After you configure your project and add a class that implements the watch face service, you can start writing code to initialize and draw your custom watch face.
Every watch face creates a custom subclass of a renderer that implements everything needed to draw the watch face.
The renderer combines the
UserStyle, the
complication information from
ComplicationSlotsManager,
the current time, and other state information to
render the watch face, as shown in the following example:
class CustomCanvasRenderer(
private val context: Context,
surfaceHolder: SurfaceHolder,
watchState: WatchState,
private val complicationSlotsManager: ComplicationSlotsManager,
currentUserStyleRepository: CurrentUserStyleRepository,
canvasType: Int
) : Renderer.CanvasRenderer(
surfaceHolder = surfaceHolder,
currentUserStyleRepository = currentUserStyleRepository,
watchState = watchState,
canvasType = canvasType,
interactiveDrawModeUpdateDelayMillis = 16L
) {
override fun render(canvas: Canvas, bounds: Rect, zonedDateTime: ZonedDateTime) {
// Draw into the canvas
}
override fun renderHighlightLayer(canvas: Canvas, bounds: Rect, zonedDateTime: ZonedDateTime) {
// Draw into the canvas
}
}