DataLayer helpers libraries¶

These libraries provides an easy means to detect and install your app across both watch and phone.

However, they are not intended to cover complex use cases, or complex interactions between watch and phone.

Getting started¶

Include the necessary dependency:

dependencies {
    implementation "com.google.android.horologist:horologist-datalayer-watch:<version>"
}

and

dependencies {
    implementation "com.google.android.horologist:horologist-datalayer-phone:<version>"
}

For your watch and phone projects respectively.

Initialize the client, including passing a WearDataLayerRegistry.

val appHelper = WearDataLayerAppHelper(context, wearDataLayerRegistry, scope)

// or
val appHelper = PhoneDataLayerAppHelper(context, wearDataLayerRegistry)

Typical use cases:¶

Connection and installation status

This is something that your app may do from time to time, or on start up.

val connectedNodes = appHelper.connectedNodes()

The resulting list might will contain entries such as:

AppHelperNodeStatus(
    id=7cd1c38a,
    displayName=Google Pixel Watch,
    appInstallationStatus=Installed(nodeType=WATCH),
    surfacesInfo=# SurfacesInfo@125fcbff
        complications {
            instance_id: 1234
            name: "MyComplication"
            timestamp {
                nanos: 738000000
                seconds: 1680015523
            }
            type: "SHORT_TEXT"
        }
        tiles {
            name: "MyTile"
            timestamp {
                nanos: 364000000
                seconds: 1680016845
            }
        }
)

Responding to availability change

Once you've established the app on both devices, you may wish to respond to when the partner device connects or disconnects. For example, you may only want to show a "launch workout" button on the phone when the watch is connected.
```
val nodes by appHelper.connectedAndInstalledNodes
    .collectAsStateWithLifecycle()
```
Installing the app on the other device

Where the app isn't installed on the other device - be that phone or watch - then the library offers a one step option to launch installation:
```
appHelper.installOnNode(node.id)
```
Launching the app on the other device

If the app is installed on the other device, you can launch it remotely:
```
val result = appHelper.startRemoteOwnApp(node.id)
```

Launching a specific activity on the other device

In addition to launching your own app, you may wish to launch a different activity as part of the user journey:

val config = activityConfig { 
    packageName = "com.example.myapp"
    classFullName = "com.example.myapp.MyActivity"
}
appHelper.startRemoteActivity(node.id, config)

Launching the companion app

In some cases, it can be useful to launch the companion app, either from the watch or the phone.

For example, if the connected device does not have your Tile installed, you may wish to offer the user the option to navigate to the companion app to install it:
```
if (node.surfacesInfo.tilesList.isEmpty() && askUserAttempts < MAX_ATTEMPTS) {
    // Show guidance to the user and then launch companion
    // to allow the to install the Tile.
    val result = appHelper.startCompanion(node.id)
}
```
Tracking Tile installation (Wear-only)

To determine whether your Tile(s) are installed, add the following to your TileService:

In onTileAddEvent:
```
wearAppHelper.markTileAsInstalled("SummaryTile")
```
In onTileRemoveEvent:
```
wearAppHelper.markTileAsRemoved("SummaryTile")
```
Tracking Complication installation (Wear-only)

To determine whether your Complication(s) are in-use, add the following to your ComplicationDataSourceService:

In onComplicationActivated:
```
wearAppHelper.markComplicationAsActivated("GoalsComplication")
```
In onComplicationDeactivated:
```
wearAppHelper.markComplicationAsDeactivated("GoalsComplication")
```
Tracking the main activity has been launched at least once (Wear-only)

To determine if your main activity has been launched once, use:

kotlin wearAppHelper.markActivityLaunchedOnce()

Tracking the app has been set up (Wear-only)

To mark that the user has completed in the app the necessary setup steps such that it is ready for use, use the following:
```
wearAppHelper.markSetupComplete()
```
And when the app is no longer considered in a fully setup state, use the following:
```
wearAppHelper.markSetupNoLongerComplete()
```