Get started with tiles

To start providing tiles from your app, include the following dependencies in your app's build.gradle file.

Groovy

dependencies {
    // Use to implement support for wear tiles
    implementation "androidx.wear.tiles:tiles:1.5.0-alpha04"

    // Use to utilize standard components and layouts in your tiles
    implementation "androidx.wear.protolayout:protolayout:1.3.0-alpha04"

    // Use to utilize components and layouts with Material Design in your tiles
    implementation "androidx.wear.protolayout:protolayout-material:1.3.0-alpha04"

    // Use to include dynamic expressions in your tiles
    implementation "androidx.wear.protolayout:protolayout-expression:1.3.0-alpha04"

    // Use to preview wear tiles in your own app
    debugImplementation "androidx.wear.tiles:tiles-renderer:1.5.0-alpha04"

    // Use to fetch tiles from a tile provider in your tests
    testImplementation "androidx.wear.tiles:tiles-testing:1.5.0-alpha04"
}

Kotlin

dependencies {
    // Use to implement support for wear tiles
    implementation("androidx.wear.tiles:tiles:1.5.0-alpha04")

    // Use to utilize standard components and layouts in your tiles
    implementation("androidx.wear.protolayout:protolayout:1.3.0-alpha04")

    // Use to utilize components and layouts with Material Design in your tiles
    implementation("androidx.wear.protolayout:protolayout-material:1.3.0-alpha04")

    // Use to include dynamic expressions in your tiles
    implementation("androidx.wear.protolayout:protolayout-expression:1.3.0-alpha04")

    // Use to preview wear tiles in your own app
    debugImplementation("androidx.wear.tiles:tiles-renderer:1.5.0-alpha04")

    // Use to fetch tiles from a tile provider in your tests
    testImplementation("androidx.wear.tiles:tiles-testing:1.5.0-alpha04")
}

Note: This API is asynchronous and relies on ListenableFuture extensively. See Use ListenableFuture for more information about this concept.

Create a tile

To provide a tile from your application, create a class that extends TileService and implement the methods, as shown in the following code sample:

class MyTileService : TileService() {

    override fun onTileRequest(requestParams: RequestBuilders.TileRequest) =
        Futures.immediateFuture(
            Tile.Builder()
                .setResourcesVersion(RESOURCES_VERSION)
                .setTileTimeline(
                    Timeline.fromLayoutElement(
                        Text.Builder(this, "Hello World!")
                            .setTypography(Typography.TYPOGRAPHY_BODY1)
                            .setColor(argb(0xFFFFFFFF.toInt()))
                            .build()
                    )
                )
                .build()
        )

    override fun onTileResourcesRequest(requestParams: ResourcesRequest) =
        Futures.immediateFuture(
            Resources.Builder()
                .setVersion(RESOURCES_VERSION)
                .build()
        )
}
Tile.kt

Next, add a service inside the <application> tag of your AndroidManifest.xml file.

<service
    android:name=".snippets.tile.MyTileService"
    android:label="@string/tile_label"
    android:description="@string/tile_description"
    android:icon="@mipmap/ic_launcher"
    android:exported="true"
    android:permission="com.google.android.wearable.permission.BIND_TILE_PROVIDER">
    <intent-filter>
        <action android:name="androidx.wear.tiles.action.BIND_TILE_PROVIDER" />
    </intent-filter>

    <meta-data android:name="androidx.wear.tiles.PREVIEW"
        android:resource="@drawable/tile_preview" />
</service>
AndroidManifest.xml

The permission and intent filter register this service as a tile provider.

The icon, label, and description is shown to the user when they configure tiles on their phone or watch.

Use the preview metadata tag to show a preview of the tile when configuring it on your phone.

The tile service lifecycle overview

Once you have created and declared your TileService in your app manifest, you can respond to the tile service's state changes.

TileService is a bound service. Your TileService is bound as a result of your app request or if the system needs to communicate with it. A typical bound-service lifecycle contains the following four callback methods: onCreate(), onBind(), onUnbind(), and onDestroy(). The system invokes these methods each time the service enters a new lifecycle phase.

Important: Your TileService will still go through the typical Service lifecycle. However, TileService differs from most other bound services because it contains TileService-specific lifecycle methods that your app can react to. The Service lifecycle methods and the TileService lifecycle methods are called in two separate asynchronous threads.

In addition to the callbacks that control the bound-service lifecycle, you can implement other methods specific to the TileService lifecycle. All tile services must implement onTileRequest() and onTileResourcesRequest() to respond to requests for updates from the system.

• onTileAddEvent(): The system calls this method only when the user adds your tile for the first time, and if the user removes and adds your tile again. This is the best time to do any one-time initialization.

  onTileAddEvent() is only called when the set of tiles are reconfigured, not whenever a tile is created by the system. For example, when the device is rebooted or powered on, onTileAddEvent() is not called for the tiles that had already been added. You can use getActiveTilesAsync() instead to get a snapshot of which tiles belonging to you are active.

• onTileRemoveEvent(): The system calls this method only if the user removes your tile.

• onTileEnterEvent(): The system calls this method when a tile provided by this provider comes into view on screen.

• onTileLeaveEvent(): The system calls this method when a tile provided by this provider goes out of view on the screen.

• onTileRequest(): The system calls this method when the system requests a new timeline from this provider.

• onTileResourcesRequest(): The system calls this method when the system requests a resource bundle from this provider. This can happen on the first time a Tile is being loaded or whenever the resource version changes.

Note: Don't require (or rely on) phases to occur in any particular order. onTileAddEvent() may only be called when your tile is added by a user. onTileEnterEvent() and onTileLeaveEvent() may be called multiple times throughout the TileService lifecycle. onTileRemoveEvent() will never be called if the user does not remove the tile.

Query which tiles are active

Active tiles are tiles which have been added for display on the watch. Use TileService's static method getActiveTilesAsync() to query which tiles belonging to your app are active.

Caution: The result reflects the list of active tiles at the time the call was made, which might have changed by the time the result is received. Use onTileAddEvent() and onTileRemoveEvent() callbacks for scheduling actions that need to happen when your tile becomes either active or inactive.

Create UI for tiles

The layout of a tile is written using a builder pattern. A tile's layout is built up like a tree that consists of layout containers and basic layout elements. Each layout element has properties, which you can set through various setter methods.

Note: There's a limit to the number of nested elements that can appear in a layout. If you exceed this limit, the system ignores the layout update and shows the tile in its previous state.

Basic layout elements

The following visual elements from the protolayout library are supported, along with Material components:

• Text: renders a string of text, optionally wrapping.
• Image: renders an image.
• Spacer: provides padding between elements or can act as a divider when you set its background color.

Material components

In addition to basic elements, the protolayout-material library provides components that ensure a tile design in line with Material Design user interface recommendations.

• Button: clickable circular component designed to contain an icon.

• Chip: clickable stadium-shaped component designed to contain up to two lines of text and an optional icon.

  Note: If you use a Chip element inside of a Column element, set both elements' widths to expand().

• CompactChip: clickable stadium-shaped component designed to contain a line of text.

• TitleChip: clickable stadium-shaped component similar to Chip but with a larger height to accommodate title text.

• CircularProgressIndicator: circular progress indicator that can be placed inside a EdgeContentLayout to display progress around the edges of the screen.

Layout containers

The following containers are supported, along with Material layouts:

• Row: lays child elements out horizontally, one after another.
• Column: lays child elements out vertically, one after another.
• Box: overlays child elements on top of one another.
• Arc: lays child elements out in a circle.
• Spannable: applies specific FontStyles to sections of text along with interleaving text and images. For more information, see Spannables.

Every container can contain one or more children, which themselves can also be containers. For example, a Column can contain multiple Row elements as children, resulting in a grid-like layout.

As an example, a tile with a container layout and two child layout elements could look like this:

Kotlin

private fun myLayout(): LayoutElement =
    Row.Builder()
        .setWidth(wrap())
        .setHeight(expand())
        .setVerticalAlignment(VALIGN_BOTTOM)
        .addContent(Text.Builder()
            .setText("Hello world")
            .build()
        )
        .addContent(Image.Builder()
            .setResourceId("image_id")
            .setWidth(dp(24f))
            .setHeight(dp(24f))
            .build()
        ).build()

Java

private LayoutElement myLayout() {
    return new Row.Builder()
        .setWidth(wrap())
        .setHeight(expand())
        .setVerticalAlignment(VALIGN_BOTTOM)
        .addContent(new Text.Builder()
            .setText("Hello world")
            .build()
        )
        .addContent(new Image.Builder()
            .setResourceId("image_id")
            .setWidth(dp(24f))
            .setHeight(dp(24f))
            .build()
        ).build();
}

Material layouts

In addition to basic layouts, the protolayout-material library provides a few opinionated layouts made to hold elements in specific "slots".

• PrimaryLayout: positions a single primary action CompactChip at the bottom with the content centered above it.

  Note: When you use this layout, you can't call expand(), to set the content's height. Otherwise, you might see a blank tile.
  
  However, you can call expand() on the content's width to use all the space between the parent element's margins.

• MultiSlotLayout: positions primary and secondary labels with optional content in between and an optional CompactChip at the bottom.

• MultiButtonLayout: positions a set of buttons that are arranged according to Material guidelines.

• EdgeContentLayout: positions content around the edge of a screen, such as a CircularProgressIndicator. When using this layout, the content within it has the appropriate margins and padding applied automatically.

Arcs

The following Arc container children are supported:

• ArcLine: renders a curved line around the Arc.
• ArcText: renders curved text in the Arc.
• ArcAdapter: renders a basic layout element in the arc, drawn at a tangent to the arc.

Note: While an ArcText draws curved text around the Arc, using a Text in an ArcAdapter draws linear text at a tangent to the arc.

For more information, see the reference documentation for each of the element types.

Modifiers

Every available layout element can optionally have modifiers applied to it. Use these modifiers for the following purposes:

• Change the visual appearance of the layout. For example, add a background, border, or padding to your layout element.
• Add metadata about the layout. For example, add a semantics modifier to your layout element for use with screen readers.
• Add functionality. For example, add a clickable modifier to your layout element to make your tile interactive. For more information, see Interact with tiles.

For example, we can customize the default look and metadata of an Image, as shown in the following code sample:

Kotlin

private fun myImage(): LayoutElement =
    Image.Builder()
        .setWidth(dp(24f))
        .setHeight(dp(24f))
        .setResourceId("image_id")
        .setModifiers(Modifiers.Builder()
            .setBackground(Background.Builder().setColor(argb(0xFFFF0000)).build())
            .setPadding(Padding.Builder().setStart(dp(12f)).build())
            .setSemantics(Semantics.builder()
                .setContentDescription("Image description")
                .build()
            ).build()
        ).build()

Java

private LayoutElement myImage() {
   return new Image.Builder()
           .setWidth(dp(24f))
           .setHeight(dp(24f))
           .setResourceId("image_id")
           .setModifiers(new Modifiers.Builder()
                   .setBackground(new Background.Builder().setColor(argb(0xFFFF0000)).build())
                   .setPadding(new Padding.Builder().setStart(dp(12f)).build())
                   .setSemantics(new Semantics.Builder()
                           .setContentDescription("Image description")
                           .build()
                   ).build()
           ).build();
}

Spannables

A Spannable is a special type of container that lays out elements similarly to text. This is useful when you want to apply a different style to only one substring in a larger block of text, something that isn't possible with the Text element.

A Spannable container is filled with Span children. Other children, or nested Spannable instances, aren't allowed.

There are two types of Span children:

• SpanText: renders text with a specific style.
• SpanImage: renders an image inline with text.

For example, you could italicize "world" in a "Hello world" tile and insert an image between the words, as shown in the following code sample:

Kotlin

private fun mySpannable(): LayoutElement =
    Spannable.Builder()
        .addSpan(SpanText.Builder()
            .setText("Hello ")
            .build()
        )
        .addSpan(SpanImage.Builder()
            .setWidth(dp(24f))
            .setHeight(dp(24f))
            .setResourceId("image_id")
            .build()
        )
        .addSpan(SpanText.Builder()
            .setText("world")
            .setFontStyle(FontStyle.Builder()
                .setItalic(true)
                .build())
            .build()
        ).build()

Java

private LayoutElement mySpannable() {
   return new Spannable.Builder()
        .addSpan(new SpanText.Builder()
            .setText("Hello ")
            .build()
        )
        .addSpan(new SpanImage.Builder()
            .setWidth(dp(24f))
            .setHeight(dp(24f))
            .setResourceId("image_id")
            .build()
        )
        .addSpan(new SpanText.Builder()
            .setText("world")
            .setFontStyle(newFontStyle.Builder()
                .setItalic(true)
                .build())
            .build()
        ).build();
}

Work with resources

Tiles don't have access to any of your app's resources. This means that you can't pass an Android image ID to an Image layout element and expect it to resolve. Instead, override the onTileResourcesRequest() method and provide any resources manually.

There are two ways to provide images within the onTileResourcesRequest() method:

• Provide a drawable resource using setAndroidResourceByResId().
• Provide a dynamic image as a ByteArray using setInlineResource().

Kotlin

override fun onTileResourcesRequest(
    requestParams: ResourcesRequest
) = Futures.immediateFuture(
Resources.Builder()
    .setVersion("1")
    .addIdToImageMapping("image_from_resource", ImageResource.Builder()
        .setAndroidResourceByResId(AndroidImageResourceByResId.Builder()
            .setResourceId(R.drawable.image_id)
            .build()
        ).build()
    )
    .addIdToImageMapping("image_inline", ImageResource.Builder()
        .setInlineResource(InlineImageResource.Builder()
            .setData(imageAsByteArray)
            .setWidthPx(48)
            .setHeightPx(48)
            .setFormat(ResourceBuilders.IMAGE_FORMAT_RGB_565)
            .build()
        ).build()
    ).build()
)

Java

@Override
protected ListenableFuture<Resources> onTileResourcesRequest(
       @NonNull ResourcesRequest requestParams
) {
return Futures.immediateFuture(
    new Resources.Builder()
        .setVersion("1")
        .addIdToImageMapping("image_from_resource", new ImageResource.Builder()
            .setAndroidResourceByResId(new AndroidImageResourceByResId.Builder()
                .setResourceId(R.drawable.image_id)
                .build()
            ).build()
        )
        .addIdToImageMapping("image_inline", new ImageResource.Builder()
            .setInlineResource(new InlineImageResource.Builder()
                .setData(imageAsByteArray)
                .setWidthPx(48)
                .setHeightPx(48)
                .setFormat(ResourceBuilders.IMAGE_FORMAT_RGB_565)
                .build()
            ).build()
        ).build()
);
}