Android Wear is a software platform for wearable devices like smartwatches. It allows devices to be context aware, suggest information to users based on location and time, and features simple interactions like cards and lists. Notifications, voice replies, and media controls can be integrated. Activities have optimized layouts and UI for small screens. Sensors, data syncing between devices, and messaging APIs allow communication. Custom watch faces can be built with ambient mode support and settings screens.

1. Android Wear
an Overview
Paul Trebilcox-Ruiz

2. Context Aware

Event Driven
– In a restaurant
– Near a sports stadium
– Time Passed (ex: oil change reminder)

Launch Automatically

Suggest
– User asks questions
– Provide information

3. No to Low Interactions

Keep it simple - Glancable
– Cards
– Lists
– Buttons

Allow voice interactions

4. Additional Resources
Design Principles:
https://developer.android.com/design/wear/principles.html
Designing for Android Wear:
https://www.youtube.com/watch?v=4JcDYkgqksY

5. Notifications

6. Cards

7. NotificationCompat.Builder builder =
new NotificationCompat
.Builder( context )
.setSmallIcon( R.drawable.icon )
.setContentTitle( "Title" )
.setContentText( "Text" );
NotificationManagerCompat
.from( context )
.notify( id, builder.build() );

8. Action Buttons

9. NotificationCompat.Action action =
new NotificationCompat.Action.Builder(
R.drawable.ic_action,
"Check-in",
pendingIntent )
.build();
NotificationCompat.Builder builder =
new NotificationCompat.Builder( context )
.setSmallIcon( R.drawable.icon )
.setContentTitle( "Title" )
.setContentText( "Text" )
.extend( new WearableExtender()
.addAction( action ) );
NotificationManagerCompat
.from( context )
.notify( id, builder.build() );

10. Voice Reply

11. RemoteInput remoteInput = new
RemoteInput.Builder( "extra_voice_reply" )
.setLabel( "Label" )
.build();
Intent replyIntent = new Intent( context,
ReplyActivity.class );
PendingIntent pendingIntent =
PendingIntent.getActivity( context, 0,
replyIntent, PendingIntent.FLAG_UPDATE_CURRENT );
NotificationCompat.Action action =
new
NotificationCompat.Action.Builder( R.drawable.icon,
"Label", pendingIntent )
.addRemoteInput( remoteInput )
.build();

12. Quick Reply

13. String[] choices = [ "Yes", "No", "Maybe-So" ];
RemoteInput remoteInput = new
RemoteInput.Builder( "extra_voice_reply" )
.setLabel( "Say Something" )
.setChoices( choices )
.build();
//Attach to action and build notification

14. Media Control

15. Custom Notification

16. Intent displayIntent = new
Intent( context, displayActivity.class );
PendingIntent pendingIntent =
PendingIntent.getActivity( context,
0, displayIntent, 0 );
NotificationCompat.Builder builder =
new NotificationCompat.Builder( context )
.setSmallIcon( R.drawable.icon )
.setContentTitle( "Title" )
.setContentText( "Text" )
.extend( new WearableExtender()
.setDisplayIntent( pendingIntent )
.setCustomSizePreset( SIZE_FULL_SCREEN );
NotificationManagerCompat
.from( context )
.notify( id, builder.build() );

17. Additional Resources
Documentation:
https://developer.android.com/training/wearables/notificat
ions/index.html
I/O Bytes:
https://www.youtube.com/watch?v=tKoQatxG0_8

18. Activities and UI

Short and Simple

Always-On Mode

Provided UI and Optimized Layouts
– WatchViewStub
– BoxInsetLayout
– WearableListView

19. ConfirmationActivity

20. Not BoxInsetLayout

21. BoxInsetLayout

22. WearableListView

23. Additional Resources
Documentation:
https://developer.android.com/training/wearables/apps/la
youts.html
Building Advanced UIs for Wear:
https://www.youtube.com/watch?v=uTQ9KKyM9wo

24. Hardware

Optical Heart Rate Monitor

Accelerometer

Gyroscope

Compass

Vibrator

Ambient Light

GPS

25. Vibrator vibrator = (Vibrator)
getSystemService( Context.VIBRATOR_SERVICE );
long[] pattern = { 0, 10000 };
vibrator.vibrate( pattern, -1 );

26. //Implement SensorEventListener
Sensor heartRateSensor =
sensorManager.getDefaultSensor( Sensor.TYPE_HEART_RATE );
if ( heartRateSensor != null ) {
sensorManager.registerListener( this,
heartRateSensor,
SensorManager.SENSOR_DELAY_FASTEST );
}
@Override
public void onSensorChanged( SensorEvent event ) {
if( event.sensor.getType() == Sensor.TYPE_HEART_RATE ) {
Log.e( "Wear Sensor",
"HeartRate: " + event.values[0] );
}
}

27. Tips

Phone Sensors before Wear

Unregister sensors when done

Don't reinvent the wheel ( ex: step sensor )

28. Device Communication

Play Services

Activity Interfaces and
WearableListenerService

DataLayer Api
– Sync Data ( Limited to 100KB )
– Send Assets ( Unlimited Size )

29. GoogleApiClient mGoogleApiClient = new
GoogleApiClient.Builder( context )
.addConnectionCallbacks(
new ConnectionCallbacks()
{
@Override
public void onConnected( Bundle hint )
{
//Add listeners
}
@Override
public void onConnectionSuspended( int code )
{
//Remove listeners
}
} )
.addApiIfAvailable( Wearable.API )
.build();

30. //Syncing Data: Place data on the channel
PutDataMapRequest mapReq =
PutDataMapRequest.create( "/path" );
mapReq.getDataMap().putInt( KEY, 42 );
PutDataRequest dataReq = mapReq.asPutDataRequest();
PendingResult<DataApi.DataItemResult> pendingResult =
Wearable.DataApi
.putDataItem( mGoogleApiClient, dataReq );
pendingResult.setResultCallback( new
ResultCallback<DataItemResult>() {
@Override
public void onResult( final DataItemResult result ) {
if( result.getStatus().isSuccess() ) {
//Sweet, it worked
}
}
} );

31. //Syncing Data: Receive in a class listening to the
//DataLayer Api
@Override
public void onDataChanged( DataEventBuffer events ) {
for( DataEvent event : events ) {
if( event.getType() == DataEvent.TYPE_CHANGED ) {
DataItem item = event.getDataItem();
if( item.getUri().getPath().equals( "/path" ) ) {
DataMap map = DataMapItem
.fromDataItem( item )
.getDataMap();
Log.e( "Ultimate Question",
"Answer: " + map.getInt( KEY ) );
}
}
}
}

32. Device Communication

Capabilities Api

Node Api
– Connected Devices

Message Api
– Fire and Forget

33. //Declare capability in /res/values/wear.xml
<resources>
<string-array name="android_wear_capabilities">
<item>some_capability</item>
</string-array>
</resources>

34. //Initialize Node
CapabilityApi.GetCapabilityResult result =
Wearable.CapabilityApi.getCapability(
mGoogleApiClient,
CAPABILITY,
CapabilityApi.FILTER_REACHABLE).await();
selectedNode =
pickBestNodeId( result.getCapability().getNodes() );
}
private String pickBestNodeId(Set<Node> nodes) {
String bestNodeId = null;
for( Node node : nodes ) {
if( node.isNearby() ) {
return node.getId();
}
bestNodeId = node.getId();
}
return bestNodeId;
}

35. //Listen for nodes connecting/disconnecting
CapabilityApi.CapabilityListener capabilityListener =
new CapabilityApi.CapabilityListener() {
@Override
public void onCapabilityChanged(
CapabilityInfo capabilityInfo) {
//capabilityInfo.getCapability().getNodes()
}
};
Wearable.CapabilityApi.addCapabilityListener(
mGoogleApiClient,
capabilityListener,
CAPABILITY );

36. //Sending a message to a node
private void sendMessage( byte[] message ) {
Wearable.MessageApi.sendMessage(
mGoogleApiClient,
bestNode,
"/path",
message );
}
//Receive in a WearableListenerService or Activity
@Override
public void onMessageReceived( MessageEvent message ) {
if(message.getPath().equals( "/path" ) ) {
Log.e( "Message", "Data: " + message.getData() );
}
}

37. Message Api Communication

38. Tips

Transmissions
– Only send what's needed
– Only send when things have changed

Batch data into maps to limit overhead

Phone is your workhorse

39. Additional Resources
Message Api Tutorial:
http://ptrprograms.blogspot.com/2014/10/a-guide-to-
android-wear-message-api.html
Documentation:
http://developer.android.com/training/wearables/data-
layer/index.html

40. Watch Faces

Watch Face Service
– Canvas

Watch Face Engine
– Timer
– Ambient Mode

Settings Screen

41. <service android:name=".CustomWatchFaceService"
android:label="Wear Watch Face"
android:permission="android.permission.BIND_WALLPAPER">
<meta-data
android:name="android.service.wallpaper"
android:resource="@xml/watch_face" />
<meta-data
android:name="com.google.android.wearable.watchface.preview"
android:resource="@mipmap/ic_launcher" />
<meta-data
android:name="com.google.android.wearable.watchface.preview_circular"
android:resource="@mipmap/ic_launcher" />
<intent-filter>
<action android:name="android.service.wallpaper.WallpaperService" />
<category
android:name="com.google.android.wearable.watchface.category.WATCH_FACE" />
</intent-filter>
</service>

42. @Override
public void onCreate(SurfaceHolder holder) {
super.onCreate(holder);
setWatchFaceStyle( new
WatchFaceStyle
.Builder( CustomWatchFaceService.this )
.setBackgroundVisibility(
BACKGROUND_VISIBILITY_INTERRUPTIVE )
.setCardPeekMode(
PEEK_MODE_VARIABLE )
.setShowSystemUiTime( false )
.build()
);
mDisplayTime = new Time();
initBackgroundPaint();
initDisplayTextPaint();
}

43. @Override
public void onApplyWindowInsets( WindowInsets insets ) {
super.onApplyWindowInsets( insets );
mYOffset = getDimension( R.dimen.y_offset );
if( insets.isRound() ) {
MXOffset = getDimension( R.dimen.x_offset_round );
} else {
MXOffset = getDimension( R.dimen.x_offset_square );
}
}

44. Custom Watch Face

45. Custom Watch Face

46. @Override
public void onAmbientModeChanged(boolean inAmbientMode) {
super.onAmbientModeChanged( inAmbientMode );
if( inAmbientMode ) {
mTextColorPaint.setColor(
Color.parseColor( "white" ) );
} else {
mTextColorPaint.setColor(
Color.parseColor( "red" ) );
}
if( mIsLowBitAmbient ) {
mTextColorPaint.setAntiAlias( !inAmbientMode );
}
invalidate();
updateTimer();
}

47. Ambient Mode

48. <activity
android:name=".WatchFaceConfigActivity"
android:label="@string/app_name">
<intent-filter>
<action
android:name="yourpackage.CONFIG_BACKGROUND" />
<category android:name="
com.google.android.wearable.watchface
.category.WEARABLE_CONFIGURATION" />
<category
android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
Watch Face Settings

49. Watch Face Settings

50. Watch Face Settings

51. Additional Resources
Watch Face Tutorial:
https://code.tutsplus.com/tutorials/creating-an-android-
wear-watch-face—cms-23718
DevBytes: Watch Faces for Android Wear:
https://www.youtube.com/watch?v=AK38PJZmIW8
DevBytes: Developing an Android Wear Watch Face:
https://www.youtube.com/watch?v=VkvHKtmsvYA
Documentation:
https://developer.android.com/training/wearables/watch-
faces/index.html

52. Slide Deck:
http://www.slideshare.net/PaulTrebilcoxRuiz/android-
wearpp
Tuts+ Tutorials:
https://tutsplus.com/authors/paul-trebilcox-ruiz
Personal Android Blog:
http://ptrprograms.blogspot.com/
LinkedIn:
https://www.linkedin.com/in/paultruiz
Google+:
+PaulTrebilcoxRuiz