Up close and personal with Nearby (DevFest Trondheim)

Updated presentation for DevFest Trondheim

Transcript

1. Up close & personal with Nearby Hugo Visser @botteaap hugo@littlerobots.nl
2. Demo app bit.ly/nearby-demo
3. What is Nearby? Create features based on proximity Android (Play Services) + iOS https://developers.google.com/nearby/
4. Nearby Messages → Publish & Subscribe Connections → P2P connections Notifications → Contextual notifications
5. Messages
6. Messages Android & iOS Publish & Subscribe Ideally less than 3 KB, max 100 KB
7. Messages Message is created an associated with a unique token Device emits the token using wifi, bluetooth, audio Subscribing devices look up message when receiving the token
8. Messages Nearby API 111001011 010010101 110011100 abc123 abc123 abc123 abc123 111001011 010010101 110011100
9. Setup Create project → https://console.cloud.google.com/apis/ Enable Nearby Messages API Create API key
10. API key in AndroidManifest.xml <application ..> <meta-data android:name="com.google.android.nearby.messages.API_KEY” android:value="your_api_key" /> </application>
11. Publish a message // Create once and keep a reference val client = Nearby.getMessagesClient(this) val payload = byteArrayOf(...) val message = Message(payload, "my_message_type") client.publish(message).addOnSuccessListener { // yay }.addOnFailureListener({ // exception is ApiException })
12. Receiving messages class MyMessageListener: MessageListener() { override fun onFound(message: Message) { } override fun onLost(message: Message) { } } client.subscribe(MyMessageListener()).addOnSuccessListener { // we're listening }.addOnFailureListener { // oh no! }
13. User consent High battery use Invoke on user action No sensitive information
14. Demo
16. Beacons Bluetooth device broadcasting id + tx power, telemetry Standards: iBeacon, Eddystone, Altbeacon Often used for (course) location
17. Nearby + Google Beacon Platform The beacon id is a token Associate token to message → Proximity Beacon API Beacon Dashboard
19. Beacon console Set beacon metadata Monitor health, location, alerts Beacon vendor agnostic
20. Beacon console Manage attachments (messages) → associate different projects! Sharable beacon infrastructure Proximity Beacon API
21. Nearby + beacons Subscribe to beacon messages only Background scanning (screen on) Distance and signal changes for foreground apps Abstracts out the physical beacon from the purpose (message)
22. Subscribe to beacon messages client = Nearby.getMessagesClient(this, MessagesOptions.Builder(). setPermissions(NearbyPermissions.BLE).build()) // This requires android.permission.BLUETOOTH and ACCESS_COARSE_LOCATION // Android 6.0 and up requires location to be enabled too! client.subscribe(messageListener, SubscribeOptions.Builder(). setStrategy(Strategy.BLE_ONLY).build()). addOnFailureListener { }
23. Subscribe to beacon messages class MyMessagesListener: MessageListener() { override fun onFound(message: Message) { // May receive non-project messages here (check message.namespace) } override fun onBleSignalChanged(message: Message, signal: BleSignal) { } override fun onDistanceChanged(message: Message, distance: Distance) { } }
24. Background subscription client = Nearby.getMessagesClient(this, MessagesOptions.Builder(). setPermissions(NearbyPermissions.BLE).build()) // You can register up to 5 pending intents val pendingIntent = PendingIntent.getBroadcast(...) client.subscribe(pendingIntent, SubscribeOptions.Builder(). setStrategy(Strategy.BLE_ONLY).build()). addOnFailureListener { }
25. Background subscription class MyReceiver: BroadcastReceiver() { override fun onReceive(context: Context, intent: Intent) { Nearby.getMessagesClient(context).handleIntent(intent, MyMessagesListener()) } }
26. Just beacons, no attachments Use MessageFilter.Builder() to scan for specific beacons iBeacon proximity id w/ optional major and minor ids Eddystone namespace with optional instance Obtain beacon id from a Message using IBeaconId and EddystoneUid
27. Demo
28. Notifications
29. Nearby notifications Show notification on Android devices based on beacons Launch url or deep link to app Proxied, filtered, based on relevance, etc, etc Special type of attachment, set by beacon owners Will be turned off dec 6 2018
30. How do you prove you own a beacon? A beacon signal is public... So what if I register a large portion of beacons at a national airport?
33. Connections
34. Connections Connect devices in a P2P fashion Uses Bluetooth & WIFI Topologies: P2P_STAR, P2P_CLUSTER, P2P_POINT_TO_POINT
35. Setup <manifest ...> <uses-permission android:name="android.permission.BLUETOOTH" /> <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" /> <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" /> <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" /> <!-- Request at runtime on M and up --> <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" /> </manifest>
36. Basic steps Advertise & discover Request connection → supplies auth token Accept connection Send payloads
37. Advertising class MyConnectionCallback: ConnectionLifecycleCallback() { override fun onConnectionResult(endpoint: String, result: ConnectionResolution) { } override fun onDisconnected(endpoint: String) { } override fun onConnectionInitiated(endpoint: String, info: ConnectionInfo) { // Make sure to failures from the resulting task! // Instead of accepting, you can also reject or accept later // ConnectionInfo contains an auth token for OOB use client.acceptConnection(endpoint, MyPayloadCallback()) } }
38. Advertising // Get a connections client client = Nearby.getConnectionsClient(this) // First argument is the name for this device // Empty string generates a name client.startAdvertising("", BuildConfig.APPLICATION_ID, MyConnectionCallback(), AdvertisingOptions(Strategy.P2P_CLUSTER)). addOnFailureListener { }
39. Discovery class MyDiscoveryCallback: EndpointDiscoveryCallback() { override fun onEndpointFound(endpoint: String, info: DiscoveredEndpointInfo) { } override fun onEndpointLost(endpoint: String) { } }
40. Discovery client.startDiscovery(BuildConfig.APPLICATION_ID, MyDiscoveryCallback(), DiscoveryOptions(Strategy.P2P_CLUSTER)). addOnFailureListener { }
41. Connection // First parameter is the device name, or generated if empty client.requestConnection("", endpoint, MyConnectionCallback()). addOnFailureListener { // Use status code from ApiException // to check what went wrong }
42. Transfer data class MyPayloadCallback : PayloadCallback() { override fun onPayloadReceived(endpoint: String, payload: Payload) { // Check payload type and handle the (partial) payload } override fun onPayloadTransferUpdate(endpoint: String, update: PayloadTransferUpdate) { // for Payload.Type.Bytes this is not needed, for other types // reports progress (both incoming and outgoing) } } // When accepting the connection client.acceptConnection(endpoint, MyPayloadCallback())
43. Disconnect // Disconnect a single endpoint, keep other processes going client.disconnectFromEndpoint(endpoint) client.stopDiscovery() client.stopAdvertising() // Prevents accepting and requesting new connections & disconnects everything client.stopAllEndpoints()
44. Demo
45. github.com/DanielMartinus/Konfetti
46. Connections Hit or miss due to bluetooth issues? Don’t forget to check for errors Stop discovery / advertising before connecting
47. Conclusion Concise and small API Messages, beacon messages Notifications: nice try -- RIP. Connections powerful, but not always reliable
48. Thanks! @botteaap hugo@littlerobots.nl speakerdeck.com/hugovisser