NfcDebugMessageHandler::PeerFound(NfcAdapter* adaper, NfcPeer* peer) {
+  VLOG(1) << "Found NFC peer device: " << peer->GetIdentifier();
+  peer->AddObserver(this);
+  peer_identifier_ = peer->GetIdentifier();
+  UpdateAdapterInfo();
+  UpdatePeerInfo();
+}
+
+void NfcDebugMessageHandler::PeerLost(NfcAdapter* adapter, NfcPeer* peer) {
+  VLOG(1) << "Lost NFC peer device: " << peer->GetIdentifier();
+  peer->RemoveObserver(this);
+  peer_identifier_.clear();
+  UpdateAdapterInfo();
+  UpdatePeerInfo();
+}
+
+void NfcDebugMessageHandler::RecordReceived(
+      NfcTag* tag, const NfcNdefRecord* record) {

[stevenjb, 2014/01/23 21:57:57]

one line per arg, here and below

[armansito, 2014/01/24 20:50:33]

Done.

+  if (tag->GetIdentifier() != tag_identifier_) {
+    LOG(WARNING) << "Records received from unknown tag: "
+                 << tag->GetIdentifier();
+    return;
+  }
+  UpdateTagInfo();
+}
+
+void NfcDebugMessageHandler::RecordReceived(
+      NfcPeer* peer, const NfcNdefRecord* record) {
+  if (peer->GetIdentifier() != peer_identifier_) {
+    LOG(WARNING) << "Records received from unknown peer: "
+                 << peer->GetIdentifier();
+    return;
+  }
+  UpdatePeerInfo();
+}
+
+void NfcDebugMessageHandler::TagReady(NfcTag* tag) {
+  if (tag_identifier_ != tag->GetIdentifier()) {
+    LOG(WARNING) << "Unknown tag became ready: " << tag->GetIdentifier();
+    return;
+  }
+  VLOG(1) << "Tag ready: " << tag->GetIdentifier();
+  UpdateTagInfo();
+}
+
+void NfcDebugMessageHandler::RegisterMessages() {
+  web_ui()->RegisterMessageCallback(
+      kInitializeCallback,
+      base::Bind(&NfcDebugMessageHandler::Initialize,
+                 base::Unretained(this)));
+  web_ui()->RegisterMessageCallback(
+      kSetAdapterPowerCallback,
+      base::Bind(&NfcDebugMessageHandler::SetAdapterPower,
+                 base::Unretained(this)));
+  web_ui()->RegisterMessageCallback(
+      kSetAdapterPollingCallback,
+      base::Bind(&NfcDebugMessageHandler::SetAdapterPolling,
+                 base::Unretained(this)));
+  web_ui()->RegisterMessageCallback(
+      kSubmitRecordFormCallback,
+      base::Bind(&NfcDebugMessageHandler::SubmitRecordForm,
+                 base::Unretained(this)));
+}
+
+void NfcDebugMessageHandler::Initialize(const base::ListValue* args) {
+  bool nfc_available = NfcAdapterFactory::IsNfcAvailable();
+  base::FundamentalValue available(nfc_available);
+  web_ui()->CallJavascriptFunction(kOnNfcAvailabilityDeterminedFunction,
+                                   available);
+  if (!nfc_available) {
+    LOG(WARNING) << "NFC is not available on current platform.";
+    return;
+  }
+  NfcAdapterFactory::GetAdapter(
+      base::Bind(&NfcDebugMessageHandler::OnGetAdapter,
+                 base::Unretained(this)));
+}
+
+void NfcDebugMessageHandler::SetAdapterPower(const base::ListValue* args) {
+  DCHECK(1 == args->GetSize());
+  DCHECK(nfc_adapter_.get());
+  bool powered;
+  args->GetBoolean(0, &powered);
+  VLOG(1) << "Setting adapter power: " << powered;
+  nfc_adapter_->SetPowered(
+      powered, base::Bind(&base::DoNothing),
+      base::Bind(&NfcDebugMessageHandler::OnSetAdapterPowerError,
+                 base::Unretained(this)));
+}
+
+void NfcDebugMessageHandler::OnSetAdapterPowerError() {
+  LOG(ERROR) << "Failed to set NFC adapter power.";
+  web_ui()->CallJavascriptFunction(kOnSetAdapterPowerFailedFunction);
+}
+
+void NfcDebugMessageHandler:: SetAdapterPolling(const base::ListValue* args) {
+  DCHECK(1 == args->GetSize());
+  DCHECK(nfc_adapter_.get());
+  bool start;

[stevenjb, 2014/01/23 21:57:57]

Initialize start or check result of GetBoolean.

[armansito, 2014/01/24 20:50:33]

Done.

+  args->GetBoolean(0, &start);
+  if (start) {
+    VLOG(1) << "Starting NFC poll loop.";
+    nfc_adapter_->StartPolling(
+        base::Bind(&base::DoNothing),
+        base::Bind(&NfcDebugMessageHandler::OnSetAdapterPollingError,
+                   base::Unretained(this)));
+  } else {
+    VLOG(1) << "Stopping NFC poll loop.";
+    nfc_adapter_->StopPolling(
+        base::Bind(&base::DoNothing),
+        base::Bind(&NfcDebugMessageHandler::OnSetAdapterPollingError,
+                   base::Unretained(this)));
+  }
+}
+
+void NfcDebugMessageHandler::OnSetAdapterPollingError() {
+  LOG(ERROR) << "Failed to start/stop polling.";
+  web_ui()->CallJavascriptFunction(kOnSetAdapterPollingFailedFunction);
+}
+
+void NfcDebugMessageHandler::SubmitRecordForm(const base::ListValue* args) {
+  DCHECK(1 == args->GetSize());
+  DCHECK(nfc_adapter_.get());
+  const base::DictionaryValue* record_data_const = NULL;
+  if (!args->GetDictionary(0, &record_data_const)) {
+    NOTREACHED();
+    return;
+  }
+
+  if (peer_identifier_.empty() && tag_identifier_.empty()) {
+    OnSubmitRecordFormFailed("No peer or tag present.");
+    return;
+  }
+
+  std::string type;
+  if (!record_data_const->GetString(kRecordTypeProperty, &type)) {
+    OnSubmitRecordFormFailed("Record type not provided.");
+    return;
+  }
+
+  base::DictionaryValue* record_data = record_data_const->DeepCopy();
+  record_data->Remove(kRecordTypeProperty, NULL);
+
+  // Convert the "targetSize" field to a double, in case JS stored it as an
+  // integer.
+  int target_size;
+  if (record_data->GetInteger(NfcNdefRecord::kFieldTargetSize, &target_size)) {
+    record_data->SetDouble(NfcNdefRecord::kFieldTargetSize,
+                           static_cast<double>(target_size));
+  }
+
+  NfcNdefRecord record;
+  if (!record.Populate(RecordTypeStringValueToEnum(type), record_data)) {
+    OnSubmitRecordFormFailed("Invalid record data provided. Missing required "
+                             "fields?");
+    return;
+  }
+
+  if (!peer_identifier_.empty()) {
+    NfcPeer* peer = nfc_adapter_->GetPeer(peer_identifier_);
+    if (!peer) {
+      OnSubmitRecordFormFailed("The current NFC adapter doesn't seem to know "
+                               "about peer: " + peer_identifier_);
+      return;
+    }
+    NfcNdefMessage message;
+    message.AddRecord(&record);
+    peer->PushNdef(message,
+                   base::Bind(&base::DoNothing),
+                   base::Bind(&NfcDebugMessageHandler::OnSubmitRecordFormFailed,
+                              base::Unretained(this),
+                              "Failed to push NDEF record."));
+    return;
+  }
+  NfcTag* tag = nfc_adapter_->GetTag(tag_identifier_);
+  if (!tag) {
+    OnSubmitRecordFormFailed("The current NFC tag doesn't seem to known about "
+                             "tag: " + tag_identifier_);
+    return;
+  }
+  NfcNdefMessage message;
+  message.AddRecord(&record);
+  tag->GetNdefTagTechnology()->WriteNdef(
+                 message,
+                 base::Bind(&base::DoNothing),
+                 base::Bind(&NfcDebugMessageHandler::OnSubmitRecordFormFailed,
+                            base::Unretained(this),
+                            "Failed to write NDEF record."));
+}
+
+void NfcDebugMessageHandler::OnSubmitRecordFormFailed(
+    const std::string& error_message) {
+  LOG(ERROR) << "SubmitRecordForm failed: " << error_message;
+  web_ui()->CallJavascriptFunction(kOnSubmitRecordFormFailedFunction,
+                                   base::StringValue(error_message));
+}
+
+void NfcDebugMessageHandler::OnGetAdapter(
+    scoped_refptr<NfcAdapter> adapter) {
+  if (nfc_adapter_.get())
+    return;
+  nfc_adapter_ = adapter;
+  nfc_adapter_->AddObserver(this);
+  UpdateAdapterInfo();
+
+  NfcAdapter::PeerList peers;
+  nfc_adapter_->GetPeers(&peers);
+  for (NfcAdapter::PeerList::const_iterator iter = peers.begin();
+       iter != peers.end(); ++iter) {
+    PeerFound(nfc_adapter_.get(), *iter);
+  }
+}
+
+void NfcDebugMessageHandler::GetAdapterProperties(
+    base::DictionaryValue* out) {
+  if (!nfc_adapter_.get()) {
+    VLOG(1) << "NFC adapter hasn't been received yet.";
+    return;
+  }
+  out->SetBoolean(kAdapterPresentProperty, nfc_adapter_->IsPresent());
+  out->SetBoolean(kAdapterPollingProperty, nfc_adapter_->IsPolling());
+  out->SetBoolean(kAdapterPoweredProperty, nfc_adapter_->IsPowered());
+
+  NfcAdapter::PeerList peers;
+  nfc_adapter_->GetPeers(&peers);
+  out->SetInteger(kAdapterPeersProperty, static_cast<int>(peers.size()));
+
+  NfcAdapter::TagList tags;
+  nfc_adapter_->GetTags(&tags);
+  out->SetInteger(kAdapterTagsProperty, static_cast<int>(tags.size()));
+}
+
+void NfcDebugMessageHandler::GetPeerProperties(base::DictionaryValue* out) {
+  if (peer_identifier_.empty()) {
+    VLOG(1) << "No known peer exists.";
+    return;
+  }
+  if (!nfc_adapter_.get()) {
+    VLOG(1) << "NFC adapter hasn't been received yet.";
+    return;
+  }
+  NfcPeer* peer = nfc_adapter_->GetPeer(peer_identifier_);
+  if (!peer) {
+    LOG(ERROR) << "The current NFC adapter doesn't seem to know about peer: "
+               << peer_identifier_;
+    return;
+  }
+  out->SetString(kPeerIdentifierProperty, peer_identifier_);
+
+  base::ListValue* records = new base::ListValue();
+  GetRecordList(peer->GetNdefMessage(), records);
+  out->Set(kPeerRecordsProperty, records);
+}
+
+void NfcDebugMessageHandler::GetTagProperties(base::DictionaryValue* out) {
+  if (tag_identifier_.empty()) {
+    VLOG(1) << "No known tag exists.";
+    return;
+  }
+  if (!nfc_adapter_.get()) {
+    VLOG(1) << "NFC adapter hasn't been received yet.";
+    return;
+  }
+  NfcTag* tag = nfc_adapter_->GetTag(tag_identifier_);
+  if (!tag) {
+    LOG(ERROR) << "The current NFC adapter doesn't seem to know about tag: "
+               << tag_identifier_;
+    return;
+  }
+  out->SetString(kTagIdentifierProperty, tag_identifier_);
+  out->SetString(kTagTypeProperty, TagTypeToString(tag->GetType()));
+  out->SetBoolean(kTagReadOnlyProperty, tag->IsReadOnly());
+  out->SetString(kTagSupportedProtocolProperty,
+                 TagProtocolToString(tag->GetSupportedProtocol()));
+
+  base::ListValue* technologies = new base::ListValue();
+  NfcTagTechnology::TechnologyTypeMask technology_mask =
+      tag->GetSupportedTechnologies();
+  if (technology_mask & NfcTagTechnology::kTechnologyTypeNfcA)
+    technologies->AppendString(kTagTechnologyNfcA);
+  if (technology_mask & NfcTagTechnology::kTechnologyTypeNfcB)
+    technologies->AppendString(kTagTechnologyNfcB);
+  if (technology_mask & NfcTagTechnology::kTechnologyTypeNfcF)
+    technologies->AppendString(kTagTechnologyNfcF);
+  if (technology_mask & NfcTagTechnology::kTechnologyTypeNfcV)
+    technologies->AppendString(kTagTechnologyNfcV);
+  if (technology_mask & NfcTagTechnology::kTechnologyTypeIsoDep)
+    technologies->AppendString(kTagTechnologyIsoDep);
+  if (technology_mask & NfcTagTechnology::kTechnologyTypeNdef)
+    technologies->AppendString(kTagTechnologyNdef);
+  out->Set(kTagSupportedTechnologiesProperty, technologies);
+
+  base::ListValue* records = new base::ListValue();
+  GetRecordList(tag->GetNdefTagTechnology()->GetNdefMessage(), records);
+  out->Set(kTagRecordsProperty, records);
+}
+
+void NfcDebugMessageHandler::GetRecordList(const NfcNdefMessage& message,
+                                           base::ListValue* out) {
+  for (NfcNdefMessage::RecordList::const_iterator iter =
+          message.records().begin();
+      iter != message.records().end(); ++iter) {
+    const NfcNdefRecord* record = (*iter);
+    base::DictionaryValue* record_data = record->data().DeepCopy();
+    record_data->SetString(kRecordTypeProperty,
+                           RecordTypeToString(record->type()));
+    out->Append(record_data);
+  }
+}
+
+void NfcDebugMessageHandler::UpdateAdapterInfo() {
+  base::DictionaryValue data;
+  GetAdapterProperties(&data);
+  web_ui()->CallJavascriptFunction(kOnNfcAdapterInfoChangedFunction, data);
+}
+
+void NfcDebugMessageHandler::UpdatePeerInfo() {
+  base::DictionaryValue data;
+  GetPeerProperties(&data);
+  web_ui()->CallJavascriptFunction(kOnNfcPeerDeviceInfoChangedFunction, data);
+}
+
+void NfcDebugMessageHandler::UpdateTagInfo() {
+  base::DictionaryValue data;
+  GetTagProperties(&data);
+  web_ui()->CallJavascriptFunction(kOnNfcTagInfoChangedFunction, data);
+}
+
+}  // namespace
+
+NfcDebugUI::NfcDebugUI(content::WebUI* web_ui)
+    : content::WebUIController(web_ui) {
+  web_ui->AddMessageHandler(new NfcDebugMessageHandler());
+
+  content::WebUIDataSource* html_source =
+    content::WebUIDataSource::Create(chrome::kChromeUINfcDebugHost);
+  html_source->SetUseJsonJSFormatV2();
+
+  html_source->SetJsonPath("strings.js");
+
+  // Add required resources.
+  html_source->AddResourcePath("nfc_debug.css", IDR_NFC_DEBUG_CSS);
+  html_source->AddResourcePath("nfc_debug.js", IDR_NFC_DEBUG_JS);
+  html_source->SetDefaultResource(IDR_NFC_DEBUG_HTML);
+
+  Profile* profile = Profile::FromWebUI(web_ui);
+  content::WebUIDataSource::Add(profile, html_source);
+}
+
+NfcDebugUI::~NfcDebugUI() {
+}
+
+}  // namespace chromeos